Long-term delivery of protein therapeutics.

PubMed

Vaishya, Ravi; Khurana, Varun; Patel, Sulabh; Mitra, Ashim K

2015-03-01

Proteins are effective biotherapeutics with applications in diverse ailments. Despite being specific and potent, their full clinical potential has not yet been realized. This can be attributed to short half-lives, complex structures, poor in vivo stability, low permeability, frequent parenteral administrations and poor adherence to treatment in chronic diseases. A sustained release system, providing controlled release of proteins, may overcome many of these limitations. This review focuses on recent development in approaches, especially polymer-based formulations, which can provide therapeutic levels of proteins over extended periods. Advances in particulate, gel-based formulations and novel approaches for extended protein delivery are discussed. Emphasis is placed on dosage form, method of preparation, mechanism of release and stability of biotherapeutics. Substantial advancements have been made in the field of extended protein delivery via various polymer-based formulations over last decade despite the unique delivery-related challenges posed by protein biologics. A number of injectable sustained-release formulations have reached market. However, therapeutic application of proteins is still hampered by delivery-related issues. A large number of protein molecules are under clinical trials, and hence, there is an urgent need to develop new methods to deliver these highly potent biologics.

Assessment of extended-release opioid analgesics for the treatment of chronic pain.

PubMed

Gudin, Jeffrey A

2013-03-01

Approximately 3.8 million patients annually receive extended-release (ER) or long-acting opioid prescriptions in the outpatient setting, around half of which are written by primary care physicians. Compared with short-acting, immediate-release (IR) formulations, ER and oral long-acting opioid analgesics are associated with clinical advantages, such as extended periods of time during which drug plasma levels are within the therapeutic range, decreased peak-to-trough fluctuations, and prolonged analgesia over the dosing period. Additionally, ER opioids offer a more convenient, less frequent dosing regimen to chronic pain patients who are often taking several concomitant medications. The increased utilization of ER opioids has been accompanied by a rise in the misuse and abuse of these formulations. Certain pharmacokinetic parameters (e.g., longer time to maximum drug plasma concentration, lower maximum drug plasma concentration) may decrease the abuse potential of intact ER opioids by limiting the positive subjective and reinforcing effects relative to IR formulations. Putative abuse-deterrent formulations have also recently been introduced to impede physical manipulation of these formulations, or reduce the harm resulting from such behavior. Such formulations may represent an incremental advance to reduce non-oral forms of abuse. This article reviews the pharmacokinetic profiles and abuse-deterrent features of newer ER opioid analgesics for the treatment of moderate to severe chronic pain.

The metamorphosis of hydromorphone.

PubMed

Reisfield, Gary M; Wilson, George R

2005-01-01

Hydromorphone, one of the oldest and most potent of opioids, is an effective alternative to morphine. With a variety of routes of administration, it has an efficacy similar to that of morphine. The FDA has recently approved the first commercially available extended-release formulation, a once-daily hydromorphone for the management of moderate to severe pain in opioid tolerant individuals with an anticipated extended period of use. The formulation exhibits less peak-to-trough fluctuation in plasma concentration, while providing analgesia statistically indistinguishable from its immediate-release counterpart. The manufacturer and the FDA have articulated a plan to minimize unskillful prescribing and abuse/diversion through education, supply-chain integrity, and surveillance. It is anticipated that Palladone will be a valuable addition to the limited armamentarium of extended-release opioids.

Extended release amoxicillin/clavulanate: optimizing a product for respiratory infections based on pharmacodynamic principles.

PubMed

Jacobs, Michael R

2005-06-01

Acute bacterial respiratory tract infections cause a great deal of human morbidity and mortality. Treatment guidelines for these infections include macrolides, doxycycline, beta-lactams and beta-lactam/beta-lactamase inhibitor combinations such as amoxicillin/clavulanic acid to provide coverage for the common respiratory pathogens, including penicillin and macrolide nonsusceptible Streptococcus pneumoniae, as well as beta-lactamase-producing Haemophilus influenzae and Moraxella catarrhalis. In response to recent guidelines recommending higher dose amoxicillin to extend coverage to a higher percentage of S. pneumoniae, a new formulation of amoxicillin/clavulanic acid was developed. This formulation includes a higher amoxicillin dose, with part of the amoxicillin dose being in an extended release formulation, without increasing the clavulanate dose, for twice-daily oral treatment of these infections. Clinical studies of community-acquired pneumonia and acute rhinosinusitis have shown that the new formulation is well tolerated and highly efficacious, with clinical outcomes equivalent to comparators.

Methylphenidate and dexmethylphenidate formulations for children with attention-deficit/hyperactivity disorder.

PubMed

Sugrue, David; Bogner, Robin; Ehret, Megan J

2014-07-15

Current literature on the safety and efficacy of various intermediate- and long-acting preparations of methylphenidate and dexmethylphenidate for pediatric attention-deficit/hyperactivity disorder (ADHD) is reviewed. The efficacy of methylphenidate in controlling ADHD symptoms is firmly established. Given the drug's relatively short half-life in pediatric patients (about 2.5 hours), a number of intermediate- and long-acting products have been developed; these extended-release methylphenidate products provide the same efficacy as immediate-release (IR) formulations, with the convenience of less frequent dosing. Intermediate-acting methylphenidate preparations have effects lasting as long as 8 hours, but peak concentrations are not attained for up to 5 hours, and many patients may require twice-daily dosing. Long-acting methylphenidate products developed to address these challenges include a controlled-release tablet and bimodal-delivery capsules containing mixtures of IR and extended-release beads (durations of effect, 8-12 hours). Options for patients with difficulty swallowing tablets or capsules include a once-daily transdermal delivery system and a once-daily liquid formulation. Dexmethylphenidate (the more pharmacologically active d-isomer of racemic methylphenidate) can provide efficacy comparable to that of IR methylphenidate at half the dose; an extended-release form of dexmethylphenidate can provide less fluctuation in peak and trough concentrations than the IR form. Methylphenidate and dexmethylphenidate products in capsule form can be opened and sprinkled on applesauce. The various formulations of IR and intermediate- and extended-release methylphenidate and dexmethylphenidate can be useful options in satisfying patients' individual needs in the management of ADHD. All are equally efficacious in controlling ADHD symptoms. Copyright © 2014 by the American Society of Health-System Pharmacists, Inc. All rights reserved.

Bilayer tablets of Paliperidone for Extended release osmotic drug delivery

NASA Astrophysics Data System (ADS)

Chowdary, K. Sunil; Napoleon, A. A.

2017-11-01

The purpose of this study is to develop and optimize the formulation of paliperidone bilayer tablet core and coating which should meet in vitro performance of trilayered Innovator sample Invega. Optimization of core formulations prepared by different ratio of polyox grades and optimization of coating of (i) sub-coating build-up with hydroxy ethyl cellulose (HEC) and (ii).enteric coating build-up with cellulose acetate (CA). Some important influence factors such as different core tablet compositions and different coating solution ingredients involved in the formulation procedure were investigated. The optimization of formulation and process was conducted by comparing different in vitro release behaviours of Paliperidone. In vitro dissolution studies of Innovator sample (Invega) with formulations of different release rate which ever close release pattern during the whole 24 h test is finalized.

Preparation and in-vivo pharmacokinetic study of a novel extended release compression coated tablets of fenoterol hydrobromide.

PubMed

Elshafeey, Ahmed H; Sami, Elshaimaa I

2008-01-01

The aim of this study was to formulate extended release compression coated core tablets of fenoterol hydrobromide, a selective beta(2) adrenergic receptor agonist, in an attempt to prevent nocturnal asthma. Two hydrophilic polymers viz Kollidon SR, Polyox WSR 303 and a hydrophobic one (Precirol ATO5) were employed. Compression coated tablets were formulated by preparing a core tablet containing 7.5 mg drug and various amounts of polymer and Emcompress then compressed coated with the same polymeric materials. For comparison purpose different matrix tablets were also prepared employing the same polymers. In-vitro release studies were carried out at different pH (1.2 and 6.8). Pharmacokinetics of extended release tablets as well as commercially available immediate release tablets (Berotec) were studied after oral administration to beagle dogs using a new developed LC-MS/MS method with a lower limit of quantification of 1 ng/ml. Fenoterol release from compression coated tablets was significantly lower than matrix tablets. The mechanism of release was changed with the nature and content of polymer. The release pattern of drug from F16 containing 40 mg Kollidon SR divided in the core tablet (15 mg) and the rest in the compressed coat (25 mg) showed a typical zero order release kinetic that could extend drug release >10 h and reasonable time for 75% to be released (t(75)) (8.92 h). When compared to immediate release Berotec tablet the MRT was significantly extended from 7.03 +/- 0.76 to 10.93 +/- 1.25 h (P < 0.001) and HVD(t 50%Cmax) was also significantly extended from 2.71 +/- 0.68 to 6.81 +/- 0.67 h with expected prevention of nocturnal asthma.

Application of Physiologically Based Absorption Modeling to Characterize the Pharmacokinetic Profiles of Oral Extended Release Methylphenidate Products in Adults

PubMed Central

Yang, Xiaoxia; Duan, John; Fisher, Jeffrey

2016-01-01

A previously presented physiologically-based pharmacokinetic model for immediate release (IR) methylphenidate (MPH) was extended to characterize the pharmacokinetic behaviors of oral extended release (ER) MPH formulations in adults for the first time. Information on the anatomy and physiology of the gastrointestinal (GI) tract, together with the biopharmaceutical properties of MPH, was integrated into the original model, with model parameters representing hepatic metabolism and intestinal non-specific loss recalibrated against in vitro and in vivo kinetic data sets with IR MPH. A Weibull function was implemented to describe the dissolution of different ER formulations. A variety of mathematical functions can be utilized to account for the engineered release/dissolution technologies to achieve better model performance. The physiological absorption model tracked well the plasma concentration profiles in adults receiving a multilayer-release MPH formulation or Metadate CD, while some degree of discrepancy was observed between predicted and observed plasma concentration profiles for Ritalin LA and Medikinet Retard. A local sensitivity analysis demonstrated that model parameters associated with the GI tract significantly influenced model predicted plasma MPH concentrations, albeit to varying degrees, suggesting the importance of better understanding the GI tract physiology, along with the intestinal non-specific loss of MPH. The model provides a quantitative tool to predict the biphasic plasma time course data for ER MPH, helping elucidate factors responsible for the diverse plasma MPH concentration profiles following oral dosing of different ER formulations. PMID:27723791

Tamarind seed gum-hydrolyzed polymethacrylamide-g-gellan beads for extended release of diclofenac sodium using 32 full factorial design.

PubMed

Nandi, Gouranga; Nandi, Amit Kumar; Khan, Najim Sarif; Pal, Souvik; Dey, Sibasish

2018-07-15

Development of tamarind seed gum (TSG)-hydrolyzed polymethacrylamide-g-gellan (h-Pmaa-g-GG) composite beads for extended release of diclofenac sodium using 3 2 full factorial design is the main purpose of this study. The ratio of h-Pmaa-g-GG and TSG and concentration of cross-linker CaCl 2 were taken as independent factors with three different levels of each. Effects of polymer ratio and CaCl 2 on drug entrapment efficiency (DEE), drug release, bead size and swelling were investigated. Responses such as DEE and different drug release parameters were statistically analyzed by 3 2 full factorial design using Design-Expert software and finally the formulation factors were optimized to obtain USP-reference release profile. Drug release rate was found to decrease with decrease in the ratio of h-Pmaa-g-GG:TSG and increase in the concentration of Ca 2+ ions in cross-linking medium. The optimized formulation showed DEE of 93.25% and an extended drug release profile over a period of 10h with f 2 =80.13. Kinetic modeling unveiled case-I-Fickian diffusion based drug release mechanism. Copyright © 2018 Elsevier B.V. All rights reserved.

Extended release dosage form of glipizide: development and validation of a level A in vitro-in vivo correlation.

PubMed

Ghosh, Animesh; Bhaumik, Uttam Kumar; Bose, Anirbandeep; Mandal, Uttam; Gowda, Veeran; Chatterjee, Bappaditya; Chakrabarty, Uday Sankar; Pal, Tapan Kumar

2008-10-01

Defining a quantitative and reliable relationship between in vitro drug release and in vivo absorption is highly desired for rational development, optimization, and evaluation of controlled-release dosage forms and manufacturing process. During the development of once daily extended-release (ER) tablet of glipizide, a predictive in vitro drug release method was designed and statistically evaluated using three formulations with varying release rates. In order to establish internally and externally validated level A in vitro-in vivo correlation (IVIVC), a total of three different ER formulations of glipizide were used to evaluate a linear IVIVC model based on the in vitro test method. For internal validation, a single-dose four-way cross over study (n=6) was performed using fast-, moderate-, and slow-releasing ER formulations and an immediate-release (IR) of glipizide as reference. In vitro release rate data were obtained for each formulation using the United States Pharmacopeia (USP) apparatus II, paddle stirrer at 50 and 100 rev. min(-1) in 0.1 M hydrochloric acid (HCl) and pH 6.8 phosphate buffer. The f(2) metric (similarity factor) was used to analyze the dissolution data. The formulations were compared using area under the plasma concentration-time curve, AUC(0-infinity), time to reach peak plasma concentration, T(max), and peak plasma concentration, C(max), while correlation was determined between in vitro release and in vivo absorption. A linear correlation model was developed using percent absorbed data versus percent dissolved from the three formulations. Predicted glipizide concentrations were obtained by convolution of the in vivo absorption rates. Prediction errors were estimated for C(max) and AUC(0-infinity) to determine the validity of the correlation. Apparatus II, pH 6.8 at 100 rev. min(-1) was found to be the most discriminating dissolution method. Linear regression analysis of the mean percentage of dose absorbed versus the mean percentage of in vitro release resulted in a significant correlation (r(2)>or=0.9) for the three formulations.

Development of in vitro-in vivo correlation for extended-release niacin after administration of hypromellose-based matrix formulations to healthy volunteers.

PubMed

Kesisoglou, Filippos; Rossenu, Stefaan; Farrell, Colm; Van Den Heuvel, Michiel; Prohn, Marita; Fitzpatrick, Shaun; De Kam, Pieter-Jan; Vargo, Ryan

2014-11-01

Development of in vitro-in vivo correlations (IVIVCs) for extended-release (ER) products is commonly pursued during pharmaceutical development to increase product understanding, set release specifications, and support biowaivers. This manuscript details the development of Level C and Level A IVIVCs for ER formulations of niacin, a highly variable and extensively metabolized compound. Three ER formulations were screened in a cross-over study against immediate-release niacin. A Multiple Level C IVIVC was established for both niacin and its primary metabolite nicotinuric acid (NUA) as well as total niacin metabolites urinary excretion. For NUA, but not for niacin, Level A IVIVC models with acceptable prediction errors were achievable via a modified IVIVC rather than a traditional deconvolution/convolution approach. Hence, this is in contradiction with current regulatory guidelines that suggest that when a Multiple Level C IVIVC is established, Level A models should also be readily achievable. We demonstrate that for a highly variable, highly metabolized compound such as niacin, development of a Level A IVIVC model fully validated according to agency guidelines may be challenging. However, Multiple Level C models are achievable and could be used to guide release specifications and formulation/manufacturing changes. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Extended-Release Once-Daily Formulation of Tofacitinib: Evaluation of Pharmacokinetics Compared With Immediate-Release Tofacitinib and Impact of Food.

PubMed

Lamba, Manisha; Wang, Rong; Fletcher, Tracey; Alvey, Christine; Kushner, Joseph; Stock, Thomas C

2016-11-01

Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis. An extended-release (XR) formulation has been designed to provide a once-daily (QD) dosing option to patients to achieve comparable pharmacokinetic (PK) parameters to the twice-daily immediate-release (IR) formulation. We conducted 2 randomized, open-label, phase 1 studies in healthy volunteers. Study A characterized single-dose and steady-state PK of tofacitinib XR 11 mg QD and intended to demonstrate equivalence of exposure under single-dose and steady-state conditions to tofacitinib IR 5 mg twice daily. Study B assessed the effect of a high-fat meal on the bioavailability of tofacitinib from the XR formulation. Safety and tolerability were monitored in both studies. In study A (N = 24), the XR and IR formulations achieved time to maximum plasma concentration at 4 hours and 0.5 hours postdose, respectively; terminal half-life was 5.9 hours and 3.2 hours, respectively. Area under plasma concentration-time curve (AUC) and maximum plasma concentration (C max ) after single- and multiple-dose administration were equivalent between the XR and IR formulations. In study B (N = 24), no difference in AUC was observed for fed vs fasted conditions. C max increased by 27% under the fed state. On repeat administration, negligible accumulation (<20%) of systemic exposures was observed for both formulations. Steady state was achieved within 48 hours of dosing with the XR formulation. Tofacitinib administration as an XR or IR formulation was generally well tolerated in these studies. © 2016, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

Evaluation of the resistance of a geopolymer-based drug delivery system to tampering.

PubMed

Cai, Bing; Engqvist, Håkan; Bredenberg, Susanne

2014-04-25

Tamper-resistance is an important property of controlled-release formulations of opioid drugs. Tamper-resistant formulations aim to increase the degree of effort required to override the controlled release of the drug molecules from extended-release formulations for the purpose of non-medical use. In this study, the resistance of a geopolymer-based formulation to tampering was evaluated by comparing it with a commercial controlled-release tablet using several methods commonly used by drug abusers. Because of its high compressive strength and resistance to heat, much more effort and time was required to extract the drug from the geopolymer-based formulation. Moreover, in the drug-release test, the geopolymer-based formulation maintained its controlled-release characteristics after milling, while the drug was released immediately from the milled commercial tablets, potentially resulting in dose dumping. Although the tampering methods used in this study does not cover all methods that abuser could access, the results obtained by the described methods showed that the geopolymer matrix increased the degree of effort required to override the controlled release of the drug, suggesting that the formulation has improved resistance to some common drug-abuse tampering methods. The geopolymer matrix has the potential to make the opioid product less accessible and attractive to non-medical users. Copyright © 2014 Elsevier B.V. All rights reserved.

Formulation and evaluation of delayed-onset extended-release tablets of metoprolol tartrate using hydrophilic-swellable polymers.

PubMed

Dadarwal, Subhash Chand; Madan, Sarika; Agrawal, Shyam Sunder

2012-03-01

In view of the circadian rhythm of cardiovascular diseases, a delayed-onset extended-release (DOER) formulation of metoprolol tartrate (MT) was prepared. This was achieved through dissolution-guided optimization of the proportion of Methocel K4M and Methocel K15M. Core erosion ratio was greater than 50 %, thereby showing steady release of the drug after the lag time until complete dissolution. Optimized formulation produced a lag phase of 6 h followed by complete release of 98.7 ± 2.1 % in 24 h. Water uptake study revealed that Methocel K15M has lower water uptake (30 ± 1 %) than Methocel K4M (40 ± 2 %) after 24 h. Axial swelling of polymers was higher than swelling in the radial direction. Drug-polymer interaction study precludes any interaction between drug and polymer. Such a drug delivery system may provide a viable alternative for effective management of hypertension and other related disorders. This work also proposes an approach to attain DOER for a hydrophilic drug by using a hydrophilic swellable polymer in press coat.

Steady-State Clinical Pharmacokinetics of Bupropion Extended-Release In Youths

ERIC Educational Resources Information Center

Daviss, W. Burleson; Perel, James M.; Birmaher, Boris; Rudolph, George R.; Melhem, Imad; Axelson, David A.; Brent, David A.

2006-01-01

Objective: To examine in children and adolescents the 24-hour, steady-state clinical pharmacokinetics of an extended-release (XL) formulation of bupropion (Wellbutrin XL). Method: Subjects were six male and four female patients (ages 11.5-16.2 years) prescribed bupropion XL in morning daily doses of either 150 mg (n = 5) or 300 mg (n = 5) for at…

In Vitro Drug Release After Crushing: Evaluation of Xtampza® ER and Other ER Opioid Formulations.

PubMed

Mayock, Stephen P; Saim, Said; Fleming, Alison B

2017-12-01

Extended-release (ER) opioids are associated with high rates of abuse. Recreational opioid users often manipulate ER formulations to achieve a high plasma concentration in a short amount of time, resulting in a more rapid and intense high. Patients may also manipulate ER tablets to facilitate swallowing, without recognizing that manipulation could increase release rate. The goal of this study was to assess the ability of oxycodone DETERx (Xtampza ® ER, Collegium Pharmaceutical, Inc., Canton, MA, USA) and other commercially available ER opioid formulations with and without physicochemical abuse-deterrent characteristics to be manipulated by crushing in an in vitro setting. In vitro dissolution techniques were used to compare the opioid release from a variety of ER opioid formulations. Dissolution was assessed for intact and crushed dosage forms. Opioid release was quantified using high-performance liquid chromatography. Intact formulations exhibited drug release rates characteristic of 12- or 24-h dosage forms. After crushing using commonly available household tools, only Xtampza ER maintained ER of opioid. Xtampza ER maintained its ER characteristics after crushing, unlike many other commercially available opioid formulations, including some formulated with abuse-deterrent properties. As such, Xtampza ER may be less appealing to abusers and offer a margin of safety for patients who manipulate dosage forms to facilitate swallowing.

An understanding of modified release matrix tablets behavior during drug dissolution as the key for prediction of pharmaceutical product performance - case study of multimodal characterization of quetiapine fumarate tablets.

PubMed

Kulinowski, Piotr; Woyna-Orlewicz, Krzysztof; Rappen, Gerd-Martin; Haznar-Garbacz, Dorota; Węglarz, Władysław P; Dorożyński, Przemysław P

2015-04-30

Motivation for the study was the lack of dedicated and effective research and development (R&D) in vitro methods for oral, generic, modified release formulations. The purpose of the research was to assess multimodal in vitro methodology for further bioequivalence study risk minimization. Principal results of the study are as follows: (i) Pharmaceutically equivalent quetiapine fumarate extended release dosage form of Seroquel XR was developed using a quality by design/design of experiment (QbD/DoE) paradigm. (ii) The developed formulation was then compared with originator using X-ray microtomography, magnetic resonance imaging and texture analysis. Despite similarity in terms of compendial dissolution test, developed and original dosage forms differed in micro/meso structure and consequently in mechanical properties. (iii) These differences were found to be the key factors of failure of biorelevant dissolution test using the stress dissolution apparatus. Major conclusions are as follows: (i) Imaging methods allow to assess internal features of the hydrating extended release matrix and together with the stress dissolution test allow to rationalize the design of generic formulations at the in vitro level. (ii) Technological impact on formulation properties e.g., on pore formation in hydrating matrices cannot be overlooked when designing modified release dosage forms. Copyright © 2015 Elsevier B.V. All rights reserved.

Development of In Vitro-In Vivo Correlation for Potassium Chloride Extended Release Tablet Formulation Using Urinary Pharmacokinetic Data.

PubMed

Mittapalli, Rajendar K; Marroum, Patrick; Qiu, Yihong; Apfelbaum, Kathleen; Xiong, Hao

2017-07-01

To develop and validate a Level A in vitro-in vivo correlation (IVIVC) for potassium chloride extended-release (ER) formulations. Three prototype ER formulations of potassium chloride with different in vitro release rates were developed and their urinary pharmacokinetic profiles were evaluated in healthy subjects. A mathematical model between in vitro dissolution and in vivo urinary excretion, a surrogate for measuring in vivo absorption, was developed using time-scale and time-shift parameters. The IVIVC model was then validated based on internal and external predictability. With the established IVIVC model, there was a good correlation between the observed fraction of dose excreted in urine and the time-scaled and time-shifted fraction of the drug dissolved, and between the in vitro dissolution time and the in vivo urinary excretion time for the ER formulations. The percent prediction error (%PE) on cumulative urinary excretion over the 24 h interval (A e0-24h ) and maximum urinary excretion rate (R max ) was less than 15% for the individual formulations and less than 10% for the average of the two formulations used to develop the model. Further, the %PE values using external predictability were below 10%. A novel Level A IVIVC was successfully developed and validated for the new potassium chloride ER formulations using urinary pharmacokinetic data. This successful IVIVC may facilitate future development or manufacturing changes to the potassium chloride ER formulation.

An oral multi-particulate, modified release, hydrocortisone replacement therapy that provides physiological cortisol exposure

PubMed Central

Huatan, Hiep; Merke, Deborah; Arlt, Wiebke; Ross, Richard J.

2013-01-01

Objective It is not possible with current hydrocortisone replacement to mimic the diurnal cortisol profile in patients with adrenal insufficiency. Previous attempts with modified release technology were unsuccessful. Our objective was to develop hydrocortisone formulations that recreate the diurnal cortisol profile using multi-particulate technology. Design and Measurements Screening by in-vitro dissolution profiles, pharmacokinetic testing in dexamethasone suppressed dogs and humans, and comparison to a reference population. Setting Field laboratories and clinical research facility. Results Formulations were generated using an enteric (delayed-release) design configuration with an extended (sustained-release) dissolution profile. In-vitro dissolution confirmed delayed and sustained hydrocortisone release. However, in dogs and humans, sustained release resulted in reduced bioavailability. A formulation, DIURF-006, was developed that maintained delayed release but omitted the sustained release functionality. Pharmacokinetic characterisation of DIURF-006 showed that, despite absence of a sustained release component, absorption was sufficiently sustained to deliver extended hydrocortisone absorption. In dexamethasone-suppressed volunteers (n=16) receiving a twice daily ‘toothbrush’ regimen (20mg at 23:00h and 10mg at 07:00h), DIURF-006 gave a similar cortisol profile to physiological cortisol levels: DIURF-006 vs physiological, Geomean AUC 5610 vs 4706 hr*nmol/l, Geomean Cmax 665 vs 594 nmol/l and Median Tmax 8.5h vs clock time 08:12 hours for peak cortisol. The relative bioavailability of DIURF-006 vs hydrocortisone was 89% and cortisol levels increased linearly with doses between 5 and 30mg. Conclusion A multi-particulate oral hydrocortisone formulation with only an enteric coat provides delayed and sustained absorption and when given in a ‘toothbrush’ regimen provides physiological cortisol exposure. PMID:23980724

An oral multiparticulate, modified-release, hydrocortisone replacement therapy that provides physiological cortisol exposure.

PubMed

Whitaker, Martin; Debono, Miguel; Huatan, Hiep; Merke, Deborah; Arlt, Wiebke; Ross, Richard J

2014-04-01

It is not possible with current hydrocortisone replacement to mimic the diurnal cortisol profile in patients with adrenal insufficiency. Previous attempts with modified-release technology were unsuccessful. Our objective was to develop hydrocortisone formulations that recreate the diurnal cortisol profile using multiparticulate technology. Screening by in vitro dissolution profiles, pharmacokinetic (PK) testing in dexamethasone-suppressed dogs and humans, and comparison with a reference population. Field laboratories and clinical research facility. Formulations were generated using an enteric (delayed release) design configuration with an extended (sustained release) dissolution profile. In vitro dissolution confirmed delayed and sustained hydrocortisone release. However, in dogs and humans, sustained release resulted in reduced bioavailability. A formulation, DIURF-006, was developed that maintained delayed release but omitted the sustained-release functionality. PK characterization of DIURF-006 showed that, despite absence of a sustained-release component, absorption was sufficiently sustained to deliver extended hydrocortisone absorption. In dexamethasone-suppressed volunteers (n = 16) receiving a twice-daily 'toothbrush' regimen (20 mg at 23:00 h and 10 mg at 07:00 h), DIURF-006 gave a similar cortisol profile to physiological cortisol levels: DIURF-006 vs physiological, Geomean AUC 5610 vs 4706 h * nmol/l, Geomean Cmax 665 vs 594 nmol/l and Median Tmax 8·5 h vs clock time 08:12 h for peak cortisol. The relative bioavailability of DIURF-006 vs hydrocortisone was 89%, and cortisol levels increased linearly with doses between 5 and 30 mg. A multiparticulate oral hydrocortisone formulation with only an enteric coat provides delayed and sustained absorption and when given in a 'toothbrush' regimen provides physiological cortisol exposure. © 2013 John Wiley & Sons Ltd.

Development and evaluation of accelerated drug release testing methods for a matrix-type intravaginal ring.

PubMed

Externbrink, Anna; Eggenreich, Karin; Eder, Simone; Mohr, Stefan; Nickisch, Klaus; Klein, Sandra

2017-01-01

Accelerated drug release testing is a valuable quality control tool for long-acting non-oral extended release formulations. Currently, several intravaginal ring candidates designed for the long-term delivery of steroids or anti-infective drugs are being in the developing pipeline. The present article addresses the demand for accelerated drug release methods for these formulations. We describe the development and evaluation of accelerated release methods for a steroid releasing matrix-type intravaginal ring. The drug release properties of the formulation were evaluated under real-time and accelerated test conditions. Under real-time test conditions drug release from the intravaginal ring was strongly affected by the steroid solubility in the release medium. Under sufficient sink conditions that were provided in release media containing surfactants drug release was Fickian diffusion driven. Both temperature and hydro-organic dissolution media were successfully employed to accelerate drug release from the formulation. Drug release could be further increased by combining the temperature effect with the application of a hydro-organic release medium. The formulation continued to exhibit a diffusion controlled release kinetic under the investigated accelerated conditions. Moreover, the accelerated methods were able to differentiate between different prototypes of the intravaginal ring that exhibited different release profiles under real-time test conditions. Overall, the results of the present study indicate that both temperature and hydro-organic release media are valid parameters for accelerating drug release from the intravaginal ring. Variation of either a single or both parameters yielded release profiles that correlated well with real-time release. Copyright © 2016 Elsevier B.V. All rights reserved.

Transdermal glimepiride delivery system based on optimized ethosomal nano-vesicles: Preparation, characterization, in vitro, ex vivo and clinical evaluation.

PubMed

Ahmed, Tarek A; El-Say, Khalid M; Aljaeid, Bader M; Fahmy, Usama A; Abd-Allah, Fathy I

2016-03-16

This work aimed to develop an optimized ethosomal formulation of glimepiride then loading into transdermal films to offer lower drug side effect, extended release behavior and avoid first pass effect. Four formulation factors were optimized for their effects on vesicle size (Y1), entrapment efficiency (Y2) and vesicle flexibility (Y3). Optimum desirability was identified and, an optimized formulation was prepared, characterized and loaded into transdermal films. Ex-vivo permeation study for the prepared films was conducted and, the permeation parameters and drug permeation mechanism were identified. Penetration through rat skin was studied using confocal laser microscope. In-vivo study was performed following transdermal application on human volunteers. The percent of alcohol was significantly affecting all the studied responses while the other factors and their interaction effects were varied on their effects on each response. The optimized ethosomal formulation showed observed values for Y1, Y2 and Y3 of 61 nm, 97.12% and 54.03, respectively. Ex-vivo permeation of films loaded with optimized ethosomal formulation was superior to that of the corresponding pure drug transdermal films and this finding was also confirmed after confocal laser microscope study. Permeation of glimepiride from the prepared films was in favor of Higushi-diffusion model and exhibited non-Fickian or anomalous release mechanism. In-vivo study revealed extended drug release behavior and lower maximum drug plasma level from transdermal films loaded with drug ethosomal formulation. So, the ethosomal formulation could be considered a suitable drug delivery system especially when loaded into transdermal vehicle with possible reduction in side effects and controlling the drug release. Copyright © 2016 Elsevier B.V. All rights reserved.

Effect of food on early drug exposure from extended-release stimulants: results from the Concerta, Adderall XR Food Evaluation (CAFE) Study.

PubMed

Auiler, J F; Liu, K; Lynch, J M; Gelotte, C K

2002-01-01

Stimulant therapy is the mainstay of treatment for children, adolescents and adults with attention-deficit/hyperactivity disorder (ADHD). Once-daily, extended-release oral formulations offer long acting control of symptoms by modifying drug delivery and absorption. In particular, consistency in early drug exposure is important for symptom control during school or work hours. Because these once-daily formulations are usually taken in the morning, the timing of the doses with breakfast is important. This study compared the effect of a high-fat breakfast on early drug exposure from a morning dose of two extended-release stimulant formulations: the osmotic-controlled OROS tablet of methylphenidate HCI (CONCERTA) and the capsule containing extended-release beads of mixed amphetamine salts (ADDERALL XR). The study had a single-dose, open-label, randomised, four-treatment, crossover design in which healthy subjects received either 36 mg CONCERTA or 20 mg ADDERALL XR in the morning after an overnight fast or a high-fat breakfast. Serial blood samples were collected over 28h to determine plasma concentrations of methylphenidate and amphetamine. The food effect on early drug exposure and the pharmacokinetic profiles up to 8 h after dosing of the two extended-release stimulants were directly compared using partial area (AUC(p4h), AUC(p6h) and AUC(p8h)) fed/fasted ratios. Amphetamine concentrations were markedly lower when the subjects had eaten breakfast, resulting in lower early drug exposures (p < 0.0001). By contrast, methylphenidate concentrations over the same 8 h were unaffected by breakfast, providing consistent levels of early drug exposure. Therefore, as a child's or adult's eating pattern varies, methylphenidate exposure over the first 8 h would be expected to have less day-to-day variation compared with amphetamine exposure. The osmotic-controlled OROS tablet provides a reliable and consistent delivery of methylphenidate HCI, independent of food, for patients with ADHD.

Gastroretentive extended-release floating granules prepared using a novel fluidized hot melt granulation (FHMG) technique.

PubMed

Zhai, H; Jones, D S; McCoy, C P; Madi, A M; Tian, Y; Andrews, G P

2014-10-06

The objective of this work was to investigate the feasibility of using a novel granulation technique, namely, fluidized hot melt granulation (FHMG), to prepare gastroretentive extended-release floating granules. In this study we have utilized FHMG, a solvent free process in which granulation is achieved with the aid of low melting point materials, using Compritol 888 ATO and Gelucire 50/13 as meltable binders, in place of conventional liquid binders. The physicochemical properties, morphology, floating properties, and drug release of the manufactured granules were investigated. Granules prepared by this method were spherical in shape and showed good flowability. The floating granules exhibited sustained release exceeding 10 h. Granule buoyancy (floating time and strength) and drug release properties were significantly influenced by formulation variables such as excipient type and concentration, and the physical characteristics (particle size, hydrophilicity) of the excipients. Drug release rate was increased by increasing the concentration of hydroxypropyl cellulose (HPC) and Gelucire 50/13, or by decreasing the particle size of HPC. Floating strength was improved through the incorporation of sodium bicarbonate and citric acid. Furthermore, floating strength was influenced by the concentration of HPC within the formulation. Granules prepared in this way show good physical characteristics, floating ability, and drug release properties when placed in simulated gastric fluid. Moreover, the drug release and floating properties can be controlled by modification of the ratio or physical characteristics of the excipients used in the formulation.

Benznidazole Extended-Release Tablets for Improved Treatment of Chagas Disease: Preclinical Pharmacokinetic Study

PubMed Central

Campos, Michel Leandro; Rosa, Talita Atanazio; Padilha, Elias Carvalho; Alzate, Alejandro Henao; Rolim, Larissa Araújo; Rolim-Neto, Pedro José

2016-01-01

Benznidazole (BNZ) is the first-line drug for the treatment of Chagas disease. The drug is available in the form of immediate-release tablets for 100-mg (adult) and 12.5-mg (pediatric) doses. The drug is administered two or three times daily for 60 days. The high frequency of daily administrations and the long period of treatment are factors that significantly contribute to the abandonment of therapy, affecting therapeutic success. Accordingly, this study aimed to evaluate the preclinical pharmacokinetics of BNZ administered as extended-release tablets (200-mg dose) formulated with different types of polymers (hydroxypropyl methylcellulose K4M and K100M), compared to the tablets currently available. The studies were conducted with rabbits, and BNZ quantification was performed in plasma and urine by ultraperformance liquid chromatography methods previously validated. The bioavailability of BNZ was adequate in the administration of extended-release tablets; however, with the administration of the pediatric tablet, the bioavailability was lower than with other tablets, which showed that the clinical use of this formulation should be monitored. The pharmacokinetic parameters demonstrated that the extended-release tablets prolonged drug release from the pharmaceutical matrix and provided an increase in the maintenance of the drug concentration in vivo, which would allow the frequency of administration to be reduced. Thus, a relative bioavailability study in humans will be planned for implementation of a new product for the treatment of Chagas disease. PMID:26883698

Gastroretentive behavior of orally administered radiolabeled tamarind seed formulations in rabbits validated by gamma scintigraphy.

PubMed

Razavi, Mahboubeh; Karimian, Hamed; Yeong, Chai Hong; Fadaeinasab, Mehran; Khaing, Si Lay; Chung, Lip Yong; Mohamad Haron, Didi Erwandi B; Noordin, Mohamed Ibrahim

2017-01-01

This study aimed to formulate floating gastroretentive tablets containing metformin hydrochloric acid (HCl), using various grades of hydrogel such as tamarind powders and xanthan to overcome short gastric residence time of the conventional dosage forms. Different concentrations of the hydrogels were tested to determine the formulation that could provide a sustained release of 12 h. Eleven formulations with different ratios of tamarind seed powder/tamarind kernel powder (TKP):xanthan were prepared. The physical parameters were observed, and in vitro drug-release studies of the prepared formulations were carried out. Optimal formulation was assessed for physicochemical properties, thermal stability, and chemical interaction followed by in vivo gamma scintigraphy study. MKP3 formulation with a TKP:xanthan ratio of 3:2 was found to have 99.87% release over 12 h. Furthermore, in vivo gamma scintigraphy study was carried out for the optimized formulation in healthy New Zealand White rabbits, and the pharmacokinetic parameters of developed formulations were obtained. 153 Sm 2 O 3 was used to trace the profile of release in the gastrointestinal tract of the rabbits, and the drug release was analyzed. The time ( T max ) at which the maximum concentration of metformin HCl in the blood ( C max ) was observed, and it was extended four times for the gastroretentive formulation in comparison with the formulation without polymers. C max and the half-life were found to be within an acceptable range. It is therefore concluded that MKP3 is the optimal formulation for sustained release of metformin HCl over a period of 12 h as a result of its floating properties in the gastric region.

Gastroretentive behavior of orally administered radiolabeled tamarind seed formulations in rabbits validated by gamma scintigraphy

PubMed Central

Razavi, Mahboubeh; Karimian, Hamed; Yeong, Chai Hong; Fadaeinasab, Mehran; Khaing, Si Lay; Chung, Lip Yong; Mohamad Haron, Didi Erwandi B; Noordin, Mohamed Ibrahim

2017-01-01

This study aimed to formulate floating gastroretentive tablets containing metformin hydrochloric acid (HCl), using various grades of hydrogel such as tamarind powders and xanthan to overcome short gastric residence time of the conventional dosage forms. Different concentrations of the hydrogels were tested to determine the formulation that could provide a sustained release of 12 h. Eleven formulations with different ratios of tamarind seed powder/tamarind kernel powder (TKP):xanthan were prepared. The physical parameters were observed, and in vitro drug-release studies of the prepared formulations were carried out. Optimal formulation was assessed for physicochemical properties, thermal stability, and chemical interaction followed by in vivo gamma scintigraphy study. MKP3 formulation with a TKP:xanthan ratio of 3:2 was found to have 99.87% release over 12 h. Furthermore, in vivo gamma scintigraphy study was carried out for the optimized formulation in healthy New Zealand White rabbits, and the pharmacokinetic parameters of developed formulations were obtained. 153Sm2O3 was used to trace the profile of release in the gastrointestinal tract of the rabbits, and the drug release was analyzed. The time (Tmax) at which the maximum concentration of metformin HCl in the blood (Cmax) was observed, and it was extended four times for the gastroretentive formulation in comparison with the formulation without polymers. Cmax and the half-life were found to be within an acceptable range. It is therefore concluded that MKP3 is the optimal formulation for sustained release of metformin HCl over a period of 12 h as a result of its floating properties in the gastric region. PMID:28031701

An extended-release formulation of oxybutynin chloride for the treatment of overactive urinary bladder.

PubMed

Goldenberg, M M

1999-04-01

Detrusor instability, or urinary incontinence, is common in elderly patients, particularly elderly women. The clinical symptoms of overactive, or unstable, urinary bladder include urge urinary incontinence, urgency, and frequency. Mixed urinary incontinence, which comprises urge urinary incontinence and stress incontinence, is manifested by increased intraabdominal pressure on coughing or sneezing. The detrusor muscle of the bladder is under the control of the parasympathetic, or muscarinic, nervous system. The drug of choice in this condition is oxybutynin chloride, which has the ability to block acetylcholine released from parasympathetic nerves in the urinary bladder, preventing contractions of the muscle and exerting a direct spasmolytic effect on the bladder. A new extended-release oral tablet formulation, OROS oxybutynin, uses osmotic pressure to deliver the drug at a controlled rate over approximately 24 hours. It resembles a conventional tablet but has a two-part core consisting of a drug layer and below it, a "push" layer containing osmotically active components, the whole surrounded by a semipermeable membrane with a laser-drilled opening in the drug side. Water in the gastrointestinal tract enters the tablet and mixes with the drug to form a suspension. The "push" layer expands and pushes the suspended drug out of the orifice and into the gastrointestinal tract for eventual absorption. Pharmacokinetic studies have indicated a slow rise in mean plasma concentration of the isomer R-oxybutynin for 4 to 6 hours after a single dose of OROS oxybutynin, followed by maintenance of steady concentrations for up to 24 hours, minimizing the fluctuations between peak and trough associated with TID dosing of 5-mg immediate-release oxybutynin tablets. Efficacy and safety studies comparing the extended-release with the immediate-release formulation of oxybutynin demonstrated equivalent efficacy in patients with overactive urinary bladder. The adverse-event profile of oxybutynin is similar to that of a typical anticholinergic agent such as atropine--dry mouth, constipation, somnolence, blurred vision, headache, and gastrointestinal pain--although in 2 clinical studies, the incidence of dry mouth was less with the extended-release formulation. Once-daily dosing with OROS oxybutynin appears to be well tolerated and effective, as well as convenient, for the treatment of overactive bladder, particularly for elderly patients using multiple medications.

Development of metoprolol tartrate extended-release matrix tablet formulations for regulatory policy consideration.

PubMed

Nellore, R V; Rekhi, G S; Hussain, A S; Tillman, L G; Augsburger, L L

1998-01-02

This research study was designed to develop model extended-release (ER) matrix tablet formulations for metoprolol tartrate (100 mg) sufficiently sensitive to manufacturing variable and to serve as the scientific basis for regulatory policy development on scale-up and post approval changes for modified-release dosage forms (SUPAC-MR). Several grades and levels of hydroxypropyl methylcellulose (Methocel K4M, K15M, K100M and K100LV), fillers and binders and studied. Three granulation processes were evaluated; direct compression, fluid-bed or high-shear granulation. Lubrication was performed in a V-blender and tablets were compressed on an instrumented rotary tablet press. Direct compression formulations exhibited poor flow, picking and sticking problems during tableting. High-shear granulation resulted in the formation of hard granules that were difficult to mill but yielded good tablets. Fluid-bed granulations were made using various binders and appeared to be satisfactory in terms of flow and tableting performance. In vitro drug release testing was performed in pH 6.8 phosphate buffer using USP apparatus 2 (paddle) at 50 rpm. At a fixed polymer level, drug release from the higher viscosity grades (K100M) was slower as compared to the lower viscosity grades (K100LV). In addition, release from K100LV was found to be more sensitive to polymer level changes. Increased in polymer level from 10 to 40% and/or filler change from lactose to dicalcium phosphate resulted in about 25-30% decrease in the amount of metoprolol release after 12 h. The results of this study led to the choice of Methocel K100LV as the hydrophilic matrix polymer and fluid-bed granulation as the process of choice for further evaluation of critical and non-critical formulation and processing variables.

Continuous twin screw granulation of controlled release formulations with various HPMC grades.

PubMed

Vanhoorne, V; Janssens, L; Vercruysse, J; De Beer, T; Remon, J P; Vervaet, C

2016-09-25

HPMC is a popular matrix former to formulate tablets with extended drug release. Tablets with HPMC are preferentially produced by direct compression. However, granulation is often required prior to tableting to overcome poor flowability of the formulation. While continuous twin screw granulation has been extensively evaluated for granulation of immediate release formulations, twin screw granulation of controlled release formulations including the dissolution behavior of the formulations received little attention. Therefore, the influence of the HPMC grade (viscosity and substitution degree) and the particle size of theophylline on critical quality attributes of granules (continuously produced via twin screw granulation) and tablets was investigated in the current study. Formulations with 20 or 40% HPMC, 20% theophylline and lactose were granulated with water at fixed process parameters via twin screw granulation. The torque was influenced by the viscosity and substitution degree of HPMC, but was not a limiting factor for the granulation process. An optimal L/S ratio was selected for each formulation based on the granule size distribution. The granule size distributions were influenced by the substitution degree and concentration of HPMC and the particle size of theophylline. Raman and UV spectroscopic analysis on 8 sieve fractions of granules indicated an inhomogeneous distribution of theophylline over the size fractions. However, this phenomenon was not correlated with the hydration rate or viscosity of HPMC. Controlled release of theophylline could be obtained over 24h with release profiles close to zero-order. The release of theophylline could be tailored via selection of the substitution degree and viscosity of HPMC. Copyright © 2016 Elsevier B.V. All rights reserved.

Can dosage form-dependent food effects be predicted using biorelevant dissolution tests? Case example extended release nifedipine.

PubMed

Andreas, Cord J; Tomaszewska, Irena; Muenster, Uwe; van der Mey, Dorina; Mueck, Wolfgang; Dressman, Jennifer B

2016-08-01

Food intake is known to have various effects on gastrointestinal luminal conditions in terms of transit times, hydrodynamic forces and/or luminal fluid composition and can therefore affect the dissolution behavior of solid oral dosage forms. The aim of this study was to investigate and detect the dosage form-dependent food effect that has been observed for two extended-release formulations of nifedipine using in vitro dissolution tests. Two monolithic extended release formulations, the osmotic pump Adalat® XL 60mg and matrix-type Adalat® Eins 30mg formulation, were investigated with biorelevant dissolution methods using the USP apparatus III and IV under both simulated prandial states, and their corresponding quality control dissolution method. In vitro data were compared to published and unpublished in vivo data using deconvolution-based in vitro - in vivo correlation (IVIVC) approaches. Quality control dissolution methods tended to overestimate the dissolution rate due to the excessive solubilizing capabilities of the sodium dodecyl sulfate (SDS)-containing dissolution media. Using Level II biorelevant media the dosage form dependent food effect for nifedipine was described well when studied with the USP apparatus III, whereas the USP apparatus IV failed to detect the positive food effect for the matrix-type dosage form. It was demonstrated that biorelevant methods can serve as a useful tool during formulation development as they were able to qualitatively reflect the in vivo data. Copyright © 2016 Elsevier B.V. All rights reserved.

Interchangeability, Safety and Efficacy of Modified-Release Drug Formulations in the USA: The Case of Opioid and Other Nervous System Drugs.

PubMed

Seoane-Vazquez, Enrique; Rodriguez-Monguio, Rosa; Hansen, Richard

2016-04-01

Modified-release drugs may provide clinical advantages compared to immediate-release forms and improve convenience to the patient and health outcomes. Concerns have been raised regarding interchangeability, efficacy, and safety of modified-release formulations. This study analyses all US Food and Drug Administration (FDA)-approved modified-release formulations and market trends, and illustrates how bioequivalence and safety of generic modified-release products compare to their respective brand name drugs and other generic drugs with different formulation design characteristics. This study also examines major concerns related to modified-release formulations: safety of opioids and bioequivalence of generic bupropion and methylphenidate. Study data were derived from the FDA electronic versions of the FDA's Orange Book (OB) and the FDA safety communications web page. Medicare Part D utilization and expenditures data were extracted from the Centers for Medicare and Medicaid. In May 2015, 276 (11.9 %) of the 2325 active ingredients and fixed-dose combinations listed in the FDA's Orange Book had at least one modified-release form approved by the FDA. The number of approvals increased over time; 52.5 % of modified releases were approved in the period 2000-May 2015. The FDA required a risk evaluation and mitigation strategy (REMS) to ensure that the benefits of extended-release opioids outweighed its risks of overdose and abuse. The REMS involved 16 new drug applications and 25 abbreviated new drug applications. The FDA addressed interchangeability problems with generic modified-release alternatives of bupropion and methylphenidate including lack of bioequivalence, reduced efficacy, and increased incidence of adverse events. Systematic post-marketing surveillance studies are needed to assess differences in safety, interchangeability, and efficacy of drugs with modified- and immediate-release formulations.

A Randomized, Single-Blind, Substitution Study of OROS Methylphenidate (Concerta) in ADHD Adults Receiving Immediate Release Methylphenidate

ERIC Educational Resources Information Center

Spencer, Thomas J.; Mick, Eric; Surman, Craig B. H.; Hammerness, Paul; Doyle, Robert; Aleardi, Megan; Kotarski, Meghan; Williams, Courtney G.; Biederman, Joseph

2011-01-01

Objective: The main aim of this study was to examine the efficacy, tolerability, and compliance of an extended-release formulation of methylphenidate (OROS-MPH) in adults with ADHD receiving immediate-release methylphenidate (IR-MPH). Method: Participants were outpatient adults with ADHD who were stable on IR-MPH-administered TID. Participants…

Developing dissolution testing methodologies for extended-release oral dosage forms with supersaturating properties. Case example: Solid dispersion matrix of indomethacin.

PubMed

Tajiri, Tomokazu; Morita, Shigeaki; Sakamoto, Ryosaku; Mimura, Hisahi; Ozaki, Yukihiro; Reppas, Christos; Kitamura, Satoshi

2015-07-25

The objective of this study was to develop an in vitro dissolution test method with discrimination ability for an extended-release solid dispersion matrix of a lipophilic drug using the United States Pharmacopeia (USP) Apparatus 4, flow-through cell apparatus. In the open-loop configuration, the sink condition was maintained by manipulating the flow rate of the dissolution medium. To evaluate the testing conditions, the drug release mechanism from an extended-release solid dispersion matrix containing hydrophobic and hydrophilic polymers was investigated. As the hydroxypropyl methylcellulose (HPMC) maintained concentrations of indomethacin higher than the solubility in a dissolution medium, the release of HPMC into the dissolution medium was also quantified using size-exclusion chromatography. We concluded that the USP Apparatus 4 is suitable for application to an in vitro dissolution method for orally administered extended-release solid dispersion matrix formulations containing poorly water-soluble drugs. Copyright © 2015 Elsevier B.V. All rights reserved.

Dosage form design and in vitro/in vivo evaluation of cevimeline extended-release tablet formulations.

PubMed

Tajiri, Shinichiro; Kanamaru, Taro; Kamada, Makoto; Makoto, Kamada; Konno, Tsutomu; Nakagami, Hiroaki

2010-01-04

The objective of the present work is to develop an extended-release dosage form of cevimeline. Two types of extended-release tablets (simple matrix tablets and press-coated tablets) were prepared and their potential as extended-release dosage forms were assessed. Simple matrix tablets have a large amount of hydroxypropylcellulose as a rate-controlling polymer and the matrix is homogeneous throughout the tablet. The press-coated tablets consisted of a matrix core tablet, which was completely surrounded by an outer shell containing a large amount of hydroxypropylcellulose. The simple matrix tablets could not sustain the release of cevimeline effectively. In contrast, the press-coated tablets showed a slower dissolution rate compared with simple matrix tablets and the release curve was nearly linear. The dissolution of cevimeline from the press-coated tablets was not markedly affected by the pH of the dissolution medium or by a paddle rotating speed over the range of 50-200 rpm. Furthermore, cevimeline was constantly released from the press-coated tablets in the gastrointestinal tract and the steady-state plasma drug levels were maintained in beagle dogs. These results suggested that the designed PC tablets have a potential for extended-release dosage forms.

Tailoring the mucoadhesive and sustained release characteristics of mesalamine loaded formulations for local treatment of distal forms of ulcerative colitis.

PubMed

Ali, Hany S M; Hanafy, Ahmed F; El Achy, Samar N

2016-10-10

Direct delivery of sustained therapeutic levels of mesalamine (MS) via rectal systems to manage distal forms of ulcerative colitis was studied. The High molecular weight hydroxypropyl methylcellulose (HPMC K4M) polymer was combined with hydrophilic surfactants to control polymer hydration process allowing optimization of the mucoadhesive and controlled drug release properties for the rectal systems. Physical mixtures and granules of MS and HPMC K4M were prepared and in vitro characterized using scanning electron microscope, differential scanning calorimetry and X-ray diffraction techniques. Rectal formulations were prepared utilizing MS-HPMC K4M mixtures in different polyethylene glycol (PEG) combination bases. The developed rectal formulations were investigated for physical, mucoadhesion, in-vitro drug release and swelling characteristics. Results revealed acceptable physical characteristics of the prepared formulations with good content uniformity and minimum weight variation. Sustained release patterns of MS form HPMC K4M based formulations were observed. Formulations prepared using high proportions of the polymer or PEG 400 showed higher extent of mucoadhesion, swelling and greatly extended drug release time. Efficacy of an optimized formulation was assessed using the acetic acid induced colitis model in rats and compared to a reference polymer-free formulation of the drug. Clinical evaluation included bleeding from rectum, consistency of animal stool and colon/body weight ratio. Furthermore, histopathological analysis was carried out to evaluate the degree of inflammation and mucosal damage. Overall results showed a significant enhancement in the clinical pictures and colon histopathology of animals treated by the sustained release mucoadhesive formulation compared to the reference polymer free formulation and the non-treated colitis group. Copyright © 2016 Elsevier B.V. All rights reserved.

Use of partial AUC to demonstrate bioequivalence of Zolpidem Tartrate Extended Release formulations.

PubMed

Lionberger, Robert A; Raw, Andre S; Kim, Stephanie H; Zhang, Xinyuan; Yu, Lawrence X

2012-04-01

FDA's bioequivalence recommendation for Zolpidem Tartrate Extended Release Tablets is the first to use partial AUC (pAUC) metrics for determining bioequivalence of modified-release dosage forms. Modeling and simulation studies were performed to aid in understanding the need for pAUC measures and also the proper pAUC truncation times. Deconvolution techniques, In Vitro/In Vivo Correlations, and the CAT (Compartmental Absorption and Transit) model were used to predict the PK profiles for zolpidem. Models were validated using in-house data submitted to the FDA. Using dissolution profiles expressed by the Weibull model as input for the CAT model, dissolution spaces were derived for simulated test formulations. The AUC(0-1.5) parameter was indicative of IR characteristics of early exposure and effectively distinguished among formulations that produced different pharmacodynamic effects. The AUC(1.5-t) parameter ensured equivalence with respect to the sustained release phase of Ambien CR. The variability of AUC(0-1.5) is higher than other PK parameters, but is reasonable for use in an equivalence test. In addition to the traditional PK parameters of AUCinf and Cmax, AUC(0-1.5) and AUC(1.5-t) are recommended to provide bioequivalence measures with respect to label indications for Ambien CR: onset of sleep and sleep maintenance.

Optimization of Melatonin Dissolution from Extended Release Matrices Using Artificial Neural Networking.

PubMed

Martarelli, D; Casettari, L; Shalaby, K S; Soliman, M E; Cespi, M; Bonacucina, G; Fagioli, L; Perinelli, D R; Lam, J K W; Palmieri, G F

2016-01-01

Efficacy of melatonin in treating sleep disorders has been demonstrated in numerous studies. Being with short half-life, melatonin needs to be formulated in extended-release tablets to prevent the fast drop of its plasma concentration. However, an attempt to mimic melatonin natural plasma levels during night time is challenging. In this work, Artificial Neural Networks (ANNs) were used to optimize melatonin release from hydrophilic polymer matrices. Twenty-seven different tablet formulations with different amounts of hydroxypropyl methylcellulose, xanthan gum and Carbopol®974P NF were prepared and subjected to drug release studies. Using dissolution test data as inputs for ANN designed by Visual Basic programming language, the ideal number of neurons in the hidden layer was determined trial and error methodology to guarantee the best performance of constructed ANN. Results showed that the ANN with nine neurons in the hidden layer had the best results. ANN was examined to check its predictability and then used to determine the best formula that can mimic the release of melatonin from a marketed brand using similarity fit factor. This work shows the possibility of using ANN to optimize the composition of prolonged-release melatonin tablets having dissolution profile desired.

Preparation and in vitro and in vivo evaluation of HupA PLGA microsphere.

PubMed

Ye, Liang; Fu, Fenghua; Liu, Wanhui; Sun, Kaoxiang; Li, Youxin; He, Jie; Yu, Xin; Yu, Pengfei; Tian, Jingwei

2013-03-01

Acetylcholinesterase inhibitors (AChEIs), including Huperzine A (HupA), have been the mainstay of treatment for Alzheimer's disease (AD). However, AChEIs can cause gastrointestinal side effects, which has been related to the high Cmax and short tmax after oral administration. Clinical trials have verified that extended-release formulation with lower Cmax and prolonged tmax, such as rivastigmine patch, could perform a similar efficacy with significantly improved tolerability compared with the oral formulations. In this study, we developed an extended-release microspheres formulation of HupA (called as HAM) with poly(lactide-co-glycolide) (PLGA) as drug carrier. HAM has showed the loading rate as 1.35% (w/w) and yielded 42% with mean particle size at 72.6 μm. In vitro and in vivo pharmacokinetics studies have showed that HAM produced a relatively smooth and continuous drug concentration in 14 days. Furthermore, in vivo pharmacokinetics data have demonstrated that the Cmax was lower and the tmax was considerably later in single intramuscular administration of HAM (1,000 μg/kg) than the counterparts in single intragastric administration of HAT (75 μg/kg/d). Meanwhile, HAM has performed a continuous inhibition to brain AChE activity in normal rats and improvement of memory deficit in Aβ1-40 i.c.v. infused AD rat model for 14 days. The results have suggested that HAM has performed good extended-release properties and good prolonged pharmacological efficacy in vivo in the 2-week period, and could exert a similar efficacy with significantly lowered gastrointestinal side effects as compared with oral formulation.

Pharmacokinetics of dinalbuphine sebacate and nalbuphine in human after intramuscular injection of dinalbuphine sebacate in an extended-release formulation.

PubMed

Tien, Yu En; Huang, Wen-Chuan; Kuo, Hui-Yuan; Tai, Lily; Uang, Yow-Shieng; Chern, Wendy H; Huang, Jin-Ding

2017-11-01

Nalbuphine is a semi-synthetic opioid indicated for the relief of moderate to severe pain. Its short half-life requires frequent injections in clinical practice, resulting in a greater incidence of adverse events. A prodrug of nalbuphine has been developed, dinalbuphine sebacate (DNS), dissolved in a simple oil-based injectable formulation, which could deliver and maintain an effective blood level of nalbuphine. An open-label, prospective, two-period study was performed in healthy volunteers to verify the extended blood concentration profile of nalbuphine. Twelve healthy Taiwanese were randomized to receive an intramuscular injection of 20 mg nalbuphine HCl and 150 mg DNS sequentially with a washout period of 5 days. To prevent DNS hydrolysis during sample analysis, the effect of four esterase inhibitors was evaluated in the quantitation of DNS in human whole blood and thenoyltrifluoroacetone was chosen. The bioavailability of nalbuphine from intramuscularly injected DNS relative to that from nalbuphine HCl was 85.4%. The mean absorption time of nalbuphine from DNS was 145.2 h. It took approximately 6 days for the complete release of DNS into the blood stream where DNS was rapidly hydrolysed to nalbuphine; suggesting a single injection of 150 mg DNS in our extended-release formulation could provide long-lasting pain relief. Copyright © 2017 John Wiley & Sons, Ltd.

Formulation and in vitro characterization of xanthan gum-based sustained release matrix tables of isosorbide-5- mononitrate.

PubMed

Kar, Rajat; Mohapatra, Snehamayee; Bhanja, Satyabrata; Das, Debjyoti; Barik, Bhaktibhusan

2010-01-01

In the present investigation an attempt has been made to increase therapeutic efficacy, to reduce frequency of administration and to improve patient compliance by developing a sustained release matrix tablets of isosorbide-5-mononitrate. Sustained release matrix tablets of isosorbide-5-mononitrate were developed by using different drug: polymer ratios, such in F1 (1:0.75), F2 (1:1), F3 (1:1.5), F4 (1:1.75) and F6 (1:2). Xanthan gum was used as matrix former and microcrystalline cellulose as diluent. All the lubricated formulations were compressed, using 8mm flat faced punches. Compressed tablets were evaluated for uniformity of weight, content of active ingredient, friability, hardness, thickness, in vitro dissolution study using basket method and swelling index. Each formulation showed compliance with pharmacopoeial standards. Among all formulations, F5 showed a greater sustained release pattern of drug over a 12 h period with 92.12% of drug being released. The kinetic studies showed that drug release follows the Higuchi model (r(2) =0.9851). Korsemeyer and Peppas equation gave an n-value of 0.4566, which was close to 0.5, indicating that drug release follows the Fickian diffusion. Thus, xanthan gum can be used as an effective matrix former to extend the release of isosorbide-5-mononitrate. No significant difference was observed in the dissolution profile of optimized formulation, using basket and paddle apparatus.

Matrix tablets for sustained release of repaglinide: Preparation, pharmacokinetics and hypoglycemic activity in beagle dogs.

PubMed

He, Wei; Wu, Mengmeng; Huang, Shiqing; Yin, Lifang

2015-01-15

Repaglinide (RG) is an efficient antihyperglycemic drug; however, due to its short half-life, patients are required to take the marketed products several times a day, which compromises the therapeutic effects. The present study was conducted to develop a hydrophilic sustained release matrix tablet for RG with the aims of prolonging its action time, reducing the required administration times and side effects and improving patient adherence. The matrix tablets were fabricated by a direct compression method, the optimized formulation for which was obtained by screening the factors that affected the drug release. Moreover, studies of the pharmacokinetics and hypoglycemic activity as measured by glucose assay kits were performed in dogs. Sustained drug releases profiles over 10h and a reduced influence of medium pHs on release were achieved with the optimized formulation; moreover, the in vivo performance of extended release formulation was also examined, and better absorption, a one-fold decrease in Cmax, a two-fold increase of Tmax and a prolonged hypoglycemic effect compared to the marketed product were observed. In conclusion, sustained RG release and prolonged action were observed with present matrix tablets, which therefore provide a promising formulation for T2D patients who require long-term treatment. Copyright © 2014 Elsevier B.V. All rights reserved.

Novel Pharmacokinetic-Pharmacodynamic Model for Prediction of Outcomes with an Extended-Release Formulation of Ciprofloxacin

PubMed Central

Meagher, Alison K.; Forrest, Alan; Dalhoff, Axel; Stass, Heino; Schentag, Jerome J.

2004-01-01

The pharmacokinetics of an extended-release (XR) formulation of ciprofloxacin has been compared to that of the immediate-release (IR) product in healthy volunteers. The only significant difference in pharmacokinetic parameters between the two formulations was seen in the rate constant of absorption, which was approximately 50% greater with the IR formulation. The geometric mean plasma ciprofloxacin concentrations were applied to an in vitro pharmacokinetic-pharmacodynamic model exposing three different clinical strains of Escherichia coli (MICs, 0.03, 0.5, and 2.0 mg/liter) to 24 h of simulated concentrations in plasma. A novel mathematical model was derived to describe the time course of bacterial CFU, including capacity-limited replication and first-order rate of bacterial clearance, and to model the effects of ciprofloxacin concentrations on these processes. A “mixture model” was employed which allowed as many as three bacterial subpopulations to describe the total bacterial load at any moment. Comparing the two formulations at equivalent daily doses, the rates and extents of bacterial killing were similar with the IR and XR formulations at MICs of 0.03 and 2.0 mg/liter. At an MIC of 0.5 mg/liter, however, the 1,000-mg/day XR formulation showed a moderate advantage in antibacterial effect: the area under the CFU-time curve was 45% higher for the IR regimen; the nadir log CFU and 24-h log CFU values for the IR regimen were 3.75 and 2.49, respectively; and those for XR were 4.54 and 3.13, respectively. The mathematical model explained the differences in bacterial killing rate for two regimens with identical AUC/MIC ratios. PMID:15155200

Generic products of antiepileptic drugs: a perspective on bioequivalence, bioavailability, and formulation switches using Monte Carlo simulations.

PubMed

Karalis, Vangelis; Macheras, Panos; Bialer, Meir

2014-01-01

Generic products of antiepileptic drugs (AEDs) are currently a controversial topic as neurologists and patients are reluctant to switch from brand products to generics and to switch between generics. The aim of this study was to provide enlightenment on issues of bioequivalence (BE) and interchangeability of AED products. Monte Carlo simulations of the classic 2 × 2 BE studies were performed to study the effect of sample size, within-subject variability, and the true difference in pharmacokinetic values of the products under comparison on BE acceptance of generic AED products. Simulations were extended to study the comparative performance of two generic AED products against the same innovative product. The simulated results are compared with literature data on AEDs. The question with regard to bioavailability (BA) is whether two formulations are different, while for BE the question is whether two formulations are sufficiently similar in terms of extent and rate of absorption. Therefore, the criteria for BA and BE and the statistical analysis involved in their analysis are different. Two generic formulations that meet regulatory approval requirements for generics by being bioequivalent to the same innovative AED may not be bioequivalent to one another and therefore should not be regarded as equal or as therapeutically equivalent products. A switch from a standard or an immediate-release formulation to a modified-release product, which comprises extended-release or delayed-release formulations, should not be regarded as a switch between generics, but rather as a switch between different formulation types. Switches between bioequivalent generic AED products could potentially lead to larger changes in plasma levels and exposure than the brand-to-generic switch. The simulation work verified the clinical findings that not all generic AED products bioequivalent to the same innovative product are bioequivalent to one another. Two generic formulations that meet regulatory approval requirements for generics, by being bioequivalent to the innovative AED, may not be bioequivalent to one another. Additional BE criteria are needed for a formulation switch, particularly in epilepsy, where a breakthrough seizure may change a patient's status from seizure-free to refractory.

The influence of metoprolol dosage release formulation on the pharmacokinetic drug interaction with paroxetine

PubMed Central

Stout, Stephen M.; Nielsen, Jace; Welage, Lynda S.; Shea, Michael; Brook, Robert; Kerber, Kevin; Bleske, Barry E.

2010-01-01

Studies have demonstrated an influence of dosage release formulations on drug interactions and enantiomeric plasma concentrations. Metoprolol is a commonly used β-adrenergic antagonist metabolized by CYP2D6. The CYP2D6 inhibitor paroxetine has previously been shown to interact with metoprolol tartrate. This open-label, randomized, 4 phase crossover study assessed the potential differential effects of paroxetine on stereoselective pharmacokinetics of immediate release (IR) tartrate and extended release (ER) succinate metoprolol formulations. Ten healthy subjects received metoprolol IR (50 mg) and ER (100 mg) with and without paroxetine coadministration. Blood samples were collected over 24 hours for determination of metoprolol plasma enantiomer concentrations. Paroxetine coadministration significantly increased S and R metoprolol AUC0–24h by 4 and 5 fold, respectively for IR, and 3 and 4 fold, respectively for ER. S/R AUC ratios significantly decreased. These results demonstrate a pharmacokinetic interaction between paroxetine and both formulations of metoprolol. The interaction is greater with R metoprolol and stereoselective metabolism is lost. This could theoretically result in greater β-blockade and lost cardioselectivity. The magnitude of the interaction was similar between metoprolol formulations, which may be attributable to low doses / drug input rates employed. PMID:20400652

Evaluation of an Extended-Release, Abuse-Deterrent, Microsphere-in-Capsule Analgesic for the Management of Patients with Chronic Pain With Dysphagia (CPD).

PubMed

Fleming, Alison B; Carlson, Douglas R; Varanasi, Ravi K; Grima, Michael; Mayock, Stephen P; Saim, Said; Kopecky, Ernest A

2016-03-01

Patients who have chronic pain with dysphagia (difficulty swallowing) (CPD) often have difficulty taking oral medication and, as such, alter their medications by crushing or chewing in an attempt to make it easier to swallow. Such manipulation of currently marketed, extended-release (ER) opioid analgesics can significantly alter the pharmacokinetic (PK) properties of the formulations, resulting in poor treatment outcome or serious adverse events. There is an unmet medical need for oral ER opioid formulations suitable for patients with CPD. The primary objectives of this study were to conduct in vitro studies to evaluate alternate means of administration of a new, extended-release (ER), abuse-deterrent, microsphere-in-capsule formulation of oxycodone for patients with CPD. Specifically, these studies investigated the in vitro equivalence of drug release rates from Oxycodone DETERx® ER intact capsules (control condition) and administration via alternate modes-opening the capsule and sprinkling the microspheres onto soft foods or administration through enteral tubes. Secondary objectives were to compare alternate modes of administration of Oxycodone DETERx® to a commercially available ER-morphine product. Soft food study: Oxycodone DETERx® microspheres were sprinkled onto and mixed with several soft foods (ie, applesauce, vanilla pudding, strawberry jam, yogurt, and vanilla ice cream); the effect of drug contact time (0, 30, and 60 minutes) on drug release was studied. Enteral tube study: Oxycodone DETERx® microspheres were administered through varying sizes of nasogastric (10 and 12 Fr.) tubes and a 16 Fr. gastrostomy tube using 5 different delivery vehicles (ie, water, liquid nutritional feeds [Jevity®, Ensure®], and milk [whole milk and 2% milk]). Drug release rate was characterized using a standard in vitro dissolution methodology; dissolution of intact Oxycodone DETERx® capsules served as the control for both the soft food and enteral tube studies. Oxycodone concentration was measured using a standardized high-performance liquid chromatography (HPLC) assay. Similarity factor (f2) analysis was used to compare similarity of the dissolution profiles of test and control conditions. The mean dissolution profile of Oxycodone DETERx® microspheres sprinkled onto and mixed with each of the soft foods were similar (f2 > 50) to that of the control. Study drug-food contact time did not impact dissolution profiles. The dissolution data obtained from Oxycodone DETERx® microspheres passed through enteral feeding tubes of varying sizes were similar (f2 > 50) to that of the control. Unlike a marketed morphine sulfate ER pellet formulation, Oxycodone DETERx® did not clog any of the studied enteral tubes. A new ER, abuse-deterrent, microsphere-in-capsule formulation of oxycodone can be administered by sprinkling onto soft food without affecting the drug release profile of the formulation. The formulation can also be administered directly via enteral tubes without affecting drug release and without clogging enteral tubes. Oxycodone DETERx® may offer physicians and patients with CPD an alternate treatment option, especially in those patients who have dysphagia or an aversion to swallowing monolithic tablet/capsule formulations and for whom analgesic patches or other opioid formulations are not a viable therapeutic option. © 2015 World Institute of Pain.

Advances in mechanistic understanding of release rate control mechanisms of extended-release hydrophilic matrix tablets.

PubMed

Timmins, Peter; Desai, Divyakant; Chen, Wei; Wray, Patrick; Brown, Jonathan; Hanley, Sarah

2016-08-01

Approaches to characterizing and developing understanding around the mechanisms that control the release of drugs from hydrophilic matrix tablets are reviewed. While historical context is provided and direct physical characterization methods are described, recent advances including the role of percolation thresholds, the application on magnetic resonance and other spectroscopic imaging techniques are considered. The influence of polymer and dosage form characteristics are reviewed. The utility of mathematical modeling is described. Finally, how all the information derived from applying the developed mechanistic understanding from all of these tools can be brought together to develop a robust and reliable hydrophilic matrix extended-release tablet formulation is proposed.

Impact of abuse-deterrent OxyContin on prescription opioid utilization.

PubMed

Hwang, Catherine S; Chang, Hsien-Yen; Alexander, G Caleb

2015-02-01

We quantified the degree to which the August 2010 reformulation of abuse-deterrent OxyContin affected its use, as well as the use of alternative extended-release and immediate-release opioids. We used the IMS Health National Prescription Audit, a nationally representative source of prescription activity in the USA, to conduct a segmented time-series analysis of the use of OxyContin and other prescription opioids. Our primary time period of interest was 12 months prior to and following August 2010. We performed model checks and sensitivity analyses, such as adjusting for marketing and promotion, using alternative lag periods, and adding extra observation points. OxyContin sales were similar before and after the August 2010 reformulation, with approximately 550 000 monthly prescriptions. After adjusting for declines in the generic extended-release oxycodone market, the formulation change was associated with a reduction of approximately 18 000 OxyContin prescription sales per month (p = 0.02). This decline corresponded to a change in the annual growth rate of OxyContin use, from 4.9% prior to the reformulation to -23.8% during the year after the reformulation. There were no statistically significant changes associated with the sales of alternative extended-release (p = 0.42) or immediate-release (p = 0.70) opioids. Multiple sensitivity analyses supported these findings and their substantive interpretation. The market debut of abuse-deterrent OxyContin was associated with declines in its use after accounting for the simultaneous contraction of the generic extended-release oxycodone market. Further scrutiny into the effect of abuse-deterrent formulations on medication use and health outcomes is vital given their popularity in opioid drug development. Copyright © 2014 John Wiley & Sons, Ltd.

Evaluation of extended-life pheromone formulations used with and without dichlorvos for boll weevil (Coleoptera: Curculionidae) trapping.

PubMed

Armstrong, J Scott; Greenberg, Shoil M

2008-04-01

Boll weevil traps baited with a ComboLure (25 of mg grandlure + 30 mg of eugenol + 90 of mg dichlorvos [DDVP]), an extended-release lure (25 mg of grandlure + 30 mg of eugenol + 60 of mg DDVP kill-strip), and extended-release lure with no DDVP were evaluated for boll weevil, Anthonomus grandis grandis Boheman (Coleoptera: Curculionidae), captures in South Texas cotton, Gossypium hirsutum L., fields during February-March 2005 and March-April 2006. The traps were serviced once a week for five consecutive weeks by using the same methodology as active boll weevil eradication programs. Mean captured boll weevils from extended-release lures with no DDVP were significantly higher in five of 10 trapping weeks compared with captures of the ComboLure and extended lure. Weekly mortality of boll weevils captured was similar for the ComboLure (72.6 +/- 4.7%) and extended lure + DDVP (73.5 +/- 4.0%), and both were significantly higher than the extended lure (32.8 +/- 5.0%) with no DDVP. The presence or absence of DDVP did not significantly affect the sex ratio of field-captured boll weevils. We found no functional reasoning for using DDVP in large scale trapping of boll weevils regardless of the formulation or presentation in the trap. We conducted two additional trapping evaluations after the 2005 and 2006 studies, but the numbers of boll weevils captured were too low for statistical comparisons, indicating that boll weevil eradication is reducing populations in the Rio Grande Valley of Texas.

Managing severe pain and abuse potential: the potential impact of a new abuse-deterrent formulation oxycodone/naltrexone extended-release product.

PubMed

Pergolizzi, Joseph V; Taylor, Robert; LeQuang, Jo Ann; Raffa, Robert B

2018-01-01

Proper management of severe pain represents one of the most challenging clinical dilemmas. Two equally important goals must be attained: the humanitarian/medical goal to relieve suffering and the societal/legal goal to not contribute to the drug abuse problem. This is an age-old problem, and the prevailing emphasis placed on one or the other goal has resulted in pendulum swings that have resulted in either undertreatment of pain or the current epidemic of misuse and abuse. In an effort to provide efficacious strong pain relievers (opioids) that are more difficult to abuse by the most dangerous routes of administration, pharmaceutical companies are developing products in which the opioid is manufactured in a formulation that is designed to be tamper resistant. Such a product is known as an abuse-deterrent formulation (ADF). ADF opioid products are designed to deter or resist abuse by making it difficult to tamper with the product and extracting the opioid for inhalation or injection. To date, less than a dozen opioid formulations have been approved by the US Food and Drug Administration to carry specific ADF labeling, but this number will likely increase in the coming years. Most of these products are extended-release formulations.

Comparative steady-state pharmacokinetic study of an extended-release formulation of itopride and its immediate-release reference formulation in healthy volunteers.

PubMed

Yoon, Seonghae; Lee, Howard; Kim, Tae-Eun; Lee, SeungHwan; Chee, Dong-Hyun; Cho, Joo-Youn; Yu, Kyung-Sang; Jang, In-Jin

2014-01-01

This study was conducted to compare the oral bioavailability of an itopride extended-release (ER) formulation with that of the reference immediate-release (IR) formulation in the fasting state. The effect of food on the bioavailability of itopride ER was also assessed. A single-center, open-label, randomized, multiple-dose, three-treatment, three-sequence, crossover study was performed in 24 healthy male subjects, aged 22-48 years, who randomly received one of the following treatments for 4 days in each period: itopride 150 mg ER once daily under fasting or fed conditions, or itopride 50 mg IR three times daily in the fasting state. Steady-state pharmacokinetic parameters of itopride, including peak plasma concentration (Cmax) and area under the plasma concentration versus time curve over 24 hours after dosing (AUC(0-24h)), were determined by noncompartmental analysis. The geometric mean ratio of the pharmacokinetic parameters was derived using an analysis of variance model. A total of 24 healthy Korean subjects participated, 23 of whom completed the study. The geometric mean ratio and its 90% confidence interval of once-daily ER itopride versus IR itopride three times a day for AUC(0-24h) were contained within the conventional bioequivalence range of 0.80-1.25 (0.94 [0.88-1.01]), although Cmax was reached more slowly and was lower for itopride ER than for the IR formulation. Food delayed the time taken to reach Cmax for itopride ER, but AUC(0-24h) was not affected. There were no serious adverse events and both formulations were generally well tolerated. At steady state, once-daily itopride ER at 150 mg has a bioavailability comparable with that of itopride IR at 50 mg given three times a day under fasting conditions. Food delayed the absorption of itopride ER, with no marked change in its oral bioavailability.

Comparative steady-state pharmacokinetic study of an extended-release formulation of itopride and its immediate-release reference formulation in healthy volunteers

PubMed Central

Yoon, Seonghae; Lee, Howard; Kim, Tae-Eun; Lee, SeungHwan; Chee, Dong-Hyun; Cho, Joo-Youn; Yu, Kyung-Sang; Jang, In-Jin

2014-01-01

Background This study was conducted to compare the oral bioavailability of an itopride extended-release (ER) formulation with that of the reference immediate-release (IR) formulation in the fasting state. The effect of food on the bioavailability of itopride ER was also assessed. Methods A single-center, open-label, randomized, multiple-dose, three-treatment, three-sequence, crossover study was performed in 24 healthy male subjects, aged 22–48 years, who randomly received one of the following treatments for 4 days in each period: itopride 150 mg ER once daily under fasting or fed conditions, or itopride 50 mg IR three times daily in the fasting state. Steady-state pharmacokinetic parameters of itopride, including peak plasma concentration (Cmax) and area under the plasma concentration versus time curve over 24 hours after dosing (AUC0–24h), were determined by noncompartmental analysis. The geometric mean ratio of the pharmacokinetic parameters was derived using an analysis of variance model. Results A total of 24 healthy Korean subjects participated, 23 of whom completed the study. The geometric mean ratio and its 90% confidence interval of once-daily ER itopride versus IR itopride three times a day for AUC0–24h were contained within the conventional bioequivalence range of 0.80–1.25 (0.94 [0.88–1.01]), although Cmax was reached more slowly and was lower for itopride ER than for the IR formulation. Food delayed the time taken to reach Cmax for itopride ER, but AUC0–24h was not affected. There were no serious adverse events and both formulations were generally well tolerated. Conclusion At steady state, once-daily itopride ER at 150 mg has a bioavailability comparable with that of itopride IR at 50 mg given three times a day under fasting conditions. Food delayed the absorption of itopride ER, with no marked change in its oral bioavailability. PMID:24470753

Pediatric drug formulation of sodium benzoate extended-release granules.

PubMed

Combescot, E; Morat, G; de Lonlay, P; Boudy, V

2016-01-01

Urea cycle disorders are a group of inherited orphan diseases leading to hyperammonemia. Current therapeutic strategy includes high doses of sodium benzoate leading to three or four oral intakes per day. As this drug is currently available in capsules or in solution, children are either unable to swallow the capsule or reluctant to take the drug due to its strong bitter taste. The objective of the present study was to develop solid, multiparticulate formulations of sodium benzoate, which are suitable for pediatric patients (i.e. flavor-masked, easy to swallow and with a dosing system). Drug layering and coating in a fluidized bed were applied for preparing sustained-release granules. Two types of inert cores (GalenIQ® and Suglets®) and three different polymers (Kollicoat®, Aquacoat® and Eudragit®) were tested in order to select the most appropriate polymer and starter core for our purpose. Physical characteristics and drug release profiles of the pellets were evaluated. A Suglets® core associated with a Kollicoat® coating seems to be the best combination for an extended release of sodium benzoate. A curing period of 8 h was necessary to complete film formation and the resulting drug release pattern was found to be dependent of the acidity of the release medium.

Identification of critical formulation and processing variables for metoprolol tartrate extended-release (ER) matrix tablets.

PubMed

Rekhi, G S; Nellore, R V; Hussain, A S; Tillman, L G; Malinowski, H J; Augsburger, L L

1999-06-02

The objective of this study, was to examine the influence of critical formulation and processing variables as described in the AAPS/FDA Workshop II report on scale-up of oral extended-release dosage forms, using a hydrophilic polymer hydroxypropyl methylcellulose (Methocel K100LV). A face-centered central composite design (26 runs+3 center points) was selected and the variables studied were: filler ratio (lactose:dicalcium phosphate (50:50)), polymer level (15/32.5/50%), magnesium stearate level (1/1.5/2%), lubricant blend time (2/6/10 min) and compression force (400/600/800 kg). Granulations (1.5 kg, 3000 units) were manufactured using a fluid-bed process, lubricated and tablets (100 mg metoprolol tartrate) were compressed on an instrumented Manesty D3B rotary tablet press. Dissolution tests were performed using USP apparatus 2, at 50 rpm in 900 ml phosphate buffer (pH 6.8). Responses studied included percent drug released at Q1 (1 h), Q4, Q6, Q12. Analysis of variance indicated that change in polymer level was the most significant factor affecting drug release. Increase in dicalcium phosphate level and compression force were found to affect the percent released at the later dissolution time points. Some interaction effects between the variables studied were also found to be statistically significant. The drug release mechanism was predominantly found to be Fickian diffusion controlled (n=0.46-0.59). Response surface plots and regression models were developed which adequately described the experimental space. Three formulations having slow-, medium- and fast-releasing dissolution profiles were identified for a future bioavailability/bioequivalency study. The results of this study provided the framework for further work involving both in vivo studies and scale-up.

Single Layer Extended Release Two-in-One Guaifenesin Matrix Tablet: Formulation Method, Optimization, Release Kinetics Evaluation and Its Comparison with Mucinex® Using Box-Behnken Design.

PubMed

Morovati, Amirhosein; Ghaffari, Alireza; Erfani Jabarian, Lale; Mehramizi, Ali

2017-01-01

Guaifenesin, a highly water-soluble active (50 mg/mL), classified as a BCS class I drug. Owing to its poor flowability and compressibility, formulating tablets especially high-dose one, may be a challenge. Direct compression may not be feasible. Bilayer tablet technology applied to Mucinex®, endures challenges to deliver a robust formulation. To overcome challenges involved in bilayer-tablet manufacturing and powder compressibility, an optimized single layer tablet prepared by a binary mixture (Two-in-one), mimicking the dual drug release character of Mucinex ® was purposed. A 3-factor, 3-level Box-Behnken design was applied to optimize seven considered dependent variables (Release "%" in 1, 2, 4, 6, 8, 10 and 12 h) regarding different levels of independent one (X 1 : Cetyl alcohol, X 2 : Starch 1500 ® , X 3 : HPMC K100M amounts). Two granule portions were prepared using melt and wet granulations, blended together prior to compression. An optimum formulation was obtained (X 1 : 37.10, X 2 : 2, X 3 : 42.49 mg). Desirability function was 0.616. F2 and f1 between release profiles of Mucinex® and the optimum formulation were 74 and 3, respectively. An n-value of about 0.5 for both optimum and Mucinex® formulations showed diffusion (Fickian) control mechanism. However, HPMC K100M rise in 70 mg accompanied cetyl alcohol rise in 60 mg led to first order kinetic (n = 0.6962). The K values of 1.56 represented an identical burst drug releases. Cetyl alcohol and starch 1500 ® modulated guaifenesin release from HPMC K100M matrices, while due to their binding properties, improved its poor flowability and compressibility, too.

Single Layer Extended Release Two-in-One Guaifenesin Matrix Tablet: Formulation Method, Optimization, Release Kinetics Evaluation and Its Comparison with Mucinex® Using Box-Behnken Design

PubMed Central

Morovati, Amirhosein; Ghaffari, Alireza; Erfani jabarian, Lale; Mehramizi, Ali

2017-01-01

Guaifenesin, a highly water-soluble active (50 mg/mL), classified as a BCS class I drug. Owing to its poor flowability and compressibility, formulating tablets especially high-dose one, may be a challenge. Direct compression may not be feasible. Bilayer tablet technology applied to Mucinex®, endures challenges to deliver a robust formulation. To overcome challenges involved in bilayer-tablet manufacturing and powder compressibility, an optimized single layer tablet prepared by a binary mixture (Two-in-one), mimicking the dual drug release character of Mucinex® was purposed. A 3-factor, 3-level Box-Behnken design was applied to optimize seven considered dependent variables (Release “%” in 1, 2, 4, 6, 8, 10 and 12 h) regarding different levels of independent one (X1: Cetyl alcohol, X2: Starch 1500®, X3: HPMC K100M amounts). Two granule portions were prepared using melt and wet granulations, blended together prior to compression. An optimum formulation was obtained (X1: 37.10, X2: 2, X3: 42.49 mg). Desirability function was 0.616. F2 and f1 between release profiles of Mucinex® and the optimum formulation were 74 and 3, respectively. An n-value of about 0.5 for both optimum and Mucinex® formulations showed diffusion (Fickian) control mechanism. However, HPMC K100M rise in 70 mg accompanied cetyl alcohol rise in 60 mg led to first order kinetic (n = 0.6962). The K values of 1.56 represented an identical burst drug releases. Cetyl alcohol and starch 1500® modulated guaifenesin release from HPMC K100M matrices, while due to their binding properties, improved its poor flowability and compressibility, too. PMID:29552045

Ramizol® encapsulation into extended release PLGA micro- and nanoparticle systems for subcutaneous and intramuscular administration: in vitro and in vivo evaluation.

PubMed

Wright, Leah; Rao, Shasha; Thomas, Nicky; Boulos, Ramiz A; Prestidge, Clive A

2018-04-11

Novel antibiotic Ramizol ® is advancing to clinical trials for the treatment of gastrointestinal Clostridium difficile associated disease. Despite this, previous studies have shown a rapid plasma clearance upon intravenous administration and low oral bioavailability indicating pure drug is unsuitable for systemic infection treatment following oral dosing. The current study aims to investigate the development of poly-lactic-(co-glycolic) acid (PLGA) particles to overcome this limitation and increase the systemic half-life following subcutaneous and intramuscular dosing. The development of new antibiotic treatments will help in combatting the rising incidence of antimicrobial resistance. Ramizol ® was encapsulated into PLGA nano and microparticles using nanoprecipitation and emulsification solvent evaporation techniques. Formulations were analyzed for particle size, loading level and encapsulation efficiency as well as in vitro drug release profiles. Final formulation was advanced to in vivo pharmacokinetic studies in Sprague-Dawley rats. Formulation technique showed major influence on particle size and loading levels with optimal loading of 9.4% and encapsulation efficiency of 92.06%, observed using emulsification solvent evaporation. Differences in formulation technique were also linked with subsequent differences in release profiles. Pharmacokinetic studies in Sprague-Dawley rats confirmed extended absorption and enhanced bioavailability following subcutaneous and intramuscular dosing with up to an 8-fold increase in T max and T 1/2 when compared to the oral and IV routes. Subcutaneous and intramuscular dosing of PLGA particles successfully increased systemic half-life and bioavailability of Ramizol ® . This formulation will allow further development of Ramizol ® for systemic infection eradication.

Memantine extended release (28 mg once daily): a review of its use in Alzheimer's disease.

PubMed

Plosker, Greg L

2015-05-01

Memantine is an uncompetitive N-methyl-D-aspartate (NMDA) receptor antagonist that is a well-established treatment option for moderate to severe dementia of the Alzheimer's type, either alone or in combination with cholinesterase inhibitors. The immediate-release (IR) formulations of memantine (tablets and oral solution) have been available in numerous countries, including the USA, for more than a decade and are administered orally twice daily at a maximum recommended total daily dosage of 20 mg/day. The memantine extended-release (ER) (Namenda XR(®)) 28 mg once-daily capsule formulation was approved in the USA in 2010 and became available more recently. The potential advantages of memantine ER over the IR formulation include a more convenient dosage regimen and lower pill burden that may improve adherence to therapy; also, memantine ER capsules may be opened and the contents sprinkled on applesauce for patients who have difficulty swallowing. Memantine ER provides a higher total daily dosage than the recommended memantine IR regimen and pharmacokinetic data indicate greater exposure with the ER formulation, but the clinical implications of this are unclear, as the two formulations have not been assessed in a comparative clinical trial. The efficacy of memantine ER 28 mg once daily was demonstrated in a large, multinational, phase III trial, which showed that the addition of memantine ER to ongoing oral cholinesterase inhibitors improved key outcomes compared with cholinesterase inhibitor monotherapy, including measures of cognition and global status, which were the co-primary endpoints of the study. The most common adverse events were headache, diarrhoea and dizziness.

Are in situ formulations the keys for the therapeutic future of S-nitrosothiols?

PubMed

Parent, Marianne; Boudier, Ariane; Dupuis, François; Nouvel, Cécile; Sapin, Anne; Lartaud, Isabelle; Six, Jean-Luc; Leroy, Pierre; Maincent, Philippe

2013-11-01

S-nitrosoglutathione (GSNO) and S-nitroso-N-acetylpenicillamine (SNAP) were formulated into in situ forming implants (ISI) and microparticles (ISM) using PLGA and either N-methyl-2-pyrrolidone (NMP) or triacetin. Physicochemical characterization was carried out, including the study of matrix structure and degradation. A strong correlation between drug hydrophobicity and the in vitro release profiles was observed: whatever the formulation, GSNO and SNAP were completely released after ca. 1 day and 1 week, respectively. Then, selected formulations (i.e., SNAP-loaded NMP formulations) demonstrated the ability to sustain the vasodilation effect of SNAP, as shown by monitoring the arterial pressure (telemetry) of Wistar rats after subcutaneous injection. Both ISI and ISM injections resulted in a 3-fold extended decrease in pulse arterial pressure compared with the unloaded drug, without significant decrease in the mean arterial pressure. Hence, the results emphasize the suitability of these formulations as drug delivery systems for S-nitrosothiols, widening their therapeutic potential. Copyright © 2013 Elsevier B.V. All rights reserved.

Update on tolterodine extended-release for treatment of overactive bladder

PubMed Central

Omotosho, Tola; Chen, Chi Chiung Grace

2010-01-01

Overactive bladder is a prevalent condition which negatively impacts quality of life and puts a significant economical burden on society. First-line therapy often includes pharmacotherapy with antimuscarinic medications, and numerous research studies have demonstrated that tolterodine extended-release (ER) is an efficacious and tolerable formulation of this class of medication. This review provides an update on the clinical use of tolterodine ER, detailing the current literature on its efficacy, tolerability, adverse effects, and comparability with other commonly prescribed medications for the treatment of overactive bladder. PMID:24198627

Extended release of high molecular weight hydroxypropyl methylcellulose from molecularly imprinted, extended wear silicone hydrogel contact lenses.

PubMed

White, Charles J; McBride, Matthew K; Pate, Kayla M; Tieppo, Arianna; Byrne, Mark E

2011-08-01

Symptoms of contact lenses induced dry eye (CLIDE) are typically treated through application of macromolecular re-wetting agents via eye drops. Therapeutic soft contact lenses can be formulated to alleviate CLIDE symptoms by slowly releasing comfort agent from the lens. In this paper, we present an extended wear silicone hydrogel contact lens with extended, controllable release of 120 kDa hydroxypropyl methylcellulose (HPMC) using a molecular imprinting strategy. A commercial silicone hydrogel lens was tailored to release approximately 1000 μg of HPMC over a period of up to 60 days in a constant manner at a rate of 16 μg/day under physiological flowrates, releasing over the entire range of continuous wear. Release rates could be significantly varied by the imprinting effect and functional monomer to template ratio (M/T) with M/T values 0, 0.2, 2.8, 3.4 corresponding to HPMC release durations of 10, 13, 23, and 53 days, respectively. Lenses had high optical quality and adequate mechanical properties for contact lens use. This work highlights the potential of imprinting in the design and engineering of silicone hydrogel lenses to release macromolecules for the duration of wear, which may lead to decreased CLIDE symptoms and more comfortable contact lenses. Copyright © 2011 Elsevier Ltd. All rights reserved.

Baclofen novel gastroretentive extended release gellan gum superporous hydrogel hybrid system: in vitro and in vivo evaluation.

PubMed

El-Said, Ibrahim A; Aboelwafa, Ahmed A; Khalil, Rawia M; ElGazayerly, Omaima N

2016-01-01

Baclofen is a centrally acting skeletal muscle relaxant with a short elimination half-life, which results in frequent daily dosing and subsequent poor patient compliance. The narrow absorption window of baclofen in the upper gastrointestinal tract limits its formulation as extended release dosage forms. In this study, baclofen extended release superporous hydrogel (SPH) systems, including conventional SPH, SPH composite and SPH hybrid (SPHH), were prepared aiming to increase the residence of baclofen at its absorption window. The applicability of different polymers, namely, gellan gum, guar gum, polyvinyl alcohol and gelatin, was investigated in preparation of SPHH systems. The prepared SPH systems were evaluated regarding weight and volume swelling ratio, porosity, mechanical properties, incorporation efficiency, degree of erosion and drug release. In vivo assessment was performed in dogs to evaluate gastric residence time by X-ray studies. In addition, the oral bioavailability of baclofen relative to commercially available Lioresal® immediate release tablets was also investigated. The novel baclofen gellan SPHH cross linked with calcium chloride was characterized by optimum mechanical properties, acceptable swelling properties as well as extended drug release. It also exhibited a prolonged plasma profile when compared to twice daily administered Lioresal®.

Preparation of acetaminophen capsules containing beads prepared by hot-melt direct blend coating.

PubMed

Pham, Loan; Christensen, John M

2014-02-01

Twelve hydrophobic coating agents were assessed for their effects on drug release after coating sugar cores by a flexible hot-melt coating method using direct blending. Drug-containing pellets were also produced and used as cores. The cores were coated with single or double wax layers containing acetaminophen (APAP). The harder the wax, the slower the resultant drug releases from single-coated beads. Wax coating can be deposited on cores up to 28% of the beads final weight and reaching 58% with wax and drug. Carnauba-coated beads dissolved in approximately 6 h releasing 80% of the loaded drug. Applying another wax layer extended drug release over 20 h, while still delivering 80% of the loaded drug. When drug-containing pellets (33-58% drug loading) were used as cores, double wax-coated pellets exhibited a near zero-order drug release for 16 h, releasing 80% of the loaded drug delivering 18 mg/h. The simple process of hot-melt coating by direct blending of pellet-containing drug-coated formulations provides excellent options for immediate and sustained release formulations when higher lipid coating or drug loading is warranted. Predicted plasma drug concentration time profiles using convolution and in vitro drug release properties of the beads were performed for optimal formulations.

Pharmacokinetic Studies in Healthy Subjects for the Development of an Extended-Release Tablet Formulation of Guaifenesin: A 505(b)(2) New Drug Application Approval.

PubMed

Vilson, Lineau; Owen, Joel S

2013-01-01

Guaifenesin is an expectorant used to improve mucociliary clearance (MCC) and relieve chest congestion from upper respiratory tract infections. Immediate-release (IR) guaifenesin requires dosing every 4 hours to maintain efficacy because of the drug's short half-life. Extended-release (ER) guaifenesin has been developed to prolong efficacy and reduce dosing frequency. As part of the 505(b)(2) new drug application (NDA), the pharmacokinetics (PK) of an ER bi-layer tablet formulation of guaifenesin (Mucinex®) and bioequivalence to an over-the-counter (OTC) monograph IR formulation were evaluated in healthy subjects. In one study, subjects received 1,200 mg ER guaifenesin every 12 hours or 400 mg IR guaifenesin every 4 hours for 6 days. Steady-state exposures were equivalent between the two products, as demonstrated by AUC and Cmax . In another study, subjects received a single dose of 600 mg (fasted) or 1,200 mg (fasted or fed) ER bi-layer tablet formulations. AUC and Cmax were equivalent between both states for the 1,200 mg ER dose. However, Tmax of 1,200 mg ER guaifenesin was later in the fed than the fasted state. ER guaifenesin is bioequivalent to corresponding OTC monograph doses of IR guaifenesin. ER guaifenesin offers a convenient 12-hour dosing alternative to 4-hour dosing of IR guaifenesin. © The Author(s) 2013.

Advagraf® with or without an induction therapy for de novo kidney-transplant recipients.

PubMed

Noble, Johan; Jouve, Thomas; Rostaing, Lionel; Malvezzi, Paolo

2018-06-01

Cornerstone immunosuppressive therapy currently relies on immediate-release tacrolimus, a calcineurin inhibitor (CNI) that is potentially nephrotoxic and is more diabetogenic than cyclosporine A. Two new formulations of tacrolimus have been launched: an extended-release formulation (Advagraf®/Astagraf XL®, Astellas company) and a long-lasting formulation (Envarsus®, Veloxis company). Area covered: Herein, we assess the efficacy of an extended-release formulation of tacrolimus (Advagraf®/Astagraf XL®) used in conjunction with or without an induction therapy (i.e., basiliximab) in de novo kidney-transplant recipients. To achieve this, we searched for suitable articles through PubMed. Expert commentary: Phases-III and -IV studies comparing Advagraf®/Astagraf XL® to Prograf® in association with mycophenolate mofetil (more than 2,500 patients) have demonstrated overall similar results with regards to patient/graft survival, biopsy-proven acute-rejection rate, and renal function (p > 0.05). A randomized controlled study in maintenance kidney transplant patients has shown (using electronic monitoring) that, as compared to Prograf®, Advagraf® significantly improved adherence to medication. Other studies report that Advagraf®-treated patients receiving a mTOR-inhibitor agent (sirolimus or everolimus) instead of MMF: this was associated with good allograft outcome, and might also prevent late-onset cytomegalovirus infection. Advagraf®-based immunosuppression given to de novo kidney-transplant recipients, with or without an induction therapy, provided excellent results compared to Prograf®; it also increased patients' adherence to treatment.

Factors Affecting the Design of Slow Release Formulations of Herbicides Based on Clay-Surfactant Systems. A Methodological Approach

PubMed Central

Galán-Jiménez, María del Carmen; Mishael, Yael-Golda; Nir, Shlomo; Morillo, Esmeralda; Undabeytia, Tomás

2013-01-01

A search for clay-surfactant based formulations with high percentage of the active ingredient, which can yield slow release of active molecules is described. The active ingredients were the herbicides metribuzin (MZ), mesotrione (MS) and flurtamone (FL), whose solubilities were examined in the presence of four commercial surfactants; (i) neutral: two berols (B048, B266) and an alkylpolyglucoside (AG6202); (ii) cationic: an ethoxylated amine (ET/15). Significant percent of active ingredient (a.i.) in the clay/surfactant/herbicide formulations could be achieved only when most of the surfactant was added as micelles. MZ and FL were well solubilized by berols, whereas MS by ET/15. Sorption of surfactants on the clay mineral sepiolite occurred mostly by sorption of micelles, and the loadings exceeded the CEC. Higher loadings were determined for B266 and ET/15. The sorption of surfactants was modeled by using the Langmuir-Scatchard equation which permitted the determination of binding coefficients that could be used for further predictions of the sorbed amounts of surfactants under a wide range of clay/surfactant ratios. A possibility was tested of designing clay-surfactant based formulations of certain herbicides by assuming the same ratio between herbicides and surfactants in the formulations as for herbicides incorporated in micelles in solution. Calculations indicated that satisfactory FL formulations could not be synthesized. The experimental fractions of herbicides in the formulations were in agreement with the predicted ones for MS and MZ. The validity of this approach was confirmed in in vitro release tests that showed a slowing down of the release of a.i. from the designed formulations relative to the technical products. Soil dissipation studies with MS formulations also showed improved bioactivity of the clay-surfactant formulation relative to the commercial one. This methodological approach can be extended to other clay-surfactant systems for encapsulation and slow release of target molecules of interest. PMID:23527087

Extended-release mesalamine granules for ulcerative colitis.

PubMed

Love, Bryan L; Miller, April D

2012-11-01

To evaluate the efficacy and safety of extended-release mesalamine granules in the maintenance of remission in ulcerative colitis (UC). Literature was obtained through searches of MEDLINE (1990-June 2012) using the terms mesalamine granules, ulcerative colitis, Apriso, and Salofalk. Bibliographies from retrieved articles were searched for additional citations. All English-language articles reporting on use of extended-release mesalamine granules in humans identified through the search were evaluated and included. The preferred initial treatment for induction and maintenance of remission in mild to moderate UC is agents from the 5-aminosalicylate class (balsalazide, mesalamine, olsalazine, sulfasalazine). Mesalamine granules are available as an encapsulated product in the US and as a nonencapsulated formulation in Europe. Data evaluating encapsulated mesalamine granules for induction of remission are lacking; however, the European mesalamine granule formulation has been evaluated for induction of remission. Patients receiving mesalamine granules for induction achieved clinical and endoscopic remission more frequently than those receiving placebo. Two pivotal, randomized, double-blind, placebo-controlled, multicenter studies have evaluated encapsulated mesalamine granules for maintenance in 562 adults in remission from UC. In both studies, the proportion of patients who remained relapse-free at 6 months was higher for those receiving encapsulated mesalamine granules than placebo. Mesalamine granules are well tolerated, with headache, nausea, and upper respiratory infections being the most frequently reported adverse effects. Current evidence supports the use of extended-release mesalamine granules for maintenance of remission in mild to moderate UC. Further studies are necessary to examine the ideal dose and regimen of encapsulated mesalamine granules for induction of remission in UC.

Formulation and evaluation of polyelectrolyte complex-based matrix tablet of Isosorbide Mononitrate

PubMed Central

Syed, Iizhar Ahmed; Niveditha, P.; Ahmad, Ismail

2014-01-01

Introduction: The polyelectrolyte Complexes (PECs) are based on ionic cross-linking. They have been employed to prepare a sustained release matrix tablets. These systems are based upon the fact that their structure can entrap the drug within them. Isosorbide Mononitrate (ISMN) is an anti-anginal organic nitrate vasodilator used in the treatment of various cardiovascular disorders and prophylaxis of angina Pectoris, which is poorly absorbed from the upper GIT, hence CR formulation is desirable. Materials and Methods: Chitosan (CH)/Sodium alginate (SA), Guar gum (GG), and Xanthan gum (XG) were used as PECs, and were prepared using different proportions i.e., in 1:1 and 1:2 ratio. The optimum ratio of CH: SA, CH: GG and CH: XG was in the ratio was 1:2; these are formed due to electrostatic interaction between oppositely charged poly ions. These normally employ a hydrophilic matrix system. Matrix tablet of ISMN was formulated by using PECs as matrix forming agent by wet granulation technique. Results: The tablets were evaluated for hardness, wt variation, drug content, and in-vitro dissolution studies and found to be within limits. Release kinetics data indicated that ISMN released from the PECs-based matrix tablets of CH-SA, CH-GG and CH-XG CP in 1:1 and 1:2 ratio, followed Fickian and non-Fickian diffusion mechanism respectively. Thus, the drug release rate was extended for over a period of more than 12 h stability studies. There is no significant difference in the mean % drug released from formulation CH-X2 after storing for 3 months at 40°C/75% RH. The FT-IR spectra revealed that there was no interaction between polymers and drug, Statistical analysis showed a significant differences (P < 0.05) for the amount of ISMN released from the formulations (MXG) and formulations (CH-X2). Conclusion: Formulation CH-XG2 (1:2) showed better sustained release of highly water-soluble ISMN with the desired release rate. Thus, the formulated PECs-based matrix tablets seems to be a potential candidate for sustained drug delivery of highly soluble drug ISMN in the symptomatic therapy of angina pectoris. PMID:24678461

Sustained release of intravitreal flurbiprofen from a novel drug-in-liposome-in-hydrogel formulation.

PubMed

Pachis, K; Blazaki, S; Tzatzarakis, M; Klepetsanis, P; Naoumidi, E; Tsilimbaris, M; Antimisiaris, S G

2017-11-15

A novel Flurbiprofen (FLB)-in-liposome-in-hydrogel formulation was developed, as a method to sustain the release and increase the ocular bioavailability of FLB following intravitreal injection. For this, FLB loading into liposomes was optimized and liposomes were entrapped in thermosensitive hydrogels consisted of Pluronic F-127 (P). FLB solution, liposomes, and FLB dissolved in hydrogel were also used as control formulations. Actively loaded liposomes were found to be optimal for high FLB loading and small size, while in vitro studies revealed that P concentration of 18% (w/v) was best to retain the integrity of the hydrogel-dispersed liposome, compared to a 20% concentration. The in vitro release of FLB was significantly sustained when FLB-liposomes were dispersed in the hydrogel compared to hydrogel dissolved FLB, as well as the other control formulations. In vivo studies were carried out in pigmented rabbits which were injected through a 27G needle with 1mg/mL FLB in the different formulation-types. Ophthalmic examinations after intravitreal injection of all FLB formulations, revealed no evidence of inflammation, hemorrhage, uveitis or endophthalmitis. Pharmacokinetic analysis results confirm that the hybrid drug delivery system increases the bioavailability (by 1.9 times compared to solution), and extends the presence of the drug in the vitreous cavity, while liposome and hydrogel formulations demonstrate intermediate performance. Furthermore the hybrid system increases MRT of FLB in aqueous humor and retina/choroid tissues, compared to all the control formulations. Currently the potential therapeutic advances of FLB sustained release formulations for IVT administration are being evaluated. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of some formulation variables on the optimization of pH-dependent, colon-targeted, sustained-release mesalamine microspheres.

PubMed

El-Bary, Ahmed Abd; Aboelwafa, Ahmed A; Al Sharabi, Ibrahim M

2012-03-01

The aim of this work was to understand the influence of different formulation variables on the optimization of pH-dependent, colon-targeted, sustained-release mesalamine microspheres prepared by O/O emulsion solvent evaporation method, employing pH-dependent Eudragit S and hydrophobic pH-independent ethylcellulose polymers. Formulation variables studied included concentration of Eudragit S in the internal phase and the ratios between; internal to external phase, drug to Eudragit S and Eudragit S to ethylcellulose to mesalamine. Prepared microspheres were evaluated by carrying out in vitro release studies and determination of particle size, production yield, and encapsulation efficiency. In addition, morphology of microspheres was examined using optical and scanning electron microscopy. Emulsion solvent evaporation method was found to be sensitive to the studied formulation variables. Particle size and encapsulation efficiency increased by increasing Eudragit S concentration in the internal phase, ratio of internal to external phase, and ratio of Eudragit S to the drug. Employing Eudragit S alone in preparation of the microspheres is only successful in forming acid-resistant microspheres with pulsatile release pattern at high pH. Eudragit S and ethylcellulose blend microspheres were able to control release under acidic condition and to extend drug release at high pH. The stability studies carried out at 40°C/75% RH for 6 months proved the stability of the optimized formulation. From the results of this investigation, microencapsulation of mesalamine in microspheres using blend of Eudragit S and ethylcellulose could constitute a promising approach for site-specific and controlled delivery of drug in colon.

Use of Vitelline Protein B as a Microencapsulating Additive

NASA Technical Reports Server (NTRS)

Ficht, Allison R. (Inventor); Carson, Ken (Inventor); Waite, John Herbert (Inventor); Sheffield, Cynthia (Inventor)

2017-01-01

The present invention includes compositions and methods for the use of an encapsulation additive having between about 0.1 to about 30 percent isolated and purified vitelline protein B to provide for mixed and extended release formulations.

Application of hot-melt extrusion technology in immediate-release abuse-deterrent formulations.

PubMed

Wening, Klaus; Schwier, Sebastian; Stahlberg, Hans-J; Galia, Eric

Hot-melt extrusion (HME) technology has been used for manufacturing extended-release abuse-deterrent formulations (ADFs) of opioid-type analgesics with improved tamper-resistant properties. Our objective was to describe application of this technology to immediate-release (IR) ADFs. For development of a sample IR ADF (hydrocodone 10 mg/acetaminophen 325 mg) based on HME, feasibility studies were performed using different excipients. The formulation selected for further development was evaluated via in vitro test battery. Moreover, in vivo performance of IR ADF technologies was investigated in an open-label, randomized, cross-over, phase 1, relative oral bioavailability study with another opioid (model compound). Single-center bioavailability trial. Twenty-four healthy white male subjects. ADF IR formulation of an opioid and marketed IR formulation. For feasibility and in vitro studies, dissolution profiles, syringeability, particle size distribution after physical manipulation, and extractability were evaluated. For the phase 1 study, pharmacokinetic parameters were evaluated and compared for ADF IR and a marketed IR formulation. After manipulation, the majority of particles from the ADF IR formulation were >500µm and, thus, not considered suitable for intranasal abuse, while the majority of particles for the reference marketed IR formulation were <500µm. The ADF IR formulation was resistant to syringing and preparation for potential intravenous injection. In healthy subjects, pharmacokinetics of an ADF and marketed IR formulation of an opioid were nearly identical. Application of HME to IR formulations led to development of products with improved mechanical resistance to manipulation for intranasal or intravenous preparation, but similar bioavailability.

Development, characterization, and in vivo assessment of mucoadhesive nanoparticles containing fluconazole for the local treatment of oral candidiasis.

PubMed

Rençber, Seda; Karavana, Sinem Yaprak; Yılmaz, Fethiye Ferda; Eraç, Bayri; Nenni, Merve; Özbal, Seda; Pekçetin, Çetin; Gurer-Orhan, Hande; Hoşgör-Limoncu, Mine; Güneri, Pelin; Ertan, Gökhan

2016-01-01

This study aimed to develop a suitable buccal mucoadhesive nanoparticle (NP) formulation containing fluconazole for the local treatment of oral candidiasis. The suitability of the prepared formulations was assessed by means of particle size (PS), polydispersity index, and zeta potential measurements, morphology analysis, mucoadhesion studies, drug entrapment efficiency (EE), in vitro drug release, and stability studies. Based on the optimum NP formulation, ex vivo drug diffusion and in vitro cytotoxicity studies were performed. Besides, evaluation of the antifungal effect of the optimum formulation was evaluated using agar diffusion method, fungicidal activity-related in vitro release study, and time-dependent fungicidal activity. The effect of the optimum NP formulation on the healing of oral candidiasis was investigated in an animal model, which was employed for the first time in this study. The zeta potential, mucoadhesion, and in vitro drug release studies of various NP formulations revealed that chitosan-coated NP formulation containing EUDRAGIT(®) RS 2.5% had superior properties than other formulations. Concerning the stability study of the selected formulation, the formulation was found to be stable for 6 months. During the ex vivo drug diffusion study, no drug was found in receptor phase, and this is an indication of local effect. The in vitro antifungal activity studies showed the in vitro efficacy of the NP against Candida albicans for an extended period. Also, the formulation had no cytotoxic effect at the tested concentration. For the in vivo experiments, infected rabbits were successfully treated with local administration of the optimum NP formulation once a day. This study has shown that the mucoadhesive NP formulation containing fluconazole is a promising candidate with once-a-day application for the local treatment of oral candidiasis.

Development and in vitro evaluation of carboxymethyl chitosan based drug delivery system for the controlled release of propranolol hydrochloride

NASA Astrophysics Data System (ADS)

Hernawan; Nur Hayati, Septi; Nisa, Khoirun; Wheni Indrianingsih, Anastasia; Darsih, Cici; Kismurtono, Muhammad

2017-12-01

Propranolol hydrochloride is a nonselective β-adrenergic drug and has been used as angina pectoris, antihypertensive, and that of many other cardiovascular disorders. It has a relatively short plasma half-life and duration of action are considered too short in certain circumstances. Thus, it’s fascinating to elongate the action. The tablet formula was based on extended-release by a propranolol hydrochloride based carboxymethyl chitosan matrix. Here we used direct compression technique with internal wet granulation to prepare the tablets. The tablets were evaluated for physical properties (hardness, weight variation test, friability) and in vitro release studies. There was no interaction observed between propranolol hydrochloride and excipients. Dissolution profiles of each formulation were followed zero order model. In conclusion, these results strongly suggest that in appropriate proportions carboxymethyl chitosan with internal granulation is suitable for formulating propranolol hydrochloride controlled release.

A randomized, double-blind study of hydromorphone hydrochloride extended-release tablets versus oxycodone hydrochloride extended-release tablets for cancer pain: efficacy and safety in Japanese cancer patients (EXHEAL: a Phase III study of EXtended-release HydromorphonE for cAncer pain reLief).

PubMed

Inoue, Satoshi; Saito, Yoji; Tsuneto, Satoru; Aruga, Etsuko; Ide, Azusa; Kakurai, Yasuyuki

2017-01-01

In Japan, there are limited options for switching opioid analgesics. Hydromorphone is an opioid analgesic that is routinely used instead of morphine for cancer pain; however, it is not yet available in Japan. The aim of this study was to assess the efficacy and safety of hydromorphone (DS-7113b) extended-release tablets in opioid-naïve patients with cancer pain not relieved by non-opioid analgesics. This was a multicenter, randomized, double-blind, parallel-group trial. A double-dummy method was used for blinding. Each randomized subject received either hydromorphone extended-release tablets plus placebo oxycodone hydrochloride extended-release tablets 4 mg/day (n=88) or placebo hydromorphone extended-release tablets plus oxycodone hydrochloride extended-release tablets 10 mg/day (n=93) orally for 7 days (once-daily dosing for hydromorphone and twice-daily dosing for oxycodone). The doses were adjusted as necessary. Efficacy was evaluated by change in visual analog scale (VAS) score from baseline to completion of treatment. The between-group difference in least squares mean changes in VAS score from baseline to completion or discontinuation of treatment was -0.4 mm (95% CI -5.9 to 5 mm) by analysis of covariance where the baseline VAS score was used as a covariate. The upper limit of the 95% CI was below 10 mm, which was predefined as the noninferiority limit. This verified the noninferiority of hydromorphone tablets relative to oxycodone tablets. The incidence of adverse events was 80.7% (71 of 88) in the hydromorphone group and 83.7% (77 of 93) in the oxycodone group. The most common adverse events were nausea, vomiting, somnolence, diarrhea, and constipation, most of which are commonly observed with opioid analgesics. The efficacy and safety of hydromorphone extended-release tablets were equivalent to those of the oxycodone extended-release formulation.

An abuse-deterrent, microsphere-in-capsule formulation of extended-release oxycodone: alternative modes of administration to facilitate pain management in patients with dysphagia.

PubMed

McCarberg, Bill H; Kopecky, Ernest A; O'Connor, Melinda; Marseilles, Ann; Varanasi, Ravi K; Thompson, Christy; Fleming, Alison B

2016-12-01

Patients with chronic pain may experience difficulty swallowing, in part due to worsening disease, comorbid conditions, iatrogenic etiology, or age. Patients or caregivers may manipulate extended-release (ER) opioid formulations to facilitate oral dosing due to a lack of therapeutic options that allow for sprinkle or enteral feeding tube administration. If crushed or broken, current oral ER opioids can be associated with adverse sequelae, including risk of potentially fatal overdose. To review the safety, in vitro dissolution data, and in vivo pharmacokinetic data that support alternative modes of administration of oxycodone DETERx (Xtampza ER) via sprinkling onto soft foods for oral ingestion or via enteral feeding tubes. A review of oxycodone DETERx data from in vitro and in vivo studies was conducted to demonstrate support for alternative routes and modes of administration. There was no difference in the dissolution profile when administered with various soft foods or when mixed with various liquid vehicles and administered via nasogastric (NG) or gastrostomy (G) tubes, based on in vitro studies. When sprinkled onto applesauce and administered orally, the microspheres were bioequivalent to the intact oxycodone capsules. When crushed or chewed, the formulation maintained its pharmacokinetic profile; no bolus dose of opioid was released. The sprinkle-dose study was limited by the single-dose study design, as well as the small sample size. Oxycodone DETERx is the first ER oxycodone formulation that can be administered either intact, sprinkled onto soft foods, or via NG/G tubes, thereby providing options for treating pain in patients who have difficulty swallowing.

Justification of disintegration testing beyond current FDA criteria using in vitro and in silico models.

PubMed

Uebbing, Lukas; Klumpp, Lukas; Webster, Gregory K; Löbenberg, Raimar

2017-01-01

Drug product performance testing is an important part of quality-by-design approaches, but this process often lacks the underlying mechanistic understanding of the complex interactions between the disintegration and dissolution processes involved. Whereas a recent draft guideline by the US Food and Drug Administration (FDA) has allowed the replacement of dissolution testing with disintegration testing, the mentioned criteria are not globally accepted. This study provides scientific justification for using disintegration testing rather than dissolution testing as a quality control method for certain immediate release (IR) formulations. A mechanistic approach, which is beyond the current FDA criteria, is presented. Dissolution testing via United States Pharmacopeial Convention Apparatus II at various paddle speeds was performed for immediate and extended release formulations of metronidazole. Dissolution profile fitting via DDSolver and dissolution profile predictions via DDDPlus™ were performed. The results showed that Fickian diffusion and drug particle properties (DPP) were responsible for the dissolution of the IR tablets, and that formulation factors (eg, coning) impacted dissolution only at lower rotation speeds. Dissolution was completely formulation controlled if extended release tablets were tested and DPP were not important. To demonstrate that disintegration is the most important dosage form attribute when dissolution is DPP controlled, disintegration, intrinsic dissolution and dissolution testing were performed in conventional and disintegration impacting media (DIM). Tablet disintegration was affected by DIM and model fitting to the Korsmeyer-Peppas equation showed a growing effect of the formulation in DIM. DDDPlus was able to predict tablet dissolution and the intrinsic dissolution profiles in conventional media and DIM. The study showed that disintegration has to occur before DPP-dependent dissolution can happen. The study suggests that disintegration can be used as performance test of rapidly disintegrating tablets beyond the FDA criteria. The scientific criteria and justification is that dissolution has to be DPP dependent, originated from active pharmaceutical ingredient characteristics and formulations factors have to be negligible.

Justification of disintegration testing beyond current FDA criteria using in vitro and in silico models

PubMed Central

Uebbing, Lukas; Klumpp, Lukas; Webster, Gregory K; Löbenberg, Raimar

2017-01-01

Drug product performance testing is an important part of quality-by-design approaches, but this process often lacks the underlying mechanistic understanding of the complex interactions between the disintegration and dissolution processes involved. Whereas a recent draft guideline by the US Food and Drug Administration (FDA) has allowed the replacement of dissolution testing with disintegration testing, the mentioned criteria are not globally accepted. This study provides scientific justification for using disintegration testing rather than dissolution testing as a quality control method for certain immediate release (IR) formulations. A mechanistic approach, which is beyond the current FDA criteria, is presented. Dissolution testing via United States Pharmacopeial Convention Apparatus II at various paddle speeds was performed for immediate and extended release formulations of metronidazole. Dissolution profile fitting via DDSolver and dissolution profile predictions via DDDPlus™ were performed. The results showed that Fickian diffusion and drug particle properties (DPP) were responsible for the dissolution of the IR tablets, and that formulation factors (eg, coning) impacted dissolution only at lower rotation speeds. Dissolution was completely formulation controlled if extended release tablets were tested and DPP were not important. To demonstrate that disintegration is the most important dosage form attribute when dissolution is DPP controlled, disintegration, intrinsic dissolution and dissolution testing were performed in conventional and disintegration impacting media (DIM). Tablet disintegration was affected by DIM and model fitting to the Korsmeyer–Peppas equation showed a growing effect of the formulation in DIM. DDDPlus was able to predict tablet dissolution and the intrinsic dissolution profiles in conventional media and DIM. The study showed that disintegration has to occur before DPP-dependent dissolution can happen. The study suggests that disintegration can be used as performance test of rapidly disintegrating tablets beyond the FDA criteria. The scientific criteria and justification is that dissolution has to be DPP dependent, originated from active pharmaceutical ingredient characteristics and formulations factors have to be negligible. PMID:28442890

Assessment of the bioequivalence of two formulations of clarithromycin extended-release 500-mg tablets under fasting and fed conditions: a single-dose, randomized, open-label, two-period, two-way crossover study in healthy Jordanian male volunteers.

PubMed

Alkhalidi, Bashar A; Tamimi, Jaafar J; Salem, Isam I; Ibrahim, Husain; Sallam, Alsayed Alarabi I

2008-10-01

Clarithromycin extended-release tablets are indicated for the treatment of adults with acute maxillary sinusitis caused by Haemophilus influenzae, Moraxella catarrhalis, or Streptococcus pneumoniae; acute bacterial exacerbation of chronic bronchitis due to H influenzae, Haemophilus parainfluenzae, M catarrhalis, or S pneumoniae; or community acquired pneumonia due to H influenzae, H parainfluenzae, M catarrhalis, S pneumoniae, Chlamydia pneumoniae, or Mycoplasma pneumoniae. This study was conducted to assess the bioequivalence of test and reference formulations of clarithromycin extended-release 500-mg tablets under fasting and fed conditions. This was a single-dose, randomized, open-label, 2-period, 2-way crossover study with a 1-week washout period between doses. Separate bioequivalence studies (fasting and fed) were performed in 2 groups of healthy male Jordanian volunteers. Eighteen blood samples were obtained from each volunteer over 38 hours after drug administration. Clarithromycin concentrations were determined in plasma using a validated high-performance liquid chromatography method with electrochemical detection. Pharmacokinetic parameters of clarithromycin (C(max), T(max), AUC(0-t), AUC(0-infinity), lambda(z) [first-order elimination rate constant], and t((1/2))) were calculated and analyzed statistically. Tolerability was assessed based on changes in vital signs and laboratory tests, and by questioning subjects about adverse events. Thirty-eight volunteers each participated in the fasting and fed studies. The mean ages of participants in the fasting and fed studies were 26.7 and 27.6 years, respectively; their mean weight was 71.2 and 70.9 kg and mean height was 171.3 and 179.0 cm. Under fasting conditions, the arithmetic mean (SD) C(max) was 569.4 (189.3) ng/mL for the test formulation and 641.2 (202.0) ng/mL for the reference formulation, with a geometric mean ratio of 0.88. The arithmetic mean AUC(0-t) was 8602.9 (4105.1) and 8245.3 (4122.4) ng . h/mL in the respective formulations, with a geometric mean ratio of 1.06. The arithmetic mean T(max) was 8.0 (5.6) and 6.1 (3.8) hours. In the fed study, the C(max) and AUC of both formulations were significantly increased relative to the fasting study (P < 0.05). The arithmetic mean C(max) of the 2 formulations was 1183.0 (637.5) and 1199.6 (496.3) ng/mL, with a geometric mean ratio of 0.93. The arithmetic mean AUC(0-t) was 12,981.2 (7849.0) and 11,822.9 (5790.2) ng . h/mL, with a geometric mean ratio of 1.06. The arithmetic mean T(max) was 5.7 (2.8) and 6.7 (2.5) hours. The 90% CI for the ratio (test:reference) of log-transformed C(max) and AUC values was within the acceptance range of 0.80 to 1.25. The 2 formulations were both well tolerated, and no adverse events were reported during the study. In these fasting and fed studies in healthy male Jordanian volunteers, the 2 formulations of clarithromycin extended-release 500-mg tablets were found to be bioequivalent according to the US Food and Drug Administration regulatory definition. Administration with food significantly increased the rate and extent of absorption of both products, with no significant effect on their bioequivalence.

Predictability of drug release from water-insoluble polymeric matrix tablets.

PubMed

Grund, Julia; Körber, Martin; Bodmeier, Roland

2013-11-01

The purpose of this study was to extend the predictability of an established solution of Fick's second law of diffusion with formulation-relevant parameters and including percolation theory. Kollidon SR (polyvinyl acetate/polyvinylpyrrolidone, 80/20 w/w) matrix tablets with various porosities (10-30% v/v) containing model drugs with different solubilities (Cs=10-170 mg/ml) and in different amounts (A=10-90% w/w) were prepared by direct compression and characterized by drug release and mass loss studies. Drug release was fitted to Fick's second law to obtain the apparent diffusion coefficient. Its changes were correlated with the total porosity of the matrix and the solubility of the drug. The apparent diffusion coefficient was best described by a cumulative normal distribution over the range of total porosities. The mean of the distribution coincided with the polymer percolation threshold, and the minimum and maximum of the distribution were represented by the diffusion coefficient in pore-free polymer and in aqueous medium, respectively. The derived model was verified, and the applicability further extended to a drug solubility range of 10-1000 mg/ml. The developed mathematical model accurately describes and predicts drug release from Kollidon SR matrix tablets. It can efficiently reduce experimental trials during formulation development. Copyright © 2013 Elsevier B.V. All rights reserved.

Stabilization of the Nitric Oxide (NO) Prodrugs and Anti-Cancer Leads, PABA/NO and Double JS-K through Incorporation into PEG-Protected Nanoparticles

PubMed Central

Kumar, Varun; Hong, Sam Y.; Maciag, Anna E.; Saavedra, Joseph E.; Adamson, Douglas H.; Prud'homme, Robert K.; Keefer, Larry K.; Chakrapani, Harinath

2009-01-01

Here we report the stabilization of the nitric oxide (NO) prodrugs and anti-cancer lead compounds, PABA/NO (O2-{2,4-dinitro-5-[4-(N-methylamino)benzoyloxy]phenyl} 1-(N,N-dimethylamino)diazen-1-ium-1,2-diolate) and “Double JS-K” (1,5-bis{[1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diol-2-ato]-2,4-dinitrobenzene), through their incorporation into polymer-protected nanoparticles. The prodrugs were formulated in block copolymer-stabilized nanoparticles with sizes from 220 to 450 nm by a novel rapid precipitation process. The block copolymers, with polyethylene glycol (PEG) soluble blocks, provide a steric barrier against NO prodrug activation by glutathione. Too rapid activation and NO release has been a major barrier to effective administration of this class of compounds. The nanoparticle stabilized PABA/NO from attack by glutathione as evidenced by a significant increase in time taken for 50% decomposition from 15 min (unformulated) to 5 h (formulated); in the case of Double JS-K, the 50% decomposition time was extended from 4.5 min (unformulated) to 40 min (formulated). The more hydrophobic PABA/NO produced more stable nanoparticles and correspondingly more extended release times in comparison with Double JS-K. The hydrophobic blocks of the polymer were either polystyrene or polylactide. Both blocks produced nanoparticles of approximately the same size and release kinetics. This combination of PEG-protected nanoparticles with sizes appropriate for cancer targeting by enhanced permeation and retention (EPR) and delayed release of NO may afford enhanced therapeutic benefit. PMID:20000791

Stabilization of the nitric oxide (NO) prodrugs and anticancer leads, PABA/NO and Double JS-K, through incorporation into PEG-protected nanoparticles.

PubMed

Kumar, Varun; Hong, Sam Y; Maciag, Anna E; Saavedra, Joseph E; Adamson, Douglas H; Prud'homme, Robert K; Keefer, Larry K; Chakrapani, Harinath

2010-02-01

We report the stabilization of the nitric oxide (NO) prodrugs and anticancer lead compounds, PABA/NO (O(2)-{2,4-dinitro-5-[4-(N-methylamino)benzoyloxy]phenyl} 1-(N,N-dimethylamino)diazen-1-ium-1,2-diolate) and "Double JS-K" 1,5-bis-{1-[(4-ethoxycarbonyl)piperazin-1-yl]diazen-1-ium-1,2-diol-2-ato}-2,4-dinitrobenzene, through their incorporation into polymer-protected nanoparticles. The prodrugs were formulated in block copolymer-stabilized nanoparticles with sizes from 220 to 450 nm by a novel rapid precipitation process. The block copolymers, with polyethylene glycol (PEG) soluble blocks, provide a steric barrier against NO prodrug activation by glutathione. Too rapid activation and NO release has been a major barrier to effective administration of this class of compounds. The nanoparticle stabilized PABA/NO are protected from attack by glutathione as evidenced by a significant increase in time taken for 50% decomposition from 15 min (unformulated) to 5 h (formulated); in the case of Double JS-K, the 50% decomposition time was extended from 4.5 min (unformulated) to 40 min (formulated). The more hydrophobic PABA/NO produced more stable nanoparticles and correspondingly more extended release times in comparison with Double JS-K. The hydrophobic blocks of the polymer were either polystyrene or polylactide. Both blocks produced nanoparticles of approximately the same size and release kinetics. This combination of PEG-protected nanoparticles with sizes appropriate for cancer targeting by enhanced permeation and retention (EPR) and delayed release of NO may afford enhanced therapeutic benefit.

Enteric polymers as acidifiers for the pH-independent sustained delivery of a weakly basic drug salt from coated pellets.

PubMed

Körber, Martin; Ciper, Mesut; Hoffart, Valerie; Pearnchob, Nantharat; Walther, Mathias; Macrae, Ross J; Bodmeier, Roland

2011-08-01

Weakly basic drugs and their salts exhibit a decrease in aqueous solubility at higher pH, which can result in pH-dependent or even incomplete release of these drugs from extended release formulations. The objective of this study was to evaluate strategies to set-off the very strong pH-dependent solubility (solubility: 80 mg/ml at pH 2 and 0.02 mg/ml at pH 7.5, factor 4000) of a mesylate salt of weakly basic model drug (pK(a) 6.5), in order to obtain pH-independent extended drug release. Three approaches for pH-independent release were investigated: (1) organic acid addition in the core, (2) enteric polymer addition to the extended release coating and (3) an enteric polymer subcoating below the extended release coating. The layering of aspartic acid onto drug cores as well as the coating of drug cores with an ethylcellulose/Eudragit L (enteric polymer) blend were not effective to avoid the formation of the free base at pH 7.5 and thus failed to significantly improve the completeness of the release compared to standard ethylcellulose/hydroxypropyl cellulose (EC/HPC)-coated drug pellets. Interestingly, the incorporation of an enteric polymer layer underneath the EC/HPC coating decreased the free base formation at pH 7.5 and thus resulted in a more complete release of up to 90% of the drug loading over 18 h. The release enhancing effect was attributed to an extended acidification through the enteric polymer layer. Flexible release patterns with approximately pH-independent characteristics were successfully achieved. Copyright © 2011 Elsevier B.V. All rights reserved.

In-vitro release and permeation studies of ketoconazole from optimized dermatological vehicles using powder, nanoparticles and solid dispersion forms of drug

NASA Astrophysics Data System (ADS)

Mohammed, Irfan A.

To optimize the clinical efficacy of Ketoconazole from an externally applied product, this project was undertaken to evaluate the drug release/permeation profile from various dermatological vehicles using regular powder, nanoparticles and solid dispersion forms with reduced level of drug. Nanoparticles of drug were prepared by wet media milling method using Polyvinylpyrrolidone (PVP-10K) as a stabilizer. The nanoparticles were in the size range of 250-300nm. Solid dispersion was prepared by solvent evaporation method using drug to PVP-10K at a weight ratio of (1:2). Formulations containing 1% w/w drug were developed using HPMC gel, Carbomer gel and a cationic cream as the vehicles. Penetration enhancers including propylene glycol (PG), dimethylsulfoxide (DMSO) and polyethylene glycol 400 (PEG-400) at various levels were evaluated. A commercial 2% w/w ketoconazole product was included as a control for comparison. Studies were carried out with Franz Diffusion Cells using cellulose membrane and human cadaver skin for two and six hour studies. Among the formulations evaluated, the general rank order of the drug release through the cellulose membrane was observed to be: HPMC gel base > Anionic gel base > Cationic gel base > Commercial product. The addition of penetration enhancers showed variable effects in all samples evaluated. However, the HPMC gel-based vehicle showed significant effect in enhancing the drug release in the presence of DMSO. The formulation containing 1% w/w ketoconazole and 20% w/w DMSO gave a maximum drug release of 20.21% when compared to only 1.60% from the commercial product. This represents a twelve fold increase in the release of ketoconazole from the formulation. Furthermore, when the optimum gel-based formulation containing 1% w/w ketoconazole was studied over an extended period of 6 hours, it gave 36.01% drug release from the sample formulation compared to only 2.00% from the commercial product. Finally, this formulation was selected to study for its drug release/permeation profile using the human cadaver skin as the diffusion barrier. Here, as expected, the drug release from both the formulations tested was significantly reduced due to the resistance posed by the skin. After 6 hours, the drug release form the commercial product was 0.17% when compared to 2.80% from the optimum formulation. Once again, this indicated that the experimental formulation exhibits superior drug release dynamics. The selected formulations were further evaluated for their in-vitro anti-fungal activities using yeast microorganisms. The results correlated to the in-vitro drug release profile, where HPMC based formulations exhibited a greater area of zone of inhibition for the growth of microorganisms when compared to diminutive area of zone of inhibition for the commercial product. The release data from all the samples were treated to calculate various physical parameters including: diffusion co-efficient, partition co-efficient, steady state flux and lag period etc. Interestingly, the values for the steady state flux and diffusion coefficient were found to be the highest from the optimum formulation and the values for the lag time and partition coefficient were observed to be the lowest. This supports the evidence that the drug from this formulation is readily diffusible to the skin at a steady rate after its application at the site. In-vitro drug diffusion studies and in-vitro anti-fungal studies proved useful in screening various dermatological formulations of ketoconazole compared to the commercial product containing 2% w/w drug. The HPMC based optimum formulation with reduced level of drug represents 15 folds increase through human cadaver skin and also exhibited augmented anti-fungal activity. This supports that by using an appropriate vehicle and proper incorporation of drug, one can optimize the drug release from topical formulation for maximum therapeutic effect.

A stable fixed-dose combination tablet of pseudoephedrine and KOB extracts for the extended release.

PubMed

Hwang, C-J; Park, M-H; Jung, H-W; Park, Y-K; Kim, Y-H; Kang, J-S; Cho, C-W

2013-11-01

Allergic rhinitis (AR) is characterized by inflammation of the nasal mucosa with hypersensitivity resulting from seasonal or perennial responses to specific environmental allergens and by symptoms like nasal rubbing, sneezing, rhinorrhea, lacrimation, nasal congestion and obstruction, and less frequently cough. KOB extracts, which is a polyherbal medicine consisting of 5 different herbs (Atractylodes macrocephala, Astragalus membranaceus, Saposhnikovia divaricata, Ostericum koreanum and Scutellaria baicalensis) had commonly been used for the treatment of various allergic diseases showed an anti-allergic effect by modulating mast cell-mediated allergic responses in allergic rhinitis, recently. On the other hand, pseudoephedrine is a sympathomimetic amine commonly used to relieve congestion in patients with allergic rhinitis and common colds. Considering the KOB's therapeutic mechanism, the combination with pseudoephedrine would be suitable for allergic rhinitis. This study is to obtain an effective extended release formulation using pseudoephedrine and KOB extracts to reduce side effects of drug due to repeated dosing and improve the compliance of patients for treatment of rhinitis and nasal decongestion. So, the fixed-dose combination tablet of pseudoephedrine and KOB extracts was prepared by direct compression and characterized by drug content, flowing characteristics and dissolution test. The drug content of baicalin of KOB extracts was within the range of 95-105% except for T1 formulation. The hardness and friability values of all formulations ranged from 9 to 13 kp and less than 1%, respectively. Taken together, T4 or T8 could be a stable fixed-dose combination tablet for extended release of pseudoephedrine and KOB extracts for nasal rhinitis. © Georg Thieme Verlag KG Stuttgart · New York.

Preparation and In Vitro/Ex Vivo Evaluation of Moxifloxacin-Loaded PLGA Nanosuspensions for Ophthalmic Application.

PubMed

Mudgil, Meetali; Pawar, Pravin K

2013-01-01

The aim of the present investigation was to prepare a colloidal ophthalmic formulation to improve the residence time of moxifloxacin. Moxifloxacin-loaded poly(dl-lactide-co-glycolide) (PLGA) nanosuspensions were prepared by using the solvent evaporation technique. The nanosuspensions were characterised physically by using different techniques like particle size, zeta potential, FTIR, DSC, and XRD analysis. In vitro and ex vivo studies of nanosuspensions were carried out using a modified USP dissolution apparatus and all-glass Franz diffusion cells, respectively. The antibacterial activities of the nanosuspension and marketed formulations were performed against S. aureus and P. aeroginosa. The moxifloxacin-loaded PLGA nanosuspensions showed uniform particle size, ranging between 164-490 nm with negative zeta potential for all batches. The percentage entrapment efficiency of the drug-loaded nano-suspension was found to be between 84.09 to 92.05%. In vitro drug release studies suggest that all of the formulations showed extended drug release profiles and follow Korsemeyer-Peppas release kinetics. In vitro corneal permeability was found to be comparable with that of the marketed formulation across isolated goat cornea, indicating the suitability of the nanosuspension formulation in the ophthalmic delivery of moxifloxacin. The optimised nano-suspension was found to be more active against S. aureus and P. aeruginosa compared to the marketed eye drops.

Formulation and in-vitro evaluation of floating bilayer tablet of lisinopril maleate and metoprolol tartrate.

PubMed

Ijaz, Hira; Qureshi, Junaid; Danish, Zeeshan; Zaman, Muhammad; Abdel-Daim, Mohamed; Hanif, Muhammad; Waheed, Imran; Mohammad, Imran Shair

2015-11-01

The purpose of this study was to introduce the technology for the development of rate-controlled oral drug delivery system to overcome various physiological problems. Several approaches are being used for the purpose of increasing the gastric retentive time, including floating drug delivery system. Gastric floating lisinopril maleate and metoprolol tartrate bilayer tablets were formulated by direct compression method using the sodium starch glycolate, crosscarmellose sodium for IR layer. Eudragit L100, pectin, acacia as sustained release polymers in different ratios for SR metoprolol tartrate layer and sodium bicarbonate, citric acid as gas generating agents for the floating extended release layer. The floating bilayer tablets of lisinopril maleate and metoprolol tartrate were designed to overcome the various problems associated with conventional oral dosage form. Floating tablets were evaluated for floating lag time, drug contents and in-vitro dissolution profile and different kinetic release models were applied. It was clear that the different ratios of polymers affected the drug release and floating time. L2 and M4 showed good drug release profile and floating behavior. The linear regression and model fitting showed that all formulation followed Higuchi model of drug release model except M4 that followed zero order kinetic. From the study it is evident that a promising controlled release by floating bilyer tablets of lisinopril maleate and metoprolol tartrate can be developed successfully.

Tapioca starch blended alginate mucoadhesive-floating beads for intragastric delivery of Metoprolol Tartrate.

PubMed

Biswas, Nikhil; Sahoo, Ranjan Kumar

2016-02-01

The objective of the study was to develop tapioca starch blended alginate mucoadhesive-floating beads for the intragastric delivery of Metoprolol Tartrate (MT). The beads were prepared by ionotropic gelation method using calcium chloride as crosslinker and gas forming calcium carbonate (CaCO3) as floating inducer. The alginate gel beads having 51-58% entrapped MT showed 90% release within 45 min in gastric medium (pH 1.2). Tapioca starch blending markedly improved the entrapment efficiency (88%) and sustained the release for 3-4 h. A 12% w/w HPMC coating on these beads extended the release upto 9-11 h. In vitro wash off and buoyancy test in gastric media revealed that the beads containing CaCO3 has gastric residence of more than 12 h. In vitro optimized multi-unit formulation consisting of immediate and sustained release mucoadhesive-floating beads (40:60) showed good initial release of 42% MT within 1h followed by a sustained release of over 90% for 11 h. Pharmacokinetic study performed in rabbit model showed that the relative oral bioavailability of MT after administration of oral solution, sustain release and optimized formulation was 51%, 67% and 87%, respectively. Optimized formulation showed a higher percent inhibition of isoprenaline induced heart rate in rabbits for almost 12 h. Copyright © 2015 Elsevier B.V. All rights reserved.

A comparison of the extended-release and standard-release formulations of tacrolimus in de novo kidney transplant recipients: a 12-month outcome study.

PubMed

Fanous, Helen; Zheng, Rebecca; Campbell, Carolyn; Huang, Michael; Nash, Michelle M; Rapi, Lindita; Zaltzman, Jeffrey S; Prasad, G V Ramesh

2013-02-01

BACKGROUND: Limited comparative data are available on the outcomes between extended-release and standard-release tacrolimus when used de novo in kidney transplant recipients (KTRs). METHODS: We identified KTRs transplanted at our institution during 2009-10 routinely prescribed extended-release tacrolimus and compared them with those transplanted during 2008-09 prescribed standard-release tacrolimus. Graft function (eGFR by MDRD-7 equation) at 12 months post-transplant (primary outcome); new-onset diabetes and other cardiovascular risk factors, BK viremia incidence, acute rejection, and graft survival to 12 months (secondary outcomes) were compared by intent-to-treat analysis. Time-to-steady-state concentration and number of dose adjustments required to attain steady state were recorded. RESULTS: There were no important demographic differences between the extended-release (N = 106) and standard-release (N = 95) cohorts. The estimated glomerular filtration rate (eGFR) at 12 months was similar (58.8 ± 17 versus 59.2 ± 18 mL/min/1.73 m(2), P = 0.307). There was no difference in new-onset diabetes (17 versus 20%, P = 0.581), BK viremia (10 versus 7%, P = 0.450), acute rejection (7 versus 16%, P = 0.067) or graft survival (97 versus 95%, P = 0.301). Time-to-steady state was similar (9.2 ± 1.1 versus 8.1 ± 4.7 days, P = 0.490) although extended-release patients required fewer adjustments to attain steady state (1.2 ± 1.7 [0-8] versus 1.7 ± 1.5 [0-7], P = 0.030) but a similar dose (7.2 ± 2.4 [2-17] versus 7 ± 2.7 [2-16] mg/day, P = 0.697). CONCLUSION: De novo KTRs prescribed extended-release or standard-release tacrolimus demonstrate similar 12-month outcomes.

An open-label, parallel, multiple-dose study comparing the pharmacokinetics and gastric acid suppression of rabeprazole extended-release with esomeprazole 40 mg and rabeprazole delayed-release 20 mg in healthy volunteers.

PubMed

Morelli, G; Chen, H; Rossiter, G; Rege, B; Lu, Y

2011-04-01

Novel rabeprazole extended-release (ER) formulations were developed to provide prolonged gastric acid suppression and potentially improved clinical outcomes in GERD patients. To evaluate the pharmacodynamics and pharmacokinetics of six rabeprazole-ER formulations vs. esomeprazole 40 mg and rabeprazole delayed-release (DR) 20 mg. Helicobacter pylori-negative healthy subjects were randomised to receive one of eight treatments once daily for 5 days. Twenty-four-hour intragastric pH was monitored on days -1, 1 and 5. Rabeprazole plasma concentrations were measured on day 5. A total of 248 subjects (N=31/group) were enrolled in the study. On day 5, rabeprazole-ER groups provided mean durations of 18.5-20.2 h (77.0-84.1% of 24-h) with intragastric pH >4.0 vs. esomeprazole 40 mg (15.9 h/66.1% of 24-h) and rabeprazole-DR 20 mg (15.2 h/63.2% of 24-h). A similar increase was observed on day 1. While percentage of daytime (8 am-10 pm) with intragastric pH >4.0 on day 5 was overall similar across the groups, percentage of night-time (10 pm-8 am) with intragastric pH >4.0 was higher with the rabeprazole-ER groups (57.0-72.4%) vs. esomeprazole 40 mg (32.8%) and rabeprazole-DR 20 mg (34.0%). Rabeprazole-ER once daily for 5 days demonstrated a significantly longer duration of gastric acid suppression in 24 h vs. esomeprazole 40 mg and rabeprazole-DR 20 mg. The increase in acid suppression was predominantly due to prolonged acid suppression during the night-time; this was supported by the extended-release pharmacokinetic characteristics. © 2011 Blackwell Publishing Ltd.

Spotlight on amoxicillin/clavulanic acid 2000 mg/125 mg extended release (XR) in respiratory tract infections in adults.

PubMed

McCormack, Paul L; Keating, Gillian M

2005-01-01

Amoxicillin/clavulanic acid 2000 mg/125 mg extended release (Augmentin XR), referred to herein as amoxicillin/clavulanic acid XR, is a pharmacokinetically enhanced formulation designed to provide more effective therapy in adults and adolescents than conventional formulations against community-acquired respiratory tract pathogens, particularly Streptococcus pneumoniae, with reduced susceptibility to amoxicillin.Amoxicillin/clavulanic acid XR maintains plasma amoxicillin concentrations >4 microg/mL for a mean of 49% of the dosing interval indicating that it would be highly effective against S. pneumoniae strains with minimum inhibitory concentrations (MICs) above the National Committee for Clinical Laboratory Standard's amoxicillin +/- clavulanic acid susceptibility breakpoint of < or = 2 microg/mL. Amoxicillin/clavulanic acid XR is at least as effective as conventional amoxicillin/clavulanic acid formulations, levofloxacin, and clarithromycin in treating community-acquired pneumonia, acute bacterial sinusitis, or acute exacerbations of chronic bronchitis, and has a tolerability profile comparable to that of conventional amoxicillin/clavulanic acid formulations. While the incidence of amoxicillin- or multidrug-resistant S. pneumoniae is not currently sufficient in most regions to warrant the routine empiric use of amoxicillin/clavulanic acid XR, the drug would be extremely useful in those regions with a high incidence of resistant pathogens or in selected patients (i.e. those with S. pneumoniae isolates having amoxicillin MICs > or = 2 microg/mL but < or = 4 microg/mL).

Amoxicillin/clavulanic acid 2000mg/125mg extended release (XR): a review of its use in the treatment of respiratory tract infections in adults.

PubMed

McCormack, Paul L; Keating, Gillian M

2005-01-01

Amoxicillin/clavulanic acid 2000mg/125mg extended release (Augmentin XR), referred to herein as amoxicillin/clavulanic acid XR, is a pharmacokinetically enhanced formulation designed to provide more effective therapy in adults and adolescents than conventional formulations against community-acquired respiratory tract pathogens, particularly Streptococcus pneumoniae, with reduced susceptibility to amoxicillin. Amoxicillin/clavulanic acid XR maintains plasma amoxicillin concentrations above 4 microg/mL for a mean of 49% of the dosing interval indicating that it would be highly effective against S. pneumoniae strains with minimum inhibitory concentrations (MICs) above the National Committee for Clinical Laboratory Standard's amoxicillin +/- clavulanic acid susceptibility breakpoint of < or =2 microg/mL. Amoxicillin/clavulanic acid XR is at least as effective as conventional amoxicillin/clavulanic acid formulations, levofloxacin and clarithromycin in treating community-acquired pneumonia, acute bacterial sinusitis or acute exacerbations of chronic bronchitis, and has a tolerability profile comparable to that of conventional amoxicillin/clavulanic acid formulations. While the incidence of amoxicillin- or multidrug-resistant S. pneumoniae is not currently sufficient in most regions to warrant the routine empirical use of amoxicillin/clavulanic acid XR, the drug would be extremely useful in those regions with a high incidence of resistant pathogens or in selected patients (i.e. those with S. pneumoniae isolates having amoxicillin MICs > or =2 microg/mL but < or =4 microg/mL).

Pharmacokinetic drug evaluation of extended release lorcaserin for the treatment of obesity.

PubMed

Hurren, Kathryn M; Dunham, Marissa W

2017-08-01

Lorcaserin is a serotonin 2C receptor antagonist that was FDA approved in 2012. Lorcaserin is recently available as an extended-release (ER) formulation for the treatment of obesity as an adjunct to lifestyle modification. Areas covered: The pharmacokinetics, pharmacodynamics, efficacy, and safety of lorcaserin ER will be reviewed. Expert opinion: Lorcaserin ER 20mg daily provides drug exposure bioequivalent to lorcaserin immediate release (IR) 10mg twice daily. Lorcaserin IR is associated with 3.3 and 3.0% placebo-subtracted weight loss in patients without and with diabetes, respectively. A1C was reduced by 0.9% in patients with diabetes. Common side effects include headache, dry mouth, constipation, dizziness, fatigue, and nausea. Lorcaserin provides potential advantages over other antiobesity medications in regards to tolerability and simplicity of medication initiation, but may not be as effective as other options. Lorcaserin ER offers improved ease of administration and anticipated adherence compared to the IR formulation. The place in therapy for lorcaserin ER and other antiobesity medications will be further clarified by results of pending clinical trials addressing cardiovascular outcomes as well as the role pharmacogenomics and comorbid disease states may play in choosing patient-specific therapy.

Methylphenidate Efficacy: Immediate versus Extended Release at Short Term in Mexican Children with ADHD Assessed by Conners Scale and EEG

PubMed Central

Alatorre-Miguel, Efren; Zambrano-Sánchez, Elizabeth; Reyes-Legorreta, Celia

2015-01-01

Attention deficit hyperactivity disorder (ADHD) affects 5-6% of school aged children worldwide. Pharmacological therapy is considered the first-line treatment and methylphenidate (MPH) is considered the first-choice medication. There are two formulations: immediate release (IR) MPH and long-acting (or extended release) formulation (MPH-ER). In this work, we measure the efficacy of treatment for both presentations in one month with Conners' scales and electroencephalography (EEG). Results. for IR group, in parents and teachers Conners test, all items showed significant differences, towards improvement, except for teachers in perfectionism and emotional instability. For ER group in parent's Conners test, the items in which there were no significant differences are psychosomatic and emotional instability. For teachers, there were no significant differences in: hyperactivity and perfectionism. Comparing the Conners questionnaires (parents versus teachers) we find significant differences before and after treatment in hyperactivity, perfectionism, psychosomatics, DSM-IV hyperactive-impulsive, and DSM-IV total. In the EEG the Wilcoxon test showed a significant difference (P < 0.0001). As we can see, both presentations are suitable for managing the ADHD and have the same effect on the symptomatology and in the EEG. PMID:25838946

Methylphenidate Efficacy: Immediate versus Extended Release at Short Term in Mexican Children with ADHD Assessed by Conners Scale and EEG.

PubMed

Durand-Rivera, Alfredo; Alatorre-Miguel, Efren; Zambrano-Sánchez, Elizabeth; Reyes-Legorreta, Celia

2015-01-01

Attention deficit hyperactivity disorder (ADHD) affects 5-6% of school aged children worldwide. Pharmacological therapy is considered the first-line treatment and methylphenidate (MPH) is considered the first-choice medication. There are two formulations: immediate release (IR) MPH and long-acting (or extended release) formulation (MPH-ER). In this work, we measure the efficacy of treatment for both presentations in one month with Conners' scales and electroencephalography (EEG). Results. for IR group, in parents and teachers Conners test, all items showed significant differences, towards improvement, except for teachers in perfectionism and emotional instability. For ER group in parent's Conners test, the items in which there were no significant differences are psychosomatic and emotional instability. For teachers, there were no significant differences in: hyperactivity and perfectionism. Comparing the Conners questionnaires (parents versus teachers) we find significant differences before and after treatment in hyperactivity, perfectionism, psychosomatics, DSM-IV hyperactive-impulsive, and DSM-IV total. In the EEG the Wilcoxon test showed a significant difference (P < 0.0001). As we can see, both presentations are suitable for managing the ADHD and have the same effect on the symptomatology and in the EEG.

Development of a Novel Simplified PBPK Absorption Model to Explain the Higher Relative Bioavailability of the OROS® Formulation of Oxybutynin.

PubMed

Olivares-Morales, Andrés; Ghosh, Avijit; Aarons, Leon; Rostami-Hodjegan, Amin

2016-11-01

A new minimal Segmented Transit and Absorption model (mSAT) model has been recently proposed and combined with intrinsic intestinal effective permeability (P eff,int ) to predict the regional gastrointestinal (GI) absorption (f abs ) of several drugs. Herein, this model was extended and applied for the prediction of oral bioavailability and pharmacokinetics of oxybutynin and its enantiomers to provide a mechanistic explanation of the higher relative bioavailability observed for oxybutynin's modified-release OROS® formulation compared to its immediate-release (IR) counterpart. The expansion of the model involved the incorporation of mechanistic equations for the prediction of release, transit, dissolution, permeation and first-pass metabolism. The predicted pharmacokinetics of oxybutynin enantiomers after oral administration for both the IR and OROS® formulations were in close agreement with the observed data. The predicted absolute bioavailability for the IR formulation was within 5% of the observed value, and the model adequately predicted the higher relative bioavailability observed for the OROS® formulation vs. the IR counterpart. From the model predictions, it can be noticed that the higher bioavailability observed for the OROS® formulation was mainly attributable to differences in the intestinal availability (F G ) rather than due to a higher colonic f abs , thus confirming previous hypotheses. The predicted f abs was almost 70% lower for the OROS® formulation compared to the IR formulation, whereas the F G was almost eightfold higher than in the IR formulation. These results provide further support to the hypothesis of an increased F G as the main factor responsible for the higher bioavailability of oxybutynin's OROS® formulation vs. the IR.

Microencapsulation Approach for Orally Extended Delivery of Glipizide: In vitro and in vivo Evaluation

PubMed Central

Abdelbary, A.; El-gendy, N. A.; Hosny, A.

2012-01-01

Glipizide is an effective antidiabetic agent, however, it suffers from relatively short biological half-life. To solve this encumbrance, it is a prospective candidate for fabricating glipizide extended release microcapsules. Microencapsulation of glipizde with a coat of alginate alone or in combination with chitosan or carbomer 934P was prepared employing ionotropic gelation process. The prepared microcapsules were evaluated in vitro by microscopical examination, determination of the particle size, yield and microencapsulation efficiency. The filled capsules were assessed for content uniformity and drug release characteristics. Stability study of the optimised formulas was carried out at three different temperatures over 12 weeks. In vivo bioavailability study and hypoglycemic activity of C9 microcapsules were done on albino rabbits. All formulas achieved high yield, microencapsulation efficiency and extended t1/2. C9 and C19 microcapsules attained the most optimised results in all tests and complied with the dissolution requirements for extended release dosage forms. These two formulas were selected for stability studies. C9 exhibited longer shelf-life and hence was chosen for in vivo studies. C9 microcapsules showed an improvement in the drug bioavailability and significant hypoglycemic activity compared to immediate release tablets (Minidiab® 5 mg). The optimised microcapsule formulation developed was found to produce extended antidiabetic activity. PMID:23626387

Optimization of propranolol HCl release kinetics from press coated sustained release tablets.

PubMed

Ali, Adel Ahmed; Ali, Ahmed Mahmoud

2013-01-01

Press-coated sustained release tablets offer a valuable, cheap and easy manufacture alternative to the highly expensive, multi-step manufacture and filling of coated beads. In this study, propranolol HCl press-coated tablets were prepared using hydroxylpropylmethylcellulose (HPMC) as tablet coating material together with carbopol 971P and compressol as release modifiers. The prepared formulations were optimized for zero-order release using artificial neural network program (INForm, Intelligensys Ltd, North Yorkshire, UK). Typical zero-order release kinetics with extended release profile for more than 12 h was obtained. The most important variables considered by the program in optimizing formulations were type and proportion of polymer mixture in the coat layer and distribution ratio of drug between core and coat. The key elements found were; incorporation of 31-38 % of the drug in the coat, fixing the amount of polymer in coat to be not less than 50 % of coat layer. Optimum zero-order release kinetics (linear regression r2 = 0.997 and Peppas model n value > 0.80) were obtained when 2.5-10 % carbopol and 25-42.5% compressol were incorporated into the 50 % HPMC coat layer.

Clinical applications of oxymorphone.

PubMed

Vadivelu, Nalini; Maria, Monisa; Jolly, Suneil; Rosenbloom, Julia; Prasad, Arun; Kaye, Alan David

2013-01-01

Oxymorphone (14-hydroxydihydromorphinone), a pyridine ring unsubstituted pyridomorphinan, a semisynthetic opioid analgesic derived from thebaine, first developed in the year 1914 and has been available as oxymorphone hydrochloride parenteral forms in the United States since 1959, when the US Food and Drug Administration approved it. Over the years, it has been used for the alleviation of moderate-to-severe pain. Pharmacological considerations, new and traditional formulations, clinical indications, and recent study populations are examined in this review. Specific considerations for oxymorphone interactions are focused on as well as specific side effects and end organ considerations. Although discovered many decades ago and used as parenteral formulation, the newer oral preparations of oxymorphone (immediate release and extended release) that were approved in 2006 can provide additional options for customizing therapy to accommodate various patient needs. This newer oral formulation could make this powerful agent an important drug in the armamentarium of the healthcare provider caring for patients with pain.

Formulation and evaluation of novel coated floating tablets of bergenin and cetirizine dihydrochloride for gastric delivery.

PubMed

He, Shuang; Li, Feng; Zhou, Dan; Du, Junrong; Huang, Yuan

2012-10-01

A novel coated gastric floating drug-delivery system (GFDDS) of bergenin (BN) and cetirizine dihydrochloride (CET) was developed. First, the pharmacodynamic studies were performed and the results revealed that the new compounds of bergenin/cetirizine dihydrochloride had comparative efficacy as commercial products (bergenin/chlorphenamine maleate) but with fewer side effects on central nervous system (CNS). Subsequently, bergenin was formulated as an extended-release core tablet while cetirizine dihydrochloride was incorporated into the gastric coating film for immediate release. The formulation of GFDDS was optimized by CET content uniformity test, in vitro buoyancy and drug release. Herein, the effects of sodium bicarbonate (effervescent), hydroxypropyl methylcellulose (HPMC, matrix polymer) and coating weight gain were investigated respectively. The optimized GFDDS exhibited good floating properties (buoyancy lag time < 2 min; floating duration > 10 h) and satisfactory drug-release profiles (immediate release of CET in 10 min and sustained release of BN for 12 h). In vivo gamma scintigraphy proved that the optimized GFDDS could retain in the stomach with a prolonged gastric retention time (GRT) of 5 h, and the coating layer showed no side effect for gastric retention. The novel coated gastric floating drug-delivery system offers a new approach to enhance BN's absorption at its absorption site and the efficacy of both CET and BN.

A Three-Pulse Release Tablet for Amoxicillin: Preparation, Pharmacokinetic Study and Physiologically Based Pharmacokinetic Modeling.

PubMed

Li, Jin; Chai, Hongyu; Li, Yang; Chai, Xuyu; Zhao, Yan; Zhao, Yunfan; Tao, Tao; Xiang, Xiaoqiang

2016-01-01

Amoxicillin is a commonly used antibiotic which has a short half-life in human. The frequent administration of amoxicillin is often required to keep the plasma drug level in an effective range. The short dosing interval of amoxicillin could also cause some side effects and drug resistance, and impair its therapeutic efficacy and patients' compliance. Therefore, a three-pulse release tablet of amoxicillin is desired to generate sustained release in vivo, and thus to avoid the above mentioned disadvantages. The pulsatile release tablet consists of three pulsatile components: one immediate-release granule and two delayed release pellets, all containing amoxicillin. The preparation of a pulsatile release tablet of amoxicillin mainly includes wet granulation craft, extrusion/spheronization craft, pellet coating craft, mixing craft, tablet compression craft and film coating craft. Box-Behnken design, Scanning Electron Microscope and in vitro drug release test were used to help the optimization of formulations. A crossover pharmacokinetic study was performed to compare the pharmacokinetic profile of our in-house pulsatile tablet with that of commercial immediate release tablet. The pharmacokinetic profile of this pulse formulation was simulated by physiologically based pharmacokinetic (PBPK) model with the help of Simcyp®. Single factor experiments identify four important factors of the formulation, namely, coating weight of Eudragit L30 D-55 (X1), coating weight of AQOAT AS-HF (X2), the extrusion screen aperture (X3) and compression forces (X4). The interrelations of the four factors were uncovered by a Box-Behnken design to help to determine the optimal formulation. The immediate-release granule, two delayed release pellets, together with other excipients, namely, Avicel PH 102, colloidal silicon dioxide, polyplasdone and magnesium stearate were mixed, and compressed into tablets, which was subsequently coated with Opadry® film to produce pulsatile tablet of amoxicillin. In vitro release study firstly indicated a three-pulse release profile of the tablet. Later the pulse tablet was found to generate the sustained release of amoxicillin in beagle dogs. Furthermore, the Simcyp® software was used to simulate the in vivo concentration time curve model of the three-pulse release tablet for amoxicillin in both human and beagle dog. The prediction by PBPK model nicely fitted the observation in human and beagle dog. This study has demonstrated the interrelation of factors affecting the pulsatile formulation of amoxicillin using a Box-Behnken design. The three-pulse release tablets of amoxicillin were proven to generate pulsatile release in vitro and sustained release in vivo. This formulation was also found to extend the effective plasma concentration in human compared to the tablet of immediate release based on the simulation data by PBPK modeling. This study provides an example of using PBPK to guide the development of pulsatile dosage forms.

Pharmaceutical Product Lead Optimization for Better In vivo Bioequivalence Performance: A case study of Diclofenac Sodium Extended Release Matrix Tablets.

PubMed

Shahiwala, Aliasgar; Zarar, Aisha

2018-01-01

In order to prove the validity of a new formulation, a considerable amount of effort is required to study bioequivalence, which not only increases the burden of carrying out a number of bioequivalence studies but also eventually increases the cost of the optimization process. The aim of the present study was to develop sustained release matrix tablets containing diclofenac sodium using natural polymers and to demonstrate step by step process of product development till the prediction of in vivo marketed product equivalence of the developed product. Different batches of tablets were prepared by direct compression. In vitro drug release studies were performed as per USP. The drug release data were assessed using model-dependent, modelindependent and convolution approaches. Drug release profiles showed that extended release action were in the following order: Gum Tragacanth > Sodium Alginate > Gum Acacia. Amongst the different batches prepared, only F1 and F8 passed the USP criteria of drug release. Developed formulas were found to fit Higuchi kinetics model with Fickian (case I) diffusion-mediated release mechanism. Model- independent kinetics confirmed that total of four batches were passed depending on the similarity factors based on the comparison with the marketed Diclofenac. The results of in vivo predictive convolution model indicated that predicted AUC, Cmax and Tmax values for batch F8 were similar to that of marketed product. This study provides simple yet effective outline of pharmaceutical product development process that will minimize the formulation development trials and maximize the product success in bioequivalence studies. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Evolution of the treatment of attention-deficit/hyperactivity disorder in children: a review.

PubMed

Findling, Robert L

2008-05-01

Efficacious and well-tolerated medications are available for the treatment of attention-deficit/hyperactivity disorder (ADHD). Stimulants such as methylphenidate (MPH) and amphetamines are the most widely used medications approved by the US Food and Drug Administration for the treatment of ADHDin children. This article reviews the literature on the development and use of medications for the treatment of ADHD in children. A search of MEDLINE was conducted toidentify relevant studies and critical reviews on the treatment of ADHD in children. The main criteria for inclusion of a study were that it have a controlled design, enroll >100 subjects if a clinical trial and >20 subjects if a classroom study, assess symptoms with the most widely used scales and tests,and be published from 2000 to 2008.A few older pivotal studies were also included. Many studies have reported the long-term efficacy and tolerability of immediate-release formulations of MPH. The disadvantages of such formulations include the need for multiple daily dosing and a potential for abuse. Various extended-release formulations of MPH have been found effective in controlled studies enrolling large numbers of children with ADHD. The efficacy and tolerability of dexmethylphenidate, the active D-isomer of MPH, in an extended-release formulation have also been reported. An extended-release formulation of mixed amphetamine salts (MMAS-XR) that is dosed once daily has been found to be efficacious and well tolerated. The non-stimulant atomoxetine has been reported to be well tolerated and efficacious, although it may not be as effective as stimulants; this formulation is, however, less likely than stimulants to be associated with abuse and diversion. A recently approved prodrug stimulant, lisdexamfetamine dimesylate (LDX), was developed to provide a long duration of effect that is consistent throughout the day, with a reduced potential for abuse. In a placebo-controlled study in children with ADHD, less intersubject variability in T(max), C(max), and AUC from time zero to the last quantifiable concentration was seen in the 8 subjects who received LDX (percent coefficient of variation, 15.3, 20.3, and 21.6, respectively) compared with the 9 subjects who received MAS-XR (52.8, 44.0, and 42.8).In 2 clinical trials, significantly greater improvements in teacher and parent ratings of ADHD symptoms were seen with LDX compared with placebo (P<0.001).A study of the abuse potential of LDX evaluated subjective responses to the effects of oral LDX and immediate-release d-amphetamine in adults with a history of stimulant abuse. LDX was associated with a significantly lower abuse-related liking effect than d-aamphetamine (P = 0.039). Currently available treatments for ADHD in children are efficacious and well tolerated, but many of them are limited by the requirement for multiple daily dosing and abuse potential. LDX, a long-acting prodrug of d-amphetamine, has been reported to be effective and appears to overcome some of these limitations.

Development and validation of stability indicating method for the quantitative determination of venlafaxine hydrochloride in extended release formulation using high performance liquid chromatography

PubMed Central

Kaur, Jaspreet; Srinivasan, K. K.; Joseph, Alex; Gupta, Abhishek; Singh, Yogendra; Srinivas, Kona S.; Jain, Garima

2010-01-01

Objective: Venlafaxine,hydrochloride is a structurally novel phenethyl bicyclic antidepressant, and is usually categorized as a serotonin–norepinephrine reuptake inhibitor (SNRI) but it has been referred to as a serotonin–norepinephrine–dopamine reuptake inhibitor. It inhibits the reuptake of dopamine. Venlafaxine HCL is widely prescribed in the form of sustained release formulations. In the current article we are reporting the development and validation of a fast and simple stability indicating, isocratic high performance liquid chromatographic (HPLC) method for the determination of venlafaxine hydrochloride in sustained release formulations. Materials and Methods: The quantitative determination of venlafaxine hydrochloride was performed on a Kromasil C18 analytical column (250 × 4.6 mm i.d., 5 μm particle size) with 0.01 M phosphate buffer (pH 4.5): methanol (40: 60) as a mobile phase, at a flow rate of 1.0 ml/min. For HPLC methods, UV detection was made at 225 nm. Results: During method validation, parameters such as precision, linearity, accuracy, stability, limit of quantification and detection and specificity were evaluated, which remained within acceptable limits. Conclusions: The method has been successfully applied for the quantification and dissolution profiling of Venlafaxine HCL in sustained release formulation. The method presents a simple and reliable solution for the routine quantitative analysis of Venlafaxine HCL. PMID:21814426

Development of a CO2 -releasing coformulation based on starch, Saccharomyces cerevisiae and Beauveria bassiana attractive towards western corn rootworm larvae.

PubMed

Vemmer, Marina; Schumann, Mario; Beitzen-Heineke, Wilhelm; French, Bryan W; Vidal, Stefan; Patel, Anant V

2016-11-01

CO 2 is known as an attractant for many soil-dwelling pests. To implement an attract-and-kill strategy for soil pest control, CO 2 -emitting formulations need to be developed. The aim of the present work was to develop a slow-release bead system in order to bridge the gap between application and hatching of western corn rootworm larvae. We compared different Ca-alginate beads containing Saccharomyces cerevisiae for their potential to release CO 2 over a period of several weeks. The addition of starch improved CO 2 release, resulting in significantly higher CO 2 concentrations in soil for at least 4 weeks. The missing amylase activity was compensated for either by microorganisms present in the soil or by coencapsulation of Beauveria bassiana. Formulations containing S. cerevisiae, starch and B. bassiana were attractive for western corn rootworm larvae within the first 4 h following exposure; however, when considering the whole testing period, the maize root systems remained more attractive for the larvae. Coencapsulation of S. cerevisiae, starch and B. bassiana is a promising approach for the development of attractive formulations for soil applications. For biological control strategies, the attractiveness needs to be increased by phagostimuli to extend contact between larvae and the entomopathogenic fungus growing out of these formulations. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Physiologically Based Absorption Modeling to Design Extended-Release Clinical Products for an Ester Prodrug.

PubMed

Ding, Xuan; Day, Jeffrey S; Sperry, David C

2016-11-01

Absorption modeling has demonstrated its great value in modern drug product development due to its utility in understanding and predicting in vivo performance. In this case, we integrated physiologically based modeling in the development processes to effectively design extended-release (ER) clinical products for an ester prodrug LY545694. By simulating the trial results of immediate-release products, we delineated complex pharmacokinetics due to prodrug conversion and established an absorption model to describe the clinical observations. This model suggested the prodrug has optimal biopharmaceutical properties to warrant developing an ER product. Subsequently, we incorporated release profiles of prototype ER tablets into the absorption model to simulate the in vivo performance of these products observed in an exploratory trial. The models suggested that the absorption of these ER tablets was lower than the IR products because the extended release from the formulations prevented the drug from taking advantage of the optimal absorption window. Using these models, we formed a strategy to optimize the ER product to minimize the impact of the absorption window limitation. Accurate prediction of the performance of these optimized products by modeling was confirmed in a third clinical trial.

Controlled-release of Bacillus thurigiensis formulations encapsulated in light-resistant colloidosomal microcapsules for the management of lepidopteran pests of Brassica crops.

PubMed

Bashir, Oumar; Claverie, Jerome P; Lemoyne, Pierre; Vincent, Charles

2016-01-01

Bacillus thuringiensis ( B. t. ) based formulations have been widely used to control lepidopteran pests in agriculture and forestry. One of their weaknesses is their short residual activity when sprayed in the field. Using Pickering emulsions, mixtures of spores and crystals from three B. t. serovars were successfully encapsulated in colloïdosomal microparticles (50 μm) using innocuous chemicals (acrylic particles, sunflower oil, iron oxide nanoparticles, ethanol and water). A pH trigger mechanism was incorporated within the particles so that B. t. release occurred only at pH > 8.5 which corresponds to the midgut pH of the target pests. Laboratory assays performed on Trichoplusia ni ( T. ni ) larvae demonstrated that the microencapsulation process did not impair B. t. bioactivity. The best formulations were field-tested on three key lepidopteran pests that attack Brassica crops, i.e., the imported cabbageworm, the cabbage looper and the diamondback moth. After 12 days, the mean number of larvae was significantly lower in microencapsulated formulations than in a commercial B. t. formulation, and the effect of microencapsulated formulations was comparable to a chemical pesticide (lambda-cyhalothrin). Therefore, colloïdosomal microcapsule formulations successfully extend the bioactivity of B. t. for the management of lepidopteran pests of Brassica crops.

Formulation of Saudi Propolis into Biodegradable Chitosan Chips for Vital Pulpotomy.

PubMed

Balata, Gihan F; Abdelhady, Mohamed I S; Mahmoud, Ghada M; Matar, Moustafa A; Abd El-Latif, Amani N

2018-01-01

Propolis has been widely used to treat oral cavity disorders, such as endodontal and periodontal diseases and microbial infections. The study aimed at the formulation of commercial Saudi propolis into biodegradable chitosan chips and evaluation of its effectiveness as a pulpotomy agent. The standardization of 80% ethanolic propolis extract was performed regarding its total phenolic content, total flavonoid content, quantitative estimation of main polyphenolic constituents and antioxidant activity. Chitosan chips containing propolis extract were prepared by the solvent/ casting method. The investigated variables were % of chitosan polymer (2, 2.5 and 3%), % of plasticizer (1, 5 and 10%) and incorporation of different concentrations of hydroxypropyl methylcellulose (5, 10 and 20% of polymer weight). The chips were characterized for weight and thickness uniformity, content uniformity, pH, percentage moisture loss, swelling index, tensile strength and in vitro propolis release. The optimal propolis chip formulation was further investigated in dogs regarding the short term response of primary dental pulp to propolis chips compared with the most commonly used formocresol preparation. The prepared films were flexible and demonstrated satisfactory physicochemical characteristics. The optimal formulation showed an initial release of about 41.7% of the loaded propolis followed by a sustained release extended up to 7 days. The kinetics study demonstrated that propolis release was controlled by Fick´s diffusion. The optimal propolis chip formulation resulted in less pulpal inflammation compared to formocresol, and produced hard tissue formation in all specimens. Formulation of commercial Saudi propolis as a biodegradable chitosan chip is an effective alternative to the commercially available chemical agents for the treatment of vital pulpotomy. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Preparation and In Vitro/Ex Vivo Evaluation of Moxifloxacin-Loaded PLGA Nanosuspensions for Ophthalmic Application

PubMed Central

Mudgil, Meetali; Pawar, Pravin K.

2013-01-01

The aim of the present investigation was to prepare a colloidal ophthalmic formulation to improve the residence time of moxifloxacin. Moxifloxacin-loaded poly(dl-lactide-co-glycolide) (PLGA) nanosuspensions were prepared by using the solvent evaporation technique. The nanosuspensions were characterised physically by using different techniques like particle size, zeta potential, FTIR, DSC, and XRD analysis. In vitro and ex vivo studies of nanosuspensions were carried out using a modified USP dissolution apparatus and all-glass Franz diffusion cells, respectively. The antibacterial activities of the nanosuspension and marketed formulations were performed against S. aureus and P. aeroginosa. The moxifloxacin-loaded PLGA nanosuspensions showed uniform particle size, ranging between 164–490 nm with negative zeta potential for all batches. The percentage entrapment efficiency of the drug-loaded nano-suspension was found to be between 84.09 to 92.05%. In vitro drug release studies suggest that all of the formulations showed extended drug release profiles and follow Korsemeyer-Peppas release kinetics. In vitro corneal permeability was found to be comparable with that of the marketed formulation across isolated goat cornea, indicating the suitability of the nanosuspension formulation in the ophthalmic delivery of moxifloxacin. The optimised nano-suspension was found to be more active against S. aureus and P. aeruginosa compared to the marketed eye drops. PMID:23833723

Experience with an extended-release opioid formulation designed to reduce abuse liability in a community-based pain management clinic

PubMed Central

Rubino, Daniel

2011-01-01

Context With the growing public health concern over rising rates of opioid abuse, physicians have a responsibility to incorporate safeguards into their practice to minimize the potential for opioid misuse, abuse, and diversion. Patient-specific treatment regimens should include steps to monitor treatment success with regard to optimal pain management as well as inappropriate use of opioids and other substances. Opioid formulations designed to be less attractive for abuse are also being developed. While future studies are needed to determine the impact of such formulations in addressing the issue of opioid misuse in the community as a whole, the experience of practitioners who have utilized these formulations can highlight the practical steps to incorporate such formulations into the everyday patient-care setting. Purpose The purpose of this report is to describe experience in managing patients with chronic, moderate-to-severe pain using morphine sulfate and naltrexone hydrochloride extended release capsules (MS-sNT) (EMBEDA®, King Pharmaceuticals® Inc, Bristol, TN, which was acquired by Pfizer Inc, New York, NY, in March 2011), a formulation designed with features to deter abuse/misuse, in a community-based pain management clinic. Case presentations Case reports demonstrating a clinical management plan for assessment, initial interview procedures, explanation/discussion of proposed therapies, patients’ treatment goals, conversion to MS-sNT, and titration and treatment outcomes are provided. Results The management approach yielded successful outcomes including pain relief, improved quality of life, treatment satisfaction, and patient acceptance of a formulation designed to deter abuse/misuse. Discussion The cases presented demonstrate that the communication accompanying complete pretreatment assessment, goal-setting and expectations, and attention to individual patient needs can enable optimization of pain-related outcomes, resulting in improved quality of life for patients and fostering patient acceptance of formulations designed to help address opioid abuse/misuse issues in the community at large. PMID:22069367

Development of a novel osmotically driven drug delivery system for weakly basic drugs.

PubMed

Guthmann, C; Lipp, R; Wagner, T; Kranz, H

2008-06-01

The drug substance SAG/ZK has a short biological half-life and because of its weakly basic nature a strong pH-dependent solubility was observed. The aim of this study was to develop a controlled release (cr) multiple unit pellet formulation for SAG/ZK with pH-independent drug release. Pellets with a drug load of 60% were prepared by extrusion/spheronization followed by cr-film coating with an extended release polyvinyl acetate/polyvinyl pyrrolidone dispersion (Kollidon SR 30 D). To overcome the problem of pH-dependent drug release the pellets were then coated with a second layer of an enteric methacrylic acid and ethyl acrylate copolymer (Kollicoat MAE 30 DP). To increase the drug release rates from the double layered cr-pellets different osmotically active ionic (sodium and potassium chloride) and nonionic (sucrose) additives were incorporated into the pellet core. Drug release studies were performed in media of different osmotic pressure to clarify the main release mechanism. Extended release coated pellets of SAG/ZK demonstrated pH-dependent drug release. Applying a second enteric coat on top of the extended release film coat failed in order to achieve pH-independent drug release. Already low enteric polymer levels on top of the extended release coated pellets decreased drug release rates at pH 1 drastically, thus resulting in a reversal of the pH-dependency (faster release at pH 6.8 than in 0.1N HCl). The addition of osmotically active ingredients (sodium and potassium chloride, and sucrose) increased the imbibing of aqueous fluids into the pellet cores thus providing a saturated drug solution inside the beads and increasing drug concentration gradients. In addition, for these pellets increased formation of pores and cracks in the polymer coating was observed. Hence drug release rates from double layered beads increased significantly. Therefore, pH-independent osmotically driven SAG/ZK release was achieved from pellets containing osmotically active ingredients and coated with an extended and enteric polymer. In contrast, with increasing osmotic pressure of the dissolution medium the in vitro drug release rates decreased significantly.

Microsponges based novel drug delivery system for augmented arthritis therapy

PubMed Central

Osmani, Riyaz Ali M.; Aloorkar, Nagesh H.; Ingale, Dipti J.; Kulkarni, Parthasarathi K.; Hani, Umme; Bhosale, Rohit R.; Jayachandra Dev, Dandasi

2015-01-01

The motive behind present work was to formulate and evaluate gel containing microsponges of diclofenac diethylamine to provide prolonged release for proficient arthritis therapy. Quasi-emulsion solvent diffusion method was implied using Eudragit RS-100 and microsponges with varied drug–polymer ratios were prepared. For the sake of optimization, diverse factors affecting microparticles physical properties were too investigated. Microsponges were characterized by SEM, DSC, FT-IR, XRPD and particle size analysis, and evaluated for morphology, drug loading, in vitro drug release and ex vivo diffusion as well. There were no chemical interactions between drug and polymers used as revealed by compatibility studies outcomes. The drug polymer ratio reflected notable effect on drug content, encapsulation efficiency and particle size. SEM results revealed spherical microsponges with porous surface, and had 7.21 μm mean particle size. The microsponges were then incorporated in gel; which exhibited viscous modulus along with pseudoplastic behavior. In vitro drug release results depicted that microsponges with 1:2 drug–polymer ratio were more efficient to give extended drug release of 75.88% at the end of 8 h; while conventional formulation get exhausted incredibly earlier by releasing 81.11% drug at the end of 4 h only. Thus the formulated microsponge-based gel of diclofenac diethylamine would be a promising alternative to conventional therapy for safer and efficient treatment of arthritis and musculoskeletal disorders. PMID:26594124

Microsponges based novel drug delivery system for augmented arthritis therapy.

PubMed

Osmani, Riyaz Ali M; Aloorkar, Nagesh H; Ingale, Dipti J; Kulkarni, Parthasarathi K; Hani, Umme; Bhosale, Rohit R; Jayachandra Dev, Dandasi

2015-10-01

The motive behind present work was to formulate and evaluate gel containing microsponges of diclofenac diethylamine to provide prolonged release for proficient arthritis therapy. Quasi-emulsion solvent diffusion method was implied using Eudragit RS-100 and microsponges with varied drug-polymer ratios were prepared. For the sake of optimization, diverse factors affecting microparticles physical properties were too investigated. Microsponges were characterized by SEM, DSC, FT-IR, XRPD and particle size analysis, and evaluated for morphology, drug loading, in vitro drug release and ex vivo diffusion as well. There were no chemical interactions between drug and polymers used as revealed by compatibility studies outcomes. The drug polymer ratio reflected notable effect on drug content, encapsulation efficiency and particle size. SEM results revealed spherical microsponges with porous surface, and had 7.21 μm mean particle size. The microsponges were then incorporated in gel; which exhibited viscous modulus along with pseudoplastic behavior. In vitro drug release results depicted that microsponges with 1:2 drug-polymer ratio were more efficient to give extended drug release of 75.88% at the end of 8 h; while conventional formulation get exhausted incredibly earlier by releasing 81.11% drug at the end of 4 h only. Thus the formulated microsponge-based gel of diclofenac diethylamine would be a promising alternative to conventional therapy for safer and efficient treatment of arthritis and musculoskeletal disorders.

A Three-Pulse Release Tablet for Amoxicillin: Preparation, Pharmacokinetic Study and Physiologically Based Pharmacokinetic Modeling

PubMed Central

Li, Jin; Chai, Hongyu; Li, Yang; Chai, Xuyu; Zhao, Yan; Zhao, Yunfan; Tao, Tao; Xiang, Xiaoqiang

2016-01-01

Background Amoxicillin is a commonly used antibiotic which has a short half-life in human. The frequent administration of amoxicillin is often required to keep the plasma drug level in an effective range. The short dosing interval of amoxicillin could also cause some side effects and drug resistance, and impair its therapeutic efficacy and patients’ compliance. Therefore, a three-pulse release tablet of amoxicillin is desired to generate sustained release in vivo, and thus to avoid the above mentioned disadvantages. Methods The pulsatile release tablet consists of three pulsatile components: one immediate-release granule and two delayed release pellets, all containing amoxicillin. The preparation of a pulsatile release tablet of amoxicillin mainly includes wet granulation craft, extrusion/spheronization craft, pellet coating craft, mixing craft, tablet compression craft and film coating craft. Box–Behnken design, Scanning Electron Microscope and in vitro drug release test were used to help the optimization of formulations. A crossover pharmacokinetic study was performed to compare the pharmacokinetic profile of our in-house pulsatile tablet with that of commercial immediate release tablet. The pharmacokinetic profile of this pulse formulation was simulated by physiologically based pharmacokinetic (PBPK) model with the help of Simcyp®. Results and Discussion Single factor experiments identify four important factors of the formulation, namely, coating weight of Eudragit L30 D-55 (X1), coating weight of AQOAT AS-HF (X2), the extrusion screen aperture (X3) and compression forces (X4). The interrelations of the four factors were uncovered by a Box–Behnken design to help to determine the optimal formulation. The immediate-release granule, two delayed release pellets, together with other excipients, namely, Avicel PH 102, colloidal silicon dioxide, polyplasdone and magnesium stearate were mixed, and compressed into tablets, which was subsequently coated with Opadry® film to produce pulsatile tablet of amoxicillin. In vitro release study firstly indicated a three-pulse release profile of the tablet. Later the pulse tablet was found to generate the sustained release of amoxicillin in beagle dogs. Furthermore, the Simcyp® software was used to simulate the in vivo concentration time curve model of the three-pulse release tablet for amoxicillin in both human and beagle dog. The prediction by PBPK model nicely fitted the observation in human and beagle dog. Conclusions This study has demonstrated the interrelation of factors affecting the pulsatile formulation of amoxicillin using a Box–Behnken design. The three-pulse release tablets of amoxicillin were proven to generate pulsatile release in vitro and sustained release in vivo. This formulation was also found to extend the effective plasma concentration in human compared to the tablet of immediate release based on the simulation data by PBPK modeling. This study provides an example of using PBPK to guide the development of pulsatile dosage forms. PMID:27479702

Formulation and evaluation of Bacillus coagulans-loaded hypromellose mucoadhesive microspheres.

PubMed

Alli, Sk Md Athar

2011-01-01

Development of a novel delivery system has been attempted to deliver viable probiotic cells into the gut for a prolonged period of time while maintaining high numbers of viable cells within the formulation throughout the shelf-life of the product and during the gastrointestinal transit. Core mucoadhesive microspheres of Bacillus coagulans were developed employing several grades of hypromellose, a mucoadhesive polymer, following coacervation and phase separation technique and were subsequently enteric-coated with hypromellose phthalate. Microspheres were evaluated for percent yield; entrapment efficiency; in vitro swelling; surface morphology; particle size, size distribution, and zeta potential; flow property, mucoadhesion property by the ex vivo mucoadhesive strength test and the in vitro wash off test; in vitro release profile and release kinetic; in vivo probiotic activity; and stability. The values for the kinetic constant and regression coefficient of model-dependent approaches and the difference factor (f(1)), the similarity factor (f(2)), and the Rescigno index (ξ(1) and ξ(2)) of model independent approaches were determined for comparing in vitro dissolution profiles. Freeze dried B. coagulans cells were successfully formulated as enteric-coated mucoadhesive microspheres with satisfactory physical structure and yield. The viability of B. coagulans was maintained in the simulated gastric conditions and during processing; in simulated intestinal conditions exhibiting mucoadhesion, and controlling and extending the viable cell release following zero-order; and was satisfactorily stable at room temperature. Test results depict statistically significant effects of the hypromellose grade and their concentration on the performance and release profile of formulations.

Formulation and evaluation of Bacillus coagulans-loaded hypromellose mucoadhesive microspheres

PubMed Central

Alli, Sk Md Athar

2011-01-01

Development of a novel delivery system has been attempted to deliver viable probiotic cells into the gut for a prolonged period of time while maintaining high numbers of viable cells within the formulation throughout the shelf-life of the product and during the gastrointestinal transit. Core mucoadhesive microspheres of Bacillus coagulans were developed employing several grades of hypromellose, a mucoadhesive polymer, following coacervation and phase separation technique and were subsequently enteric-coated with hypromellose phthalate. Microspheres were evaluated for percent yield; entrapment efficiency; in vitro swelling; surface morphology; particle size, size distribution, and zeta potential; flow property, mucoadhesion property by the ex vivo mucoadhesive strength test and the in vitro wash off test; in vitro release profile and release kinetic; in vivo probiotic activity; and stability. The values for the kinetic constant and regression coefficient of model-dependent approaches and the difference factor (f1), the similarity factor (f2), and the Rescigno index (ξ1 and ξ2) of model independent approaches were determined for comparing in vitro dissolution profiles. Freeze dried B. coagulans cells were successfully formulated as enteric-coated mucoadhesive microspheres with satisfactory physical structure and yield. The viability of B. coagulans was maintained in the simulated gastric conditions and during processing; in simulated intestinal conditions exhibiting mucoadhesion, and controlling and extending the viable cell release following zero-order; and was satisfactorily stable at room temperature. Test results depict statistically significant effects of the hypromellose grade and their concentration on the performance and release profile of formulations. PMID:21674019

Pharmacokinetics of an oral extended-release formulation of doxycycline hyclate containing acrylic acid and polymethacrylate in dogs.

PubMed

Ruiz, Sara Melisa Arciniegas; Olvera, Lilia Gutiérrez; Chacón, Sara del Carmen Caballero; Estrada, Dinorah Vargas

2015-04-01

To determine the pharmacokinetics of doxycycline hyclate administered orally in the form of experimental formulations with different proportions of acrylic acid-polymethacrylate-based matrices. 30 healthy adult dogs. In a crossover study, dogs were randomly assigned (in groups of 10) to receive a single oral dose (20 mg/kg) of doxycycline hyclate without excipients (control) or extended-release formulations (ERFs) containing doxycycline, acrylic acid polymer, and polymethacrylate in the following proportions: 1:0.5:0.0075 (ERF1) or 1:1:0.015 (ERF2). Serum concentrations of doxycycline were determined for pharmacokinetic analysis before and at several intervals after each treatment. Following oral administration to the study dogs, each ERF resulted in therapeutic serum doxycycline concentrations for 48 hours, whereas the control treatment resulted in therapeutic serum doxycycline concentrations for only 24 hours. All pharmacokinetic parameters for ERF1 and ERF2 were significantly different; however, findings for ERF1 did not differ significantly from those for the control treatment. Results indicated that both ERFs containing doxycycline, acrylic acid polymer, and polymethacrylate had an adequate pharmacokinetic-pharmacodynamic relationship for a time-dependent drug and a longer release time than doxycycline alone following oral administration in dogs. Given the minimum effective serum doxycycline concentration of 0.26 μg/mL, a dose interval of 48 hours can be achieved for each tested ERF. This minimum inhibitory concentration has the potential to be effective against several susceptible bacteria involved in important infections in dogs. Treatment of dogs with either ERF may have several benefits over treatment with doxycycline alone.

Urinary excretion of ciprofloxacin after administration of extended release tablets in healthy volunteers. Swellable drug-polyelectrolyte matrix versus bilayer tablets.

PubMed

Guzmán, M L; Romañuk, C B; Sanchez, M F; Luciani Giacobbe, L C; Alarcón-Ramirez, L P; Battistini, F D; Alovero, F L; Jimenez-Kairuz, A F; Manzo, R H; Olivera, María Eugenia

2018-02-01

This paper builds on a previous paper in which new ciprofloxacin extended-release tablets were developed based on a ciprofloxacin-based swellable drug polyelectrolyte matrix (SDPM-CIP). The matrix contains a molecular dispersion of ciprofloxacin ionically bonded to the acidic groups of carbomer, forming the polyelectrolyte-drug complex CB-CIP. This formulation showed that the release profile of the ciprofloxacin bilayer tablets currently commercialised can be achieved with a simpler strategy. Thus, since ciprofloxacin urine concentrations are associated with the clinical cure of urinary tract infections, the goal of this work was to compare the urinary excretion of SDPM-CIP tablets with those of the CIPRO XR® bilayer tablets. A batch of SDPM-CIP tablets was manufactured by the wet granulation method and the CB-CIP ionic complex was obtained in situ. Fasted healthy volunteers received a single oral dose of 500 mg ciprofloxacin of either formulation in a randomised crossover study. Urinary concentrations were assessed by HPLC at intervals up to 36 h. Pharmacokinetic parameters (rate of urinary excretion, maximum urine excretion rate, t max , area under the curve, amount and percentage of the ciprofloxacin dose excreted in urine) showed no statistical differences between both formulations at any of the time intervals of collection. The processing conditions to obtain SDPM-CIP tablets are easy to scale up since they involve technology currently employed in the pharmaceutical industry and the process is less challenging to implement. In addition, SDPM-CIP tablets met pharmacopoeial quality specifications.

Development and evaluation of natural gum-based extended release matrix tablets of two model drugs of different water solubilities by direct compression.

PubMed

Ofori-Kwakye, Kwabena; Mfoafo, Kwadwo Amanor; Kipo, Samuel Lugrie; Kuntworbe, Noble; Boakye-Gyasi, Mariam El

2016-01-01

The study was aimed at developing extended release matrix tablets of poorly water-soluble diclofenac sodium and highly water-soluble metformin hydrochloride by direct compression using cashew gum, xanthan gum and hydroxypropylmethylcellulose (HPMC) as release retardants. The suitability of light grade cashew gum as a direct compression excipient was studied using the SeDeM Diagram Expert System. Thirteen tablet formulations of diclofenac sodium (∼100 mg) and metformin hydrochloride (∼200 mg) were prepared with varying amounts of cashew gum, xanthan gum and HPMC by direct compression. The flow properties of blended powders and the uniformity of weight, crushing strength, friability, swelling index and drug content of compressed tablets were determined. In vitro drug release studies of the matrix tablets were conducted in phosphate buffer (diclofenac: pH 7.4; metformin: pH 6.8) and the kinetics of drug release was determined by fitting the release data to five kinetic models. Cashew gum was found to be suitable for direct compression, having a good compressibility index (ICG) value of 5.173. The diclofenac and metformin matrix tablets produced generally possessed fairly good physical properties. Tablet swelling and drug release in aqueous medium were dependent on the type and amount of release retarding polymer and the solubility of drug used. Extended release of diclofenac (∼24 h) and metformin (∼8-12 h) from the matrix tablets in aqueous medium was achieved using various blends of the polymers. Drug release from diclofenac tablets fitted zero order, first order or Higuchi model while release from metformin tablets followed Higuchi or Hixson-Crowell model. The mechanism of release of the two drugs was mostly through Fickian diffusion and anomalous non-Fickian diffusion. The study has demonstrated the potential of blended hydrophilic polymers in the design and optimization of extended release matrix tablets for soluble and poorly soluble drugs by direct compression.

Formulation, characterization and pharmacokinetics of praziquantel-loaded hydrogenated castor oil solid lipid nanoparticles.

PubMed

Xie, Shuyu; Pan, Baoliang; Wang, Ming; Zhu, Luyan; Wang, Fenghua; Dong, Zhao; Wang, Xiaofang; Zhou, WenZhong

2010-07-01

The purpose of this study was to formulate praziquantel (PZQ)-loaded hydrogenated castor oil (HCO) solid lipid nanoparticles (SLN) to enhance the bioavailability and prolong the systemic circulation of the drug. PZQ was encapsulated into HCO nanoparticles by a hot homogenization and ultrasonication method. The physicochemical characteristics of SLN were investigated by optical microscope, scanning electron microscopy and photon correlation spectroscopy. Pharmacokinetics were studied after oral, subcutaneous and intramuscular administration in mice. The diameter, polydispersivity index, zeta potential, encapsulation efficiency and loading capacity of the nanoparticles were 344.0 +/- 15.1 nm, 0.31 +/- 0.08, -16.7 +/- 0.5 mV, 62.17 +/- 6.53% and 12.43 +/- 1.31%, respectively. In vitro release of PZQ-loaded HCO-SLN exhibited an initial burst release followed by a sustained release. SLN increased the bioavailability of PZQ by 14.9-, 16.1- and 2.6-fold, and extended the mean residence time of the drug from 7.6, 6.6 and 8.2 to 95.9, 151.6 and 48.2 h after oral, subcutaneous and intramuscular administration, respectively. The PZQ-loaded HCO-SLN could be a promising formulation to enhance the pharmacological activity of PZQ.

Single-dose evaluation of safety, tolerability and pharmacokinetics of newly formulated hydromorphone immediate-release and hydrophilic matrix extended-release tablets in healthy Japanese subjects without co-administration of an opioid antagonist.

PubMed

Toyama, Kaoru; Uchida, Naoki; Ishizuka, Hitoshi; Sambe, Takehiko; Kobayashi, Shinichi

2015-09-01

This single dose, open-label study investigated the safety, tolerability and pharmacokinetics of single oral doses of newly formulated immediate-release (IR) and hydrophilic matrix extended-release (ER) hydromorphone tablets in healthy Japanese subjects without co-administration of an opioid antagonist under fasting and fed conditions. Plasma and urinary concentrations of hydromorphone and metabolites were measured by liquid-chromatography tandem mass-spectroscopy. Following administration of the ER tablet, plasma concentrations of hydromorphone slowly increased with a median tmax of 5.0 h and the Cmax decreased to 37% of the IR tablet, while the AUC0-inf was comparable with that of the IR tablet when administered at the same dose. The degree of fluctuation in the plasma concentration for the ER tablet was much lower than that of the IR tablet and certain levels of plasma concentrations were maintained after 24 h of ER dosing. The AUC0-inf and Cmax increased with food for both IR and ER tablets. The AUC0-inf of hydromorphone-3-glucoside was one-tenth of that of hydromorphone-3-glucuronide. A single oral administration of the hydromorphone tablets would be well-tolerated in healthy Japanese subjects despite a lack of co-administration of an opioid antagonist and the newly developed ER hydromorphone tablets may have the appropriate PK characteristics for once-daily dosing. © 2015, The American College of Clinical Pharmacology.

Lipids bearing extruded-spheronized pellets for extended release of poorly soluble antiemetic agent-Meclizine HCl.

PubMed

Qazi, Faaiza; Shoaib, Muhammad Harris; Yousuf, Rabia Ismail; Nasiri, Muhammad Iqbal; Ahmed, Kamran; Ahmad, Mansoor

2017-04-12

Antiemetic agent Meclizine HCl, widely prescribed in vertigo, is available only in immediate release dosage forms. The approved therapeutic dose and shorter elimination half-life make Meclizine HCl a potential candidate to be formulated in extended release dosage form. This study was aimed to develop extended release Meclizine HCl pellets by extrusion spheronization using natural and synthetic lipids. Influence of lipid type, drug/lipid ratio and combinations of different lipids on drug release and sphericity of pellets were evaluated. Thirty two formulations were prepared with four different lipids, Glyceryl monostearate (Geleol ® ), Glyceryl palmitostearate (Precirol ® ), Glyceryl behenate (Compritol ® ) and Carnauba wax, utilized either alone or in combinations of drug/lipid ratio of 1:0.5-1:3. Dissolution studies were performed at variable pH and release kinetics were analyzed. Fourier transform infrared spectroscopy was conducted and no drug lipid interaction was found. Sphericity indicated by shape factor (e R ) varied with type and concentration of lipids: Geleol ® (e R  = 0.891-0.997), Precirol ® (e R  = 0.611-0.743), Compritol ® (e R  = 0.665-0.729) and Carnauba wax (e R  = 0.499-0.551). Highly spherical pellets were obtained with Geleol ® (Aspect ratio = 1.005-1.052) whereas irregularly shaped pellets were formed using Carnauba wax (Aspect ratio = 1.153-1.309). Drug release was effectively controlled by three different combinations of lipids: (i) Geleol ® and Compritol ® , (ii) Geleol ® and Carnauba wax and (iii) Geleol ® , Compritol ® and Carnauba wax. Scanning electron microscopy of Compritol ® pellets showed smooth surface with pores, whereas, irregular rough surface with hollow depressions was observed in Carnauba wax pellets. Energy dispersive spectroscopy indicated elemental composition of lipid matrix pellets. Kinetics of (i) Geleol ® and Compritol ® pellets, explained by Korsmeyer-Peppas (R 2  = 0.978-0.993) indicated non-Fickian diffusion (n = 0.519-0.597). Combinations of (ii) Geleol ® and Carnauba wax and (iii) Geleol ® , Compritol ® and Carnauba wax pellets followed Zero-order (R 2  = 0.991-0.995). Similarity test was performed using combination of Geleol ® and Compritol ® (i) as a reference. Matrices for the extended release of Meclizine HCl from extruded-spheronized pellets were successfully formed by using three lipids (Geleol ® , Compritol ® and Carnauba wax) in different combinations. The encapsulated pellets of Meclizine HCl can be effectively used for treatment of motion sickness, nausea and vertigo for extended period of time.

Influence of the Formulation Parameters on the Particle Size and Encapsulation Efficiency of Resveratrol in PLA and PLA-PEG Blend Nanoparticles: A Factorial Design.

PubMed

Lindner, Gabriela da Rocha; Dalmolin, Luciana Facco; Khalil, Najeh Maissar; Mainardes, Rubiana Mara

2015-12-01

Polymeric nanoparticles are colloidal systems that promote protection and modification of physicochemical characteristics of a drug and that also ensure controlled and extended drug release. This paper reports a 2(3) factorial design study to optimize poly(lactide) (PLA) and poly(lactide)-polyethylene glycol (PLA-PEG) blend nanoparticles containing resveratrol (RVT) for prolonged release. The independent variables analyzed were solvent composition, surfactant concentration and ratio of aqueous to organic phase (two levels each factor). Mean particle size and RVT encapsulation efficiency were set as the dependent variables. The selected optimized parameters were set as organic phase comprised of a mixture of dichloromethane and ethyl acetate, 1% of surfactant polyvinyl alcohol and a 3:1 ratio of aqueous to organic phase, for both PLA and PLA-PEG blend nanoparticles. This formulation originated nanoparticles with size of 228 ± 10 nm and 185 ± 70 nm and RVT encapsulation efficiency of 82 ± 10% and 76 ± 7% for PLA and PLA-PEG blend nanoparticles, respectively. The in vitro release study showed a biphasic pattern with prolonged RVT release and PEG did not influence the RVT release. The in vitro release data were in favor of Higuchi-diffusion kinetics for both nanoformulations and the Kossmeyer-Peppas coefficient indicated that anomalous transport was the main release mechanism of RVT. PLA and PLA-PEG blend nanoparticles produced with single emulsion-solvent evaporation technology were found to be a promising approach for the incorporation of RVT and promoted its controlled release. The factorial design is a tool of great value in choosing formulations with optimized parameters.

Glipizide. A review of the pharmacoeconomic implications of the extended-release formulation in type 2 diabetes mellitus.

PubMed

Foster, R H; Plosker, G L

2000-09-01

Glipizide is a second generation sulphonylurea agent that is available in a Gastrointestinal Therapeutic System (GITS) extended-release formulation. Glipizide GITS provides more stable plasma drug concentrations than the immediate-release formulation and the once-daily regimen may optimise patient compliance. In patients with type 2 diabetes mellitus, glipizide GITS is at least as effective as the immediate-release formulation of glipizide in providing glycaemic control, and may have a greater effect on fasting plasma glucose levels. Any therapeutic advantage over other antidiabetic agents remains to be established, but in a preliminary report (n = 40) glipizide GITS provided better glycaemic control and produced less fasting insulinaemia than glibenclamide (glyburide). The incidence of hypoglycaemic symptoms with glipizide GITS is low (< or = 3%). Quality of life was improved compared with baseline after 12 weeks' treatment with glipizide GITS 5 to 20 mg/day plus diet in a US double-blind, placebo-controlled trial in 569 patients with type 2 diabetes mellitus. Hyperglycaemic symptom-related distress decreased with glipizide GITS treatment, while hypoglycaemic symptom-related distress was not significantly increased compared with placebo plus diet. Quality of life during glipizide GITS treatment has not been compared with that during treatment with other antidiabetic agents. Monthly productivity losses related to absenteeism were $US91 (1995 values) per patient lower in the glipizide GITS group compared with the placebo group in the latter prospective study. Productivity parameters improved slightly or did not change significantly in the glipizide GITS group, but deteriorated in the placebo group. Differences in direct healthcare costs between groups were small and not comprehensively reported. Glipizide GITS was the least costly strategy for first-line therapy in a US cost-of-treatment model of the first 3 years after diagnosis of type 2 diabetes mellitus. The total per-patient cost was $US4867 with glipizide GITS, $US5196 with metformin and $US5249 with acarbose (1996/1997 values). Monthly drug acquisition costs were lower, and glycosylated haemoglobin levels and patient compliance were improved, after formulary conversion from the immediate-release to the GITS formulation of glipizide in a US single-hospital retrospective analysis. Glipizide GITS produced better cost outcomes than metformin and acarbose in a model of 3 years' treatment of type 2 diabetes mellitus. Glipizide GITS had pharmacoeconomic and quality of life advantages over diet alone in the short term, but more clinically relevant comparisons with other antidiabetic agents are needed. There are limitations to the present data, but the available pharmacoeconomic data have been favourable for glipizide GITS.

Biorelevant in-vitro performance testing of orally administered dosage forms.

PubMed

Reppas, Christos; Vertzoni, Maria

2012-07-01

This review focuses on the evolution and current status of biorelevant media and hydrodynamics, and discusses the usefulness of biorelevant performance testing in the evaluation of specific dosage form related lumenal processes. During the last 15 years our knowledge of the gastrointestinal environment (including the lower gut) has improved dramatically and biorelevant media composition and, to a lesser extent, biorelevant hydrodynamics, have been refined. Biorelevant dissolution/release testing is useful for the evaluation of formulation and food effects on plasma levels after administration of immediate release dosage forms containing low solubility compounds and after administration of extended release products. Lumenal disintegration times of immediate release dosage forms and the bile acid sequestering activity of resins in the lumen can also be successfully forecasted with biorelevant in vitro testing. Biorelevant in-vitro performance testing is an important tool for evaluating intralumenal dosage form performance. Since the formulation of new active pharmaceutical ingredients for oral delivery is more challenging than ever before, efforts to improve the predictability of biorelevant tests are expected to continue. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

Conversion from twice-daily tacrolimus to once-daily extended release tacrolimus (LCPT): the phase III randomized MELT trial.

PubMed

Bunnapradist, S; Ciechanowski, K; West-Thielke, P; Mulgaonkar, S; Rostaing, L; Vasudev, B; Budde, K

2013-03-01

Phase III noninferiority trial examining efficacy and safety of converting stable renal transplant recipients from twice-daily tacrolimus to a novel extended-release once-daily tacrolimus formulation (LCPT) with a controlled agglomeration technology. Controls maintained tacrolimus twice daily. The primary efficacy endpoint was proportion of patients with efficacy failures (death, graft failure, locally read biopsy-proven acute rejection [BPAR], or loss to follow-up) within 12 months. Starting LCPT dose was 30% lower (15% for blacks) than preconversion tacrolimus dose; target trough levels were 4-15 ng/mL. A total of 326 patients were randomized; the mITT population (n = 162 each group) was similar demographically in the two groups. Mean daily dose of LCPT was significantly (p < 0.0001) lower than preconversion tacrolimus dose at each visit; mean trough levels between groups were similar. There were four efficacy failures in each group; safety outcomes were similar between groups. Frequency of premature study drug discontinuation was LCPT: 12% versus tacrolimus twice daily: 5% (p = 0.028). LCPT demonstrated noninferiority to tacrolimus twice daily in efficacy failure rates. LCPT may offer a safe and effective alternative for converting patients to a once-daily formulation. Compared to currently available tacrolimus formulation, LCPT requires lower doses to achieve target trough levels. © Copyright 2012 The American Society of Transplantation and the American Society of Transplant Surgeons.

In vivo assessment of parenteral formulations of oligo(3-hydroxybutyric Acid) conjugates with the model compound Ibuprofen.

PubMed

Stasiak, Pawel; Sznitowska, Malgorzata; Ehrhardt, Carsten; Luczyk-Juzwa, Maria; Grieb, Pawel

2010-12-01

Polymer-drug conjugates have gained significant attention as pro-drugs releasing an active substance as a result of enzymatic hydrolysis in physiological environment. In this study, a conjugate of 3-hydroxybutyric acid oligomers with a carboxylic acid group-bearing model drug (ibuprofen) was evaluated in vivo as a potential pro-drug for parenteral administration. Two different formulations, an oily solution and an o/w emulsion were prepared and administered intramuscularly (IM) to rabbits in a dose corresponding to 40 mg of ibuprofen/kilogramme. The concentration of ibuprofen in blood plasma was analysed by HPLC, following solid-phase extraction and using indometacin as internal standard (detection limit, 0.05 microg/ml). No significant differences in the pharmacokinetic parameters (C (max), T (max), AUC) were observed between the two tested formulations of the 3-hydroxybutyric acid conjugate. In comparison to the non-conjugated drug in oily solution, the relative bioavailability of ibuprofen conjugates from oily solution, and o/w emulsion was reduced to 17% and 10%, respectively. The 3-hydroxybutyric acid formulations released the active substance over a significantly extended period of time with ibuprofen still being detectable 24 h post-injection, whereas the free compound was almost completely eliminated as early as 6 h after administration. The conjugates remained in a muscle tissue for a prolonged time and can hence be considered as sustained release systems for carboxylic acid derivatives.

Voluntary Running-Wheel Activity, Arterial Blood Gases, and Thermal Antinociception in Rats after 3 Buprenorphine Formulations

PubMed Central

Johnson, Rebecca A

2016-01-01

Buprenorphine HCl (BUP) is a μ-opioid agonist used in laboratory rodents. New formulations of buprenorphine (for example, sustained-released buprenorphine [BUP SR], extended-release buprenorphine [BUP ER]) have been developed to extend the analgesic duration. In a crossover design, 8 adult rats were injected subcutaneously with either BUP, BUP SR, BUP ER, or saline, after which voluntary running-wheel activity, arterial blood gases, and thermal withdrawal latency were assessed. Wheel running was decreased at 24 h compared with baseline in all treatment groups but returned to baseline by 48 h. Arterial pH, HCO3–, and CO2 were not changed between groups or over time. However, arterial oxygen was lower than baseline in the BUP (–8 ± 2 mm Hg), BUP SR (–7 ± 1 mm Hg), and BUP ER (–17 ± 2 mm Hg) groups compared with saline controls (3 ± 2 mm Hg); the BUP ER group showed the greatest decrease when all time points were combined. BUP increased the withdrawal latency at 1 h (15% ± 3%), whereas BUP ER increased latencies at 4, 8, 12, and 48 h (35% ± 11%, 21% ± 7%, 26% ± 7%, and 22% ± 9%, respectively) and BUP SR prolonged latencies at 24, 48, and 72 h (15% ± 6%, 18% ± 5%, and 20% ± 8%, respectively). The duration of thermal analgesia varied between buprenorphine formulations, but all 3 formulations reduced voluntary-running activity at 24 h after injection and might cause hypoxemia in normal adult rats. PMID:27177564

Preparation, characterization and pharmacokinetics of enrofloxacin-loaded solid lipid nanoparticles: influences of fatty acids.

PubMed

Xie, Shuyu; Zhu, Luyan; Dong, Zhao; Wang, Xiaofang; Wang, Yan; Li, Xihe; Zhou, WenZhong

2011-04-01

Enrofloxacin-loaded solid lipid nanoparticles (SLN) were prepared using fatty acids (tetradecanoic acid, palmitic acid, stearic acid) as lipid matrix by hot homogenization and ultrasonication method. The effect of fatty acids on the characteristics and pharmacokinetics of the SLN were investigated. The results showed that the encapsulation efficiency and loading capacity of nanoparticles varied with fatty acids in the order of stearic acid>palmitic acid>tetradecanoic acid. Furthermore, stearic acid-SLN had larger particle size, bigger polydispersity index (PDI) and higher zeta potential compared with the other two fatty acid formulated SLN. The SLN showed sustained releases in vitro and the released enrofloxacin had the same antibacterial activity as that of the native enrofloxacin. Although in vitro release exhibited similar patterns, within 24 h the releasing rates of the three formulations were significantly different (tetradecanoic acid-SLN>palmitic acid-SLN>stearic acid-SLN). Pharmacokinetic study after a single dose of intramuscular administration to mice demonstrated that tetradecanoic acid-SLN, palmitic acid-SLN, and stearic acid-SLN increased the bioavailability by 6.79, 3.56 and 2.39 folds, and extended the mean residence time (MRT) of the drug from 10.60 h to 180.36, 46.26 and 19.09 h, respectively. These results suggest that the enrofloxacin-fatty acid SLN are promising formulations for sustained release while fatty acids had significant influences on the characteristics and performances of the SLN. Copyright © 2010 Elsevier B.V. All rights reserved.

Diazepam-loaded solid lipid nanoparticles: design and characterization.

PubMed

Abdelbary, Ghada; Fahmy, Rania H

2009-01-01

The aim of the present study was to investigate the feasibility of the inclusion of a water-insoluble drug (diazepam, DZ) into solid lipid nanoparticles (SLNs), which offer combined advantages of rapid onset and prolonged release of the drug. This work also describes a new approach to prepare suppositories containing DZ-loaded SLN dispersions, as potential drug carrier for the rectal route. Modified high-shear homogenization and ultrasound techniques were employed to prepare SLNs. The effect of incorporation of different concentrations of Compritol ATO 888 or Imwitor 900K and Poloxamer 188 or Tween 80 was investigated. Results showed that varying the type or concentration of lipid matrix or surfactant had a noticeable influence on the entrapment efficiencies, particle size, and release profiles of prepared SLNs. Differential scanning calorimetry and X-ray diffraction measurements showed that the majority of SLNs possessed less ordered arrangements of crystals than the corresponding bulk lipids, which was favorable for increasing the drug loading capacity. Transmission electron microscopy and laser diffractometry studies revealed that the prepared nanoparticles were round and homogeneous and 60% of the formulations were less than 500 nm. Additionally, SLN formulations showed significant (P < 0.05) prolonged release than DZ solution. The subsequent step encompassed the preparation and evaluation of SLN-based suppositories utilizing SLN formulations that illustrated optimal release profiles. The in vitro release of DZ from the suppositories prepared using DZ-loaded SLN dispersions (equivalent to 2 mg DZ) was significantly (P < 0.05) extended compared to suppositories containing 2 mg DZ free drug.

Change in formulation and its potential clinical and pharmacoeconomic value: example of extended release venlafaxine.

PubMed

Haeusler, Jean-Marc C

2009-05-01

The 505(b)(2) route of a New Drug Application (NDA) allows published literature or previous FDA findings of safety and effectiveness to be used for approval. Such drugs are not therapeutic equivalents (i.e., generics); instead, the FDA calls them pharmaceutical alternatives. A recent example is the approval of venlafaxine extended-release (ER) tablets, developed as an alternative to the widely used ER venlafaxine capsules. The smaller size of the tablets makes them available in a 225-mg strength, which is the approved maximum dose in major depressive disorder after up-titration but currently unavailable in the capsule formulation, requiring patients on this dose to take two or three capsules; in addition, the tablets are priced at a discount compared to the capsules. The objective of this review was to investigate how the change in formulation of ER venlafaxine from capsules to tablets, as an example of such a change in formulation, can potentially offer value to patients and society, with a specific focus on pill burden, drug cost, and adherence. Based on a MEDLINE literature search, the pertinent literature was reviewed in a qualitative manner. Simplifying treatment regimens, reducing pill burden, and reducing drug costs are recognized strategies for improving adherence. This can be of particular benefit in psychiatric illness because of high rates of nonadherence to treatment. Lack of adherence may negatively impact treatment outcomes and increase disease cost. As such, the ER venlafaxine tablets have the potential to reduce pill burden, improve adherence and outcomes, and reduce cost to patients and society. These preliminary findings need to be corroborated with more primary research and a systematic review of formulation changes. A change in formulation of established therapies such as ER venlafaxine has the potential to offer clinical and pharmacoeconomic benefits to patients and society.

Drug delivery systems with modified release for systemic and biophase bioavailability.

PubMed

Leucuta, Sorin E

2012-11-01

This review describes the most important new generations of pharmaceutical systems: medicines with extended release, controlled release pharmaceutical systems, pharmaceutical systems for the targeted delivery of drug substances. The latest advances and approaches for delivering small molecular weight drugs and other biologically active agents such as proteins and nucleic acids require novel delivery technologies, the success of a drug being many times dependent on the delivery method. All these dosage forms are qualitatively superior to medicines with immediate release, in that they ensure optimal drug concentrations depending on specific demands of different disease particularities of the body. Drug delivery of these pharmaceutical formulations has the benefit of improving product efficacy and safety, as well as patient convenience and compliance. This paper describes the biopharmaceutical, pharmacokinetic, pharmacologic and technological principles in the design of drug delivery systems with modified release as well as the formulation criteria of prolonged and controlled release drug delivery systems. The paper presents pharmaceutical prolonged and controlled release dosage forms intended for different routes of administration: oral, ocular, transdermal, parenteral, pulmonary, mucoadhesive, but also orally fast dissolving tablets, gastroretentive drug delivery systems, colon-specific drug delivery systems, pulsatile drug delivery systems and carrier or ligand mediated transport for site specific or receptor drug targeting. Specific technologies are given on the dosage forms with modified release as well as examples of marketed products, and current research in these areas.

Efficacy and safety of extended- versus immediate-release pramipexole in Japanese patients with advanced and L-dopa-undertreated Parkinson disease: a double-blind, randomized trial.

PubMed

Mizuno, Yoshikuni; Yamamoto, Mitsutoshi; Kuno, Sadako; Hasegawa, Kazuko; Hattori, Nobutaka; Kagimura, Tatsuro; Sarashina, Akiko; Rascol, Olivier; Schapira, Anthony H V; Barone, Paolo; Hauser, Robert A; Poewe, Werner

2012-01-01

To compare the efficacy, safety, tolerability, and trough plasma levels of pramipexole extended-release (ER) and pramipexole immediate-release (IR), and to assess the effects of overnight switching from an IR to an ER formulation, in L-dopa-treated patients with Parkinson disease (PD). After a 1- to 4-week screening/enrollment, 112 patients who had exhibited L-dopa-related problems or were receiving suboptimal L-dopa dosage were randomized in double-blind, double-dummy, 1:1 fashion to pramipexole ER once daily or pramipexole IR 2 to 3 times daily for 12 weeks, both titrated to a maximum daily dose of 4.5 mg. Successful completers of double-blind treatment were switched to open-label pramipexole ER, beginning with a 4-week dose-adjustment phase. Among the double-blind treatment patients (n = 56 in each group), Unified Parkinson's Disease Rating Scale Parts II+III total scores decreased significantly from baseline and to a similar degree with pramipexole ER and IR formulations. In each group, 47 double-blind patients (83.9%) reported adverse events (AEs), requiring withdrawal of 3 ER patients (5.4%) and 2 IR patients (3.6%). Trough plasma levels at steady state (at the same doses and dose-normalized concentrations) were also similar with both formulations. Among open-label treatment patients (n = 53 from IR to ER), 83% were successfully switched (no worsening of PD symptoms) to pramipexole ER. In L-dopa-treated patients, pramipexole ER and pramipexole IR demonstrated similar efficacy, safety, tolerability, and trough plasma levels. Patients can be safely switched overnight from pramipexole IR to pramipexole ER with no impact on efficacy.

Assessment of Tapentadol API Abuse Liability With the Researched Abuse, Diversion and Addiction-Related Surveillance System.

PubMed

Vosburg, Suzanne K; Severtson, S Geoffrey; Dart, Richard C; Cicero, Theodore J; Kurtz, Steven P; Parrino, Mark W; Green, Jody L

2018-04-01

Tapentadol, a Schedule II opioid with a combination of µ-opioid activity and norepinephrine reuptake inhibition, is used for the management of moderate to severe acute and chronic pain. Its dual mechanism of action is thought to reduce opioid-related side effects that can complicate pain management. Since approval, tapentadol has been tracked across multiple outcomes suggesting abuse liability, and a pattern of relatively low, although not absent, abuse liability has been found. This retrospective cohort study further details the abuse liability of tapentadol as an active pharmaceutical ingredient (API) when immediate-release as well as extended-release formulations were on the market together (fourth quarter of 2011 to second quarter of 2016). Tapentadol (API) was compared with tramadol, hydrocodone, morphine, oxycodone, hydromorphone, and oxymorphone across Poison Center, Drug Diversion, and Treatment Center Programs Combined data streams from the Researched Abuse, Diversion and Addiction-Related Surveillance system. Findings suggest the public health burden related to tapentadol to date is low, but present. Event rates of abuse per population-level denominators were significantly lower than all other opioids examined. However, when adjusted for drug availability, event rates of abuse were lower than most Schedule II opioids studied, but were not the lowest. Disentangling these 2 sets of findings further by examining various opioid formulations, such as extended-release and the role of abuse-deterrent formulations, is warranted. This article presents the results from an examination of tapentadol API across the Researched Abuse, Diversion and Addiction-Related Surveillance System: a broad and carefully designed postmarketing mosaic. Data to date from Poison Center, Drug Diversion, and Treatment Centers combined suggest a low, but present public health burden related to tapentadol. Copyright © 2018. Published by Elsevier Inc.

The cost effectiveness of long-acting/extended-release antipsychotics for the treatment of schizophrenia: a systematic review of economic evaluations.

PubMed

Achilla, Evanthia; McCrone, Paul

2013-04-01

Antipsychotic medication is the mainstay of treatment in schizophrenia. Long-acting medication has potential advantages over daily medication in improving compliance and thus reducing hospitalization and relapse rates. The high acquisition and administration costs of such formulations raise the need for pharmacoeconomic evaluation. The aim of this article is to provide a comprehensive review of the available evidence on the cost effectiveness of long-acting/extended-release antipsychotic medication and critically appraise the strength of evidence reported in the studies from a methodological viewpoint. Relevant studies were identified by searching five electronic databases: PsycINFO, MEDLINE, EMBASE, the NHS Economic Evaluation Database and the Health Technology Assessment database (HTA). Search terms included, but were not limited to, 'long-acting injection', 'economic evaluation', 'cost-effectiveness' and 'cost-utility'. No limits were applied for publication dates and language. Full economic evaluations on long-acting/extended-release antipsychotics were eligible for inclusion. Observational studies and clinical trials were also checked for cost-effectiveness information. Conference abstracts and poster presentations on the cost effectiveness of long-acting antipsychotics were excluded. Thirty-two percent of identified studies met the selection criteria. Pertinent abstracts were reviewed independently by two reviewers. Relevant studies underwent data extraction by one reviewer and were checked by a second, with any discrepancies being clarified during consensus meetings. Eligible studies were assessed for methodological quality using the quality checklist for economic studies recommended by the NICE guideline on interventions in the treatment and management of schizophrenia. After applying the selection criteria, the final sample consisted of 28 studies. The majority of studies demonstrated that risperidone long-acting injection, relative to oral or other long-acting injectable drugs, was associated with cost savings and additional clinical benefits and was the dominant strategy in terms of cost effectiveness. However, olanzapine in either oral or long-acting injectable formulation dominated risperidone long-acting injection in a Slovenian and a US study. Furthermore, in two UK studies, the use of long-acting risperidone increased the hospitalization days and overall healthcare costs, relative to other atypical or typical long-acting antipsychotics. Finally, paliperidone extended-release was the most cost-effective treatment compared with atypical oral or typical long-acting formulations. From a methodological viewpoint, most studies employed decision analytic models, presented results using average cost-effectiveness ratios and conducted comprehensive sensitivity analyses to test the robustness of the results. Variations in study methodologies restrict consistent and direct comparisons across countries. The exclusion of a large body of potentially relevant conference abstracts as well as some papers being unobtainable may have increased the likelihood of misrepresenting the overall cost effectiveness of long-acting antipsychotics. Finally, the review process was restricted to qualitative assessment rather than a quantitative synthesis of results, which could provide more robust conclusions. Atypical long-acting (especially risperidone)/extended-release antipsychotic medication is likely to be a cost-effective, first-line strategy for managing schizophrenia, compared with long-acting haloperidol and other oral or depot formulations, irrespective of country-specific differences. However, inconsistencies in study methodologies and in the reporting of study findings suggest caution needs to be applied in interpreting these findings.

Abuse and Diversion of Immediate Release Opioid Analgesics as Compared to Extended Release Formulations in the United States

PubMed Central

Iwanicki, Janetta L.; Severtson, S. Geoff; McDaniel, Heather; Rosenblum, Andrew; Fong, Chunki; Cicero, Theodore J.; Ellis, Matthew S.; Kurtz, Steven P.; Buttram, Mance E.; Dart, Richard C.

2016-01-01

Background Therapeutic use and abuse of prescription opioids in the United States increased substantially between 1990 and 2010. The Centers for Disease Control estimated deaths related to pharmaceutical opioids reached nearly 19,000 in 2014. Of prescription opioids sold, 10% are extended release (ER) and 90% immediate release (IR). However, most regulations and interventions have focused on decreasing ER abuse. Our objective was to compare rates of abuse and diversion of ER and IR opioid analgesics over time using multiple surveillance programs. Methods Rates of abuse and diversion of ER and IR opioid formulations were compared using data from four surveillance programs in the Researched Abuse, Diversion and Addiction Related Surveillance (RADARS®) System. Data were evaluated from 2009 through 2015, and Poisson regression used to compare IR and ER opioid cases over time. Results From 2009 to 2015, IR opioids were prescribed at a rate 12 to 16 times higher than ER. In the Poison Center Program, population-adjusted rates of Intentional Abuse for IR were 4.6 fold higher than ER opioids (p<0.001). In the Drug Diversion Program, population-adjusted rates of diversion were 6.1 fold higher for IR than ER opioids (p<0.001). In the Opioid Treatment Program, population-adjusted rates of endorsements for abuse were 1.6 fold higher for IR opioids than ER (p = 0.002). In the Survey of Key Informants' Patients Program, population-adjusted rates of endorsements for abuse were 1.5 fold higher for IR opioids than ER (p<0.001). Conclusions Between 2009 and 2015, IR opioids were prescribed at a much higher rate than ER opioids. Results from four surveillance programs show population-adjusted rates of prescription opioid abuse were markedly higher for IR than ER medications. For the greatest public health benefit, future interventions to decrease prescription opioid abuse should focus on both IR and ER formulations. PMID:27936038

Abuse and Diversion of Immediate Release Opioid Analgesics as Compared to Extended Release Formulations in the United States.

PubMed

Iwanicki, Janetta L; Severtson, S Geoff; McDaniel, Heather; Rosenblum, Andrew; Fong, Chunki; Cicero, Theodore J; Ellis, Matthew S; Kurtz, Steven P; Buttram, Mance E; Dart, Richard C

2016-01-01

Therapeutic use and abuse of prescription opioids in the United States increased substantially between 1990 and 2010. The Centers for Disease Control estimated deaths related to pharmaceutical opioids reached nearly 19,000 in 2014. Of prescription opioids sold, 10% are extended release (ER) and 90% immediate release (IR). However, most regulations and interventions have focused on decreasing ER abuse. Our objective was to compare rates of abuse and diversion of ER and IR opioid analgesics over time using multiple surveillance programs. Rates of abuse and diversion of ER and IR opioid formulations were compared using data from four surveillance programs in the Researched Abuse, Diversion and Addiction Related Surveillance (RADARS®) System. Data were evaluated from 2009 through 2015, and Poisson regression used to compare IR and ER opioid cases over time. From 2009 to 2015, IR opioids were prescribed at a rate 12 to 16 times higher than ER. In the Poison Center Program, population-adjusted rates of Intentional Abuse for IR were 4.6 fold higher than ER opioids (p<0.001). In the Drug Diversion Program, population-adjusted rates of diversion were 6.1 fold higher for IR than ER opioids (p<0.001). In the Opioid Treatment Program, population-adjusted rates of endorsements for abuse were 1.6 fold higher for IR opioids than ER (p = 0.002). In the Survey of Key Informants' Patients Program, population-adjusted rates of endorsements for abuse were 1.5 fold higher for IR opioids than ER (p<0.001). Between 2009 and 2015, IR opioids were prescribed at a much higher rate than ER opioids. Results from four surveillance programs show population-adjusted rates of prescription opioid abuse were markedly higher for IR than ER medications. For the greatest public health benefit, future interventions to decrease prescription opioid abuse should focus on both IR and ER formulations.

Bilayer Tablet Formulation of Metformin HCl and Acarbose: A Novel Approach To Control Diabetes.

PubMed

Tiwari, Ruchi; Gupta, Ankita; Joshi, Meenakshi; Tiwari, Gaurav

2014-01-01

The present investigation studied a novel bilayer tablet having an extended release system of metformin HCl with Eudragit RS 100 and RL 100 and an immediate release system of acarbose with polyvinylpyrrolidone K30 (PVP K30) and polyethylene glycol 6000 (PEG 6000) in different ratios using solvent evaporation and cogrinding techniques. Solid dispersions (SDs) were characterized by Fourier transform infrared spectroscopy (FT-IR), differential scanning calorimetry (DSC), powder x-ray diffractometry (XRD), scanning electron microscopy (SEM), as well as by content uniformity, in vitro dissolution studies, and release kinetics. The selected SD system was subjected to bilayer tablet preparation by direct compression. Compressed tablets were evaluated for drug content, weight variation, friability, hardness, and thickness, and they underwent in vitro dissolution studies. The progressive disappearance of IR, x-ray, and thermotropic drug signals in SDs and physical mixtures were related to increasing amount of polymer. SEM studies suggested the homogenous dispersion of drug in polymers. FT-IR studies confirmed the formation of hydrogen bonding between drug and polymer. All tablet formulations showed compliance with pharmacopoeial standards. The formulations gave an initial burst effect to provide the loading dose of the drug followed by extended release for 12 h (Higuchi model via a non-Fickian diffusion controlled release mechanism). Stability studies conducted for the optimized formulation did not show any change in physical properties, drug content, or in vitro drug release. The goal of diabetes therapy today is to achieve and maintain as near normal glycemia as possible to prevent the long-term microvascular and macrovascular complications of elevated blood glucose levels. Oral therapeutic options for the treatment of type 2 diabetes mellitus, until recently, have been severely limited. Metformin, a biguanide, targets additional mechanisms of hyperglycemia by inhibiting hepatic glucose production and enhancing peripheral glucose uptake and thereby reducing insulin resistance; acarbose reversibly bind to pancreatic alpha-amylase and membrane-bound intestinal alpha-glucoside hydrolases. These enzymes inhibit hydrolysis of complex starches to oligosaccharides in the lumen of the small intestine and hydrolysis of oligosaccharides, trisaccharides, and disaccharides to glucose and other monosaccharides in the brush border of the small intestine. The two agents were found to have a remarkable effect on glycemic control. In the present investigation a bilayer tablet was prepared in which one layer gives instant action against diabetes and another layer maintain concentration of drug in plasma for longer periods.

Repellent effects of Melaleuca alternifolia (tea tree) oil against cattle tick larvae (Rhipicephalus australis) when formulated as emulsions and in β-cyclodextrin inclusion complexes.

PubMed

Yim, Wei Tsun; Bhandari, Bhesh; Jackson, Louise; James, Peter

2016-07-30

Rhipicephalus australis (formerly Boophilus microplus) is a one host tick responsible for major economic loss in tropical and subtropical cattle production enterprises. Control is largely dependent on the application of acaricides but resistance has developed to most currently registered chemical groups. Repellent compounds that prevent initial attachment of tick larvae offer a potential alternative to control with chemical toxicants. The repellent effects of Melaleuca alternifolia oil (TTO) emulsions and two β-cyclodextrin complex formulations, a slow release form (SR) and a modified faster release form (FR), were examined in a series of laboratory studies. Emulsions containing 4% and 5% TTO applied to cattle hair in laboratory studies completely repelled ascending tick larvae for 24h whereas 2% and 3% formulations provided 80% protection. At 48h, 5% TTO provided 78% repellency but lower concentrations repelled less than 60% of larvae. In a study conducted over 15 days, 3% TTO emulsion applied to cattle hair provided close to 100% repellency for 2 days, but then protection fell to 23% by day 15. The FR formulation gave significantly greater repellency than the emulsion and the SR formulation from day 3 until the end of the study (P<0.05), providing almost complete repellency at day 3 (99.5%), then decreasing over the period of the study to 49% repellency at day 15. Proof of concept is established for the use of appropriately designed controlled-release formulations to extend the period of repellency provided by TTO against R. australis larvae. Copyright © 2016 Elsevier B.V. All rights reserved.

On demand manufacturing of patient-specific liquid capsules via co-ordinated 3D printing and liquid dispensing.

PubMed

Okwuosa, Tochukwu C; Soares, Cindy; Gollwitzer, Verena; Habashy, Rober; Timmins, Peter; Alhnan, Mohamed A

2018-06-15

A method for the production of liquid capsules with the potential of modifying drug dose and release is presented. For the first time, the co-ordinated use of fused deposition modelling (FDM), 3D printing and liquid dispensing to fabricate individualised dosage form on demand in a fully automated fashion has been demonstrated. Polymethacrylate shells (Eudragit EPO and RL) for immediate and extended release were fabricated using FDM 3D printing and simultaneously filled using a computer-controlled liquid dispenser loaded with model drug solution (theophylline) or suspension (dipyridamole). The impact of printing modes: simultaneous shell printing and filling (single-phase) or sequential 3D printing of shell bottom, filling and shell cap (multi-phase), nozzle size, syringe volume, and shell structure has been reported. The use of shell thickness of 1.6 mm, and concentric architecture allowed successful containment of liquid core whilst maintaining the release properties of the 3D printed liquid capsule. The linear relationship between the theoretical and the actual volumes from the dispenser reflected its potential for accurate dosing (R 2  = 0.9985). Modifying the shell thickness of Eudragit RL capsule allowed a controlled extended drug release without the need for formulation change. Owing to its low cost and versatility, this approach can be adapted to wide spectrum of liquid formulations such as small and large molecule solutions and obviate the need for compatibility with the high temperature of FDM 3D printing process. In a clinical setting, health care staff will be able to instantly manufacture in small volumes liquid capsules with individualised dose contents and release pattern in response to specific patient's needs. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of extended release dosage forms using non-uniform drug distribution techniques.

PubMed

Huang, Kuo-Kuang; Wang, Da-Peng; Meng, Chung-Ling

2002-05-01

Development of an extended release oral dosage form for nifedipine using the non-uniform drug distribution matrix method was conducted. The process conducted in a fluid bed processing unit was optimized by controlling the concentration gradient of nifedipine in the coating solution and the spray rate applied to the non-pareil beads. The concentration of nifedipine in the coating was controlled by instantaneous dilutions of coating solution with polymer dispersion transported from another reservoir into the coating solution at a controlled rate. The USP dissolution method equipped with paddles at 100 rpm in 0.1 N hydrochloric acid solution maintained at 37 degrees C was used for the evaluation of release rate characteristics. Results indicated that (1) an increase in the ethyl cellulose content in the coated beads decreased the nifedipine release rate, (2) incorporation of water-soluble sucrose into the formulation increased the release rate of nifedipine, and (3) adjustment of the spray coating solution and the transport rate of polymer dispersion could achieve a dosage form with a zero-order release rate. Since zero-order release rate and constant plasma concentration were achieved in this study using the non-uniform drug distribution technique, further studies to determine in vivo/in vitro correlation with various non-uniform drug distribution dosage forms will be conducted.

Release of 5-Aminosalicylic Acid (5-ASA) from Mesalamine Formulations at Various pH Levels.

PubMed

Abinusawa, Adeyinka; Tenjarla, Srini

2015-05-01

Oral formulations of 5-aminosalicylic acid (5-ASA) for treatment of ulcerative colitis have been developed to minimize absorption prior to the drug reaching the colon. In this study, we investigate the release of 5-ASA from available oral mesalamine formulations in physiologically relevant pH conditions. Release of 5-ASA from 6 mesalamine formulations (APRISO®, Salix Pharmaceuticals, Inc., USA; ASACOL® MR, Procter & Gamble Pharmaceuticals UK Ltd.; ASACOL® HD, Procter & Gamble Pharmaceuticals, USA; MEZAVANT XL®, Shire US Inc.; PENTASA®, Ferring Pharmaceuticals, Ltd., UK; SALOFALK®, Dr. Falk Pharma UK Ltd.) was evaluated using United States Pharmacopeia apparatus I and II at pH values of 1.0 (2 h), 6.0 (1 h), and 6.8 (8 h). Dissolution profiles were determined for each formulation, respectively. Of the tested formulations, only the PENTASA formulation demonstrated release of 5-ASA at pH 1.0 (48%), with 56% cumulative release after exposure to pH 6.0 and 92% 5-ASA release after 6-8 h at pH 6.8. No other mesalamine formulation showed >1% drug release at pH 1.0. The APRISO formulation revealed 36% 5-ASA release at pH 6.0, with 100% release after 3 h at pH 6.8. The SALOFALK formulation revealed 11% 5-ASA release at pH 6.0, with 100% release after 1 h at pH 6.8. No 5-ASA was released by the ASACOL MR, ASACOL HD, and MEZAVANT XL formulations at pH 6.0. At pH 6.8, the ASACOL MR and ASACOL HD formulations exhibited complete release of 5-ASA after 4 and 2 h, respectively, and the MEZAVANT XL formulation demonstrated complete 5-ASA release over 6-7 h. 5-Aminosalicylic acid release profiles were variable among various commercially available formulations. Shire Development LLC.

Insomnia: Zolpidem Extended-Release for the Treatment of Sleep Induction and Sleep Maintenance Symptoms

PubMed Central

Doghramji, Paul P.

2007-01-01

Insomnia impairs daytime functioning or causes clinically significant daytime distress. The consequences of insomnia, if left untreated, may contribute to the risks of developing additional serious conditions, such as psychiatric illness, cardiovascular disease, or metabolic issues. Furthermore, some comorbidities associated with insomnia may be bidirectional in their causality because psychiatric and other medical problems can increase the risk for insomnia. Regardless of the serious consequences of inadequately treated insomnia, clinicians often do not inquire into their patients' sleep habits, and patients, in turn, are not forthcoming with details of their sleep difficulties. The continuing education of physicians and patients with regard to insomnia and currently available therapies for the treatment of insomnia is, therefore, essential. Insomnia may present as either a difficulty falling asleep, difficulty maintaining sleep, or waking too early without being able to return to sleep. Furthermore, these symptoms often change over time in an unpredictable manner. Therefore, when considering a sleep medication, one with efficacy for the treatment of multiple insomnia symptoms is recommended. A modified-release formulation of zolpidem, zolpidem extended-release, has been approved for the treatment of insomnia characterized by both difficulty in falling asleep and maintaining sleep. Here, we review studies supporting the use of zolpidem extended-release in the treatment of sleep-onset and sleep maintenance difficulties. PMID:17435620

A simple and rapid approach to evaluate the in vitro in vivo role of release controlling agent ethyl cellulose ether derivative polymer.

PubMed

Akhlaq, Muhammad; Khan, Gul Majid; Jan, Syed Umer; Wahab, Abdul; Hussain, Abid; Nawaz, Asif; Abdelkader, Hamdy

2014-11-01

Diclofenac sodium (DCL-Na) conventional oral tablets exhibit serious side effects when given for a longer period leading to noncompliance. Controlled release matrix tablets of diclofenac sodium were formulated using simple blending (F-1), solvent evaporation (F-2) and co-precipitation techniques (F-3). Ethocel® Standard 7 FP Premium Polymer (15%) was used as a release controlling agent. Drug release study was conducted in 7.4 pH phosphate buffer solutions as dissolution medium in vitro. Pharmacokinetic parameters were evaluated using albino rabbits. Solvent evaporation technique was found to be the best release controlling technique thereby prolonging the release rate up to 24 hours. Accelerated stability studies of the optimized test formulation (F-2) did not show any significant change (p<0.05) in the physicochemical characteristics and release rate when stored for six months. A simple and rapid method was developed for DCL-Na active moiety using HPLC-UV at 276nm. The optimized test tablets (F-2) significantly (p<0.05) exhibited peaks plasma concentration (cmax=237.66±1.98) and extended the peak time (tmax=4.63±0.24). Good in-vitro in vivo correlation was found (R(2)=0.9883) against drug absorption and drug release. The study showed that once-daily controlled release matrix tablets of DCL-Na were successfully developed using Ethocel® Standard 7 FP Premium.

A randomized crossover study to assess the pharmacokinetics of a novel amphetamine extended-release orally disintegrating tablet in healthy adults.

PubMed

Stark, Jeffrey G; Engelking, Dorothy; McMahen, Russ; Sikes, Carolyn

2016-09-01

In this pharmacokinetic (PK) study in healthy adults, we sought to: (1) compare the PK properties of a novel amphetamine extended-release orally disintegrating tablet formulation (Adzenys XR-ODT™ [AMP XR-ODT]) to a reference extended-release mixed amphetamine salts (MAS ER) formulation and (2) assess the effect of food on AMP XR-ODT. Forty-two adults were enrolled in a single-dose, open-label, 3-period, 3-treatment, randomized crossover study and received an 18.8-mg dose of AMP XR-ODT (fasted or fed) or equivalent dose (30 mg) of MAS ER (fasted). Plasma samples were analyzed for d-and l-amphetamine. Maximum plasma concentration (Cmax), time to maximum plasma concentration (Tmax), elimination half-life (T1/2), area under the concentration-time curve from time zero to last quantifiable concentration (AUClast), from time zero to infinity (AUCinf), relevant partial AUCs, and weight-normalized clearance (CL/F/kg) were assessed. The PK parameters were compared across treatments using an ANOVA. Safety was also assessed. A total of 39 adults completed this study. The geometric mean ratios (90% confidence interval [CI]) for AMP XR-ODT/MAS ER Cmax, AUC5-last, AUClast, and AUCinf were within 80%-125% for both d-and l-amphetamine. The 90% CIs for AUC0-5 were slightly below the 80%-125% range. When AMP XR-ODT was administered with food, there was a slight decrease in the d-and l-amphetamine Cmax and approximately a 2-hour delay in Tmax. The most common adverse events reported (>5% of participants) were dry mouth, palpitations, nausea, dizziness, headache, anxiety, and nasal congestion. AMP XR-ODT displayed a PK profile similar to MAS ER, and no clinically relevant food effect was observed.

Extended release local anesthetic agents in a postoperative arthritic pain model.

PubMed

Ickowicz, Diana E; Golovanevski, Ludmila; Haze, Amir; Domb, Abraham J; Weiniger, Carolyn F

2014-01-01

Local anesthetics play an important role in postoperative pain management in orthopedic joint procedures. The aim of this study was to determine the effect of an intraoperative extra-articular injection of poly(DL-lactic acid co castor oil 3:7), p(DLLA:CO) 3:7 loaded with 15% bupivacaine, for postoperative analgesia following knee arthroplasty. Prolonged release local anesthetic formulation was synthesized by mixing p(DLLA:CO) 3:7 with bupivacaine base. Under anesthesia, the knee joint of Sprague-Dawley rats was exposed, a hole drilled in the femoral trochlea. 0.2 mL of either 15% polymer-bupivacaine formulation or plain bupivacaine (control) was injected locally and compared with a nonsurgery control group. Mechanical hyperalgesia was determined by counting the vocalizations and leg withdrawal after joint squeezing. Behavioral assessments over a day postoperative period revealed a reduction in rearing and ambulation in an open-field apparatus in animals of both experimental groups compared with the nonsurgery control. The vocalizations during the hyperalgesia test increased compared with the control at 24 h. At 48 h, 3.667 ± 0.5138, p = 0.0076 vocalizations were recorded for the plain bupivacaine group versus 1.417 ± 0.5138, p < 0.0001 in the 15% polymer-bupivacaine formulation. Bupivacaine encapsulated in p(DLLA:CO) 3:7 extended the duration of the analgesia compared with plain drug in rats and could represent effective postoperative analgesic in orthopedic joint procedures. © 2013 Wiley Periodicals, Inc. and the American Pharmacists Association.

Comparative in vitro activity of a pharmacokinetically enhanced oral formulation of amoxicillin/clavulanic acid (2000/125 mg twice daily) against 9172 respiratory isolates collected worldwide in 2000.

PubMed

Koeth, Laura M; Jacobs, Michael R; Good, Caryn E; Bajaksouzian, Saralee; Windau, Anne; Jakielaszek, Charles; Saunders, Kay A

2004-11-01

A new, pharmacokinetically enhanced, oral formulation of amoxicillin/clavulanic acid has been developed to overcome resistance in the major bacterial respiratory pathogen Streptococcus pneumoniae, while maintaining excellent activity against Haemophilus influenzae and Moraxella catarrhalis, including beta-lactamase producing strains. This study was conducted to provide in vitro susceptibility data for amoxicillin/clavulanic acid and 16 comparator agents against the key respiratory tract pathogens. Susceptibility testing was performed on 9172 isolates collected from 95 centers in North America, Europe, Australia, and Hong Kong by broth microdilution MIC determination, according to NCCLS methods, using amoxicillin/clavulanic acid and 16 comparator antimicrobial agents. Results were interpreted according to NCCLS breakpoints and pharmacokinetic/pharmacodynamic (PK/PD) breakpoints based on oral dosing regimens. Overall, 93.5% of Streptococcus pneumoniae isolates were susceptible to amoxicillin/clavulanic acid at the current susceptible breakpoint of < or =2 microg/mL and 97.3% at the PK/PD susceptible breakpoint of < or =4 microg/mL for the extended release formulation. Proportions of isolates that were penicillin intermediate and resistant were 13% and 16.5%, respectively, while 25% were macrolide resistant and 21.8% trimethoprim/sulfamethoxazole resistant. 21.9% of Haemophilus influenzae were beta-lactamase producers and 16.8% trimethoprim/sulfamethoxazole resistant, >99% of isolates were susceptible to amoxicillin/clavulanic acid, cefixime, ciprofloxacin and levofloxacin at NCCLS breakpoints. The most active agents against Moraxella catarrhalis were amoxicillin/clavulanic acid, macrolides, cefixime, fluoroquinolones, and doxycycline. Overall, 13% of Streptococcus pyogenes were resistant to macrolides. The extended release formulation of amoxicillin/clavulanic acid has potential for empiric use against many respiratory tract infections worldwide due to its activity against species resistant to many agents currently in use.

Fabrication, characterization, and evaluation of microsponge delivery system for facilitated fungal therapy

PubMed Central

Moin, Afrasim; Deb, Tamal K.; Osmani, Riyaz Ali M.; Bhosale, Rohit R.; Hani, Umme

2016-01-01

Objective: The rationale behind present research vocation was to develop and investigate a novel microsponge based gel as a topical carrier for the prolonged release and cutaneous drug deposition of fluconazole (FLZ); destined for facilitated fungal therapy. Materials and Methods: Microsponges were prepared using quasi-emulsion solvent diffusion method using Eudragit S-100. In the direction of optimization, the effect of formulation variables (drug-polymer ratio and amount of emulsifier) and diverse factors affecting physical characteristics of microsponge were investigated as well. Fabricated microsponges were characterized by differential scanning calorimetry, Fourier transform-infrared, scanning electron microscopy (SEM), particle size analysis, and also evaluated for drug content, encapsulation efficiency, in vitro drug release and in vitro antifungal activity. Results: Compatibility studies results reflected no sign of any chemical interaction between the drug and polymers used. Whereas, varied drug-polymer ratios and emulsifier concentration indicated significant effect on production yield, drug content, encapsulation efficiency, particle size and drug release. Spherical microsponges with a porous surface and 29.327 ± 0.31 μm mean particle size were evident from SEM micrographs. In vitro release outcomes, from microsponge loaded gels depicted that F1 formulation was more efficient to give extended drug release of 85.38% at the end of 8 h, while conventional formulation by releasing 83.17% of drug got exhausted incredibly earlier at the end of 4 h merely. Moreover, microsponge gels demonstrated substantial spreadability and extrudability along with promising antifungal activity. Conclusions: Fabricated microsponges would be impending pharmaceutical topical carriers of FLZ and a leading alternative to conventional therapy for efficient, safe and facilitated eradication of fungal infections. PMID:27057125

Regenerated cellulose capsules for controlled drug delivery: Part III. Developing a fabrication method and evaluating extemporaneous utility for controlled-release.

PubMed

Bhatt, Bhavik; Kumar, Vijay

2016-08-25

In this article, we describe a method to utilize cellulose dissolved in dimethyl sulfoxide and paraformaldehyde solvent system to fabricate two-piece regenerated cellulose hard shell capsules for their potential use as an oral controlled drug delivery a priori vehicle. A systematic evaluation of solution rheology as well as resulting capsule mechanical, visual and thermal analysis was performed to develop a suitable method to repeatedly fabricate RC hard shell capsule halves. Because of the viscoelastic nature of the cellulose solution, a combination of dip-coating and casting method, herein referred to as dip-casting method, was developed. The dip-casting method was formalized by utilizing two-stage 2(2) full factorial design approach in order to determine a suitable approach to fabricate capsules with minimal variability. Thermal annealing is responsible for imparting shape rigidity of the capsules. Proof-of-concept analysis for the utility of these capsules in controlled drug delivery was performed by evaluating the release of KCl from them as well as from commercially available USP equivalent formulations. Release of KCl from cellulose capsules was comparable to extended release capsule formulation. Copyright © 2016 Elsevier B.V. All rights reserved.

Release behavior and bioefficacy of imazethapyr formulations based on biopolymeric hydrogels.

PubMed

Kumar, Vikas; Singh, Anupama; Das, T K; Sarkar, Dhruba Jyoti; Singh, Shashi Bala; Dhaka, Rashmi; Kumar, Anil

2017-06-03

Controlled release formulations of imazethapyr herbicide have been developed employing guar gum-g-cl-polyacrylate/bentonite clay hydrogel composite (GG-HG) and guar gum-g-cl-PNIPAm nano hydrogel (GG-NHG) as carriers, to assess the suitability of biopolymeric hydrogels as controlled herbicide release devices. The kinetics of imazethapyr release from the developed formulations was studied in water and it revealed that the developed formulations of imazethapyr behaved as slow release formulations as compared to commercial formulation. The calculated diffusion exponent (n) values showed that Fickian diffusion was the predominant mechanism of imazethapyr release from the developed formulations. Time for release of half of the loaded imazethapyr (t 1/2 ) ranged between 0.06 and 4.8 days in case of GG-NHG and 4.4 and 12.6 days for the GG-HG formulations. Weed control index (WCI) of GG-HG and GG-NHG formulations was similar to that of the commercial formulation and the herbicidal effect was observed for relatively longer period. Guar gum-based biopolymeric hydrogels in both macro and nano particle size range can serve as potential carriers in developing slow release herbicide formulations.

Formulation Optimization of Gastro-Retention Tablets of Paeonol and Efficacy in Treatment of Experimental Gastric Ulcer.

PubMed

Zhang, Xitong; Zhang, Yue; Han, Han; Yang, Jun; Xu, Benliang; Wang, Bing; Zhang, Tong

2017-08-01

This study aims to develop a gastroretentive sustained-release drug delivery system of paeonol using floating properties and to investigate its therapeutic effects in rat models. The gastric retention tablets of paeonol (GRT-Ps) were prepared by a direct compression method, and the Box-Behnken design was used to optimize its formulation. The optimized formulation containing 15% NaHCO 3 and a 2 : 1 ratio of paeonol and HPMC-K4M floated within 1 min and remained afloat for more than 8 h in the simulated gastric fluid (200 mL, pH=1.2) and simultaneously showed the desired sustained drug release. Moreover, small tablets (3 mm) were prepared according to the same formulation and the process technology of big tablets (8 mm). A similar drug release behavior was observed between two kinds of tablets (f 2 =52), and then the evaluations of efficacy and retention capacity in vivo were conducted with small tablets. In vivo retention studies showed that the T max (2 h) of GRT-P in rat stomachs was significantly extended compared with the T max (0.5 h) of normal reference preparation. Compared with the model group, low and high doses of GRT-P could significantly inhibit the increase of malondialdehyde (MDA) in serum. Studies showed that the higher MDA content in inflammation tissue increases the inflammatory response. The ulcer inhibition rates of GRT-P in the high-dose group were 59.0 and 64.1% in the ranitidine group. Results indicated that GRT-Ps had the potential for a sustained drug release and an enhanced gastric residence time with relatively high drug concentrations in the tissue distribution.

Bioequivalence and Safety of Twice-Daily Sustained-Release Paracetamol (Acetaminophen) Compared With 3- and 4-Times-Daily Paracetamol: A Repeat-Dose, Crossover Pharmacokinetic Study in Healthy Volunteers.

PubMed

Liu, Dongzhou J; Collaku, Agron

2018-01-01

Twice-daily sustained-release (SR) paracetamol (acetaminophen) offers convenient administration to chronic users. This study investigated at steady state (during the last 24 hours of a 3-day dosing period) the pharmacokinetics, bioequivalence, and safety of twice-daily SR paracetamol compared with extended-release (ER) and immediate-release (IR) paracetamol. In this open-label, randomized, multidose, 3-way crossover study, 28 healthy subjects received paracetamol SR (2 × 1000 mg twice daily), ER (2 × 665 mg 3 times daily), and IR (2 × 500 mg 4 times daily). At steady state, twice-daily SR paracetamol was bioequivalent to ER and IR paracetamol. The 90% confidence intervals for the ratios of geometric means were within the acceptance interval for SR/ER paracetamol (AUC 0-t , 0.973-1.033; AUC 0-24 , 0.974-1.034; AUC 0-∞ , 0.948-1.011; C max , 1.082-1.212; C av , 1.011-1.106) and SR/IR paracetamol (AUC 0-t , 0.969-1.029; AUC 0-24 , 0.968-1.027; AUC 0-∞ , 0.963-1.026; C max , 0.902-1.010; C av , 1.004-1.098). Given twice daily, the SR formulation demonstrated SR properties as expected. Mean time at or above a 4 μg/mL plasma concentration of paracetamol from 2 daily doses of the SR formulation was significantly longer than that from 4 daily doses of IR paracetamol. SR formulation also had a greater T max , a longer half-life, and lower C min compared with ER and IR paracetamol. All formulations were well tolerated. © 2017, The American College of Clinical Pharmacology.

Water-soluble carbon nanotube compositions for drug delivery and medicinal applications

DOEpatents

Tour, James M.; Lucente-Schultz, Rebecca; Leonard, Ashley; Kosynkin, Dmitry V.; Price, Brandi Katherine; Hudson, Jared L.; Conyers, Jr., Jodie L.; Moore, Valerie C.; Casscells, S. Ward; Myers, Jeffrey N.; Milas, Zvonimir L.; Mason, Kathy A.; Milas, Luka

2014-07-22

Compositions comprising a plurality of functionalized carbon nanotubes and at least one type of payload molecule are provided herein. The compositions are soluble in water and PBS in some embodiments. In certain embodiments, the payload molecules are insoluble in water. Methods are described for making the compositions and administering the compositions. An extended release formulation for paclitaxel utilizing functionalized carbon nanotubes is also described.

Legal liability perspectives on abuse-deterrent opioids in the treatment of chronic pain.

PubMed

Brushwood, David B; Rich, Ben A; Coleman, John J; Bolen, Jennifer; Wong, Winston

2010-12-01

Abuse-deterrent opioid analgesic formulations can help reduce the risk of opioid diversion and abuse. Not all opioid analgesics are available as both extended- and immediate-release dosage forms in abuse-deterrent formulations. Clinicians may have to balance the clinical benefit of a product that does not use abuse-deterrent technology versus the regulatory benefit of using a product with this technology. There is the possibility that a health care professional may be held legally liable when a product without abuse-deterrent qualities is used and a person suffers harm that would not have occurred had an abuse-deterrent formulation been provided. This article reviews legal precedents that inform an understanding of the need to reduce malpractice exposure by identifying patients who are at high risk of opioid diversion and/or abuse and considering the use of an abuse-deterrent formulation for these patients.

Hollow microspheres of diclofenac sodium - a gastroretentive controlled delivery system.

PubMed

Bv, Basavaraj; R, Deveswaran; S, Bharath; Abraham, Sindhu; Furtado, Sharon; V, Madhavan

2008-10-01

Most of the floating systems have an inherent drawback of high variability in the GI transit time, invariably affecting the bioavailability of drug. To overcome it, a multiple unit floating system with extended GI transit time, capable of distributing widely throughout the GIT for effective enteric release of the drug has been sought. Microballoons loaded with drug in their outer polymer shells were prepared by novel emulsion solvent diffusion method. The ethanol: dicloromethane solution of drug and Eudragit-S were poured into an aqueous solution of PVA that was thermally controlled at 40 degrees C. The gas phase generated in the dispersed polymer droplet by the evaporation of solvent formed an internal cavity in the microsphere of the polymer with the drug. The flowability of the resulting microballoons improved when compared to pure drug. The microballoons on floatation along with the surfactant, floated continuously for more than 12 hours in the acidic medium in-vitro conditions. The in-vitro drug release profile of the formulation in the simulated gastric buffer showed no drug release, which emphasizes the enteric release property and in simulated intestinal buffer, a slow and controlled drug release of 60 to 84% was obtained over a period of 8 hours. Drug release was significantly affected by increased drug to polymer concentration at pH 6.8. The formulation was found to be physically and chemically stable as per the ICH guidelines.

A new apatinib microcrystal formulation enhances the effect of radiofrequency ablation treatment on hepatocellular carcinoma.

PubMed

Xie, Hui; Tian, Shengtao; Yu, Haipeng; Yang, Xueling; Liu, Jia; Wang, Huaming; Feng, Fan; Guo, Zhi

2018-01-01

Radiofrequency ablation (RFA) is the foremost treatment option for advanced hepatocellular carcinoma (HCC), however, rapid and aggressive recurrence of HCC often occurs after RFA due to epithelial-mesenchymal transition process. Although combination of RFA with sorafenib, a molecular targeted agent, could attenuate the recurrence of HCC, application of this molecular targeted agent poses a heavy medical burden and oral administration of sorafenib also brings severe side effects. In this study, we prepared an apatinib microcrystal formulation (Apa-MS) that sustainably releases apatinib, a novel molecular targeted agent, for advanced HCC treatment. We injected apatinib solution or Apa-MS into subcutaneous HCC tumors. It was found that Apa-MS exhibited slow apatinib release in vivo and in turn inhibited the epithelial-mesenchymal transition of HCC cells for extended time. Moreover, in rodent HCC model, Apa-MS enhanced the antitumor effect of RFA treatment. Based on these results, we conclude that Apa-MS, a slow releasing system of apatinib, allows apatinib to remain effective in tumor tissues for a long time and could enhance the antitumor effect of RFA on HCC.

Tramadol extended-release in the management of chronic pain

PubMed Central

McCarberg, Bill

2007-01-01

Chronic, noncancer pain such as that associated with osteoarthritis of the hip and knee is typically managed according to American College of Rheumatology guidelines. Patients unresponsive to first-line treatment with acetaminophen receive nonsteroidal antiinflammatory drugs (NSAIDs), including cyclooxygenase-2 (COX-2) inhibitors. However, many patients may have chronic pain that is refractory to these agents, or they may be at risk for the gastrointestinal, renal, and cardiovascular complications associated with their use. Tramadol, a mild opioid agonist and norepinephrine and serotonin reuptake inhibitor, is recommended by current guidelines for the treatment of moderate to moderately severe pain in patients who have not responded to previous oral therapy, or in patients who have contraindications to COX-2 inhibitors and nonselective NSAIDs. An extended-release (ER) formulation of tramadol was approved by the US Food and Drug Administration in September 2005. In contrast with immediate-release (IR) tramadol, this ER formulation allows once-daily dosing, providing around-the-clock analgesia. In clinical studies, tramadol ER has demonstrated a lower incidence of adverse events than that reported for IR tramadol. Unlike nonselective NSAIDs and COX-2 inhibitors, tramadol ER is not associated with gastrointestinal, renal, or cardiovascular complications. Although tramadol is an opioid agonist, significant abuse has not been demonstrated after long-term therapy. It is concluded that tramadol ER has an efficacy and safety profile that warrants its early use for the management of chronic pain, either alone or in conjunction with nonselective NSAIDs and COX-2 inhibitors. PMID:18488071

Extended-release hydrocodone – gift or curse?

PubMed Central

Krashin, Daniel; Murinova, Natalia; Trescot, Andrea M

2013-01-01

Hydrocodone is a semisynthetic opioid, which has been used for decades as a short-acting analgesic combined with acetaminophen (or less commonly ibuprofen). Several long-acting, non-acetaminophen-containing hydrocodone formulations are undergoing trials in the US under the auspices of the US Food and Drug Administration, and may be available shortly. This article reviews some of the advantages (including drug familiarity and lack of acetaminophen toxicity) and potential disadvantages (including altered use patterns and high morphine equivalent dosing) of such a medication formulation. We also discuss the abuse potential of long-acting versus short-acting opioids in general and hydrocodone specifically, as well as the metabolism of hydrocodone. PMID:23358452

Oral matrix tablet formulations for concomitant controlled release of anti-tubercular drugs: design and in vitro evaluations.

PubMed

Hiremath, Praveen S; Saha, Ranendra N

2008-10-01

The aim of the present investigation was to develop controlled release (C.R.) matrix tablet formulations of rifampicin and isoniazid combination, to study the design parameters and to evaluate in vitro release characteristics. In the present study, a series of formulations were developed with different release rates and duration using hydrophilic polymers hydroxypropyl methylcellulose (HPMC) and hydroxypropyl cellulose (HPC). The duration of rifampicin and isoniazid release could be tailored by varying the polymer type, polymer ratio and processing techniques. Further, Eudragit L100-55 was incorporated in the matrix tablets to compensate for the pH-dependent release of rifampicin. Rifampicin was found to follow linear release profile with time from HPMC formulations. In case of formulations with HPC, there was an initial higher release in simulated gastric fluid (SGF) followed by zero order release profiles in simulated intestinal fluid (SIFsp) for rifampicin. The release of isoniazid was found to be predominantly by diffusion mechanism in case of HPMC formulations, and with HPC formulations release was due to combination of diffusion and erosion. The initial release was sufficiently higher for rifampicin from HPC thus ruling out the need to incorporate a separate loading dose. The initial release was sufficiently higher for isoniazid in all formulations. Thus, with the use of suitable polymer or polymer combinations and with the proper optimization of the processing techniques it was possible to design the C.R. formulations of rifampicin and isoniazid combination that could provide the sufficient initial release and release extension up to 24h for both the drugs despite of the wide variations in their physicochemical properties.

Effect of alginate composition on profile release and characteristics of chitosan-alginate microparticles loaded with mangosteen extract

NASA Astrophysics Data System (ADS)

Mulia, Kamarza; Halimah, Nur; Krisanti, Elsa

2017-03-01

Preparation of mangostin-loaded chitosan-alginate microparticles, chemical and physical characterization of the particles, and mangostin release profiles, are described herein. Mangostin rich fraction was obtained from Garcinia mangostana L. pericarp by extraction followed by fractionation. Mangostin-loaded chitosan-alginate microparticles were prepared by ionic gelation method using tripolyphosphate as the linking agent and various concentration of alginate. Mangostin was effectively loaded in all microparticle formulations, resulting in ˜97% encapsulation efficiencies. The loading of mangostin and the in-vitro release profiles in simulated gastrointestinal fluids were affected by the chitosan to alginate ratios used in the preparation of the microparticles. Increased alginate concentration resulted in lowered release of mangostin from microparticles immersed in simulated gastric fluid (pH 1.2) up to two hours. Low release of mangostin in acidic fluid but high release in simulated colon fluid, indicated that the chitosan-alginate microparticles are prospective carrier for extended release of active compound in gastrointestinal system.

Chitosan Nanolayered Cisplatin-Loaded Lipid Nanoparticles for Enhanced Anticancer Efficacy in Cervical Cancer

NASA Astrophysics Data System (ADS)

Wang, Jing-yi; Wang, Yu; Meng, Xia

2016-11-01

In this study, cisplatin (CDDP)-loaded chitosan-coated solid lipid nanoparticles (SLN) was successfully formulated to treat HeLa cervical carcinoma. The formulation nanoparticles were nanosized and exhibited a controlled release of drug in physiological conditions. The blank nanoparticles exhibited an excellent biocompatibility profile indicating its suitability for cancer targeting. The incorporation of CDDP in SLN remarkably increased the cancer cell death as evident from the MTT assay. Importantly, CDDP-loaded chitosan-coated SLN (CChSLN) significantly ( P < 0.05) decreased the viability of cancer cells even at low concentration. The higher cytotoxicity potential of CChSLN was attributed to the higher cellular uptake as well as the sustained drug release manner in comparison with CSLN. Consistent with the cytotoxicity assay, CChSLN showed the lowest IC50 value of 0.6125 μg/ml while CSLN presented 1.156 μg/ml. CChSLN showed a significantly higher apoptosis in cancer cells compared to that of CSLN and CDDP, which is attributed to the better internalization of nanocarriers and controlled release of anticancer drugs in the intracellular environment. Our findings suggest that this new formulation could be a promising alternative for the treatment of cervical cancers. These findings are encouraging us to continue our research, with a more extended investigation of cellular response in real time and in animal models.

Development and evaluation of a novel biodegradable sustained release microsphere formulation of paclitaxel intended to treat breast cancer

PubMed Central

Shiny, Jacob; Ramchander, Thadkapally; Goverdhan, Puchchakayala; Habibuddin, Mohammad; Aukunuru, Jithan Venkata

2013-01-01

Objective: The objective of this study was to develop a novel 1 month depot paclitaxel (PTX) microspheres that give a sustained and complete drug release. Materials and Methods: PTX loaded microspheres were prepared by o/w emulsion solvent evaporation technique using the blends of poly(lactic-co-glycolic acid) (PLGA) 75/25, polycaprolactone 14,000 and polycaprolactone 80,000. Fourier transform infrared spectroscopy was used to investigate drug excipient compatibility. Compatible blends were used to prepare F1-F6 microspheres, the process was characterised and the optimum formulation was selected based on the release. Optimised formulation was characterised for solid state of the drug using the differential scanning calorimetry (DSC) studies, surface morphology using the scanning electron microscopy (SEM), in vivo drug release, in vitro in vivo correlation (IVIVC) and anticancer activity. Anticancer activity of release medium was determined using the cell viability assay in Michigan Cancer Foundation (MCF-7) cell line. Results: Blend of PLGA with polycaprolactone (Mwt 14,000) at a ratio of 1:1 (F5) resulted in complete release of the drug in a time frame of 30 days. F5 was considered as the optimised formulation. Incomplete release of the drug resulted from other formulations. The surface of the optimised formulation was smooth and the drug changed its solid state upon fabrication. The formulation also resulted in 1-month drug release in vivo. The released drug from F5 demonstrated anticancer activity for 1-month. Cell viability was reduced drastically with the release medium from F5 formulation. A 100% IVIVC was obtained with F5 formulation suggesting the authenticity of in vitro release, in vivo release and the use of the formulation in breast cancer. Conclusions: From our study, it was concluded that with careful selection of different polymers and their combinations, PTX 1 month depot formulation with 100% drug release and that can be used in breast cancer was developed. PMID:24167783

Paliperidone for the treatment of schizoaffective disorder.

PubMed

Alphs, Larry; Fu, Dong-Jing; Turkoz, Ibrahim

2016-01-01

Schizoaffective disorder (SCA) is a complex mental illness characterized by psychosis and affective symptoms. Treatment usually involves concomitant therapy with antipsychotics, mood stabilizers, and/or antidepressants. Effective treatment must address acute symptoms, maintain long-term stability, promote recovery, and improve patient functioning. Data from 3 pivotal studies evaluating the acute and maintenance treatment of SCA with paliperidone are reviewed. Two formulations of paliperidone have been studied for these indications: an extended-release oral formulation (NCT00397033, NCT00412373) and long-acting injectable once-monthly paliperidone palmitate (NCT01193153). The reported effects of these formulations on psychotic, depressive, and manic symptoms are discussed. Both formulations were found to be safe and effective for the acute and maintenance treatment of SCA. Of critical importance for this treatment population is that rapid improvement was seen in all major symptoms of SCA, including psychosis, depression, and mania. Mediation analyses suggest that the known antipsychotic effects of paliperidone occur independently of its antidepressant effects. Both formulations of the drug are effective when used as monotherapy or adjunctively with antidepressants or mood stabilizers. Beyond symptom control, both formulations improved patient functioning and increased patient satisfaction.

Use of Oxycodone in Pain Management

PubMed Central

Moradi, Mohammad; Esmaeili, Sara; Shoar, Saeed; Safari, Saeid

2012-01-01

Oxycodone is widely used to alleviate moderate-to severe acute pain, It is an effective analgesic for many types of pain, and is especially useful for paroxysmal spontaneous pain, steady pain, allodynia associated with postherpetic neuralgia, and it is also increasingly used in the management of cancer-related and chronic pain, oxycodone has been found to improve the quality of life of patients with many types of pain. In 2011, following chemical and physical manipulation, an extended-release form of oxycodone was developed in order to maintain its rate-controlling mechanism. This new formulation significantly improved analgesia among patients with moderate-to-severe chronic osteoarthritis pain with an adverse event profile similar to that of other opioids. The long-term safety and efficacy of extended-release form of oxycodone in relieving moderate-to-severe chronic pain has been demonstrated. In this study we discussed about different aspects of this drug in managing of various types of pain. PMID:24904812

Single processing step toward injectable sustained-release formulations of Triptorelin based on a novel degradable semi-solid polymer.

PubMed

Asmus, Lutz R; Kaufmann, Béatrice; Melander, Louise; Weiss, Torsten; Schwach, Grégoire; Gurny, Robert; Möller, Michael

2012-08-01

Poly(lactic acid) is a widely used polymer for parenteral sustained-release formulations. But its solid state at room-temperature complicates the formulation process, and elaborate formulation systems like microparticles and self-precipitating implants are required for administration. In contrast, hexylsubstituted poly(lactic acid) (hexPLA) is a viscous, biodegradable liquid, which can simply be mixed with the active compound. In this study, the feasibility to prepare injectable suspension formulations with peptides was addressed on the example of the GnRH-agonist Triptorelin. Two formulation procedures, of which one was a straight forward one-step cryo-milling-mixing process, were compared regarding the particle size of the peptide in the polymer matrix, distribution, and drug release. This beneficial method resulted in a homogeneous formulation with an average particle diameter of the incorporated Triptorelin of only 4.1 μm. The rheological behavior of the Triptorelin-hexPLA formulations was assessed and showed thixotropic and shear-thinning behavior. Viscosity and injectability were highly dependent on the drug loading, polymer molecular weight, and temperature. Nine formulations with drug loadings from 2.5% to 10% and hexPLA molecular weights between 1500 and 5000 g/mol were investigated in release experiments, and all displayed a long-term release for over 3 months. Formulations with hexPLA of 1500 g/mol showed a viscosity-dependent release and hexPLA-Triptorelin formulations of over 2500 g/mol a molecular weight-dependent release profile. In consequence, the burst release and rate of release were controllable by adapting the drug loading and the molecular weight of the hexPLA. The degradation characteristics of the hexPLA polymer during the in vitro release experiment were studied by following the molecular weight decrease and weight loss. Triptorelin-hexPLA formulations had interesting sustained-release characteristics justifying further investigations in the drug-polymer interactions and the in vivo behavior. Copyright © 2012 Elsevier B.V. All rights reserved.

Development and experimental design of a novel controlled-release matrix tablet formulation for indapamide hemihydrate.

PubMed

Antovska, Packa; Ugarkovic, Sonja; Petruševski, Gjorgji; Stefanova, Bosilka; Manchevska, Blagica; Petkovska, Rumenka; Makreski, Petre

2017-11-01

Development, experimental design and in vitro in vivo correlation (IVIVC) of controlled-release matrix formulation. Development of novel oral controlled delivery system for indapamide hemihydrate, optimization of the formulation by experimental design and evaluation regarding IVIVC on a pilot scale batch as a confirmation of a well-established formulation. In vitro dissolution profiles of controlled-release tablets of indapamide hemihydrate from four different matrices had been evaluated in comparison to the originator's product Natrilix (Servier) as a direction for further development and optimization of a hydroxyethylcellulose-based matrix controlled-release formulation. A central composite factorial design had been applied for the optimization of a chosen controlled-release tablet formulation. The controlled-release tablets with appropriate physical and technological properties had been obtained with a matrix: binder concentration variations in the range: 20-40w/w% for the matrix and 1-3w/w% for the binder. The experimental design had defined the design space for the formulation and was prerequisite for extraction of a particular formulation that would be a subject for transfer on pilot scale and IVIV correlation. The release model of the optimized formulation has shown best fit to the zero order kinetics depicted with the Hixson-Crowell erosion-dependent mechanism of release. Level A correlation was obtained.

Investigating the feasibility of temperature-controlled accelerated drug release testing for an intravaginal ring.

PubMed

Externbrink, Anna; Clark, Meredith R; Friend, David R; Klein, Sandra

2013-11-01

The objective of the present study was to investigate if temperature can be utilized to accelerate drug release from Nuvaring®, a reservoir type intravaginal ring based on polyethylene vinyl acetate copolymer that releases a constant dose of contraceptive steroids over a duration of 3 weeks. The reciprocating holder apparatus (USP 7) was utilized to determine real-time and accelerated etonogestrel release from ring segments. It was demonstrated that drug release increased with increasing temperature which can be attributed to enhanced drug diffusion. An Arrhenius relationship of the zero-order release constants was established, indicating that temperature is a valid parameter to accelerate drug release from this dosage form and that the release mechanism is maintained under these accelerated test conditions. Accelerated release tests are particularly useful for routine quality control to assist during batch release of extended release formulations that typically release the active over several weeks, months or even years, since they can increase the product shelf life. The accelerated method should therefore be able to discriminate between formulations with different release characteristics that can result from normal manufacturing variance. In the case of Nuvaring®, it is well known that the process parameters during the extrusion process strongly influence the polymeric structure. These changes in the polymeric structure can affect the permeability which, in turn, is reflected in the release properties. Results from this study indicate that changes in the polymeric structure can lead to a different temperature dependence of the release rate, and as a consequence, the accelerated method can become less sensitive to detect changes in the release properties. When the accelerated method is utilized during batch release, it is therefore important to take this possible restriction into account and to evaluate the accelerated method with samples from non-conforming batches that are explicitly "out of specification" under real-time test conditions. Copyright © 2013 Elsevier B.V. All rights reserved.

Effects of formulation variables and post-compression curing on drug release from a new sustained-release matrix material: polyvinylacetate-povidone.

PubMed

Shao, Z J; Farooqi, M I; Diaz, S; Krishna, A K; Muhammad, N A

2001-01-01

A new commercially available sustained-release matrix material, Kollidon SR, composed of polyvinylacetate and povidone, was evaluated with respect to its ability to modulate the in vitro release of a highly water-soluble model compound, diphenhydramine HCl. Kollidon SR was found to provide a sustained-release effect for the model compound, with certain formulation and processing variables playing an important role in controlling its release kinetics. Formulation variables affecting the release include the level of the polymeric material in the matrix, excipient level, as well as the nature of the excipients (water soluble vs. water insoluble). Increasing the ratio of a water-insoluble excipient, Emcompress, to Kollidon SR enhanced drug release. The incorporation of a water-soluble excipient, lactose, accelerated its release rate in a more pronounced manner. Stability studies conducted at 40 degrees C/75% RH revealed a slow-down in dissolution rate for the drug-Kollidon SR formulation, as a result of polyvinylacetate relaxation. Further studies demonstrated that a post-compression curing step effectively stabilized the release pattern of formulations containing > or = 47% Kollidon SR. The release mechanism of Kollidon-drug and drug-Kollidon-Emcompress formulations appears to be diffusion controlled, while that of the drug-Kollidon-lactose formulation appears to be controlled predominantly by diffusion along with erosion.

The potential of polymeric film-forming systems as sustained delivery platforms for topical drugs.

PubMed

Frederiksen, Kit; Guy, Richard H; Petersson, Karsten

2016-01-01

Dosing regimens requiring multiple daily applications frequently result in poor patient compliance, especially in the treatment of chronic skin diseases. Consequently, development of sustained delivery systems for topical drugs permitting less frequent dosing is of continuing interest for dermatological therapy. This potential of polymeric film-forming systems (FFS), created in situ on the skin, as sustained delivery platforms for topical drug delivery is reviewed. Key formulation parameters that determine delivery efficiency are considered focussing on those that permit a drug reservoir to be established in the upper layers of the skin and/or on the skin surface from which release can be sustained over a prolonged period. The advantageous and superior cosmetic attributes of FFS (compared to conventional semi-solid formulations) that offer significantly improved patient compliance are also addressed. The promise of polymeric FFS as convenient and aesthetic platforms for sustained topical drug delivery is clear. Manipulation of the formulation allows the delivery profile to be customized and optimized to take advantage of both a rapid, initial input of drug into the skin (likely due to a transient period of supersaturation) and a slower, controlled release over an extended time from the residual film created thereafter.

Intramuscular administration of paliperidone palmitate extended-release injectable microsuspension induces a subclinical inflammatory reaction modulating the pharmacokinetics in rats.

PubMed

Darville, Nicolas; van Heerden, Marjolein; Vynckier, An; De Meulder, Marc; Sterkens, Patrick; Annaert, Pieter; Van den Mooter, Guy

2014-07-01

The present study aims at elucidating the intricate nature of the drug release and absorption following intramuscular (i.m.) injection of sustained-release prodrug nanocrystals/microcrystals. A paliperidone palmitate (PPP) long-acting suspension was characterized with regard to particle size (Dv,50 = 1.09 μm) and morphology prior to i.m. injection in rats. The local disposition was rigorously investigated by means of (immuno)histochemistry and transmission electron microscopy while the concurrent multiphasic pharmacokinetics was linked to the microanatomy. A transient (24 h) trauma-induced inflammation promptly evolved into a subclinical but chronic granulomatous inflammatory reaction initiated by the presence of solid material. The dense inflammatory envelope (CD68(+) macrophages) led to particle agglomeration with subsequent drop in dissolution rate beyond 24 h postinjection. This was associated with a decrease in apparent paliperidone (PP) absorption (near-zero order) until 96 h and a delayed time of occurrence of observed maximum drug plasma concentration (168 h). The infiltrating macrophages phagocytosed large fractions of the depot, thereby influencing the (pro)drug release. Radial angiogenesis (CD31(+)) was observed throughout the inflammatory rim from 72 h onwards and presumably contributed to the sustained systemic PP concentrations by maintaining a sufficient absorptive capacity. No solid-state transitions of the retrieved formulation were recorded with X-ray diffraction analysis. In summary, the initial formulation-driven prodrug (PPP) dissolution and drug (PP) absorption were followed by a complex phase determined by the relative contribution of formulation factors and dynamic physiological variables. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Lycopene loaded whey protein isolate nanoparticles: An innovative endeavor for enhanced bioavailability of lycopene and anti-cancer activity.

PubMed

Jain, Ashay; Sharma, Gajanand; Ghoshal, Gargi; Kesharwani, Prashant; Singh, Bhupinder; Shivhare, U S; Katare, O P

2018-04-30

The work entails a novel strategy of formulating the lycopene loaded whey protein isolate nanoparticles (LYC-WPI-NPs) solely using the rational blend of biomacromolecule without using equipment-intensive techniques. The LYC-WPI-NPs were fabricated as a substantial drug delivery platform, with maximum entrapment, spatial and controlled release manners, exceptional plasma concentration, and perspective for discrepancy delivery of therapeutics. Prepared nano-formulations were measured in ultra-fine size (100-350 nm) with sphere-shaped. The percent lycopene entrapment of prepared LYC-WPI-NPs was estimated in the range to 50 and 65%. In vitro percent cumulative release study demonstrated deaden and extended release i.e. approximately 75% following 16th h. The in vitro percent cell survival (cytotoxicity study) of prepared nanoparticles was evaluated against MCF-7 breast cancer cells by MTT based colorimetric assay. Sub-cellular localization of lycopene when delivered by LYC-WPI-NPs was assessed by HPLC (high performance liquid chromatography). The WPI-NPs enhance the oral bioavailability of lycopene by controlling its release from nano-formulation and facilitating its absorption through lymphatic pathways. Prophylactic anticancer efficacy of LYC-WPI-NPs was evaluated thereafter on experimentally induced breast cancer animal model. Conclusively, it may quite reasonable that lycopene loaded protein nanoparticles are competent to improve the biopharmaceutical attributes of lycopene and demonstrated prophylactic anticancer activity, decrease tumor proliferation and increase the survival rate of treated animals, thus signifying their feasible usefulness in cancer therapeutic and intervention. Copyright © 2018 Elsevier B.V. All rights reserved.

Predicting Pharmacokinetic Stability by Multiple Oral Administration of Atypical Antipsychotics

PubMed Central

Aoki, Kazuo; Sakiyama, Yojiro; Ohnishi, Takashi; Sugita, Makoto

2013-01-01

Lower fluctuation, i.e., lower peak-to-trough plasma-concentration variation at steady-state pharmacokinetics, has several advantages for the treatment of schizophrenia with antipsychotics. The reduction of peak concentration can decrease the risk of dose-dependent side effects, such as extrapyramidal symptom and somnolence, and by contrast the increase in trough concentration can decrease the incidence of lack of efficacy due to subtherapeutic drug concentration. Using a one-compartment simulation technique with pharmacokinetic parameters of each atypical antipsychotic collected from package inserts, the fluctuation index was calculated. Among the antipsychotics, the indices varied from 0.018 to 1.9, depending on dosing regimens, formulations and several pharmacokinetic properties. The order of simulated fluctuation index is active-moiety aripiprazole (b.i.d.)

Shock initiated reactions of reactive multi-phase blast explosives

NASA Astrophysics Data System (ADS)

Wilson, Dennis; Granier, John; Johnson, Richard; Littrell, Donald

2017-01-01

This paper describes a new class of non-ideal explosive compositions made of perfluoropolyether (PFPE), nanoaluminum, and a micron-size, high mass density, reactive metal. Unlike high explosives, these compositions release energy via a fast self-oxidized combustion wave rather than a true self-sustaining detonation. Their reaction rates are shock dependent and they can be overdriven to change their energy release rate. These compositions are fuel rich and have an extended aerobic energy release phase. The term "reactive multiphase blast" refers to the post-dispersion blast behavior: multiphase in that there are a gas phase that imparts pressure and a solid (particulate) phase that imparts energy and momentum [1]; and reactive in that the hot metal particles react with atmospheric oxygen and the explosive gas products to give an extended pressure pulse. Tantalum-based RMBX formulations were tested in two spherical core-shell configurations - an RMBX shell exploded by a high explosive core, and an RMBX core imploded by a high explosive shell. The fireball and blast characteristics were compared to a C-4 baseline charge.

Low molecular weight polylactic acid as a matrix for the delayed release of pesticides.

PubMed

Zhao, Jing; Wilkins, Richard M

2005-05-18

Low molecular weight polylactic acid (LMW PLA) was used as a matrix to formulate biodegradable matrix granules and films with bromacil using a melt process. The compatibility of the PLA with bromacil was evaluated. The release characteristics of the formulations were investigated in vitro. The degradation and erosion of the formulations were monitored by pH and gravimetric analysis during the course of release. Various granules and films had similar biphasic release patterns, a delayed release followed by an explosive release. The release rates were independent of bromacil content in the matrix, but varied with the geometry of matrices. The mechanisms of diffusion and erosion were involved in the release. The delayed release of the formulations was dominantly governed by the degradation and erosion of PLA. LMW PLA underwent bulk erosion. LMW PLA-based matrix formulations could thus be useful for the application of pesticides to sensitive targets such as seed treatment.

Development of modified in situ gelling oral liquid sustained release formulation of dextromethorphan.

PubMed

El Maghraby, Gamal M; Elzayat, Ehab M; Alanazi, Fars K

2012-08-01

Alternative strategies are being employed to develop liquid oral sustained release formulation. These included ion exchange resin, sustained release suspensions and in situ gelling systems. The later mainly utilizes alginate solutions that form gels upon contact with calcium which may be administered separately or included in the alginate solution as citrate complex. This complex liberates calcium in the stomach with subsequent gellation. The formed gel can break after gastric emptying leading to dose dumping. Development of modified in situ gelling system which sustain dextromethorphan release in the stomach and intestine. Solutions containing alginate with calcium chloride and sodium citrate were initially prepared to select the formulation sustaining the release in the stomach. The best formulation was combined with chitosan. All formulations were characterized with respect to flow, gelling capacity, gelling strength and drug release. Increasing the concentration of alginate increased the gelling capacity and strength and reduced the rate of drug release in gastric conditions with 2% w/v alginate being the best formulation. However, these formulations failed to sustain the release in the intestinal conditions. Incorporation of chitosan with alginate increased the gelling capacity and strength and reduced the rate of drug release compared to alginate only system. The effect was optimum in formulation containing 1.5% w/v chitosan. The sustained release pattern was maintained both in the gastric and intestinal conditions and was comparable to that obtained from the marketed product. Alginate-chitosan based in situ gelling system is promising for developing liquid oral sustained release.

Changes in misuse and abuse of prescription opioids following implementation of Extended-Release and Long-Acting Opioid Analgesic Risk Evaluation and Mitigation Strategy.

PubMed

Bucher Bartelson, Becki; Le Lait, M Claire; Green, Jody L; Cepeda, M Soledad; Coplan, Paul M; Maziere, Jean-Yves; Wedin, Gregory P; Dart, Richard C

2017-09-01

An unintended consequence of extended-release (ER) and long-acting (LA) prescription opioids is that these formulations can be more attractive to abusers than immediate-release (IR) formulations. The US Food and Drug Administration recognized these risks and approved the ER/LA Opioid Analgesic Risk Evaluation and Mitigation Strategy (ER/LA REMS), which has a goal of reducing opioid misuse and abuse and their associated consequences. The primary objective of this analysis is to determine whether ER/LA REMS implementation was associated with decreased reports of misuse and abuse. Data from the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS(R)) System Poison Center Program were utilized. Poison center cases are assigned a reason for exposure, a medical outcome, and a level of health care received. Rates adjusted for population and drug utilization were analyzed over time. RADARS System Poison Center Program data indicate a notable decrease in ER/LA opioid rates of intentional abuse and misuse as well as major medical outcomes or hospitalizations following implementation of the ER/LA REMS. While similar decreases were observed for the IR prescription opioid group, the decreasing rate for the ER/LA opioids exceeded the decreasing rates for the IR prescription opioids and was distinctly different than that for the prescription stimulants, indicating that the ER/LA REMS program may have had an additional effect on decreases in opioid abuse and intentional misuse beyond secular trends. Copyright © 2017 John Wiley & Sons, Ltd.

Novel Approaches in Formulation and Drug Delivery using Contact Lenses

PubMed Central

Singh, Kishan; Nair, Anroop B; Kumar, Ashok; Kumria, Rachna

2011-01-01

The success of ocular delivery relies on the potential to enhance the drug bioavailability by controlled and extended release of drug on the eye surface. Several new approaches have been attempted to augment the competence and diminish the intrinsic side effects of existing ocular drug delivery systems. In this contest, progress has been made to develop drug-eluting contact lens using different techniques, which have the potential to control and sustain the delivery of drug. Further, the availability of novel polymers have facilitated and promoted the utility of contact lenses in ocular drug delivery. Several research groups have already explored the feasibility and potential of contact lens using conventional drugs for the treatment of periocular and intraocular diseases. Contact lenses formulated using modern technology exhibits high loading, controlled drug release, apposite thickness, water content, superior mechanical and optical properties as compared to commercial lenses. In general, this review discus various factors and approaches designed and explored for the successful delivery of ophthalmic drugs using contact lenses as drug delivery device PMID:24826007

[Modern polymers in matrix tablets technology].

PubMed

Zimmer, Łukasz; Kasperek, Regina; Poleszak, Ewa

2014-01-01

Matrix tablets are the most popular method of oral drug administration, and polymeric materials have been used broadly in matrix formulations to modify and modulate drug release rate. The main goal of the system is to extend drug release profiles to maintain a constant in vivo plasma drug concentration and a consistent pharmacological effect. Polymeric matrix tablets offer a great potential as oral controlled drug delivery systems. Cellulose derivatives, like hydroxypropyl methylcellulose (HPMC) are often used as matrix formers. However, also other types of polymers can be used for this purpose including: Kollidon SR, acrylic acid polymers such as Eudragits and Carbopols. Nevertheless, polymers of natural origin like: carragens, chitosan and alginates widely used in the food and cosmetics industry are now coming to the fore of pharmaceutical research and are used in matrix tablets technology. Modern polymers allow to obtain matrix tablets by 3D printing, which enables to develop new formulation types. In this paper, the polymers used in matrix tablets technology and examples of their applications were described.

Pharmacokinetics of 2 Novel Formulations of Modified-Release Oral Testosterone Alone and With Finasteride in Normal Men With Experimental Hypogonadism

PubMed Central

Snyder, Christin N.; Clark, Richard V.; Caricofe, Ralph B.; Bush, Mark A.; Roth, Mara Y.; Page, Stephanie T.; Bremner, William J.; Amory, John K.

2011-01-01

Oral administration of testosterone might be useful for the treatment of testosterone deficiency. However, current “immediate-release” formulations of oral testosterone exhibit suboptimal pharmacokinetics, with supraphysiologic peaks of testosterone and its metabolite, dihydrotestosterone (DHT), immediately after dosing. To dampen these peaks, we have developed 2 novel modified-release formulations of oral testosterone designed to slow absorption from the gut and improve hormone delivery. We studied these testosterone formulations in 16 normal young men enrolled in a 2-arm, open-label clinical trial. Three hundred-mg and 600-mg doses of immediate-release and modified fast-release or slow-release formulations were administered sequentially to 8 normal men rendered hypogonadal by the administration of the gonadotropin-releasing hormone antagonist acyline. Blood for measurement of serum testosterone, DHT, and estradiol was obtained before and 0.5, 1, 2, 3, 4, 6, 8, 12, and 24 hours after each dose. A second group of 8 men was studied with the coadministration of 1 mg of the 5α-reductase inhibitor finasteride daily throughout the treatment period. Serum testosterone was increased with all formulations of oral testosterone. The modified slow-release formulation significantly delayed the postdose peaks of serum testosterone and reduced peak concentrations of serum DHT compared with the immediate-release formulation. The addition of finasteride further increased serum testosterone and decreased serum DHT. We conclude that the oral modified slow-release testosterone formulation exhibits superior pharmacokinetics compared with immediate-release oral testosterone both alone and in combination with finasteride. This formulation might have efficacy for the treatment of testosterone deficiency. PMID:20378927

Development of sustained release capsules containing "coated matrix granules of metoprolol tartrate".

PubMed

Siddique, Sabahuddin; Khanam, Jasmina; Bigoniya, Papiya

2010-09-01

The objective of this investigation was to prepare sustained release capsule containing coated matrix granules of metoprolol tartrate and to study its in vitro release and in vivo absorption. The design of dosage form was performed by choosing hydrophilic hydroxypropyl methyl cellulose (HPMC K100M) and hydrophobic ethyl cellulose (EC) polymers as matrix builders and Eudragit® RL/RS as coating polymers. Granules were prepared by composing drug with HPMC K100M, EC, dicalcium phosphate by wet granulation method with subsequent coating. Optimized formulation of metoprolol tartrate was formed by using 30% HPMC K100M, 20% EC, and ratio of Eudragit® RS/RL as 97.5:2.5 at 25% coating level. Capsules were filled with free flowing optimized granules of uniform drug content. This extended the release period upto 12 h in vitro study. Similarity factor and mean dissolution time were also reported to compare various dissolution profiles. The network formed by HPMC and EC had been coupled satisfactorily with the controlled resistance offered by Eudragit® RS. The release mechanism of capsules followed Korsemeyer-Peppas model that indicated significant contribution of erosion effect of hydrophilic polymer. Biopharmaceutical study of this optimized dosage form in rabbit model showed 10 h prolonged drug release in vivo. A close correlation (R(2) = 0.9434) was established between the in vitro release and the in vivo absorption of drug. The results suggested that wet granulation with subsequent coating by fluidized bed technique, is a suitable method to formulate sustained release capsules of metoprolol tartrate and it can perform therapeutically better than conventional immediate release dosage form.

Controlled release hydrophilic matrix tablet formulations of isoniazid: design and in vitro studies.

PubMed

Hiremath, Praveen S; Saha, Ranendra N

2008-01-01

The aim of the present investigation was to develop oral controlled release matrix tablet formulations of isoniazid using hydroxypropyl methylcellulose (HPMC) as a hydrophilic release retardant polymer and to study the influence of various formulation factors like proportion of the polymer, polymer viscosity grade, compression force, and release media on the in vitro release characteristics of the drug. The formulations were developed using wet granulation technology. The in vitro release studies were performed using US Pharmacopoeia type 1 apparatus (basket method) in 900 ml of pH 7.4 phosphate buffer at 100 rpm. The release kinetics was analyzed using Korsmeyer-Peppas model. The release profiles were also analyzed using statistical method (one-way analysis of variance) and f (2) metric values. The release profiles found to follow Higuchi's square root kinetics model irrespective of the polymer ratio and the viscosity grade used. The results in the present investigation confirm that the release rate of the drug from the HPMC matrices is highly influenced by the drug/HPMC ratio and viscosity grade of the HPMC. Also, the effect of compression force and release media was found to be significant on the release profiles of isoniazid from HPMC matrix tablets. The release mechanism was found to be anomalous non-Fickian diffusion in all the cases. In the present investigation, a series of controlled release formulations of isoniazid were developed with different release rates and duration so that these formulations could further be assessed from the in vivo bioavailability studies. The formulations were found to be stable and reproducible.

Controlled release of isoproturon, imidacloprid, and cyromazine from alginate-bentonite-activated carbon formulations.

PubMed

Garrido-Herrera, F J; Gonzalez-Pradas, E; Fernandez-Pérez, M

2006-12-27

Different alginate-based systems of isoproturon, imidacloprid, and cyromazine have been investigated in order to obtain controlled release (CR) properties. The basic formulation [sodium alginate (1.50%), pesticide (0.30%), and water] was modified using different amounts of bentonite and activated carbon. The higher values of encapsulation efficiency corresponded to those formulations prepared with higher percentages of activated carbon, showing higher encapsulation efficiency values for isoproturon and imidacloprid than for cyromazine, which has a higher water solubility. The kinetic experiments of imidacloprid/isoproturon release in water have shown us that the release rate is higher in imidacloprid systems than in those prepared with isoproturon. Moreover, it can be deduced that the use of bentonite and/or activated carbon sorbents reduces the release rate of the isoproturon and imidacloprid in comparison with the technical product and with alginate formulation without modifying agents. The highest decrease in release rate corresponds to the formulations prepared with the highest percentage of activated carbon. The water uptake, permeability, and time taken for 50% of the active ingredient to be released into water, T50, were calculated to compare the formulations. On the basis of a parameter of an empirical equation used to fit the pesticide release data, the release of isoproturon and imidacloprid from the various formulations into water is controlled by a diffusion mechanism. The sorption capacity of the sorbents and the permeability of the formulations were the most important factors modulating pesticide release. Finally, a linear correlation of the T50 values and the content of activated carbon in formulations were obtained.

Pharmacokinetics of hydrocodone extended-release tablets formulated with different levels of coating to achieve abuse deterrence compared with a hydrocodone immediate-release/acetaminophen tablet in healthy subjects.

PubMed

Darwish, Mona; Bond, Mary; Tracewell, William; Robertson, Philmore; Yang, Ronghua

2015-01-01

A hydrocodone extended-release (ER) formulation employing the CIMA(®) Abuse-Deterrence Technology platform was developed to provide resistance against rapid release of hydrocodone when tablets are comminuted or taken with alcohol. This study evaluated the pharmacokinetics of three hydrocodone ER tablet prototypes with varying levels of polymer coating to identify the prototype expected to have the greatest abuse deterrence potential based on pharmacokinetic characteristics that maintain systemic exposure to hydrocodone comparable to that of a commercially available hydrocodone immediate-release (IR) product. In this four-period crossover study, healthy subjects aged 18-45 years were randomized to receive a single intact, oral 45-mg tablet of one of three hydrocodone ER prototypes (low-, intermediate-, or high-level coating) or an intact, oral tablet of hydrocodone IR/acetaminophen (APAP) 10/325 mg every 6 h until four tablets were administered, with each of the four treatments administered once over the four study periods. Dosing periods were separated by a minimum 5-day washout. Naltrexone 50 mg was administered to block opioid receptors. Blood samples for pharmacokinetic assessments were collected predose and through 72 h postdose. Parameters assessed included maximum observed plasma hydrocodone concentration (C(max)), time to C(max) (t(max)), and area under the concentration-time curve from time 0 to infinity (AUC(0-∞)). Mean C(max) values were 49.2, 32.6, and 28.4 ng/mL for the low-, intermediate-, and high-level coating hydrocodone ER tablet prototypes, respectively, and 37.3 ng/mL for the hydrocodone IR/APAP tablet; respective median t(max) values were 5.9, 8.0, 8.0, and 1.0 h. Total systemic exposure to hydrocodone (AUC(0-∞)) was comparable between hydrocodone ER tablet prototypes (640, 600, and 578 ng·h/mL, respectively) and hydrocodone IR/APAP (581 ng·h/mL). No serious adverse events or deaths were reported. The most common adverse events included headache (26%) and nausea (18%). All three hydrocodone ER tablet prototypes (low-, intermediate-, and high-level polymer coating) demonstrated ER pharmacokinetic characteristics. The hydrocodone ER tablet prototype with the high-level coating was selected for development because of its comparable exposure to the hydrocodone IR/APAP formulation and potentially increased ability to resist rapid drug release upon product tampering because of a higher polymer coating level. All study medications were well tolerated in healthy naltrexone-blocked volunteers.

A comparison study between lycobetaine-loaded nanoemulsion and liposome using nRGD as therapeutic adjuvant for lung cancer therapy.

PubMed

Chen, Tijia; Gong, Ting; Zhao, Ting; Fu, Yao; Zhang, Zhirong; Gong, Tao

2018-01-01

To achieve tumor-selective drug delivery, various nanocarriers have been explored using either passive or active targeting strategies. Despite the great number of studies published annually in the field, only nanocarriers using approved excipients reach the clinical stage. In our study, two classic nanoscale formulations, nanoemulsion (NE) and liposome (Lipo) were selected for the encapsulation of lycobetaine (LBT). To improve the lipid solubility of LBT, oleic acid (OA) was used to complex (LBT-OA) with lycobetaine (LBT). Besides, PEGylated lecithin was used to enhance the circulation time. The release behaviors of LBT from non-PEGylated and PEGylated NE and Lipo were compared. PEGylated LBT-OA loaded Lipo (LBT-OA-PEG-Lipo) exhibited a sustained release rate pattern, and in vivo pharmacokinetic profiles showed the extended circulation compared nanoemlusions. Besides, LBT-OA-PEG-Lipo showed an enhanced anti-tumor effect in the mice xenograft lung carcinoma model. Moreover, a multi-target peptide nRGD was co-administered as a therapeutic adjuvant with LBT-OA loaded formulations, which demonstrated improved tumor penetration and enhanced extravasation of formulations. Also, co-administration of nRGD significantly improved the in vivo antitumor efficacy of different formulations, likely due to the depletion of tumor-associated macrophages (TAMs). Thus, LBT-OA-PEG-Lipo+nRGD may represent a promising strategy for cancer chemotherapy against lung carcinoma. Copyright © 2017. Published by Elsevier B.V.

Mono- and biphasic plasma concentration-time curves of mesalazine from a 500 mg suppository in healthy male volunteers controlled by the time of defecation before dosing.

PubMed

Vree, T B; Dammers, E; Exler, P S; Maes, R A

2000-06-01

This study was based on data from a bioequivalence study (n=24) of two different formulations of suppositories containing 500 mg mesalazine (formulation I and II), with a similar dissolution profile in phosphate buffer pH 6.8. There was a large intra- and intersubject variability in the plasma concentration-time curves of mesalazine from both suppositories. The aim of the investigation was to identify the parameters that caused the observed large variations in release and absorption of mesalazine in the rectum. Plasma mesalazine and acetylmesalazine, and urine acetylmesalazine concentrations were determined according to validated methods involving HPLC analysis with coulometric detection. Lower limit of quantitation values were respectively 10.4 and 19.4 ng mL(-1) in plasma and 0.96 microg mL(-1) in urine. The time of defecation before and after insertion was recorded. There was a clear distinction between subjects who showed monophasic mesalazine release/absorption and those who showed biphasic and more extended release/absorption. With formulation I there was a correlation between time of defecation before dosing and the type of absorption, monophasic and biphasic absorbers showed a significant difference in the time of defecation, e.g. 9.7+/-5.6 h vs 18.8+/-11.9 h (P = 0.0218). The impact of time of defecation before dosing was non-significant with formulation II, 16.7+/-7.2 h vs 15.1+/-4.2 h (P = 0.67). The impact of the time elapsed between administration and time of defecation after the insertion of the suppository was not significant for the type of release/absorption. The plasma concentration-time curves of the metabolite ran parallel to that of the parent drug, the more parent drug was released/absorbed, the more was acetylated (P = 0.0013) and excreted into the urine (P = 0.0004). After absorption the compound was metabolized into acetylmesalazine, and renally excreted (12-13% of the dose). Monophasic release/ absorption resulted in 7.1% metabolite with I and 10.3% with II (P = 0.0004), while biphasic release/absorption gave 16.8% metabolite with I and 15.5% with II. The renal clearance of the metabolite acetylmesalazine was independent of the observed defecation patterns (300 mL min(-1), P > 0.8), stool composition, and type of absorption.

In vitro and ex vivo characterisation of an in situ gelling formulation for sustained lidocaine release with potential use following knee arthroplasty.

PubMed

Sharma, Manisha; Chandramouli, Kaushik; Curley, Louise; Pontre, Beau; Reilly, Keryn; Munro, Jacob; Hill, Andrew; Young, Simon; Svirskis, Darren

2018-06-01

Sustained lidocaine release via a thermoresponsive poloxamer-based in situ gelling system has the potential to alleviate pain following knee arthroplasty. A previously developed formulation showed a promising drug release profile in synthetic phosphate-buffered saline (PBS). To support the translation of this formulation, ex vivo characterisation was warranted. This study therefore aimed (1) to modify the previously developed formulation to reduce the burst release, (2) to compare the release behaviour into ex vivo human intra-articular fluid (IAF) and PBS and (3) to determine the formulation spread in an ex vivo human knee using magnetic resonance imaging (MRI). All formulations provided sustained release out to 72 h; polyvinyl pyrrolidone was the most effective additive yielding a small yet significant decrease (p < 0.05) in the burst release. Release of lidocaine from the formulation occurred significantly faster into IAF compared to PBS (1.4 times greater release in the first 24 h), correlating with faster rates of gel erosion in IAF. Injection was easily achieved through a 21-gauge (G) needle into the synovial space of a human cadaveric knee, and MRI scans revealed effective spreading of the formulation throughout the joint cavity. The pattern of spread is promising for the drug to reach the widespread nerve endings in the joint capsule; the effect of this spread on release in an in vivo setting will be the subject of future studies. The demonstrated properties indicate that the in situ gelling formulation has the potential to be used clinically to treat post-operative pain following knee arthroplasty.

Plasma concentrations of remoxipride and the gastrointestinal transit of 111In-marked extended-release coated spheres

DOE Office of Scientific and Technical Information (OSTI.GOV)

Graffner, C.; Wagner, Z.; Nilsson, M.I.

1990-01-01

To explore the oral absorption of remoxipride, spheres of remoxipride were labeled with indium-111 colloid before coating with a release-controlling ethylcellulose membrane. Since the labeling remained inside the coating, it was suitable as a marker. Eight healthy volunteers were given a single dose of 100 mg remoxipride in 111In-marked spheres as a multiple-unit capsule. The radioactivity and the position of the spheres (microcapsules) were followed externally for 30 hr by gamma scintigraphy. Parallel to this, plasma concentrations were drawn for 48 hr to confirm the extended dissolution and absorption of remoxipride. The hard gelatin, multiple-unit capsule released the microcapsules withinmore » the stomach. These were then rapidly emptied into the small intestine, within 0.5-1 hr. There was then an immediate distribution in the upper small intestine before collection in the lower portion, within 2-5 hr. After passing into the large intestine, there was again extended distribution of the microcapsules. A mean Cmax of 2.7 microM remoxipride was achieved 4 hr after drug administration and a mean AUC of 26.1 mumol.L-1.hr was achieved. Judging from the absorption versus time profile, calculated according to the Wagner-Nelson method, and the scintigraphic images, it is concluded that the main absorption occurs from the small intestine. Data from four volunteers, however, indicated a comparatively good absorption also from the large intestine. Due to the good absorption properties, it is reasonable to expect a low variation in the extent of bioavailability of remoxipride after administration in an extended-release, multiple-unit capsule formulation.« less

Long-term efficacy, safety and tolerability of Remoxy for the management of chronic pain.

PubMed

Pergolizzi, Joseph V; Zampogna, Gianpietro; Taylor, Robert; Raffa, Robert B

2015-03-01

Historically, chronic pain generally went under-treated for a variety of objective and subjective reasons, including difficulty to objectively diagnose and manage over a long period of time, potential serious adverse effects of commonly available medications, and patient, healthcare and societal concerns over opioid medications. More recently, in an effort to redress the under-treatment of pain, the number of prescriptions of opioid analgesics has risen dramatically. However, paralleling the increased legitimate use has been a concomitant increase in opioid abuse, misuse and diversion. Pharmaceutical companies have responded by developing a variety of opioid formulations designed to deter abuse by making the products more difficult to tamper with. One such product is Remoxy(®), an extended-release formulation of the strong opioid oxycodone. We review the efficacy, safety and tolerability of this formulation based on the available published literature.

The role of abuse-deterrent formulations in countering opioid misuse and abuse.

PubMed

Nguyen, V; Raffa, R B; Taylor, R; Pergolizzi, J V

2015-12-01

Pain is a prevalent, and due to the ageing population, increasing medical problem. Opioids are frequently prescribed to meet the unmet medical need. Unfortunately, with the increase in the legitimate use of opioids, there has been a corresponding increase in abuse. A practical way to retain the pain relief afforded by opioids while decreasing opportunities for abuse is to make it more difficult to extract the opioid from the product or to make it less desirable to do so by designing an abuse-deterrent formulation (ADF). We provide a brief overview of the strategies and early evidence related to opioid ADFs. Published and unpublished literature, websites, and other sources were searched for current opioid formulation options, including immediate-release and extended-release products. Each was summarized, reviewed and assessed. The strategies that have been used to design the current opioid ADFs involve one or more of four approaches: a physical barrier; incorporation of an opioid receptor antagonist (e.g. naloxone) that self-limits opioid action when taken in excess amount; inclusion of a noxious agent that is released during inappropriate use; or a pro-drug. Legitimate use of opioid analgesics carries with it certain risks, including the risk of abuse. The new ADFs utilize four major strategies and provide innovative additions to the armamentarium. They likely will become an important part of a comprehensive approach to limiting, although not eliminating, opioid misuse and abuse. © 2015 John Wiley & Sons Ltd.

Oseltamivir phosphate released from injectable Pickering emulsions over an extended term disables human pancreatic cancer cell survival

PubMed Central

Wood, Kurt; Szewczuk, Myron R.; Rousseau, Dérick; Neufeld, Ronald J.

2018-01-01

Pickering emulsions are colloidal dispersions stabilized by particles that either migrate to, or are formed at, the oil-water interface during emulsification. Here, we fabricated and characterized Pickering water-in-oil emulsions where molten glycerol monostearate crystallized at the surface of micron-sized water droplets and formed protective solid shells. We tested this emulsion as a reservoir delivery platform for the sustained release of low molecular weight hydrophilic molecules including sodium chloride (NaCl) and sodium citrate as model compounds, and the therapeutic oseltamivir phosphate (OP), the delivery of which was the ultimate goal of this research. The objective was to achieve long-term (30-day) release of challenging to encapsulate actives and ultimately demonstrate the sustained release of OP for 20–30 days from an injectable formulation. OP was used because of its anticancer properties targeting mammalian neuraminidase 1 (Neu1) involved in multistage tumorigenesis. All actives including OP encapsulated in Pickering emulsions displayed a near linear release profile over 30 days. It was demonstrated that the release could be modulated by the addition of a second, competing surfactant sorbitan monooleate, Span 80, to the emulsion at levels above its critical micelle concentration. OP released from the emulsions significantly reduced cell viability in the human PANC-1 pancreatic cancer cell line for up to 30 days. The findings from this study indicate a simple, potentially injectable formulation and method that is easily upscaled resulting in a stable product with the potential to fully retain small hydrophilic molecules/drugs for sustained, near linear release over days, weeks, and potentially months. PMID:29560107

Influence of Carbopol 71G-NF on the release of dextromethorphan hydrobromide from extended-release matrix tablets.

PubMed

Fayed, Mohamed H; Mahrous, Gamal M; Ibrahim, Mohamed A; Sakr, Adel

2013-01-01

The objective of this study was to evaluate the potential of Carbopol(®) 71G-NF on the release of dextromethorphan hydrobromide (DM) from matrix tablets in comparison with hydroxypropyl methylcellulose (HPMC(®) K15M) and Eudragit(®) L100-55 polymers. Controlled release DM matrix tablets were prepared using Carbopol 71G-NF, HPMC K15M, and Eudragit L100-55 at different drug to polymer ratios by direct compression technique. The mechanical properties of the tablets as tested by crushing strength and friability tests were improved as the concentration of Carbopol, HPMC, and Eudragit increased. However, Carbopol-based tablets showed a significantly (P<0.05) higher crushing strength and a lower friability than HPMC and Eudragit tablets. No significant differences in weight uniformity and thickness values were observed between the different formulations. It was also found that Carbopol significantly (P<0.05) delayed the release of DM in comparison with HPMC K15M and Eudragit L100-55. A combination of HPMC K15M and Eudragit L100-55 in a 1:1 ratio at 20 and 30% significantly (P<0.05) delayed the release of DM than Eudragit L100-55 alone. Moreover, blends of Carbopol and HPMC at a 1:1 ratio at the 10, 20, and 30% total polymer concentration were investigated. The blend of Carbopol and HPMC at 10% level significantly (P<0.05) slowed the release of DM than Carbopol or HPMC alone, whereas blends at 20 and 30% level significantly (P<0.05) delayed the release of DM compared with HPMC or Carbopol alone. The results with these polymer blends showed that it was possible to reduce the total amount of polymers when used as a combination in formulation.

Formulation and evaluation of controlled release antibiotic biodegradable implants for post operative site delivery.

PubMed

Mathur, Vijay; Mudnaik, Rajesh; Barde, Laxmikant; Roy, Arghya; Shivhare, Umesh; Bhusari, Kishore

2010-03-01

Biodegradable implants of ciprofloxacin hydrochloride for post operative site delivery were prepared using glyceryl monostearate and different concentrations of polyethylene glycol (PEG 6000), glycerol and Tween 80 as erosion enhancers by compression and molding technique. Formulations were subjected to in vitro drug release by the USP dissolution method, while promising formulations were subjected to in vitro drug release by the agar gel method and also to stability studies. It was observed that glyceryl monostearate formed hydrophobic matrix and delayed the drug delivery. Antibiotic release profile was controlled by using different combinations of erosion enhancers. The formulation prepared by the compression method showed more delayed release compared to formulations prepared by the molding method.

Controlled-release tablet formulation of isoniazid.

PubMed

Jain, N K; Kulkarni, K; Talwar, N

1992-04-01

Guar (GG) and Karaya gums (KG) alone and in combination with hydroxy-propylmethylcellulose (HPMC) were evaluated as release retarding materials to formulate a controlled-release tablet dosage form of isoniazid (1). In vitro release of 1 from tablets followed non-Fickian release profile with rapid initial release. Urinary excretion studies in normal subjects showed steady-state levels of 1 for 13 h. In vitro and in vivo data correlated (r = 0.9794). The studies suggested the potentiality of GG and KG as release retarding materials in formulating controlled-release tablet dosage forms of 1.

Evaluation of Abuse-Deterrent or Tamper-Resistant Opioid Formulations on Overall Health Care Expenditures in a State Medicaid Program.

PubMed

Keast, Shellie L; Owora, Arthur; Nesser, Nancy; Farmer, Kevin

2016-04-01

The development of abuse-deterrent opioid prescription medications is a priority at the national level. Pharmaceutical manufacturers have begun marketing new formulations of currently available opioids that meet higher abuse resistance standards. Little information is available regarding the impact of these formulations on overall health care expenditures. To (a) examine the relationship between health care expenditures and use of brand abuse-deterrent or tamper-resistant (ADTR) extended-release opioids versus standard dosage form (SDF) extended-release opioids in a state Medicaid population, and (b) determine whether this relationship was influenced by member-specific characteristics. The study is a cross-sectional review of Oklahoma Medicaid members (aged ≥ 21 years) with at least 1 paid pharmacy claim for long-acting opioids between September 2013 and August 2014. Members who were adherent to extended-release opioid products were classified into ADTR and SDF opioid groups. The relationship between health care expenditures (prescription, medical, and overall) and opioid groups was examined using multiple linear regression models. The impact of member-specific characteristics (age, sex, race, urban classifications, and various comorbidities) on this relationship was examined. Prescription spending ($9,265,554) accounted for 35% of overall health care expenditures ($26,304,693) among 938 members during the 12-month reference period. Total prescription expenditures were higher among ADTR than SDF user groups, and the difference in median expenditures between these 2 groups was larger among members with more comorbidities, as measured by the Charlson Comorbidity Index score. Overall, ADTR users had higher median total health care and medical expenditures, and the difference in median expenditures was dependent on whether a member had comorbidities of addiction or not (higher expenditures were observed among members with comorbidities of addiction). The abuse and misuse of medically prescribed opioid products is a growing health epidemic. A variety of attempts have been made to reduce the potential of abuse and misuse of these products, including changes to product formulations. The results of this study indicate that both prescription spending and physician and pharmacy spending combined may be increased with the use of these new products because of higher pricing. Study findings also suggest that the use of ADTR opioids among members with comorbidities of addiction may be related to slightly lower overall health care and medical expenditures than those among members without comorbidities of addiction. Further research is required to answer questions regarding the comparative effectiveness of existing opioid prescription formulations. No outside funding supported this research. Nesser is employed by the Oklahoma Health Care Authority, and Keast is a contractual employee for the Oklahoma Health Care Authority. The authors declare no other conflicts of interest. Study design was primarily contributed by Keast, along with Nesser and Farmer. Keast took the lead in data collection, while data interpretation was primarily performed by Owora, along with Keast and assisted by Nesser and Farmer. The manuscript was written and revised by all authors equally.

Will abuse-deterrent formulations of opioid analgesics be successful in achieving their purpose?

PubMed

Bannwarth, Bernard

2012-09-10

During the last 2 decades, there has been a dramatic increase in the use of strong opioids for chronic non-cancer pain. This increase has been accompanied by a steep increase in abuse, misuse, and both fatal and non-fatal overdoses involving prescription opioids. The situation is already alarming in the US. Prescription opioid-related harm is a complex, multifactorial issue that requires a multifaceted solution. In this respect, formulations of opioid analgesics designed to resist or deter abuse may be a useful component of a comprehensive opioid risk minimization programme. Such formulations have or are being developed. Abuse-resistant opioids include those that use some kind of physical barrier to prevent tampering with the formulation. Abuse-deterrent opioids are not necessarily resistant to tampering, but contain substances that are designed to make the formulation less attractive to abusers. This article focuses on two products intended to deter abuse that were reviewed by the US Food and Drug Administration (FDA). The first (Embeda®) consists of extended-release morphine with sequestered naltrexone, an opioid antagonist that is released if the tablet is compromised by chewing or crushing. Although Embeda® exhibited abuse-deterrent features, its label warns that it can be abused in a manner similar to other opioid agonists. Furthermore, tampering with Embeda® will result in the release of naltrexone, which may precipitate withdrawal in opioid-tolerant individuals. In March 2011, all dosage forms of Embeda® were recalled because the product failed to meet routine stability standards, and its return date to the market is currently unknown. The second product (Acurox®) was intended to be both tamper resistant and abuse deterrent. It consisted of an immediate-release oxycodone tablet with subtherapeutic niacin as an aversive agent and used a gel-forming ingredient designed to inhibit inhalation and prevent extraction of the drug for injection. The new drug application for Acurox® was rejected in 2010 by the FDA because of concerns about the potential abuse-deterrent benefits of niacin. While acknowledging that no one formulation can be expected to deter all types of opioid-abusive behaviours and no product is likely to be abuse proof in the hands of clear and determined abusers, the reductions in abuse these new products would provide may be an incremental step towards safer prescription opioids.

Continuous manufacturing of extended release tablets via powder mixing and direct compression.

PubMed

Ervasti, Tuomas; Simonaho, Simo-Pekka; Ketolainen, Jarkko; Forsberg, Peter; Fransson, Magnus; Wikström, Håkan; Folestad, Staffan; Lakio, Satu; Tajarobi, Pirjo; Abrahmsén-Alami, Susanna

2015-11-10

The aim of the current work was to explore continuous dry powder mixing and direct compression for manufacturing of extended release (ER) matrix tablets. The study was span out with a challenging formulation design comprising ibuprofen compositions with varying particle size and a relatively low amount of the matrix former hydroxypropyl methylcellulose (HPMC). Standard grade HPMC (CR) was compared to a recently developed direct compressible grade (DC2). The work demonstrate that ER tablets with desired quality attributes could be manufactured via integrated continuous mixing and direct compression. The most robust tablet quality (weight, assay, tensile strength) was obtained using high mixer speed and large particle size ibuprofen and HPMC DC2 due to good powder flow. At low mixer speed it was more difficult to achieve high quality low dose tablets. Notably, with HPMC DC2 the processing conditions had a significant effect on drug release. Longer processing time and/or faster mixer speed was needed to achieve robust release with compositions containing DC2 compared with those containing CR. This work confirms the importance of balancing process parameters and material properties to find consistent product quality. Also, adaptive control is proven a pivotal means for control of continuous manufacturing systems. Copyright © 2015 Elsevier B.V. All rights reserved.

Controlled Release of Imidacloprid from Poly Styrene-Diacetone - Nanoformulation

NASA Astrophysics Data System (ADS)

Qian, Kun; Guo, Yanzhen; He, Lin

2012-01-01

Imidacloprid is a neonicotinoids insecticide, which is important for the cash crops such as tomato, rape and so on. The conventional formulation does not only increase the loss of pesticide but also leads to environmental pollution. Controlled-release formulations of pesticide are highly desirable not only for attaining the most effective utilization of the pesticide, but also for reducing environmental pollution. Pesticide imidacloprid was incorporated in poly (styrene-diacetone crylamide)-based formulation to obtain controlled release properties, and the imidacloprid nanocontrolled release formulation was characterized by infrared (IR) and field emission scanning electron microscope (FESEM). Factors related to loading efficiency, swelling and release behaviors of the formulation were investigated. It showed that the loading efficiency could reach about 40% (w/w). The values for the diffusion exponent "n" were in the range of 0.31-0.58, which indicated that the release of imidacloprid was diffusion-controlled. The time taken for 50% of the active ingredient to be released into water, T50, was also calculated for the comparison of formulations in different conditions. The results showed that the formulation with higher temperature and more diacetone crylamide had lower value of T50, which means a quicker release of the active ingredient. This study highlighted some pieces of evidence that improved pesticide incorporation and slower release were linked to potential interactions between the pesticide and the polymer.

Formulation and optimization of zinc-pectinate beads for the controlled delivery of resveratrol.

PubMed

Das, Surajit; Ng, Ka-Yun; Ho, Paul C

2010-06-01

Preventive and therapeutic efficacies of resveratrol on several lower gastrointestinal (GI) diseases (e.g., colorectal cancer, colitis) are well documented. To overcome the problems due to its rapid absorption and metabolism at the upper GI tract, a delayed release formulation of resveratrol was designed to treat these lower GI diseases. The current study aimed to develop a delayed release formulation of resveratrol as multiparticulate pectinate beads by varying different formulation parameters. Zinc-pectinate (Zn-pectinate) beads exhibited better delayed drug release pattern than calcium-pectinate (Ca-pectinate) beads. The effects of the formulation parameters were investigated on shape, size, Zn content, moisture content, drug encapsulation efficiency, swelling-erosion, and resveratrol retention pattern of the formulated beads. Upon optimization of the formulation parameters in relative to the drug release profiles, the optimized beads were further subjected to morphological, chemical interaction, enzymatic degradation, and stability studies. Almost all prepared beads were spherical with approximately 1 mm diameter and efficiently encapsulated resveratrol. The formulation parameters revealed great influence on resveratrol retention and swelling-erosion behavior. In most of the cases, the drug release data more appropriately fitted with zero-order equation. This study demonstrates that the optimized Zn-pectinate beads can encapsulate very high amount of resveratrol and can be used as delayed release formulation of resveratrol.

In vitro solubility, dissolution and permeability studies combined with semi-mechanistic modeling to investigate the intestinal absorption of desvenlafaxine from an immediate- and extended release formulation.

PubMed

Franek, F; Jarlfors, A; Larsen, F; Holm, P; Steffansen, B

2015-09-18

Desvenlafaxine is a biopharmaceutics classification system (BCS) class 1 (high solubility, high permeability) and biopharmaceutical drug disposition classification system (BDDCS) class 3, (high solubility, poor metabolism; implying low permeability) compound. Thus the rate-limiting step for desvenlafaxine absorption (i.e. intestinal dissolution or permeation) is not fully clarified. The aim of this study was to investigate whether dissolution and/or intestinal permeability rate-limit desvenlafaxine absorption from an immediate-release formulation (IRF) and Pristiq(®), an extended release formulation (ERF). Semi-mechanistic models of desvenlafaxine were built (using SimCyp(®)) by combining in vitro data on dissolution and permeation (mechanistic part of model) with clinical data (obtained from literature) on distribution and clearance (non-mechanistic part of model). The model predictions of desvenlafaxine pharmacokinetics after IRF and ERF administration were compared with published clinical data from 14 trials. Desvenlafaxine in vivo dissolution from the IRF and ERF was predicted from in vitro solubility studies and biorelevant dissolution studies (using the USP3 dissolution apparatus), respectively. Desvenlafaxine apparent permeability (Papp) at varying apical pH was investigated using the Caco-2 cell line and extrapolated to effective intestinal permeability (Peff) in human duodenum, jejunum, ileum and colon. Desvenlafaxine pKa-values and octanol-water partition coefficients (Do:w) were determined experimentally. Due to predicted rapid dissolution after IRF administration, desvenlafaxine was predicted to be available for permeation in the duodenum. Desvenlafaxine Do:w and Papp increased approximately 13-fold when increasing apical pH from 5.5 to 7.4. Desvenlafaxine Peff thus increased with pH down the small intestine. Consequently, desvenlafaxine absorption from an IRF appears rate-limited by low Peff in the upper small intestine, which "delays" the predicted time to the maximal plasma concentration (tmax), consistent with clinical data. Conversely, desvenlafaxine absorption from the ERF appears rate-limited by dissolution due to the formulation, which tends to negate the influence of pH-dependent permeability on absorption. We suggest that desvenlafaxine Peff is mainly driven by transcellular diffusion of the unionized form. In the case of desvenlafaxine, poor metabolism does not imply low intestinal permeability, as indicated by the BDDCS, merely low duodenal/jejunal permeability. Copyright © 2015 Elsevier B.V. All rights reserved.

Formulation and in vitro evaluation of sustained release matrix tablets using cross-linked natural gum.

PubMed

Jamil, Qurratul Ain; Masood, Muhammad Irfan; Jamil, Muhammad Nauman; Masood, Imran; Iqbal, Shahid Muhammad

2017-03-01

Polysaccharide gums because of their biocompatibility, biodegradability and non-immunogenic properties are considered as the best choice for preparing sustained release tablets as compared to their synthetic counterpart. The cross linking of natural gums in matrix tablets increase the sustained release property of matrix tablets. Isoniazid is a first line therapy of tuberculosis, belongs to BCS I with half-life of 3-4 hours. These characteristics make isoniazid a good candidate for sustained release dosage form. Karaya gum crossed linked with trisodium tri metaphosphate was used as release rate retardant for preparing isoniazid cross-linked matrix tablet. Total 8 sustained release formulations were prepared. Both granules and tablets were evaluated under in vitro condition against different parameters. Dissolution studies were performed with all eight formulations for 12 hours using USP apparatus I. Four formulations designated as F1, F2, F3, F4 have drug and karaya gum while other four formulations F5, F6, F7, F8 have drug and crossed linked polymer in ratios of 1:1, 1:2, 1:3 and 1:4 respectively. Dissolution data was analyzed by using different kinetic models. Best fit model for most efficient formulation was zero order while release mechanism was super case I. Formulation 8 showed sufficiently slow release kinetics and about 83% of drug was released in 10 hours, indicating that cross-linked karaya gum proved efficient in preparing sustained release tablets.

Development and evaluation of 6-mercaptopurine and metoclopramide polypill formulation for oral administration: In-vitro and ex vivo studies

PubMed Central

Chowdhary, Rajani; Pai, Roopa S; Singh, Gurinder

2013-01-01

Introduction: The present investigation was to develop a polypill of 6-mercaptopurine and metoclopramide. A polypill with delayed release granules of an anticancer and immediate release mucoadhesive tablet of antiemetic may result in the reduction of emesis caused by oral chemotherapy. Materials and Methods: 6-Mercaptopurine granules were prepared by wet granulation process. Chitosan, hydroxypropyl methylcellulose, and ethylcellulose were used as individually as delayed release polymers. Seven granule formulations (F1-F7) were prepared and evaluated for flow properties and drug content. Immediate release mucoadhesive tablets of metoclopramide were prepared by direct compression technique using pectin and PVPK-40 as mucoadhesive polymers. Three formulations of pectin (L1-L3) and three formulations of PVPK40 (M1-M3) were prepared using lactose, magnesium stearate, and mannitol and talc as diluent and glidant, respectively. Tablets were evaluated for weight variation, hardness, friability, drug content, ex vivo mucoadhesion time, and in vitro dissolution studies. Results: Formulation F2, F4, F5, and F7 showed maximum drug content. Formulation F7 exhibited the drug release up to 2 h and was selected as the best delayed release formulation. All formulations of metoclopramide showed good drug content ranging from 97.6 % to 100.6%. Formulation M2 among tablets prepared with PVP exhibited desired mucoadhesion time of 15.33 min which prolongs the duration of drug release in gastric pouch of the male Wistar rats. Both the selected formulations F7 and M2 were filled into body of capsule size 0 and capsule was evaluated for technological properties. Conclusion: It may be concluded that polypill released the metoclopramide immediately prior to 6-mercaptopurine. PMID:24350042

Bioadhesive Controlled Metronidazole Release Matrix Based on Chitosan and Xanthan Gum

PubMed Central

Eftaiha, Ala’a F.; Qinna, Nidal; Rashid, Iyad S.; Al Remawi, Mayyas M.; Al Shami, Munther R.; Arafat, Tawfiq A.; Badwan, Adnan A.

2010-01-01

Metronidazole, a common antibacterial drug, was incorporated into a hydrophilic polymer matrix composed of chitosan xanthan gum mixture. Hydrogel formation of this binary chitosan-xanthan gum combination was tested for its ability to control the release of metronidazole as a drug model. This preparation (MZ-CR) was characterized by in vitro, ex vivo bioadhesion and in vivo bioavailability study. For comparison purposes a commercial extended release formulation of metronidazole (CMZ) was used as a reference. The in vitro drug-release profiles of metronidazole preparation and CMZ were similar in 0.1 M HCl and phosphate buffer pH 6.8. Moreover, metronidazole preparation and CMZ showed a similar detachment force to sheep stomach mucosa, while the bioadhesion of the metronidazole preparation was higher three times than CMZ to sheep duodenum. The results of in vivo study indicated that the absorption of metronidazole from the preparation was faster than that of CMZ. Also, MZ-CR leads to higher metronidazole Cmax and AUC relative to that of the CMZ. This increase in bioavailability might be explained by the bioadhesion of the preparation at the upper part of the small intestine that could result in an increase in the overall intestinal transit time. As a conclusion, formulating chitosan-xanthan gum mixture as a hydrophilic polymer matrix resulted in a superior pharmacokinetic parameters translated by better rate and extent of absorption of metronidazole. PMID:20559494

Mini-tablets versus pellets as promising multiparticulate modified release delivery systems for highly soluble drugs.

PubMed

Gaber, Dina M; Nafee, Noha; Abdallah, Osama Y

2015-07-05

Whether mini-tablets (tablets, diameters ≤6mm) belong to single- or multiple-unit dosage forms is still questionable. Accordingly, Pharmacopoeial evaluation procedures for mini-tablets are lacking. In this study, the aforementioned points were discussed. Moreover, their potential for oral controlled delivery was assessed. The antidepressant venlafaxine hydrochloride (Vx), a highly soluble drug undergoing first pass effect, low bioavailability and short half-life was selected as a challenging payload. In an attempt to weigh up mini-tablets versus pellets as multiparticulate carriers, Vx-loaded mini-tablets were compared to formulated pellets of the same composition and the innovator Effexor(®)XR pellets. Formulations were prepared using various polymer hydrogels in the core and ethyl cellulose film coating with increasing thickness. Mini-tablets (diameter 2mm) showed extended Vx release (<60%, 8h). Indeed, release profiles comparable to Effexor(®)XR pellets were obtained. Remarkably higher coating thickness was required for pellets to provide equivalent retardation. Ethyl cellulose in the core ensured faster release due to polymer migration to the surface and pore formation in the coat. mini-tablets showed higher stability to pellets upon storage. Industrially speaking, mini-tablets proved to be superior to pellets in terms of manufacturing, product quality and economical aspects. Results point out the urgent need for standardized evaluation procedures for mini-tablets. Copyright © 2015. Published by Elsevier B.V.

Acute Effects of Zolpidem Extended-Release on Cognitive Performance and Sleep in Healthy Males After Repeated Nightly Use

PubMed Central

Kleykamp, Bethea A.; Griffiths, Roland R.; McCann, Una D.; Smith, Michael T.; Mintzer, Miriam Z.

2012-01-01

The extended-release formulation of zolpidem (Ambien CR®) is approved for the treatment of insomnia without a treatment duration limit. Acutely zolpidem impairs performance, and no research to date has examined whether tolerance develops to these performance impairments during nighttime awakening. The present double-blind, placebo-controlled study examined whether tolerance develops to zolpidem-induced acute performance impairment after repeated (22–30 days) nightly use. Effects of bedtime administration of zolpidem extended-release (ZOL; 12.5 mg) were tested on a battery of performance measures assessed during a forced nighttime awakening in 15 healthy male volunteers who completed overnight polysomnographic recording sessions in our laboratory at baseline and after approximately a month of at-home ZOL. As expected, bedtime ZOL administration was associated with changes in sleep architecture and impairments across all performance domains during nighttime testing (psychomotor function, attention, working memory, episodic memory, metacognition) with no residual next morning impairment. Tolerance did not develop to the observed ZOL-related impairments on any outcome. Possible evidence of acute abstinence effects following discontinuation of ZOL was observed on some performance and sleep outcomes. Overall, these findings suggest that performance is significantly impaired during nighttime awakening even after a month of nightly ZOL administration and these impairments could significantly impact safety should nighttime awakening require unimpaired functioning (e.g., driving; combat-related activities in the military). PMID:21928913

Tramadol Extended-Release for the Management of Pain due to Osteoarthritis

PubMed Central

Guetti, Cristiana; Paladini, Antonella; Varrassi, Giustino

2013-01-01

Current knowledge on pathogenesis of osteoarticular pain, as well as the consequent several, especially on the gastrointestinal, renal, and cardiovascular systems, side effects of NSAIDs, makes it difficult to perform an optimal management of this mixed typology of pain. This is especially observable in elderly patients, the most frequently affected by osteoarthritis (OA). Tramadol is an analgesic drug, the action of which has a twofold action. It has a weak affinity to mu opioid receptors and, at the same time, can result in inhibition of the reuptake of noradrenaline and serotonin in nociceptorial descending inhibitory control system. These two mechanisms, “opioidergic” and “nonopioidergic,” are the grounds for contrasting certain types of pain that are generally less responsive to opioids, such as neuropathic pain or mixed OA pain. The extended-release formulation of tramadol has good efficacy and tolerability and acts through a dosing schedule that allows a high level of patients compliance to therapies with a good recovery outcome for the patients' functional status. PMID:27335872

Drug Release and Skin Permeation from Lipid Liquid Crystalline Phases

NASA Astrophysics Data System (ADS)

Costa-Balogh, F. O.; Sparr, E.; Sousa, J. J. S.; Pais, A. A. C. C.

We have studied drug release and skin permeation from several different liquid crystalline lipid formulations that may be used to control the respective release rates. We have studied the release and permeation through human skin of a water-soluble and amphiphilic drug, propranolol hydrochloride, from several formulations prepared with monoolein and phytantriol as permeation enhancers and controlled release excipients. Diolein and cineol were added to selected formulations. We observed that viscosity decreases with drug load, wich is compatible with the occurrence of phase changes. Diolein stabilizes the bicontinuous cubic phases leading to an increase in viscosity and sustained release of the drug. The slowest release was found for the cubic phases with higher viscosity. Studies on skin permeation showed that these latter formulations also presented lower permeability than the less viscous monoolein lamellar phases. Formulations containing cineol originated higher permeability with higher enhancement ratios. Thus, the various formulations are adapted to different circumstances and delivery routes. While a slow release is usually desired for drug sustained delivery, the transdermal route may require a faster release. Lamellar phases, which are less viscous, are more adapted to transdermal applications. Thus, systems involving lamellar phases of monoolein and cineol are good candidates to be used as skin permeation enhancers for propranolol hydrochloride.

The role of hyaluronan as a drug carrier to enhance the bioavailability of extended release ophthalmic formulations. Hyaluronan-timolol ionic complexes as a model case.

PubMed

Battistini, F D; Tártara, L I; Boiero, C; Guzmán, M L; Luciani-Giaccobbe, L C; Palma, S D; Allemandi, D A; Manzo, R H; Olivera, M E

2017-07-15

The aim of this work was to obtain information concerning the properties of ophthalmic formulations based on hyaluronic-drug ionic complexes, to identify the factors that determine the onset, intensity and duration of the pharmacotherapeutic effect. Dispersions of a complex of 0.5% w/v of sodium hyaluronate (HyNa) loaded with 0.5% w/v of timolol maleate (TM) were obtained and presented a counterionic condensation higher than 75%. For comparison a similar complex obtained with hyaluronic acid (HyH) was also prepared. Although the viscosity of HyNa-TM was significantly higher than that of HyH-TM, in vitro release of TM from both complexes showed a similar extended drug release profile (20-31% over 5h) controlled by diffusion and ionic exchange. Ocular pharmacokinetic study performed in normotensive rabbits showed that HyNa-TM complex exhibited attractive bioavailability properties in the aqueous humor (AUC and Cmax significantly higher and later Tmax) compared to commercial TM eye-drops. Moreover, a more prolonged period of lowered intra-ocular pressure (10h) and a more intense hypotensive activity was observed after instillation of a drop of HyNa-TM as compared to the eye-drops. Such behavior was related to the longer pre-corneal residence times (400%) observed with HyNa-TM complex. No significant changes in rabbit transcorneal permeation were detected upon complexation. These results demonstrate that the ability of HyNa to modulate TM release, together with its mucoadhesiveness related to the viscosity, affected both the pharmacokinetic and pharmacodynamic parameters. The HyNa-TM complex is a potentially useful carrier for ocular drug delivery, which could improve the TM efficacy and reduce the frequency of administration to improve patient compliance. Copyright © 2017 Elsevier B.V. All rights reserved.

Influence of Drug Properties and Formulation on In Vitro Drug Release and Biowaiver Regulation of Oral Extended Release Dosage Forms.

PubMed

Lin, Zhongqiang; Zhou, Deliang; Hoag, Stephen; Qiu, Yihong

2016-03-01

Bioequivalence (BE) studies are often required to ensure therapeutic equivalence for major product and manufacturing changes. Waiver of a BE study (biowaiver) is highly desired for such changes. Current regulatory guidelines allow for biowaiver of proportionally similar lower strengths of an extended release (ER) product provided it exhibits similar dissolution to the higher strength in multimedia. The objective of this study is to demonstrate that (1) proportionally similar strengths of ER tablets exhibiting similar in vitro dissolution profiles do not always assure BE and (2) different strengths that do not meet the criteria for dissolution profile similarity may still be bioequivalent. Four marketed ER tablets were used as model drug products. Higher and lower (half) strength tablets were prepared or obtained from commercial source. In vitro drug release was compared using multi-pH media (pH 1.2, 4.5, 6.8) per regulatory guidance. In vivo performance was assessed based on the available in vivo BE data or established in vitro-in vivo relationships. This study demonstrated that the relationship between in vitro dissolution and in vivo performance is complex and dependent on the characteristics of specific drug molecules, product design, and in vitro test conditions. As a result, proportionally similar strengths of ER dosage forms that meet biowaiver requirements per current regulatory guidelines cannot ensure bioequivalence in all cases. Thus, without an established relationship between in vitro and in vivo performance, granting biowaiver based on passing in vitro tests may result in the approval of certain bioinequivalent products, presenting risks to patients. To justify any biowaiver using in vitro test, it is essential to understand the effects of drug properties, formulation design, product characteristics, test method, and its in vivo relevance. Therefore, biowaiver requirements of different strengths of ER dosage forms specified in the current regulatory guidance should be reevaluated to assure consistent safety and efficacy among different strengths.

Evaluation of Flexible Tacrolimus Drug Concentration Monitoring Approach in Patients Receiving Extended-Release Once-Daily Tacrolimus Tablets.

PubMed

Philosophe, Benjamin; Leca, Nicolae; West-Thielke, Patricia M; Horwedel, Timothy; Culkin-Gemmell, Christine; Kistler, Kristin; Stevens, Daniel R

2018-02-20

The majority of United States kidney transplant patients are treated with tacrolimus, a drug effective in preventing graft rejection, but with a narrow therapeutic range, necessitating close monitoring to avoid increased risks of transplant rejection or toxicity if the tacrolimus concentration is too low or too high, respectively. The trough drug concentration tests are time sensitive; patients treated on a twice-daily basis have blood draws exactly 12 hours after their previous dose. The schedule's rigidity causes problems for both patients and health care providers. Novel once-daily tacrolimus formulations such as LCPT (an extended-release tablet by Veloxis Pharmaceuticals, Inc., Cary, North Carolina) have allowed for blood draws on a once-daily basis; however, even that schedule can be restrictive. Results from tests taken either before or after that 24-hour target time may be discarded, or worse, may lead to inappropriate dose changes. Data from ASTCOFF, a phase 3B pharmacokinetic clinical trial (NCT02339246), demonstrated that the unique pharmacokinetic curve of LCPT may allow for a therapeutic monitoring window that extends for 3 hours before or after the 24-hour monitoring target. Furthermore, important tools to help clinicians interpret these levels, such as formulas to estimate the 24-hour trough level if an alternative monitoring time is used, were constructed from these data. These study results give treating clinicians access to data that allow them to safely use and monitor LCPT in their patients and expand the body of evidence surrounding differentiation and practical application of the novel LCPT tacrolimus formulation. © 2018, The Authors. The Journal of Clinical Pharmacology published by Wiley Periodicals, Inc. on behalf of American College of Clinical Pharmacology.

Controlled delivery of metoclopramide using an injectable semi-solid poly(ortho ester) for veterinary application.

PubMed

Schwach-Abdellaoui, Khadija; Moreau, Marinette; Schneider, Marc; Boisramć, Bernard; Gurny, Robert

2002-11-06

In animal health care, current therapeutic regimens for gastrointestinal disorders require repeated oral or parenteral dosage forms of anti-emetic agents. However, fluctuations of plasma concentrations produce severe side effects. The aim of this work is to develop a subcutaneous and biodegradable controlled release system containing metoclopramide (MTC). Semi-solid poly(ortho ester)s (POE) prepared by a transesterification reaction between trimethyl orthoacetate and 1,2,6,-hexanetriol were investigated as injectable bioerodible polymers for the controlled release of MTC. MTC is present in the polymeric matrix as a solubilised form and it is released rapidly from the POE by erosion and diffusion because of its acidic character and its high hydrosolubility. If a manual injection is desired, only low molecular weight can be used. However, low molecular weight POEs release the drug rapidly. In order to extend polymer lifetime and decrease drug release rate, a sparingly water-soluble base Mg(OH)(2) was incorporated to the formulation. It was possible to produce low molecular weight POE that can be manually injected and releasing MTC over a period of several days.

Formulation and characterization of modified release tablets containing isoniazid using swellable polymers.

PubMed

Akhtar, M F; Rabbani, M; Sharif, A; Akhtar, B; Saleem, A; Murtaza, G

2011-01-01

The aim of this work was to develop swellable modified release (MR) isoniazid tablets using different combinations of polyvinyl acetate (PVAc) and sodium-carboxymethylcellulose (Na-CMC). Granules were prepared by moist granulation technique and then compressed into tablets. In vitro release studies for 12 hr were carried out in dissolution media of varying pH i.e. pH 1.2, 4.5, 7.0 and 7.5. Tablets of all formulations were found to be of good physical quality with respect to appearance (width and thickness), content uniformity, hardness, weight variation and friability. In vitro release data showed that increasing total polymer content resulted in more retarding effect. Formulation with 35% polymer content exhibited zero order release profile and it released 35% of the drug in first hr, later on, controlled drug release was observed upto the 12(th) hour. Formulations with PVAc to Na-CMC ratio 20:80 exhibited zero order release pattern at levels of studied concentrations, which suggested that this combination can be used to formulate zero order release tablets of water soluble drugs like isoniazid. Korsmeyer-Peppas modeling of drug release showed that non-Fickian transport is the primary mechanism of isoniazid release from PVAc and Na-CMC based tablets. The value of mean dissolution time decreased with the increase in the release rate of drug clearly showing the retarding behavior of the swellable polymers. The application of a mixture of PVAc to Na-CMC in a specific ratio may be feasible to formulate zero order release tablets of water soluble drugs like isoniazid.

Novel system for reducing leaching of the herbicide metribuzin using clay-gel-based formulations.

PubMed

Maqueda, Celia; Villaverde, Jaime; Sopeña, Fátima; Undabeytia, Tomás; Morillo, Esmeralda

2008-12-24

Metribuzin is an herbicide widely used for weed control that has been identified as a groundwater pollutant. It contaminates the environment even when it is used according to the manufacturer's instructions. To reduce herbicide leaching and increase weed control, new controlled release formulations were developed by entrapping metribuzin within a sepiolite-gel-based matrix using two clay/herbicide proportions (0.5/0.2 and 1/0.2) (loaded at 28.6 and 16.7% a.i.) as a gel (G28, G16) or as a powder after freeze-drying (LF28, LF16). The release of metribuzin from the control released formulations into water was retarded, when compared with commercial formulation (CF) except in the case of G28. The mobility of metribuzin from control released formulations into soil columns of sandy soil was greatly diminished in comparison with CF. Most of the metribuzin applied as control released formulations (G16, LF28 and LF16) was found at a depth of 0-8 cm depth. In contrast, residues from CF and G28 along the column were almost negligible. Bioassays from these control released formulations showed high efficacy at 0-12 cm depth. The use of these novel formulations could minimize the risk of groundwater contamination while maintaining weed control for a longer period.

A Drug-Eluting Contact Lens

PubMed Central

Ciolino, Joseph B.; Hoare, Todd R.; Iwata, Naomi G.; Behlau, Irmgard; Dohlman, Claes H.; Langer, Robert; Kohane, Daniel S.

2014-01-01

Purpose To formulate and characterize a drug-eluting contact lens designed to provide extended, controlled release of a drug. Methods Prototype contact lenses were created by coating PLGA (poly[lactic-co-glycolic acid]) films containing test compounds with pHEMA (poly[hydroxyethyl methacrylate]) by ultraviolet light polymerization. The films, containing encapsulated fluorescein or ciprofloxacin, were characterized by scanning electron microscopy. Release studies were conducted in phosphate-buffered saline at 37°C with continuous shaking. Ciprofloxacin eluted from the contact lens was studied in an antimicrobial assay to verify antimicrobial effectiveness. Results After a brief and minimal initial burst, the prototype contact lenses demonstrated controlled release of the molecules studied, with zero-order release kinetics under infinite sink conditions for over 4 weeks. The rate of drug release was controlled by changing either the ratio of drug to PLGA or the molecular mass of the PLGA used. Both the PLGA and the pHEMA affected release kinetics. Ciprofloxacin released from the contact lenses inhibited ciprofloxacin-sensitive Staphylococcus aureus at all time-points tested. Conclusions A prototype contact lens for sustained drug release consisting of a thin drug-PLGA film coated with pHEMA could be used as a platform for ocular drug delivery with widespread therapeutic applications. PMID:19136709

Pharmacokinetics of a once-daily extended-release formulation of pramipexole in healthy male volunteers: three studies.

PubMed

Jenner, Peter; Könen-Bergmann, Michael; Schepers, Cornelia; Haertter, Sebastian

2009-11-01

Pramipexole is a dopamine agonist used in the treatment of Parkinson's disease. The currently available immediate-release (IR) formulation is taken orally 3 times daily. These studies were conducted to evaluate the pharmacokinetic properties of a variety of prototypes for a once-daily extended-release (ER) formulation of pramipexole and to further characterize the prototype whose pharmacokinetics best matched those of the IR formulation. Three Phase I studies were conducted, all in healthy adult men aged

Synthesis and characterization of emamectin-benzoate slow-release microspheres with different surfactants.

PubMed

Wang, Yan; Wang, Anqi; Wang, Chunxin; Cui, Bo; Sun, Changjiao; Zhao, Xiang; Zeng, Zhanghua; Shen, Yue; Gao, Fei; Liu, Guoqiang; Cui, Haixin

2017-10-06

Pesticide slow-release formulations provide a way to increase the efficiency of active components by reducing the amount of pesticide that needs to be applied. Slow-release formulations also increase the stability and prolong the control effect of photosensitive pesticides. Surfactants are an indispensable part of pesticide formulations, and the choice of surfactant can strongly affect formulation performance. In this study, emamectin-benzoate (EMB) slow-release microspheres were prepared by the microemulsion polymerization method. We explored the effect of different surfactants on the particle size and dispersity of EMB in slow-release microspheres. The results indicated that the samples had uniform spherical shapes with an average diameter of 320.5 ±5.24 nm and good dispersity in the optimal formulation with the polymeric stabilizer polyvinyl alcohol (PVA) and composite non-ionic surfactant polyoxyethylene castor oil (EL-40). The optimal EMB pesticide slow-release microspheres had excellent anti-photolysis performance, stability, controlled release properties, and good leaf distribution. These results demonstrated that EMB slow-release microspheres are an attractive candidate for improving pesticide efficacy and prolonging the control effect of EMB in the environment.

Dissolution of Commercially Available Mesalamine Formulations at Various pH Levels.

PubMed

Tenjarla, Srini

2015-06-01

Mesalamine (5-aminosalicylic acid; 5-ASA) is recommended first-line therapy for mild-to-moderate ulcerative colitis. Many mesalamine formulations employ a pH-dependent release mechanism designed to maximize drug release in the colon. This study compared the in vitro release of 5-ASA from six commercially available mesalamine formulations at pH levels similar to those typically encountered in the human gastrointestinal tract. The release of 5-ASA from six mesalamine formulations [Mesalazin-Kohlpharma (Kohlpharma, Germany), Mesalazin-Eurim (Eurimpharm, Germany), Mesalazina-Faes (Faes Farma, Spain), Mesalazine EC (Actavis B.V., Netherlands), Mesalazine EC 500 PCH (Pharmachemie B.V., Netherlands); multimatrix mesalamine (Shire US Inc., USA)] was monitored separately at three different pH levels [1.0 (2 h), 6.4 (1 h), and 7.2 (8 h)] using United States Pharmacopeia dissolution apparatus II. The dissolution percentage was calculated as a mean of 12 units for each formulation. At pH 1.0 and 6.4, <1 % of 5-ASA release was observed for each of the mesalamine formulations tested. At pH 7.2, complete release of 5-ASA occurred within 1 h for Mesalazine EC and Mesalazine EC 500 PCH, and within 2 h for Mesalazin-Kohlpharma, Mesalazin-Eurim, and Mesalazina-Faes; complete release of 5-ASA from multimatrix mesalamine occurred within 7 h. Little variability in rate of 5-ASA dissolution was observed between tablets of each formulation. At pH 7.2, 5-ASA release profiles were variable among the commercially available mesalamine formulations that were tested.

Calcium Coordination Solids for pH-Triggered Release of Olsalazine

DOE Office of Scientific and Technical Information (OSTI.GOV)

Levine, Dana J.; Gonzalez, Miguel I.; Legendre, Christina M.

Here, calcium coordination solids were synthesized and evaluated for delivery of olsalazine (H 4olz), an anti-inflammatory compound used for treatment of ulcerative colitis. The materials include one-dimensional Ca(H 2olz)•4H 2O chains, two-dimensional Ca(H 2olz)•2H 2O sheets, and a three-dimensional metal-organic framework Ca(H 2olz)•2DMF (DMF= N,N-dimethylformamide). The framework undergoes structural changes in response to solvent, forming a dense Ca(H 2olz) phase when exposed to aqueous HCl. The compounds Ca(H 2olz)•xH 2O (x=0, 2, 4) were each pressed into pellets and exposed to simulated gastrointestinal fluids to mimic the passage of a pill from the acidic stomach to the pH-neutral intestines. Allmore » three calcium materials exhibited a delayed release of olsalazine relative to Na 2(H 2olz), the commercial formulation, illustrating how formulation of a drug within an extended coordination solid can serve to tune its solubility and performance.« less

Calcium Coordination Solids for pH-Triggered Release of Olsalazine

DOE PAGES

Levine, Dana J.; Gonzalez, Miguel I.; Legendre, Christina M.; ...

2017-09-12

Here, calcium coordination solids were synthesized and evaluated for delivery of olsalazine (H 4olz), an anti-inflammatory compound used for treatment of ulcerative colitis. The materials include one-dimensional Ca(H 2olz)•4H 2O chains, two-dimensional Ca(H 2olz)•2H 2O sheets, and a three-dimensional metal-organic framework Ca(H 2olz)•2DMF (DMF= N,N-dimethylformamide). The framework undergoes structural changes in response to solvent, forming a dense Ca(H 2olz) phase when exposed to aqueous HCl. The compounds Ca(H 2olz)•xH 2O (x=0, 2, 4) were each pressed into pellets and exposed to simulated gastrointestinal fluids to mimic the passage of a pill from the acidic stomach to the pH-neutral intestines. Allmore » three calcium materials exhibited a delayed release of olsalazine relative to Na 2(H 2olz), the commercial formulation, illustrating how formulation of a drug within an extended coordination solid can serve to tune its solubility and performance.« less

Development of controlled release formulations of azadirachtin-A employing poly(ethylene glycol) based amphiphilic copolymers.

PubMed

Kumar, Jitendra; Shakil, Najam A; Singh, Manish K; Singh, Mukesh K; Pandey, Alka; Pandey, Ravi P

2010-05-01

Controlled release (CR) formulations of azadirachtin-A, a bioactive constituent derived from the seed of Azadirachta indica A. Juss (Meliaceae), have been prepared using commercially available polyvinyl chloride, polyethylene glycol (PEG) and laboratory synthesized poly ethylene glycol-based amphiphilic copolymers. Copolymers of polyethylene glycol and various dimethyl esters, which self assemble into nano micellar aggregates in aqueous media, have been synthesized. The kinetics of azadirachtin-A, release in water from the different formulations was studied. Release from the commercial polyethylene glycol (PEG) formulation was faster than the other CR formulations. The rate of release of encapsulated azadirachtin-A from nano micellar aggregates is reduced by increasing the molecular weight of PEG. The diffusion exponent (n value) of azadirachtin-A, in water ranged from 0.47 to 1.18 in the tested formulations. The release was diffusion controlled with a half release time (t(1/2)) of 3.05 to 42.80 days in water from different matrices. The results suggest that depending upon the polymer matrix used, the application rate of azadirachtin-A can be optimized to achieve insect control at the desired level and period.

Development of Intra-knee Joint Sustained-Release Gel Formulation and Evaluation of Its Pharmacological Efficiency in Rats.

PubMed

Noda, Takehiro; Okuda, Tomoyuki; Ban, Kousuke; Mizuno, Ryota; Tagami, Tatsuaki; Ozeki, Tetsuya; Okamoto, Hirokazu

2017-06-01

In the development of a drug for intra-articular administration, a sustained-release formulation is desirable since it is difficult to sustain the effects of conventional injections due to fast drug leakage from the joint cavity. In this study, we prepared sustained release gel formulations for intra-articular administration containing indocyanine green (ICG) as a model drug to follow its fate after intra-articular administration in rats with in-vivo imaging system (IVIS). ICG administered as an aqueous solution leaked from the joint cavity in a short time and was excreted out of the body within a day. On the other hand, ICG in the sustained-release formulations was retained and released in the joint cavity for a week. Next, we prepared a sustained-release formulation with hyaluronic acid (HA) as the gel base containing a pain-relief drug (Drug A). We had administered it and other formulations into the rat knee where we injected bradykinin to evaluate their walking distance after 1 and 3 d. The effect of an aqueous solution of Drug A disappeared on day 3. The HA gel formulation without Drug A was more effective than the aqueous solution. The HA gel formulation with Drug A was the most effective; the walking distance was about 85% of the baseline on day 3. This study showed that the gel formulations were effective to sustain the release of a drug in the knee joint, and that the combination of a pain-relief drug with HA gel was effective to improve the mobility of the acute pain model rats.

pH-Controlled Bacillus thuringiensis Cry1Ac Protoxin Loading and Release from Polyelectrolyte Microcapsules

PubMed Central

Yang, Wenhui; He, Kanglai; Zhang, Jie; Guo, Shuyuan

2012-01-01

Crystal proteins synthesized by Bacillus thuringiensis (Bt) have been used as biopesticides because of their toxicity to the insect larval hosts. To protect the proteins from environmental stress to extend their activity, we have developed a new microcapsule formulation. Poly (acrylic acid) (PAH) and poly (styrene sulfonate) (PSS) were fabricated through layer-by-layer self-assembly based on a CaCO3 core. Cry1Ac protoxins were loaded into microcapsules through layer-by-layer self-assembly at low pH, and the encapsulated product was stored in water at 4°C. Scanning electron microscopy (SEM) was used to observe the morphology of the capsules. To confirm the successful encapsulation, the loading results were observed with a confocal laser scattering microscope (CLSM), using fluorescein-labeled Cry1Ac protoxin (FITC-Cry1Ac). The protoxins were released from the capsule under the alkaline condition corresponding to the midgut of certain insects, a condition which seldom exists elsewhere in the environment. The following bioassay experiment demonstrated that the microcapsules with Cry1Ac protoxins displayed approximately equivalent insecticidal activity to the Asian corn borer compared with free Cry1Ac protoxins, and empty capsules proved to have no effect on insects. Further result also indicated that the formulation could keep stable under the condition of heat and desiccation. These results suggest that this formulation provides a promising methodology that protects protoxins from the environment and releases them specifically in the target insects’ midgut, which has shown potential as biopesticide in the field. PMID:23024810

Donepezil dosing strategies: pharmacokinetic considerations.

PubMed

Gomolin, Irving H; Smith, Candace; Jeitner, Thomas M

2011-10-01

Donepezil (Aricept) is a cholinesterase inhibitor approved for the treatment of Alzheimer's disease. Immediate release formulations of 5- and 10-mg tablets were approved by the Food and Drug Administration in the United States in 1996. In July 2010, the Food and Drug Administration approved a 23-mg sustained release (SR) formulation. The SR formulation may provide additional benefit to patients receiving 10 mg daily but the incidence of adverse reactions is increased. We derived plasma concentration profiles for higher dose immediate-release formulations (15 mg once daily, 10 mg twice daily, and 20 mg once daily) and for the profile anticipated to result from the 23-mg SR formulation. Our model predicts similar steady-state concentration profiles for 10 mg twice daily, 20 mg once daily, and 23 mg SR once daily. This provides the theoretical basis for incremental immediate release dose escalation to minimize the emergence of adverse reactions and the potential to offer a cost-effective alternative to the SR formulation with currently approved generic immediate release formulations. Copyright © 2011 American Medical Directors Association. Published by Elsevier Inc. All rights reserved.

PEG-PE/clay composite carriers for doxorubicin: Effect of composite structure on release, cell interaction and cytotoxicity.

PubMed

Kohay, Hagay; Sarisozen, Can; Sawant, Rupa; Jhaveri, Aditi; Torchilin, Vladimir P; Mishael, Yael G

2017-06-01

A novel drug delivery system for doxorubicin (DOX), based on organic-inorganic composites was developed. DOX was incorporated in micelles (M-DOX) of polyethylene glycol-phosphatidylethanolamine (PEG-PE) which in turn were adsorbed by the clay, montmorillonite (MMT). The nano-structures of the PEG-PE/MMT composites of LOW and HIGH polymer loadings were characterized by XRD, TGA, FTIR, size (DLS) and zeta measurements. These measurements suggest that for the LOW composite a single layer of polymer intercalates in the clay platelets and the polymer only partially covers the external surface, while for the HIGH composite two layers of polymer intercalate and a bilayer may form on the external surface. These nanostructures have a direct effect on formulation stability and on the rate of DOX release. The release rate was reversely correlated with the degree of DOX interaction with the clay and followed the sequence: M-DOX>HIGH formulation>LOW formulation>DOX/MMT. Despite the slower release from the HIGH formulation, its cytotoxicity effect on sensitive cells was as high as the "free" DOX. Surprisingly, the LOW formulation, with the slowest release, demonstrated the highest cytotoxicity in the case of Adriamycin (ADR) resistant cells. Confocal microscopy images and association tests provided an insight into the contribution of formulation-cell interactions vs. the contribution of DOX release rate. Internalization of the formulations was suggested as a mechanism that increases DOX efficiency, particularly in the ADR resistant cell line. The employment of organic-inorganic hybrid materials as drug delivery systems, has not reached its full potential, however, its functionality as an efficient tunable release system was demonstrated. DOX PEG-PE/clay formulations were design as an efficient drug delivery system. The main aim was to develop PEG-PE/clay formulations of different structures based on various PEG-PE/clay ratios in order to achieve tunable release rates, to control the external surface characteristics and formulation stability. The formulations showed significantly higher toxicity in comparison to "free" DOX, explained by formulation internalization. For each cell line tested, sensitive and ADR resistant, a different formulation structure was found most efficient. The potential of PEG-PE/clay-DOX formulations to improve DOX administration efficacy was demonstrated and should be further explored and implemented for other cancer drugs and cells. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Emerging Treatment Options in Mild to Moderate Ulcerative Colitis

PubMed Central

Lichtenstein, Gary R.; Hanauer, Stephen B.; Sandborn, William J.

2015-01-01

Ulcerative colitis (UC) is a chronic inflammatory condition associated with rectal bleeding and urgency, tenesmus, and diarrhea. Several medical therapies can be used in the treatment of UC. Aminosalicylates are widely used based on their efficacy in the induction and maintenance of remission. Although corticosteroids are effective in patients with more severe disease, systemic use is associated with significant safety concerns. The newer corticosteroid budesonide has lower systemic bioavailability and, consequently, a more favorable safety profile. A budesonide extended-release formulation allows once-daily dosing and delivers the agent locally throughout the colon. Biologic agents used for the treatment of moderate to severe UC include the tumor necrosis factor inhibitors infliximab, adalimumab, and golimumab, and the integrin inhibitor vedolizumab. Rectally administered therapy can also be useful in the treatment of UC. In October 2014, the US Food and Drug Administration approved a budesonide foam formulation for inducing remission in patients with active mild to moderate distal UC extending up to 40 cm from the anal verge. Budesonide foam rapidly distributes to the sigmoid colon and the rectum and avoids some of the drawbacks of suppositories and enemas. PMID:26491415

Extended-release intramuscular naltrexone (VIVITROL®): a review of its use in the prevention of relapse to opioid dependence in detoxified patients.

PubMed

Syed, Yahiya Y; Keating, Gillian M

2013-10-01

Naltrexone is a μ-opioid receptor antagonist that blocks the euphoric effects of heroin and prescription opioids. In order to improve treatment adherence, a once-monthly, intramuscular, extended-release formulation of naltrexone (XR-NTX) [VIVITROL(®)] has been developed, and approved in the USA and Russia for the prevention of relapse to opioid dependence, after opioid detoxification. The clinical efficacy of this formulation in patients with opioid dependence was demonstrated in a 24-week, randomized, double-blind, placebo-controlled, multicentre, phase III trial (ALK21-013; n = 250). In this trial, opioid-detoxified patients receiving XR-NTX 380 mg once every 4 weeks, in combination with psychosocial support, had a significantly higher median proportion of weeks of confirmed opioid abstinence during weeks 5-24, compared with those receiving placebo (primary endpoint). A significantly higher proportion of patients receiving XR-NTX achieved total confirmed abstinence during this period than those receiving placebo. XR-NTX was also associated with a significantly greater reduction in opioid craving and a significantly longer treatment retention period than placebo. XR-NTX was generally well tolerated in the phase III trial. The most common (incidence ≥5 %) treatment-emergent adverse events that also occurred more frequently with XR-NTX than with placebo were hepatic enzyme abnormalities, nasopharyngitis, insomnia, hypertension, influenza and injection-site pain. Thus, XR-NTX is a useful treatment option for the prevention of relapse to opioid dependence, following opioid detoxification.

Evaluation of an extended-release formulation of ceftiofur crystalline-free acid in koi (Cyprinus carpio).

PubMed

Grosset, C; Weber, E S; Gehring, R; Sanchez-Migallon Guzman, D; Campbell, L A; Enz, C; Groff, J M; Tell, L A

2015-12-01

The use of an extended release ceftiofur crystalline-free acid formulation (CCFA, Excede For Swine(®) , Pfizer Animal Health) in koi was evaluated after administration of single intramuscular (i.m.) or intracoelomic (i.c.) doses. Twenty koi were divided randomly into a control group and four treatment groups (20 mg/kg i.m., 60 mg/kg i.m., 30 mg/kg i.c., and 60 mg/kg i.c.). Serum ceftiofur-free acid equivalents (CFAE) concentrations were quantified. The pharmacokinetic data were analyzed using a nonlinear mixed-effects approach. Following a CCFA injection of 60 mg/kg i.m., time durations that serum CFAE concentrations were above the target concentration of 4 μg/mL ranged from 0.4 to 2.5 weeks in 3 of 4 fish, while serum CFAE concentrations remained below 4 μg/mL for lower doses evaluated. Substantial inter-individual variations and intra-individual fluctuations of CFAE concentrations were observed for all treatment groups. Histological findings following euthanasia included aseptic granulomatous reactions, but no systemic adverse effects were detected. Given the unpredictable time vs. CFAE concentration profiles for treated koi, the authors would not recommend this product for therapeutic use in koi at this time. Further research would be necessary to correlate serum and tissue concentrations and to better establish MIC data for Aeromonas spp. isolated from naturally infected koi. © 2015 John Wiley & Sons Ltd.

Intermittent Drug Dosing Intervals Guided by the Operational Multiple Dosing Half Lives for Predictable Plasma Accumulation and Fluctuation

PubMed Central

Grover, Anita; Benet, Leslie Z.

2013-01-01

Intermittent drug dosing intervals are usually initially guided by the terminal pharmacokinetic half life and are dependent on drug formulation. For chronic multiple dosing and for extended release dosage forms, the terminal half life often does not predict the plasma drug accumulation or fluctuation observed. We define and advance applications for the operational multiple dosing half lives for drug accumulation and fluctuation after multiple oral dosing at steady-state. Using Monte Carlo simulation, our results predict a way to maximize the operational multiple dosing half lives relative to the terminal half life by using a first-order absorption rate constant close to the terminal elimination rate constant in the design of extended release dosage forms. In this way, drugs that may be eliminated early in the development pipeline due to a relatively short half life can be formulated to be dosed at intervals three times the terminal half life, maximizing compliance, while maintaining tight plasma concentration accumulation and fluctuation ranges. We also present situations in which the operational multiple dosing half lives will be especially relevant in the determination of dosing intervals, including for drugs that follow a direct PKPD model and have a narrow therapeutic index, as the rate of concentration decrease after chronic multiple dosing (that is not the terminal half life) can be determined via simulation. These principles are illustrated with case studies on valproic acid, diazepam, and anti-hypertensives. PMID:21499748

The tetrapeptide N-acetyl-Pro-Pro-Tyr-Leu in skin care formulations-Physicochemical and release studies.

PubMed

Olejnik, Anna; Schroeder, Grzegorz; Nowak, Izabela

2015-08-15

Recently there has been a growth of interest in the novel skin care formulations containing active ingredients such as low molecular weight peptides. In this paper we present new skincare formulations such as hydrogels, oil-in-water emulsions and water-in-oil emulsion containing a tetrapeptide (N-acetyl-Pro-Pro-Tyr-Leu). These formulations were characterized in terms of physicochemical parameters (pH, viscosity), stability and particle size distribution. Additionally, the diffusion parameters of the peptide in the obtained formulations were calculated based on the Einstein-Smoluchowski equation. Furthermore, in order to determine the penetration of the tetrapeptide through membranes its release kinetics were investigated. On the basis of release curves, the release rate constants were determined. The results proved that the properties of the formulations strongly determined the release rate of the tetrapeptide. The higher viscosity of the semisolid, the slower was the permeation through the membrane. Copyright © 2015 Elsevier B.V. All rights reserved.

Studies on a novel doughnut-shaped minitablet for intraocular drug delivery.

PubMed

Choonara, Yahya E; Pillay, Viness; Carmichael, Trevor; Danckwerts, Michael P

2007-12-28

The objective of this study was to evaluate the effect of 2 independent formulation variables on the drug release from a novel doughnut-shaped minitablet (DSMT) in order to optimize formulations for intraocular drug delivery. Formulations were based on a 3(2) full-factorial design. The 2 independent variables were the concentration of Resomer (% wt/wt) and the type of Resomer grade (RG502, RG503, and RG504), respectively. The evaluated response was the drug release rate constant computed from a referenced marketed product and in vitro drug release data obtained at pH 7.4 in simulated vitreous humor. DSMT devices were prepared containing either of 2 model drugs, ganciclovir or foscarnet, using a Manesty F3 tableting press fitted with a novel central-rod, punch, and die setup. Dissolution data revealed biphasic drug release behavior with 55% to 60% drug released over 120 days. The inherent viscosity of the various Resomer grades and the concentration were significant to achieve optimum release rate constants. Using the resultant statistical relationships with the release rate constant as a response, the optimum formulation predicted for devices formulated with foscarnet was 70% wt/wt of Resomer RG504, while 92% wt/wt of Resomer RG503 was ideal for devices formulated with ganciclovir. The results of this study revealed that the full-factorial design was a suitable tool to predict an optimized formulation for prolonged intraocular drug delivery.

Formulation and In-vitro Characterization of Sustained Release Matrix Type Ocular Timolol Maleate Mini-Tablet

PubMed Central

Mortazavi, Seyed Alireza; Jafariazar, Zahra; Ghadjahani, Yasaman; Mahmoodi, Hoda; Mehtarpour, Farzaneh

2014-01-01

The purpose of this study was preparation and evaluation of sustained release matrix type ocular mini-tablets of timolol maleate, as a potential formulation for the treatment of glaucoma. Following the initial studies on timolol maleate powder, it was formulated into ocular mini-tablets. The polymers investigated in this study included cellulose derivatives (HEC, CMC, EC) and Carbopol 971P. Mannitol was used as the solubilizing agent and magnesium stearate as the lubricant. Mini-tablets were prepared by through mixing of the ingredients, followed by direct compression. All the prepared formulations were evaluated in terms of physicochemical tests, including uniformity of weight, thickness, crushing strength, friability and in-vitro drug release. Four groups of formulations were prepared. The presence of different amounts of cellulose derivatives or Carbopol 971P, alone, was studied in group A formulations. In group B formulations, the effect of adding Carbopol 971P alongside different cellulose derivatives was investigated. Group C formulations were made by including mannitol as the solubilizing agent, alongside Carbopol 971P and a cellulose derivative. In group D formulations, mini-tablets were made using Carbopol 971P, alongside two different cellulose derivative. The selected formulation (C1) contained ethyl cellulose, Carbopol 971P, mannitol and magnesium stearate, which showed almost 100% drug release over 5 h. Based on kinetic studies, this formulation was found to best fit the zero-order model of drug release. However, the Higuchi and Hixson -Crowell models also showed a good fit. Hence, overall, formulation C1 was chosen as the best formulation. PMID:24734053

Quality evaluation of extemporaneous delayed-release liquid formulations of lansoprazole.

PubMed

Melkoumov, Alexandre; Soukrati, Amina; Elkin, Igor; Forest, Jean-Marc; Hildgen, Patrice; Leclair, Grégoire

2011-11-01

The quality attributes of extemporaneous delayed-release liquid formulations of lansoprazole for oral administration were evaluated. A novel liquid formulation (3 mg/mL) of Prevacid FasTab in an Ora-Blend vehicle was prepared and compared with the Prevacid FasTab 30 mg and Prevacid-sodium bicarbonate 1 M formulation (3 mg/mL). The latter formulation was combined with hydrochloric acid 0.1 N, and the remaining lansoprazole content was assayed by high-performance liquid chromatography (HPLC). A batch of delayed-release liquid formulation was prepared to evaluate content uniformity. For content assay, three samples were prepared for each evaluated condition and each sample was analyzed in triplicate by HPLC. The lansoprazole in the sodium bicarbonate formulation was extensively degraded by quantities of hydrochloric acid 0.1 N in excess of 100 mL. Storage time and temperature had a significant effect on lansoprazole stability in the Ora-Blend formulation. The drug remained stable for seven days when the formulation was stored at 4.5-5.5 °C, but storage at 21-22 °C or the reduction of pH with citric acid accelerated lansoprazole degradation. The amount of lansoprazole released from the Ora-Blend formulation during the buffer stage of the dissolution test decreased with increases in formulation storage time, in formulation storage temperature, and in the amount of lansoprazole released and degraded during the acid stage of the test. An extemporaneous formulation consisting of lansoprazole microgranules in Ora-Blend maintained acceptable quality attributes when stored for three days at 4.5-5.5 °C.

Solid lipid nanoparticles as carrier for sunscreens: in vitro release and in vivo skin penetration.

PubMed

Wissing, S A; Müller, R H

2002-06-17

The aim of this study was the comparison of two different formulations (solid lipid nanoparticles (SLN) and conventional o/w emulsion) as carrier systems for the molecular sunscreen oxybenzone. The influence of the carrier on the rate of release was studied in vitro with a membrane-free model. The release rate could be decreased by up to 50% with the SLN formulation. Further in vitro measurements with static Franz diffusion cells were performed. In vivo, penetration of oxybenzone into stratum corneum on the forearm was investigated by the tape stripping method. It was shown that the rate of release is strongly dependent upon the formulation and could be decreased by 30-60% in SLN formulations. In all test models, oxybenzone was released and penetrated into human skin more quickly and to a greater extent from the emulsions. The rate of release also depends upon the total concentration of oxybenzone in the formulation. In vitro-in vivo correlations could be made qualitatively.

Application of mixture experimental design in the formulation and optimization of matrix tablets containing carbomer and hydroxy-propylmethylcellulose.

PubMed

Petrovic, Aleksandra; Cvetkovic, Nebojsa; Ibric, Svetlana; Trajkovic, Svetlana; Djuric, Zorica; Popadic, Dragica; Popovic, Radmila

2009-12-01

Using mixture experimental design, the effect of carbomer (Carbopol((R)) 971P NF) and hydroxypropylmethylcellulose (Methocel((R)) K100M or Methocel((R)) K4M) combination on the release profile and on the mechanism of drug liberation from matrix tablet was investigated. The numerical optimization procedure was also applied to establish and obtain formulation with desired drug release. The amount of TP released, release rate and mechanism varied with carbomer ratio in total matrix and HPMC viscosity. Increasing carbomer fractions led to a decrease in drug release. Anomalous diffusion was found in all matrices containing carbomer, while Case - II transport was predominant for tablet based on HPMC only. The predicted and obtained profiles for optimized formulations showed similarity. Those results indicate that Simplex Lattice Mixture experimental design and numerical optimization procedure can be applied during development to obtain sustained release matrix formulation with desired release profile.

Sucrose ester stabilized solid lipid nanoparticles and nanostructured lipid carriers. II. Evaluation of the imidazole antifungal drug-loaded nanoparticle dispersions and their gel formulations.

PubMed

Das, Surajit; Ng, Wai Kiong; Tan, Reginald B H

2014-03-14

This study focused on: (i) feasibility of the previously developed sucrose ester stabilized SLNs and NLCs to encapsulate different imidazole antifungal drugs and (ii) preparation and evaluation of topical gel formulations of those SLNs and NLCs. Three imidazole antifungal drugs; clotrimazole, ketoconazole and climbazole were selected for this study. The results suggested that size, size distribution and drug encapsulation efficiency depend on the drug molecule and type of nanoparticles (SLN/NLC). The drug release experiment always showed faster drug release from NLCs than SLNs when the same drug molecule was loaded in both nanoparticles. However, drug release rate from both SLNs and NLCs followed the order of climbazole > ketoconazole > clotrimazole. NLCs demonstrated better physicochemical stability than SLNs in the case of all drugs. The drug release rate from ketoconazole- and clotrimazole-loaded SLNs became faster after three months than a fresh formulation. There was no significant change in drug release rate from climbazole-loaded SLNs and all drug-loaded NLCs. Gel formulations of SLNs and NLCs were prepared using polycarbophil polymer. Continuous flow measurements demonstrated non-Newtonian flow with shear-thinning behavior and thixotropy. Oscillation measurements depicted viscoelasticity of the gel formulations. Similar to nanoparticle dispersion, drug release rate from SLN- and NLC-gel was in the order of climbazole > ketoconazole > clotrimazole. However, significantly slower drug release was noticed from all gel formulations than their nanoparticle counterparts. Unlike nanoparticle dispersions, no significant difference in drug release from gel formulations containing SLNs and NLCs was observed for each drug. This study concludes that gel formulation of imidazole drug-loaded SLNs and NLCs can be used for sustained/prolonged topical delivery of the drugs.

Amoxicillin/clavulanate potassium extended release tablets: a new antimicrobial for the treatment of acute bacterial sinusitis and community-acquired pneumonia.

PubMed

Benninger, Michael S

2003-10-01

Community-acquired bacterial respiratory tract infections are among the most common health disorders requiring medical care and are associated with substantial morbidity, mortality, and direct and indirect costs. Recent increases in the prevalence of antimicrobial resistance have resulted in reduced susceptibility of the most common respiratory tract bacterial pathogens to a number of antimicrobials. Amoxicillin/clavulanate potassium extended release (ER) tablets (Augmentin XR, GlaxoSmithKline) is a new formulation of amoxicillin/clavulanate that retains activity against betalactamase-producing organisms whilst increasing the activity against Streptococcus pneumoniae through elevated and sustained plasma amoxicillin concentrations. The bilayer tablet provides immediate release of clavulanate and both immediate and sustained release of amoxicillin to maintain therapeutic concentrations of amoxicillin over longer periods of the dosing interval. In clinical trials of acute bacterial sinusitis (ABS) and community-acquired pneumonia (CAP), amoxicillin/clavulanate ER was shown to have excellent bacteriological and clinical success rates, even in patients infected with antimicrobial-resistant pathogens, and was found to be generally well tolerated. Amoxicillin/clavulanate ER is approved in the US for the treatment of patients with ABS or CAP caused by beta-lactamase-producing pathogens (ie, Haemophilus influenzae, Moraxella catarrhalis, Haemophilus parainfluenzae, Klebsiella pneumoniae, or methicillin-susceptible Staphylococcus aureus) and S. pneumoniae with reduced susceptibility to penicillin (penicillin minimum inhibitory concentration = 2.0 microg/ml).

Assessment of Aprotinin Loaded Microemulsion Formulations for Parenteral Drug Delivery: Preparation, Characterization, in vitro Release and Cytotoxicity Studies.

PubMed

Okur, Neslihan Üstündağ; Özdemir, Derya İlem; Kahyaoğlu, Şennur Görgülü; Şenyiğit, Zeynep Ay; Aşıkoğlu, Makbule; Genç, Lütfi; Karasulu, H Yeşim

2015-01-01

The object of the current study was to prepare novel microemulsion formulations of aprotinin for parenteral delivery and to compare in vitro characteristics and release behaviour of different Technetium-99m ((99m)Tc)-Aprotinin loaded microemulsion formulations. In addition, cytotoxicity of microemulsion formulation was evaluated with cell culture studies on human immortalized pancreatic duct epithelial-like cells. For this aim, firstly, pseudo-ternary phase diagrams were plotted to detect the formulation region and optimal microemulsions were characterized for their thermodynamic stability, conductivity, particle size, zeta potential, viscosity, pH and in vitro release properties. For in vitro release studies aprotinin was labelled with (99m)Tc and labelling efficiency, radiochemical purity and stability of the radiolabeled complex were determined by several chromatography techniques. Radiolabeling efficiency of (99m)Tc-Aprotinin was found over than 90% without any significant changes up to 6 hours after labelling at room temperature. After that, in vitro release studies of (99m)Tc-Aprotinin loaded microemulsions were performed with two different methods; dissolution from diffusion cells and dialysis bags. Both methods showed that release rate of (99m)Tc- Aprotinin from microemulsion could be controlled by microemulsion formulations. Drug release from the optimized microemulsion formulations was found lower compared to drug solution at the end of six hours. According to stability studies, the optimized formulation was found to be stable over a period of 12 months. Also, human immortalized pancreatic duct epithelial-like cells were used to evaluate the cytotoxicity of optimum formulation. Developed microemulsion did not reveal cytotoxicity. In conclusion the present study indicated that the M1-APT microemulsion is appropriate for intravenous application of aprotinin.

Comparative drug release measurements in limited amounts of liquid: a suppository formulation study.

PubMed

Welch, Ken; Ek, Ragnar; Strømme, Maria

2006-07-01

A novel method for the investigation of drug formulations in limited liquid volumes is presented. The experimental setup consists of a measurement cell containing an absorbent sponge cloth placed between two parallel electrodes. Conductivity measurements are used to monitor the drug release from the dosage form. By varying the amount of water contained in the absorbent cloth surrounding the dosage form, it is possible to measure the drug release performance of the dosage form in very limited amounts of water. The method was employed to test four different tablet formulations consisting of the model drug NaCl incorporated in excipient matrices of hard fat, polyethylene glycol, microcrystalline cellulose and a mixture of microcrystalline cellulose and croscarmellose sodium (Ac-Di-Sol). The drug release rates of the different formulations in limited water volumes differed markedly from the release rates in an excess of water. Whereas the release rates from all tablet types in an excess of water showed only minor differences among the tablet types, the release rates from the tablets formulated with disintegrating excipients were clearly superior in limited water volumes. The developed method for drug release in limited volumes of liquid should be suitable for evaluation of rectal dosage forms.

Controlled poorly soluble drug release from solid self-microemulsifying formulations with high viscosity hydroxypropylmethylcellulose.

PubMed

Yi, Tao; Wan, Jiangling; Xu, Huibi; Yang, Xiangliang

2008-08-07

The objective of this work was the development of a controlled release system based on self-microemulsifying mixture aimed for oral delivery of poorly water-soluble drugs. HPMC-based particle formulations were prepared by spray drying containing a model drug (nimodipine) of low water solubility and hydroxypropylmethylcellulose (HPMC) of high viscosity. One type of formulations contained nimodipine mixed with HPMC and the other type of formulations contained HPMC and nimodipine dissolved in a self-microemulsifying system (SMES) consisting of ethyl oleate, Cremophor RH 40 and Labrasol. Based on investigation by transmission electron microscopy (TEM), scanning electron microscopy (SEM), differential scanning calorimetry (DSC) and X-ray powder diffraction, differences were found in the particle structure between both types of formulations. In vitro release was performed and characterized by the power law. Nimodipine release from both types of formulations showed a controlled release profile and the two power law parameters, n and K, correlated to the viscosity of HPMC. The parameters were also influenced by the presence of SMES. For the controlled release solid SMES, oil droplets containing dissolved nimodipine diffused out of HPMC matrices following exposure to aqueous media. Thus, it is possible to control the in vitro release of poorly soluble drugs from solid oral dosage forms containing SMES.

Multiple response optimization of processing and formulation parameters of Eudragit RL/RS-based matrix tablets for sustained delivery of diclofenac.

PubMed

Elzayat, Ehab M; Abdel-Rahman, Ali A; Ahmed, Sayed M; Alanazi, Fars K; Habib, Walid A; Sakr, Adel

2017-11-01

Multiple response optimization is an efficient technique to develop sustained release formulation while decreasing the number of experiments based on trial and error approach. Diclofenac matrix tablets were optimized to achieve a release profile conforming to USP monograph, matching Voltaren ® SR and withstand formulation variables. The percent of drug released at predetermined multiple time points were the response variables in the design. Statistical models were obtained with relative contour diagrams being overlaid to predict process and formulation parameters expected to produce the target release profile. Tablets were prepared by wet granulation using mixture of equivalent quantities of Eudragit RL/RS at overall polymer concentration of 10-30%w/w and compressed at 5-15KN. Drug release from the optimized formulation E4 (15%w/w, 15KN) was similar to Voltaren, conformed to USP monograph and found to be stable. Substituting lactose with mannitol, reversing the ratio between lactose and microcrystalline cellulose or increasing drug load showed no significant difference in drug release. Using dextromethorphan hydrobromide as a model soluble drug showed burst release due to higher solubility and formation of micro cavities. A numerical optimization technique was employed to develop a stable consistent promising formulation for sustained delivery of diclofenac.

Pharmacokinetics and analgesic effect of ketorolac floating delivery system.

PubMed

Radwan, Mahasen A; Abou El Ela, Amal El Sayeh F; Hassan, Maha A; El-Maraghy, Dalia A

2015-05-01

The efficacy of ketorolac tromethamine (KT) floating alginate beads as a drug delivery system for better control of KT release was investigated. The formulation with the highest drug loading, entrapment efficiency, swelling, buoyancy, and in vitro release would be selected for further in vivo analgesic effect in the mice and pharmacokinetics study in rats compared to the tablet dosage form. KT floating alginate beads were prepared by extrusion congealing technique. KT in plasma samples was analyzed using a UPLC MS/MS assay. The percentage yield, drug loading and encapsulation efficiency were increased proportionally with the hydroxypropylmethyl cellulose (HPMC) polymer amount in the KT floating beads. A reverse relationship was observed between HPMC amount in the beads and the KT in vitro release rate. F3-floating beads were selected, due to its better in vitro results (continued floating for >8 h) than others. A longer analgesic effect was observed for F3 in fed mice as compared to the tablets. After F3 administration to rats, the Cmax (2.2 ± 0.3 µg/ml) was achieved at ∼2 h and the decline in KT concentration was slower. F3 showed a significant increase in the AUC (1.89 fold) in rats as compared to the tablets. KT was successfully formulated as floating beads with prolonged in vitro release extended to a better in vivo characteristic with higher bioavailability in rats. KT in floating beads shows a superior analgesic effect over tablets, especially in fed mice.

Chemotherapeutic potential of curcumin-bearing microcells against hepatocellular carcinoma in model animals

PubMed Central

Farazuddin, Mohammad; Dua, Bhavyata; Zia, Qamar; Khan, Aijaz Ahmad; Joshi, Beenu; Owais, Mohammad

2014-01-01

Curcumin (diferuloylmethane) is found in large quantities in the roots of Curcuma longa. It possesses strong antioxidant and anti-inflammatory properties, and inhibits chemically-induced carcinogenesis in the skin, forestomach, colon, and liver. Unfortunately, the poor bioavailability and hydrophobicity of curcumin pose a major hurdle to its use as a potent anticancer agent. To circumvent some of these problems, we developed a novel, dual-core microcell formulation of curcumin. The encapsulation of curcumin in microcells increases its solubility and bioavailability, and facilitates slow release kinetics over extended periods. Besides being safe, these formulations do not bear any toxicity constraints, as revealed by in vitro and in vivo studies. Histopathological analysis revealed that curcumin-bearing microcells helped in regression of hepatocellular carcinoma and the maintenance of cellular architecture in liver tissue. Free curcumin had a very mild effect on cancer suppression. Empty (sham) microcells and microparticles failed to inhibit cancer cells. The novel curcumin formulation was found to suppress hepatocellular carcinoma efficiently in Swiss albino mice. PMID:24627632

Swelling, erosion and drug release characteristics of salbutamol sulfate from hydroxypropyl methylcellulose-based matrix tablets.

PubMed

Chaibva, Faith A; Khamanga, Sandile M M; Walker, Roderick B

2010-12-01

Hydrophilic matrix formulations are important and simple technologies that are used to manufacture sustained release dosage forms. Hydroxypropyl methylcellulose-based matrix tablets, with and without additives, were manufactured to investigate the rate of hydration, rate of erosion, and rate and mechanism of drug release. Scanning electron microscopy was used to assess changes in the microstructure of the tablets during drug release testing and whether these changes could be related to the rate of drug release from the formulations. The results revealed that the rate of hydration and erosion was dependent on the polymer combination(s) used, which in turn affected the rate and mechanism of drug release from these formulations. It was also apparent that changes in the microstructure of matrix tablets could be related to the different rates of drug release that were observed from the test formulations. The use of scanning electron microscopy provides useful information to further understand drug release mechanisms from matrix tablets.

Spray-dried high-amylose sodium carboxymethyl starch: impact of α-amylase on drug-release profile.

PubMed

Nabais, Teresa; Zaraa, Sarra; Leclair, Grégoire

2016-11-01

Spray-dried high-amylose sodium carboxymethyl starch (SD HASCA) is a promising pharmaceutical excipient for sustained-release (SR) matrix tablets produced by direct compression. The presence of α-amylase in the gastrointestinal tract and the variations of the gastric residence time of non-disintegrating dosage forms may affect the presystemic metabolism of this excipient and, consequently, the drug-release profile from formulations produced with SD HASCA. In this study, the influence of α-amylase and the residence time in acidic conditions on the drug-release profile was evaluated for a once-daily acetaminophen formulation (Acetaminophen SR) and a once-daily tramadol hydrochloride formulation (Tramadol SR). Both formulations were based on SD HASCA. α-Amylase concentrations ranging from 0 IU/L to 20000 IU/L did not significantly affect the drug-release profiles of acetaminophen and tramadol hydrochloride from SD HASCA tablets (f2 > 50) for all but only one of the studied conditions (f2 = 47). Moreover, the drug-release properties from both SD HASCA formulations were not significantly different when the residence time in acidic medium was 1 h or 3 h. An increase in α-amylase concentration led to an increase in the importance of polymer erosion as the main mechanism of drug-release instead of drug diffusion, for both formulations and both residence times, even if release profiles remained comparable. As such, it is expected that α-amylase concentration and residence time in the stomach will not clinically affect the performance of both SD HASCA SR formulations, even if the mechanism of release itself may be affected.

Design, development and evaluation of clopidogrel bisulfate floating tablets.

PubMed

Rao, K Rama Koteswara; Lakshmi, K Rajya

2014-01-01

The objective of the present work was to formulate and to characterize a floating drug delivery system for clopidogrel bisulphate to improve bioavailability and to minimize the side effects of the drug such as gastric bleeding and drug resistance development. Clopidogrel floating tablets were prepared by direct compression technique by the use of three polymers xanthan gum, hydroxypropyl methylcellulose (HPMC) K15M and HPMC K4M in different concentrations (20%, 25% and 30% w/w). Sodium bicarbonate (15% w/w) and microcrystalline cellulose (30% w/w) were used as gas generating agent and diluent respectively. Studies were carried out on floating behavior and influence of type of polymer on drug release rate. All the formulations were subjected to various quality control and in-vitro dissolution studies in 0.1 N hydrochloric acid (1.2 pH) and corresponding dissolution data were fitted to popular release kinetic equations in order to evaluate release mechanisms and kinetics. All the clopidogrel floating formulations followed first order kinetics, Higuchi drug release kinetics with diffusion as the dominant mechanism of drug release. As per Korsmeyer-Peppas equation, the release exponent "n" ranged 0.452-0.654 indicating that drug release from all the formulations was by non-Fickian diffusion mechanism. The drug release rate of clopidogrel was found to be affected by the type and concentration of the polymer used in the formulation (P < 0.05). As the concentration of the polymer was increased, the drug release was found to be retarded. Based on the results, clopidogrel floating tablets prepared by employing xanthan gum at concentration 25% w/w (formulation F2) was the best formulation with desired in-vitro floating time and drug dissolution.

Development and evaluation of Ketoprofen sustained release matrix tablet using Hibiscus rosa-sinensis leaves mucilage.

PubMed

Kaleemullah, M; Jiyauddin, K; Thiban, E; Rasha, S; Al-Dhalli, S; Budiasih, S; Gamal, O E; Fadli, A; Eddy, Y

2017-07-01

Currently, the use of natural gums and mucilage is of increasing importance in pharmaceutical formulations as valuable drug excipient. Natural plant-based materials are economic, free of side effects, biocompatible and biodegradable. Therefore, Ketoprofen matrix tablets were formulated by employing Hibiscus rosa-sinensis leaves mucilage as natural polymer and HPMC (K100M) as a synthetic polymer to sustain the drug release from matrix system. Direct compression method was used to develop sustained released matrix tablets. The formulated matrix tablets were evaluated in terms of physical appearance, weight variation, thickness, diameter, hardness, friability and in vitro drug release. The difference between the natural and synthetic polymers was investigated concurrently. Matrix tablets developed from each formulation passed all standard physical evaluation tests. The dissolution studies of formulated tablets revealed sustained drug release up to 24 h compared to the reference drug Apo Keto® SR tablets. The dissolution data later were fitted into kinetic models such as zero order equation, first order equation, Higuchi equation, Hixson Crowell equation and Korsmeyer-Peppas equation to study the release of drugs from each formulation. The best formulations were selected based on the similarity factor ( f 2 ) value of 50% and more. Through the research, it is found that by increasing the polymers concentration, the rate of drug release decreased for both natural and synthetic polymers. The best formulation was found to be F3 which contained 40% Hibiscus rosa-sinensis mucilage polymer and showed comparable dissolution profile to the reference drug with f 2 value of 78.03%. The release kinetics of this formulation has shown to follow non-Fickian type which involved both diffusion and erosion mechanism. Additionally, the statistical results indicated that there was no significant difference (p > 0.05) between the F3 and reference drug in terms of MDT and T50% with p-values of 1.00 and 0.995 respectively.

Evaluation of intratympanic formulations for inner ear delivery: methodology and sustained release formulation testing

PubMed Central

Liu, Hongzhuo; Feng, Liang; Tolia, Gaurav; Liddell, Mark R.; Hao, Jinsong; Li, S. Kevin

2013-01-01

A convenient and efficient in vitro diffusion cell method to evaluate formulations for inner ear delivery via the intratympanic route is currently not available. The existing in vitro diffusion cell systems commonly used to evaluate drug formulations do not resemble the physical dimensions of the middle ear and round window membrane. The objectives of this study were to examine a modified in vitro diffusion cell system of a small diffusion area for studying sustained release formulations in inner ear drug delivery and to identify a formulation for sustained drug delivery to the inner ear. Four formulations and a control were examined in this study using cidofovir as the model drug. Drug release from the formulations in the modified diffusion cell system was slower than that in the conventional diffusion cell system due to the decrease in the diffusion surface area of the modified diffusion cell system. The modified diffusion cell system was able to show different drug release behaviors among the formulations and allowed formulation evaluation better than the conventional diffusion cell system. Among the formulations investigated, poly(lactic-co-glycolic acid)–poly(ethylene glycol)–poly(lactic-co-glycolic acid) triblock copolymer systems provided the longest sustained drug delivery, probably due to their rigid gel structures and/or polymer-to-cidofovir interactions. PMID:23631539

Kinetic Analysis of Drug Release from Compounded Slow-release Capsules of Liothyronine Sodium (T3).

PubMed

Bakhteyar, Hamid; Cassone, Clayton; Kohan, Hamed Gilzad; Sani, Shabnam N

2017-01-01

The purpose of this study was to formulate extemporaneously compounded Liothyronine Sodium (T3) slow-release capsules and to evaluate their in vitro drug release performance. Twenty-one formulations containing T3 (7.5 µg) with various compositions of two different grades of Methocel E4M and K100M premium (30% to 90%), and/or SimpleCap/Lactose (10% to 70%) were examined. Quality assessment of the capsules was conducted by standard quality control criteria of the United States Pharmacopeia (i.e., weight variation, content uniformity) to ensure their compliance. The dissolution release profile of the formulations was evaluated using United States Pharmacopeia Apparatus type II (paddle method) at a speed of 50 rpm and temperature of 37°C in phosphate buffered saline media ( pH = 7.2 to 7.4). Aliquots from the media were taken periodically up to 24 hours and analyzed using a validated enzyme-linked immunosorbent assay method. The cumulative percentage of drug release for each formulation was fitted to eleven major release kinetic equations to determine the best-fit model of drug release, as well as the mechanism of release. Assay sensitivity was as low as 1 ng/mL and the optimal calibration range was found to be between 0 ng/mL and 7.5 ng/mL, which corresponded well with the average physiological plasma concentrations of T3. Liothyronine sodium with either SimpleCap (100%) or Methocel E4M (100%) exhibited slowrelease kinetic patterns of Peppas and Zero Order, respectively. The formulation with SimpleCap (100%) had a higher percentage of drug release (as compared to 100% Methocel E4M) within the first four hours; this formulation released 80% of the drug within 12 hours when the release was plateaued thereafter. The formulation with 30% Methocel E4M and 70% SimpleCap released 100% of the drug within the initial 12 hours and exhibited a Zero Order slow-release kinetic pattern. In general, the release kinetic rate of the formulations containing Methocel K100M appeared to be slower than Methocel E4M. This alteration may be due to a higher molecular weight and apparent viscosity of Methocel K100M. While most of the formulations were fitted to a slow-release kinetic pattern, several others including Methocel E4M 100%, 30% Methocel E4M+ 70% Simple Cap, 40% Methocel K100M+ 60% SimpleCap, 50% Methocel K100M+ 50% SimpleCap, 30% Methocel E4M+ 70% Lactose, 90% Methocel E4M+ 10% Lactose, 40% Methocel K100M+ 60% Lactose, and 50% Methocel K100M+ 50% Lactose followed an ideal slow-release kinetic pattern of Zero Order or Higuchi. The results of this study successfully demonstrated the optiomal composition of slow-release compounded capsules of T3. Future studies are warranted to evaluate the in vivo performance of the optimal formulations and to establish an in vitro-in vivo correlation. Copyright© by International Journal of Pharmaceutical Compounding, Inc.

Surveillance of Diversion and Nonmedical Use of Extended-Release Prescription Amphetamine and Oral Methylphenidate in the United States

PubMed Central

Sembower, Mark A.; Ertischek, Michelle D.; Buchholtz, Chloe; Dasgupta, Nabarun; Schnoll, Sidney H.

2013-01-01

This article examines rates of nonmedical use and diversion of extended-release amphetamine and extended-release oral methylphenidate in the United States. Prescription dispensing data were sourced from retail pharmacies. Nonmedical use data were collected from the Researched Abuse, Diversion and Addiction-Related Surveillance (RADARS) System Drug Diversion Program and Poison Center Program. Drug diversion trends nearly overlapped for extended-release amphetamine and extended-release oral methylphenidate. Calls to poison centers were generally similar; however, calls regarding extended-release amphetamine trended slightly lower than those for extended-release oral methylphenidate. Data suggest similar diversion and poison center call rates for extended-release amphetamine and extended-release oral methylphenidate. PMID:23480245

Formulation development of smart gel periodontal drug delivery system for local delivery of chemotherapeutic agents with application of experimental design.

PubMed

Dabhi, Mahesh R; Nagori, Stavan A; Gohel, Mukesh C; Parikh, Rajesh K; Sheth, Navin R

2010-01-01

Smart gel periodontal drug delivery systems (SGPDDS) containing gellan gum (0.1-0.8% w/v), lutrol F127 (14, 16, and 18% w/v), and ornidazole (1% w/v) were designed for the treatment of periodontal diseases. Each formulation was characterized in terms of in vitro gelling capacity, viscosity, rheology, content uniformity, in vitro drug release, and syringeability. In vitro gelation time and the nature of the gel formed in simulated saliva for prepared formulations showed polymeric concentration dependency. Drug release data from all formulations was fitted to different kinetic models and the Korsemeyer-Peppas model was the best fit model. Drug release was significantly decreased as the concentration of each polymer component was increased. Increasing the concentration of each polymeric component significantly increased viscosity, syringeability, and time for 50%, 70%, and 90% drug release. In conclusion, the formulations described offer a wide range of physical and drug release characteristics. The formulation containing 0.8% w/v of gellan gum and 16% w/v of lutrol F127 exhibited superior physical characteristics.

Heterogeneity in the pharmacodynamics of two long-acting methylphenidate formulations for children with attention deficit/hyperactivity disorder. A growth mixture modelling analysis.

PubMed

Sonuga-Barke, Edmund J S; Van Lier, Pol; Swanson, James M; Coghill, David; Wigal, Sharon; Vandenberghe, Mieke; Hatch, Simon

2008-06-01

To use growth mixture modelling (GMM) to identify subgroups of children with attention deficit hyperactive disorder (ADHD) who have different pharmacodynamic profiles in response to extended release methylphenidate as assessed in a laboratory classroom setting. GMM analysis was performed on data from the COMACS study (Comparison of Methylphenidates in the Analog Classroom Setting): a large (n = 184) placebo-controlled cross-over study comparing three treatment conditions in the Laboratory School Protocol (with a 1.5-h cycle of attention and deportment assessments). Two orally administered, once-daily methylphenidate (MPH) bioequivalent formulations [Metadate CD/Equasym XL (MCD-EQXL) and Concerta XL (CON)] were compared with placebo (PLA). Three classes of children with distinct severity profiles in the PLA condition were identified. For both MCD-EQXL and CON, the more severe their PLA symptoms the better, the children's response. However, the formulations produced different growth curves by class, with CON having essentially a flat profile for all three classes (i.e. no effect of PLA severity) and MCD-EQXL showing a marked decline in symptoms immediately post-dosing in the two most severe classes compared with the least severe. Comparison of daily doses matched for immediate-release (IR) components accounted for this difference. The results suggest considerable heterogeneity in the pharmacodynamics of MPH response by children with ADHD. When treatment response for near-equal, bioequivalent daily doses the two formulations was compared, marked differences were seen for children in the most severe classes with a strong curvilinear trajectory for MCD-EQXL related to the greater IR component.

Formulation characteristics and in vitro release testing of cyclosporine ophthalmic ointments.

PubMed

Dong, Yixuan; Qu, Haiou; Pavurala, Naresh; Wang, Jiang; Sekar, Vasanthakumar; Martinez, Marilyn N; Fahmy, Raafat; Ashraf, Muhammad; Cruz, Celia N; Xu, Xiaoming

2018-06-10

The aim of the present study was to investigate the relationship between formulation/process variables versus the critical quality attributes (CQAs) of cyclosporine ophthalmic ointments and to explore the feasibility of using an in vitro approach to assess product sameness. A definitive screening design (DSD) was used to evaluate the impact of formulation and process variables. The formulation variables included drug percentage, percentage of corn oil and lanolin alcohol. The process variables studied were mixing temperature, mixing time and the method of mixing. The quality and performance attributes examined included drug assay, content uniformity, image analysis, rheology (storage modulus, shear viscosity) and in vitro drug release. Of the formulation variables evaluated, the percentage of the drug substance and the percentage of corn oil in the matrix were the most influential factors with respect to in vitro drug release. Conversely, the process parameters tested were observed to have minimal impact. An evaluation of the release mechanism of cyclosporine from the ointment revealed an interplay between formulation (e.g. physicochemical properties of the drug and ointment matrix type) and the release medium. These data provide a scientific basis to guide method development for in vitro drug release testing of ointment dosage forms. These results demonstrate that the in vitro methods used in this investigation were fit-for-purpose for detecting formulation and process changes and therefore amenable to assessment of product sameness. Published by Elsevier B.V.

Delayed release dexlansoprazole in the treatment of GERD and erosive esophagitis

PubMed Central

Wittbrodt, Eric T; Baum, Charles; Peura, David A

2009-01-01

Although proton pump inhibitors (PPI) have a record of remarkable effectiveness and safety in the management of gastroesophageal reflux disease (GERD), several treatment challenges with PPI have emerged. Dexlansoprazole MR is the (R)-enantiomer of lansoprazole contained in a formulation that produces two distinct releases of drug and significantly extends the duration of active plasma concentrations and % time pH > 4 beyond that of conventional single-release PPI. Dexlansoprazole MR can be administered without regard to meals or the timing of meals in most patients. Dexlansoprazole MR 60 mg demonstrated similar efficacy for healing of erosive esophagitis at 8 weeks compared with lansoprazole 30 mg, and dexlansoprazole MR 30 mg was superior to placebo for maintenance of healed erosive esophagitis at 6 months with 99% of nights and 96% of days heartburn-free over 6 months in patients taking dexlansoprazole MR 30 mg. Superior relief of heartburn occurred in patients taking dexlansoprazole MR 30 mg (55% heartburn-free 24-hour periods) vs placebo (14%) for symptomatic nonerosive GERD. The safety profile of dexlansoprazole MR is similar to that of lansoprazole. The extended pharmacodynamic effects, added convenience, and efficacy and safety of dexlansoprazole MR offer a novel approach to gastric pH control in patients with acid-related disorders. PMID:21694835

Methylphenidate bioavailability in adults when an extended-release multiparticulate formulation is administered sprinkled on food or as an intact capsule.

PubMed

Pentikis, Helen S; Simmons, Roy D; Benedict, Michael F; Hatch, Simon J

2002-04-01

To determine the single-dose bioavailability of 20-mg Metadate CD (methylphenidate HCI, USP) Extended-Release Capsules sprinkled onto 1 level tablespoon (15 mL) of applesauce relative to an intact capsule under fasted conditions in healthy adults. This was a single-center, open-label, single-dose, randomized, two-way crossover study with a 6-day washout period between doses, in healthy male and female subjects (N= 26), aged 21-40 years. Plasma concentration-time data for methylphenidate were used to calculate the pharmacokinetic parameters for each treatment. The pharmacokinetic profile for Metadate CD exhibited biphasic release characteristics with a sharp initial slope and a second rising portion. For Cmax (maximum observed concentration), AUC(0-infinity) (area under the plasma concentration curve from time 0 to infinity) and AUC(0-infinity) (area under the plasma concentration curve from time 0 to the last measurable time point), the geometric least squares mean ratios and 90% confidence intervals were within the 80% to 125% confidence interval for bioequivalence. Adverse events were similar to those reported for methylphenidate. The bioavailability of methylphenidate was not altered when Metadate CD capsules were administered by sprinkling their contents onto a small amount of applesauce.

Administration of a Sol-Gel Formulation of Phenylephrine Using Low-Temperature Hollow Microneedle for Treatment of Intermittent Fecal Incontinence.

PubMed

Lee, Hyunji; Park, Jung-Hwan; Park, Jung Ho

2017-12-01

A low temperature hollow microneedle system was devised to deliver sol-gel transition formulation near the surface of the skin for extended release and local delivery of drug by a non-invasive method. This new system can improve treatment of intermittent fecal incontinence. The low-temperature system was integrated with a hollow microneedle to maintain the low temperature of the sol formulation. Various sol-gel formulations using Pluronic F-127 (PF-127) and Hydroxy-propyl-methyl-cellulose (HPMC) were prepared, and their gelation temperature, flow property, and diffusion retardation were observed. Resting anal sphincter pressure in response to a phenylephrine (PE) sol-gel formulation was measured using an air-charged catheter. The biocompatibility of the sol-gel PE formulation was evaluated by observing the immunological response. When the PF-127 25%, HPMC 1% and PE formulation (PF25-HPMC1-PE) was injected through the peri-anal skin of the rat in vivo, the highest pressure on the anal sphincter muscle occurred at 6-8 h and anal pressure increased and lasted twice as long as with the phosphate-buffered saline (PBS)-PE formulation. There was no significant difference in the number of mast cells after administration into the rat in vivo between the PF25-HPMC1-PE formulation and the PBS-PE formulation. The combination of a low-pain hollow microneedle system and an injectable sol-gel formulation improved the efficacy of treatment of intermittent fecal incontinence. A low-temperature hollow microneedle system using a sol-gel formulation has many applications in medical treatments that require depot effect, local targeting, and pain control.

New treatments for levodopa-induced motor complications.

PubMed

Rascol, Olivier; Perez-Lloret, Santiago; Ferreira, Joaquim J

2015-09-15

Levodopa (l-dopa)-induced motor complications, including motor fluctuations and dyskinesia, affect almost all patients with Parkinson's disease (PD) at some point during the disease course, with relevant implications in global health status. Various dopaminergic and nondopaminergic pharmacological approaches as well as more invasive strategies including devices and functional surgery are available to manage such complications. In spite of undisputable improvements during the last decades, many patients remain significantly disabled, and a fully satisfying management of l-dopa-induced motor complications is still an important unmet need of PD therapy. This article reviews the recent trial results published from 2013 to April 2015 about pharmacological and nonpharmacological interventions to treat motor complications. Randomized controlled trials conducted in patients suffering from already established complications showed that new levodopa (l-dopa) formulations such as intrajejunal l-dopa-carbidopa infusion and bilayered extended-release l-dopa-carbidopa (IPX066) can improve motor fluctuations. Positive results were also obtained with a new monoamine oxidase B (MAO-B) inhibitor (safinamide) and a catechol-O-methyltransferase COMT inhibitor (opicapone). Pilot data suggest that new formulations of dopamine agonists (inhaled apomorphine) are also of potential interest. The development of novel nondopaminergic adenosine A2A antagonists (istradefylline, preladenant, and tozadenant) to treat motor fluctuations showed conflicting results in phase 2 and phase 3 trials. For dyskinesia, trials with new amantadine extended-release formulations confirmed the interest of the glutamatergic N-methyl-d-aspartate (NMDA) antagonist approach. Positive pilot antidyskinetic effects were also recently reported using serotonin agents such as eltoprazine and glutamate mGluR5 modulators such as mavoglurant. However, the translation to clinical practice of such innovative concepts remains challenging, because subsequent phase 2 trials conducted to confirm the antidyskynetic effects of mavoglurant failed, leading to the interruption of the development of this compound for this indication. © 2015 International Parkinson and Movement Disorder Society.

Encapsulation of Alpha-1 antitrypsin in PLGA nanoparticles: In Vitro characterization as an effective aerosol formulation in pulmonary diseases

PubMed Central

2012-01-01

Background Alpha 1- antitrypsin (α1AT) belongs to the superfamily of serpins and inhibits different proteases. α1AT protects the lung from cellular inflammatory enzymes. In the absence of α1AT, the degradation of lung tissue results to pulmonary complications. The pulmonary route is a potent noninvasive route for systemic and local delivery. The aerosolized α1AT not only affects locally its main site of action but also avoids remaining in circulation for a long period of time in peripheral blood. Poly (D, L lactide-co glycolide) (PLGA) is a biodegradable and biocompatible polymer approved for sustained controlled release of peptides and proteins. The aim of this work was to prepare a wide range of particle size as a carrier of protein-loaded nanoparticles to deposit in different parts of the respiratory system especially in the deep lung. Various lactide to glycolide ratio of the copolymer was used to obtain different release profile of the drug which covers extended and rapid drug release in one formulation. Results Nonaqueous and double emulsion techniques were applied for the synthesis of nanoparticles. Nanoparticles were characterized in terms of surface morphology, size distribution, powder X-ray diffraction (XRD), encapsulation efficiency, in vitro drug release, FTIR spectroscopy and differential scanning calorimetry (DSC). To evaluate the nanoparticles cytotoxicity, cell cytotoxicity test was carried out on the Cor L105 human epithelial lung cancer cell line. Nanoparticles were spherical with an average size in the range of 100 nm to 1μ. The encapsulation efficiency was found to be higher when the double emulsion technique was applied. XRD and DSC results indicated that α1AT encapsulated in the nanoparticles existed in an amorphous or disordered-crystalline status in the polymer matrix. The lactic acid to glycolic acid ratio affects the release profile of α1AT. Hence, PLGA with a 50:50 ratios exhibited the ability to release %60 of the drug within 8, but the polymer with a ratio of 75:25 had a continuous and longer release profile. Cytotoxicity studies showed that nanoparticles do not affect cell growth and were not toxic to cells. Conclusion In summary, α1AT-loaded nanoparticles may be considered as a novel formulation for efficient treatment of many pulmonary diseases. PMID:22607686

A review of OROS methylphenidate (Concerta(®)) in the treatment of attention-deficit/hyperactivity disorder.

PubMed

Katzman, Martin A; Sternat, Tia

2014-11-01

Attention-deficit/hyperactivity disorder (ADHD) is a common neurobehavioural disorder with onset during childhood. It affects a child's development, both at home and at school, and impacts on social, emotional and cognitive functioning, in both the home and the school environment. Untreated ADHD is very often associated with poor academic achievement, low occupational status, increased risk of substance abuse and delinquency. Current practice guidelines recommend a multimodal approach in the treatment of ADHD, which includes educational, behavioural and mental health interventions, and pharmacological management. Stimulant medications, including methylphenidate (MPH) and amphetamine products, are recommended as first-line pharmacotherapy in the treatment of ADHD. The choice of stimulant is influenced by several factors; the most influential factor is the duration of action. Long-acting medication provides benefits long after school and work. It also increases the likelihood of once-daily dosing, thereby eliminating the need for mid-day dosing, making the treatment more private, avoiding stigma and improving adherence to medication. MPH is the most widely used psychotropic medication in child psychiatry. It was first developed for use in children as an oral, immediate-release formulation and more recently as various extended-release formulations. These latter formulations include the 12 h preparation Concerta(®) (osmotic-release oral system [OROS] MPH), which utilizes an osmotic pump system, designed to overcome the difficulties of multiple daily dosing. Since it received approval from the US Food and Drug Administration in August 2000, OROS MPH has been quickly and widely accepted as one of the preferred treatments for ADHD because of its once-daily dosing. This paper reviews the data in support of long-acting OROS MPH in children, adolescents and adults, both in ADHD and in association with its comorbidities.

The safety, tolerability, and efficacy of once-daily memantine (28 mg): a multinational, randomized, double-blind, placebo-controlled trial in patients with moderate-to-severe Alzheimer's disease taking cholinesterase inhibitors.

PubMed

Grossberg, George T; Manes, Facundo; Allegri, Ricardo F; Gutiérrez-Robledo, Luis Miguel; Gloger, Sergio; Xie, Lei; Jia, X Daniel; Pejović, Vojislav; Miller, Michael L; Perhach, James L; Graham, Stephen M

2013-06-01

Immediate-release memantine (10 mg, twice daily) is approved in the USA for moderate-to-severe Alzheimer's disease (AD). This study evaluated the efficacy, safety, and tolerability of a higher-dose, once-daily, extended-release formulation in patients with moderate-to-severe AD concurrently taking cholinesterase inhibitors. In this 24-week, double-blind, multinational study (NCT00322153), outpatients with AD (Mini-Mental State Examination scores of 3-14) were randomized to receive once-daily, 28-mg, extended-release memantine or placebo. Co-primary efficacy parameters were the baseline-to-endpoint score change on the Severe Impairment Battery (SIB) and the endpoint score on the Clinician's Interview-Based Impression of Change Plus Caregiver Input (CIBIC-Plus). The secondary efficacy parameter was the baseline-to-endpoint score change on the 19-item Alzheimer's Disease Cooperative Study-Activities of Daily Living (ADCS-ADL19); additional parameters included the baseline-to-endpoint score changes on the Neuropsychiatric Inventory (NPI) and verbal fluency test. Data were analyzed using a two-way analysis of covariance model, except for CIBIC-Plus (Cochran-Mantel-Haenszel test). Safety and tolerability were assessed through adverse events and physical and laboratory examinations. A total of 677 patients were randomized to receive extended-release memantine (n = 342) or placebo (n = 335); completion rates were 79.8 and 81.2 %, respectively. At endpoint (week 24, last observation carried forward), memantine-treated patients significantly outperformed placebo-treated patients on the SIB (least squares mean difference [95 % CI] 2.6 [1.0, 4.2]; p = 0.001), CIBIC-Plus (p = 0.008), NPI (p = 0.005), and verbal fluency test (p = 0.004); the effect did not achieve significance on ADCS-ADL19 (p = 0.177). Adverse events with a frequency of ≥5.0 % that were more prevalent in the memantine group were headache (5.6 vs. 5.1 %) and diarrhea (5.0 vs. 3.9 %). Extended-release memantine was efficacious, safe, and well tolerated in this population.

Influence of beta-cyclodextrin and chitosan in the formulation of a colon-specific drug delivery system.

PubMed

Rehman, K; Amin, M C I M; Muda, S

2013-12-01

The increase in diseases of the colon underscores the need to develop cost-effective site-directed therapies. We formulated a polysaccharide-based matrix system that could release ibuprofen under conditions simulating those in the colon by employing a wet granulation method. Tablets were prepared in a series of formulations containing a polysaccharide (beta-cyclodextrin and chitosan) matrix system along with ethylcellulose. We characterized physicochemical properties and performed an in vitro drug release assay in the absence and presence of digestive enzymes to assess the ability of the polysaccharides to function as a protective barrier against the upper gastrointestinal environment. Fourier transform infrared spectroscopy studies revealed no chemical interaction between ibuprofen and polysaccharides; however, spectrum analysis suggested the formation of an inclusion complex of beta-cyclodextrin with ibuprofen. The formulations contained 50% ethylcellulose and 50% beta-cyclodextrins (1:1) were proven to be the better formulation that slowly released the drug until 24 h (101.04 ± 0.65% maximum drug release in which 83.08 ± 0.89% drug was released in colonic medium) showed better drug release profiles than the formulations containing chitosan. We conclude that a beta-cyclodextrin drug carrier system may represent an effective approach for treatment of diseases of the colon. © Georg Thieme Verlag KG Stuttgart · New York.

DELIVERY OF WATER-SOLUBLE DRUGS USING ACOUSTICALLY-TRIGGERED, PERFLUOROCARBON DOUBLE EMULSIONS

PubMed Central

Fabiilli, Mario L.; Lee, James A.; Kripfgans, Oliver D.; Carson, Paul L.; Fowlkes, J. Brian

2010-01-01

Purpose Ultrasound can be used to release a therapeutic payload encapsulated within a perfluorocarbon (PFC) emulsion via acoustic droplet vaporization (ADV), a process whereby the PFC phase is vaporized and the agent is released. ADV-generated microbubbles have been previously used to selectively occlude blood vessels in vivo. The coupling of ADV-generated drug delivery and occlusion has therapeutically, synergistic potentials. Methods Micron-sized, water-in-PFC-in-water (W1/PFC/W2) emulsions were prepared in a two-step process using perfluoropentane (PFP) or perfluorohexane (PFH) as the PFC phase. Fluorescein or thrombin was contained in the W1 phase. Results Double emulsions containing fluorescein in the W1 phase displayed a 5.7±1.4 fold and 8.2±1.3 fold increase in fluorescein mass flux, as measured using a Franz diffusion cell, after ADV for the PFP and PFH emulsions, respectively. Thrombin was stably retained in four out of five double emulsions. For three out of five formulations tested, the clotting time of whole blood decreased, in a statistically significant manner (p < 0.01), when incubated with thrombin-loaded emulsions exposed to ultrasound compared to emulsions not exposed to ultrasound. Conclusions ADV can be used to spatially and temporally control the delivery of water-soluble compounds formulated in PFC double emulsions. Thrombin release could extend the duration of ADV-generated, microbubble occlusions. PMID:20872050

Controlling Release of Integral Lipid Nanoparticles Based on Osmotic Pump Technology.

PubMed

Tian, Zhiqiang; Yu, Qin; Xie, Yunchang; Li, Fengqian; Lu, Yi; Dong, Xiaochun; Zhao, Weili; Qi, Jianping; Wu, Wei

2016-08-01

To achieve controlled release of integral nanoparticles by the osmotic pump strategy using nanostructured lipid carriers (NLCs) as model nanoparticles. NLCs was prepared by a hot-homogenization method, transformed into powder by lyophilization, and formulated into osmotic pump tablets (OPTs). Release of integral NLCs was visualized by live imaging after labeling with a water-quenching fluorescent probe. Effects of formulation variables on in vitro release characteristics were evaluated by measuring the model drug fenofibrate. Pharmacokinetics were studied in beagle dogs using the core tablet and a micronized fenofibrate formulation as references. NLCs are released through the release orifices of the OPTs as integral nanoparticles. Near zero-order kinetics can be achieved by optimizing the influencing variables. After oral administration, decreased C max and steady drug levels for as long as over 24 h are observed. NLC-OPTs show an oral bioavailability of the model drug fenofibrate similar to that of the core tablets, which is about 1.75 folds that of a fast-release formulation. Controlled release of integral NLCs is achieved by the osmotic pump strategy.

Development of a Sustained Antiplaque and Antimicrobial Chewing Gum of a Decapeptide.

PubMed

Al-Ghananeem, Abeer M; Leung, Kai P; Faraj, Jabar; DeLuca, Patrick P

2017-08-01

The objective of this paper was to design a chewing gum formulation delivery system in situations where typical dental hygiene practice is not practical. Thus, an analog of decapeptide KSL (KSL-W), known to possess antimicrobial and antiplaque activity, was incorporated into a chewing gum formulation containing cetylpyridinium chloride (CPC). The effect of the excipients, xylitol, and peppermint oil on active ingredients in vitro release was also assessed. Gum formulations were prepared with different excipient parameters, including heating xylitol and gum base at 65 or 85°C, using ground and unground xylitol, and the addition of 1.5, 3, and 7% peppermint oil, to determine the effect of these changes on the in vitro release of KSL-W and CPC using a chewing machine. The antimicrobial and antiplaque activities of solutions released from chewed gum formulation as well as prepared standard solutions with different concentrations were tested against placebo. The optimal temperature to avoid crystallization of xylitol during preparation was 65°C. Grinding xylitol to 104.5 μm improved release of active ingredients as compared to commercially unground xylitol. Peppermint oil had opposite effects on release of KSL-W and CPC. Peppermint oil at 1.5% was determined to be suitable (91 and 88% of KSL-W and CPC released, respectively, after 40 min). The gum formulation illustrated good sustained release of KSL-W and CPC with antibacterial and antiplaque activities after chewing. An effective antimicrobial and antiplaque chewing gum formulation was developed. This formulation has the potential to overcome oral hygiene issues in those unable to follow normal dental protocols.

Formulation and Evaluation of Multilayered Tablets of Pioglitazone Hydrochloride and Metformin Hydrochloride

PubMed Central

Chowdary, Y. Ankamma; Raparla, Ramakrishna; Madhuri, Muramshetty

2014-01-01

In the treatment of type 2 diabetes mellitus a continuous therapy is required which is a more complex one. As in these patients there may be a defect in both insulin secretion and insulin action exists. Hence, the treatment depends on the pathophysiology and the disease state. In the present study, multilayered tablets of pioglitazone hydrochloride 15 mg and metformin hydrochloride 500 mg were prepared in an attempt for combination therapy for the treatment of type 2 diabetes mellitus. Pioglitazone HCl was formulated as immediate release layer to show immediate action by direct compression method using combination of superdisintegrants, namely, crospovidone and avicel PH 102. Crospovidone at 20% concentration showed good drug release profile at 2 hrs. Metformin HCl was formulated as controlled release layer to prolong the drug action by incorporating hydrophilic polymers such as HPMC K4M by direct compression method and guar gum by wet granulation method in order to sustain the drug release from the tablets and maintain its integrity so as to provide a suitable formulation. The multilayered tablets were prepared after carrying out the optimization of immediate release layer and were evaluated for various precompression and postcompression parameters. Formulation F13 showed 99.97% of pioglitazone release at 2 hrs in 0.1 N HCl and metformin showed 98.81% drug release at 10 hrs of dissolution in 6.8 pH phosphate buffer. The developed formulation is equivalent to innovator product in view of in vitro drug release profile. The results of all these evaluation tests are within the standards. The procedure followed for the formulation of these tablets was found to be reproducible and all the formulations were stable after accelerated stability studies. Hence, multilayered tablets of pioglitazone HCl and metformin HCl can be a better alternative way to conventional dosage forms. PMID:26556204

Effects of Extended-Release Niacin and Extended-Release Niacin/Laropiprant on the Pharmacokinetics of Simvastatin in Healthy Subjects.

PubMed

Lauring, Brett; Dishy, Victor; De Kam, Pieter-Jan; Crumley, Tami; Wenning, Larissa; Liu, Fang; Sisk, Christine; Wagner, John; Lai, Eseng

2015-01-01

The use of multiple lipid-modifying agents with different mechanisms of action is often required to regulate lipid levels in patients with dyslipidemia. During combination therapy, alterations in the pharmacokinetics of any of the drugs used and their metabolites may occur. Three separate open-label, randomized, crossover studies evaluated the potential for pharmacokinetic interaction between extended-release niacin (with and without concomitant laropiprant) and simvastatin in healthy subjects. Study 1 used single doses of extended-release niacin and simvastatin; study 2 used multiple-dose coadministration of extended-release niacin/laropiprant and simvastatin in healthy subjects; and study 3 used single doses of both extended-release niacin and the coadministration of extended-release niacin/laropiprant and simvastatin in healthy Chinese subjects. During each treatment period, plasma samples were collected predose and at prespecified postdose time points for pharmacokinetic analyses. The safety and tolerability of simvastatin with and without coadministered extended-release niacin (or extended-release niacin/laropiprant) were assessed by clinical evaluation of adverse experiences. In 2 studies in healthy subjects, modest increases in exposure to simvastatin acid (by ∼60%) by extended-release niacin and extended-release niacin/laropiprant were observed. Based on the clinical experience with simvastatin, these effects are not believed to be clinically meaningful. In the third study on healthy Chinese subjects, no statistically meaningful increases in exposure to simvastatin by extended-release niacin and extended-release niacin/laropiprant were observed. In all populations examined in these studies, the coadministration of extended-release niacin and simvastatin was generally well tolerated.

Gabapentin Extended-Release - Depomed: Gabapentin ER, Gabapentin Gastric Retention, Gabapentin GR.

PubMed

2007-01-01

Depomed is developing an extended-release (ER) oral formulation of gabapentin, a GABA receptor agonist commonly used for the treatment of epilepsy and seizures, neuropathic pain and hot flushes. Gabapentin ER is based on the company's proprietary AcuForm drug delivery technology, which is part of the Gastric Retention (GR) family of technologies; this offers improved drug absorption and bioavailability compared with the existing immediate-release formulation of gabapentin (Neurontin), making gabapentin ER suitable for twice-daily dosing. The product is in clinical development for the treatment of postherpetic neuralgia and diabetic neuropathies in the US. Additionally, Depomed has commenced a phase II trial of gabapentin ER in postmenopausal patients with hot flushes. Depomed's AcuForm platform is based on polymer technology that provides targeted drug delivery for a variety of compounds. Following ingestion, AcuForm tablets swell and are retained for 6-8 hours in the stomach, enabling controlled and prolonged release of gabapentin to the upper intestinal tract; this extends the time of drug delivery to the small intestine for complete and safe elimination via the lower intestinal track. Gabapentin ER is available for licensing. Depomed acquired exclusive development and commercialisation rights to gabapentin ER in September 2003 via its subsidiary, Depomed Development Ltd (DDL). Depomed is not required to pay upfront license fees, but will make royalty and milestone payments to DDL upon successful commercialisation of gabapentin ER. Gabapentin ER was originally developed by DDL, a joint venture between Depomed and Elan established in January 2000 to design products using the GR family of technologies. However, in efforts to restructure joint venture relationships, Elan withdrew from operational involvement of DDL in September 2003, and Depomed has gained full ownership of DDL. Depomed sublicensed exclusive rights to a US patent (held by the University of Rochester) covering the use of gabapentin in the treatment of hot flushes from PharmaNova in October 2006. Under the agreement, Depomed paid PharmaNova an upfront fee of US dollars 500 000. PharmaNova is also entitled to milestone payments and royalties on sales of gabapentin ER in this indication only. Depomed has reported significant safety and efficacy benefits from gabapentin ER in its phase II trial. This study was initiated in February 2005 following positive results from a phase I trial in which gabapentin ER demonstrated a pharmacokinetic profile suitable for twice-daily dosing. In two pharmacokinetic studies, gabapentin ER achieved improved bioavailability at higher doses. This result supports Depomed's development of a once- or twice-daily product with potentially fewer adverse events. The basic US patents relating to gabapentin expired in 2000. Depomed holds exclusive rights to a US patent (No. 6 310 098) held by the University of Rochester covering the use of gabapentin to treat hot flushes.Additionally, Depomed was issued a US patent (No. 6 723 340) in May 2004 that covers proprietary polymer combinations (as used in AcuForm tablets) to create improved formulations of existing drugs.

Characterization and evaluation of self-nanoemulsifying sustained-release pellet formulation of ziprasidone with enhanced bioavailability and no food effect.

PubMed

Miao, Yanfei; Chen, Guoguang; Ren, Lili; Pingkai, Ouyang

2016-09-01

The purpose of this work was to develop self-nanomulsifying drug delivery systems (SNEDDS) in sustained-release pellets of ziprasidone to enhance the oral bioavailability and overcome the food effect of ziprasidone. Preformulation studies including screening of excipients for solubility and pseudo-ternary phase diagrams suggested the suitability of Capmul MCM as oil phase, Labrasol as surfactant, and PEG 400 as co-surfactant for preparation of self-nanoemulsifying formulations. Preliminary composition of the SNEDDS formulations were selected from the pseudo-ternary phase diagrams. The prepared ziprasidone-SNEDDS formulations were characterized for self-emulsification time, effect of pH and robustness to dilution, droplet size analysis and zeta potential. The optimized ziprasidone-SNEDDS were used to prepare ziprasidone-SNEDDS sustained-release pellets via extrusion-spheronization method. The pellets were characterized for SEM, particle size, droplet size distribution and zeta potential. In vitro drug release studies indicated the ziprsidone-SNEDDS sustained-release pellets showed sustained release profiles with 90% released within 10 h. The ziprsidone-SNEDDS sustained-release pellets were administered to fasted and fed beagle dogs and their pharmacokinetics were compared to commercial formulation of Zeldox as a control. Pharmacokinetic studies in beagle dogs showed ziprasidone with prolonged actions and enhanced bioavailability with no food effect was achieved simultaneously in ziprsidone-SNEDDS sustained-release pellets compared with Zeldox in fed state. The results indicated a sustained release with prolonged actions of schizophrenia and bipolar disorder treatment.

Glycerogelatin-based ocular inserts of aceclofenac: physicochemical, drug release studies and efficacy against prostaglandin E₂-induced ocular inflammation.

PubMed

Mathurm, Manish; Gilhotra, Ritu Mehra

2011-01-01

An attempt has been made in the present study to formulate soluble ocular inserts of aceclofenac to facilitate the bioavailability of the drug into the eye, as no eye drop solution could be formulated. Glycero-gelatin ocular inserts/films were prepared and physicochemical parameters and drug release profiles of glycerol-gelatin films of aceclofenac were compared with surface cross-linked films of similar compositions. Ocular irritation of the developed formulation was also checked by HET-CAM test and efficacy of the developed formulation against prostaglandin-induced ocular inflammation in rabbit eye was determined. The non-cross-linked films showed poor mechanical, physicochemical properties, and very little potential of sustaining drug release, however cross-linking the films enhanced tensile strength by 70%, but elasticity decreased by 95%. The cross-linked ocular inserts showed less swelling than non-cross-linked. Formulation AF8 (20% gelatin and 70% glycerin, treated by cross-linker for 1 h) demonstrated the longest drug release for 24 h. As per the kinetic models all films showed a constant drug release with Higuchi diffusion mechanism. Formulation was found to be practically non-irritant. The optimized formulation was tested and compared with eye drops of aceclofenac for anti-inflammatory activity in rabbits against PGE₂-induced inflammation. In vivo studies with developed formulation indicated a significant inhibition of PGE₂-induced PMN migration as compared to eye drops. In conclusion, ocular inserts of aceclofenac was found promising as it achieved sustained drug release and better pharmacodynamic activity.

The ameliorated longevity and pharmacokinetics of valsartan released from a gel system of ultradeformable vesicles.

PubMed

Ahad, Abdul; Aqil, Mohd; Kohli, Kanchan; Sultana, Yasmin; Mujeeb, Mohd

2016-09-01

The present study traces the development and characterization of the gel formulation of valsartan-loaded ultradeformable vesicles for management of hypertension. The prepared gel formulation of ultradeformable vesicles was evaluated for in vitro skin permeation, release kinetics, skin irritation, pharmacokinetics, and stability. The in vitro skin permeation study showed that the gel formulation of ultradeformable vesicles presented a flux value of 368.74 μg/cm(2)/h, in comparison to that of the traditional liposomal gel formulation, with an enhancement ratio of 26.91, through rat skin. The data for release kinetics showed that the release profile followed zero-order kinetics, and that the drug release mechanism was non-Fickian. The results of the skin irritation study demonstrated that the prepared formulation was safe, less irritant, and well-tolerated for transdermal delivery. The results of the pharmacokinetic study demonstrated that the AUC value of valsartan after transdermal administration was apparently increased. The formulation stored under a refrigerated condition showed greater stability, and results were found to be within the specification under storage conditions. It is evident from this study that the gel formulation of ultradeformable vesicles of valsartan is a promising delivery system for lipophilic drugs, and has reasonably good stability characteristics.

Visible-Light Organic Photocatalysis for Latent Radical-Initiated Polymerization via 2e–/1H+ Transfers: Initiation with Parallels to Photosynthesis

PubMed Central

2015-01-01

We report the latent production of free radicals from energy stored in a redox potential through a 2e–/1H+ transfer process, analogous to energy harvesting in photosynthesis, using visible-light organic photoredox catalysis (photocatalysis) of methylene blue chromophore with a sacrificial sterically hindered amine reductant and an onium salt oxidant. This enables light-initiated free-radical polymerization to continue over extended time intervals (hours) in the dark after brief (seconds) low-intensity illumination and beyond the spatial reach of light by diffusion of the metastable leuco-methylene blue photoproduct. The present organic photoredox catalysis system functions via a 2e–/1H+ shuttle mechanism, as opposed to the 1e– transfer process typical of organometallic-based and conventional organic multicomponent photoinitiator formulations. This prevents immediate formation of open-shell (radical) intermediates from the amine upon light absorption and enables the “storage” of light-energy without spontaneous initiation of the polymerization. Latent energy release and radical production are then controlled by the subsequent light-independent reaction (analogous to the Calvin cycle) between leuco-methylene blue and the onium salt oxidant that is responsible for regeneration of the organic methylene blue photocatalyst. This robust approach for photocatalysis-based energy harvesting and extended release in the dark enables temporally controlled redox initiation of polymer syntheses under low-intensity short exposure conditions and permits visible-light-mediated synthesis of polymers at least 1 order of magnitude thicker than achievable with conventional photoinitiated formulations and irradiation regimes. PMID:24786755

Visible-light organic photocatalysis for latent radical-initiated polymerization via 2e⁻/1H⁺ transfers: initiation with parallels to photosynthesis.

PubMed

Aguirre-Soto, Alan; Lim, Chern-Hooi; Hwang, Albert T; Musgrave, Charles B; Stansbury, Jeffrey W

2014-05-21

We report the latent production of free radicals from energy stored in a redox potential through a 2e(-)/1H(+) transfer process, analogous to energy harvesting in photosynthesis, using visible-light organic photoredox catalysis (photocatalysis) of methylene blue chromophore with a sacrificial sterically hindered amine reductant and an onium salt oxidant. This enables light-initiated free-radical polymerization to continue over extended time intervals (hours) in the dark after brief (seconds) low-intensity illumination and beyond the spatial reach of light by diffusion of the metastable leuco-methylene blue photoproduct. The present organic photoredox catalysis system functions via a 2e(-)/1H(+) shuttle mechanism, as opposed to the 1e(-) transfer process typical of organometallic-based and conventional organic multicomponent photoinitiator formulations. This prevents immediate formation of open-shell (radical) intermediates from the amine upon light absorption and enables the "storage" of light-energy without spontaneous initiation of the polymerization. Latent energy release and radical production are then controlled by the subsequent light-independent reaction (analogous to the Calvin cycle) between leuco-methylene blue and the onium salt oxidant that is responsible for regeneration of the organic methylene blue photocatalyst. This robust approach for photocatalysis-based energy harvesting and extended release in the dark enables temporally controlled redox initiation of polymer syntheses under low-intensity short exposure conditions and permits visible-light-mediated synthesis of polymers at least 1 order of magnitude thicker than achievable with conventional photoinitiated formulations and irradiation regimes.

Dispersion of microemulsion drops in HEMA hydrogel: a potential ophthalmic drug delivery vehicle.

PubMed

Gulsen, Derya; Chauhan, Anuj

2005-03-23

Approximately 90% of all ophthalmic drug formulations are now applied as eye-drops. While eye-drops are convenient and well accepted by patients, about 95% of the drug contained in the drops is lost due to absorption through the conjunctiva or through the tear drainage. A major fraction of the drug eventually enters the blood stream and may cause side effects. The drug loss and the side effects can be minimized by using disposable soft contact lenses for ophthalmic drug delivery. The essential idea is to encapsulate the ophthalmic drug formulations in nanoparticles, and disperse these drug-laden particles in the lens material. Upon insertion into the eye, the lens will slowly release the drug into the pre lens (the film between the air and the lens) and the post-lens (the film between the cornea and the lens) tear films, and thus provide drug delivery for extended periods of time. This paper focuses on dispersing stabilized microemulsion drops in poly-2-hydroxyethyl methacrylate (p-HEMA) hydrogels. The results of this study show that the p-HEMA gels loaded with a microemulsion that is stabilized with a silica shell are transparent and that these gels release drugs for a period of over 8 days. Contact lenses made of microemulsion-laden gels are expected to deliver drugs at therapeutic levels for a few days. The delivery rates can be tailored by controlling the particle and the drug loading. It may be possible to use this system for both therapeutic drug delivery to eyes and the provision of lubricants to alleviate eye problems prevalent in extended lens wear.

Evaluation of the Relative Abuse of an OROS® Extended-release Hydromorphone HCI Product: Results from three Post-market Surveillance Studies.

PubMed

Butler, Stephen F; McNaughton, Emily C; Black, Ryan A; Cassidy, Theresa A

2018-01-02

Formulating prescription opioids to limit abuse remains a priority. OROS® extended-release (ER) hydromorphone HCl (EXALGO®) may have low abuse potential. Three post-marketing studies of the relative abuse liability of OROS hydromorphone ER were conducted. Estimates of abuse, unadjusted and adjusted for prescription volume, were generated for OROS hydromorphone ER and comparators from Q2 2010 through Q2 2014 for a high-risk, substance abuse treatment population and the general population using poison control center data. Comparators were selected for compound, market penetration, and route of administration (ROA) profile. ROA comparisons were made among the substance abuse treatment population. Internet discussion was examined to determine abusers' interest in and desire for the OROS formulation. Examination of abuse prevalence among adults within substance abuse treatment, intentional poison exposures and Internet discussion levels generally support the hypothesis that OROS hydromorphone ER may have lower abuse potential than many other opioid products. OROS hydromorphone ER also appears to be abused less often by alternate ROAs (e.g., snorting and injection). Lower levels of online discussion were observed along with relatively low endorsement for abuse. Abuse of OROS hydromorphone ER was observed in high-risk substance abuse and general population samples but at a very low relative prevalence. Evidence suggests it may be less often abused by alternate ROAs than some comparators. Online data did not find evidence of high levels of desire for OROS hydromorphone ER by recreational abusers. Continued monitoring of this product's abuse liability is warranted.

Pharmacokinetics of prolonged-release tacrolimus and implications for use in solid organ transplant recipients.

PubMed

Tanzi, Maria G; Undre, Nasrullah; Keirns, James; Fitzsimmons, William E; Brown, Malcolm; First, M Roy

2016-08-01

Prolonged-release tacrolimus was developed as a once-daily formulation with ethylcellulose as the excipient, resulting in slower release and reduction in peak concentration (Cmax ) for a given dose compared with immediate-release tacrolimus, which is administered twice daily. This manuscript reviews pharmacokinetic information on prolonged-release tacrolimus in healthy subjects, in transplant recipients converted from immediate-release tacrolimus, and in de novo kidney and liver transplant recipients. As with the immediate-release formulation, prolonged-release tacrolimus shows a strong correlation between trough concentration (Cmin ) and area under the 24-hour time-concentration curve (AUC24 ), indicating that trough whole blood concentrations provide an accurate measure of drug exposure. We present the pharmacokinetic similarities and differences between the two formulations, so that prescribing physicians will have a better understanding of therapeutic drug monitoring in patients receiving prolonged-release tacrolimus. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Production of extended release mini-tablets using directly compressible grades of HPMC.

PubMed

Mohamed, Faiezah A A; Roberts, Matthew; Seton, Linda; Ford, James L; Levina, Marina; Rajabi-Siahboomi, Ali R

2013-11-01

Hypromellose (HPMC) has been previously used to control drug release from mini-tablets. However, owing to poor flow, production of mini-tablets containing high HPMC levels is challenging. Directly compressible (DC) HPMC grades have been developed by Dow Chemical Company. To compare the properties of HPMC DC (METHOCEL™ K4M and K100M) with regular (REG) HPMC grades. Particle size distribution and flowability of HPMC REG and DC were evaluated. 3 mm mini-tablets, containing hydrocortisone or theophylline as model drugs and 40% w/w HPMC DC or REG were produced. Mini-tablets containing HPMC DC grades were manufactured using a rotary press simulator at forces between 2-4 kN and speeds of 5, 10, 15 or 20 rpm. Mini-tablets containing HPMC REG were produced manually. The improved flowability of HPMC DC grades, which have a narrower particle size distribution and larger particle sizes, meant that simulated large scale production of mini-tablets with good weight uniformity (CV 1.79-4.65%) was feasible. It was not possible to automatically manufacture mini-tablets containing HPMC REG due to the poor flowability of the formulations. Drug release from mini-tablets comprising HPMC DC and REG were comparable. Mini-tablets containing HPMC DC illustrated a higher tensile strength compared to mini-tablets made with HPMC REG. Mini-tablets produced with HPMC DC at different compression speeds had similar drug release profiles. Production of extended release mini-tablets was successfully achieved when HPMC DC was used. Drug release rate was not influenced by the different HPMC DC grades (K4M or K100M) or production speed.

Tablet fragmentation without a disintegrant: A novel design approach for accelerating disintegration and drug release from 3D printed cellulosic tablets.

PubMed

Arafat, Basel; Wojsz, Magdalena; Isreb, Abdullah; Forbes, Robert T; Isreb, Mohammad; Ahmed, Waqar; Arafat, Tawfiq; Alhnan, Mohamed A

2018-06-15

Fused deposition modelling (FDM) 3D printing has shown the most immediate potential for on-demand dose personalisation to suit particular patient's needs. However, FDM 3D printing often involves employing a relatively large molecular weight thermoplastic polymer and results in extended release pattern. It is therefore essential to fast-track drug release from the 3D printed objects. This work employed an innovative design approach of tablets with unique built-in gaps (Gaplets) with the aim of accelerating drug release. The novel tablet design is composed of 9 repeating units (blocks) connected with 3 bridges to allow the generation of 8 gaps. The impact of size of the block, the number of bridges and the spacing between different blocks was investigated. Increasing the inter-block space reduced mechanical resistance of the unit, however, tablets continued to meet pharmacopeial standards for friability. Upon introduction into gastric medium, the 1 mm spaces gaplet broke into mini-structures within 4 min and met the USP criteria of immediate release products (86.7% drug release at 30 min). Real-time ultraviolet (UV) imaging indicated that the cellulosic matrix expanded due to swelling of hydroxypropyl cellulose (HPC) upon introduction to the dissolution medium. This was followed by a steady erosion of the polymeric matrix at a rate of 8 μm/min. The design approach was more efficient than a comparison conventional formulation approach of adding disintegrants to accelerate tablet disintegration and drug release. This work provides a novel example where computer-aided design was instrumental at modifying the performance of solid dosage forms. Such an example may serve as the foundation for a new generation of dosage forms with complicated geometric structures to achieve functionality that is usually achieved by a sophisticated formulation approach. Copyright © 2018 Elsevier B.V. All rights reserved.

[Application of an artificial neural network in the design of sustained-release dosage forms].

PubMed

Wei, X H; Wu, J J; Liang, W Q

2001-09-01

To use the artificial neural network (ANN) in Matlab 5.1 tool-boxes to predict the formulations of sustained-release tablets. The solubilities of nine drugs and various ratios of HPMC: Dextrin for 63 tablet formulations were used as the ANN model input, and in vitro accumulation released at 6 sampling times were used as output. The ANN model was constructed by selecting the optimal number of iterations (25) and model structure in which there are one hidden layer and five hidden layer nodes. The optimized ANN model was used for prediction of formulation based on desired target in vitro dissolution-time profiles. ANN predicted profiles based on ANN predicted formulations were closely similar to the target profiles. The ANN could be used for predicting the dissolution profiles of sustained release dosage form and for the design of optimal formulation.

Preparation and In Vitro/In Vivo Evaluation of Vinpocetine Elementary Osmotic Pump System

PubMed Central

Ning, Meiying; Zhou, Yue; Chen, Guojun; Mei, Xingguo

2011-01-01

Preparation and in vitro and in vivo evaluation of vinpocetine (VIN) elementary osmotic pump (EOP) formulations were investigated. A method for the preparation of VIN elementary osmotic pump tablet was obtained by adding organic acid additives to increase VIN solubility. VIN was used as the active pharmaceutical ingredient, lactose and mannitol as osmotic agent. Citric acid was used as increasing API solubility and without resulting in the API degradation. It is found that the VIN release rate was increasing with the citric acid amount at a constant range. Cellulose acetate 398-3 was employed as semipermeable membrane containing polyethylene glycol 6000 and diethyl-o-phthalate as pore-forming agent and plasticizer for controlling membrane permeability. In addition, a clear difference between the pharmacokinetic patterns of VIN immediate release and VIN elementary osmotic pump formulations was revealed. The area under the plasma concentration-time curve after oral administration of elementary osmotic pump formulations was equivalent to VIN immediate release formulation. Furthermore, significant differences found for mean residence time, elimination half-life, and elimination rate constant values corroborated prolonged release of VIN from elementary osmotic pump formulations. These results suggest that the VIN osmotic pump controlled release tablets have marked controlled release characters and the VIN osmotic pump controlled release tablets and the normal tablets were bioequivalent. PMID:21577257

Development of orally disintegrating tablets comprising controlled-release multiparticulate beads

PubMed Central

2012-01-01

Melperone is an atypical antipsychotic agent that has shown a wide spectrum of neuroleptic properties, particularly effective in the treatment of senile dementia and Parkinson’s-associated psychosis, and is marketed in Europe as an immediate-release (IR) tablet and syrup. An orally disintegrating tablet (ODT) dosage form would be advantageous for patients who experience difficulty in swallowing large tablets or capsules or those who experience dysphagia. Controlled-release (CR) capsule and ODT formulations containing melperone HCl were developed with target in vitro release profiles suitable for a once-daily dosing regimen. Both dosage forms allow for the convenient production of dose-proportional multiple strengths. Two ODT formulations exhibiting fast and medium release profiles and one medium release profile capsule formulation (each 50 mg) were tested in vivo using IR syrup as the reference. The two medium release formulations were shown to be bioequivalent to each other and are suitable for once-daily dosing. Based on the analytical and organoleptic test results, as well as the blend uniformity and in-process compression data at various compression forces using coated beads produced at one-tenth (1/10) commercial scale, both formulations in the form of CR capsules and CR ODTs have shown suitability for progression into further clinical development. PMID:22356215

Release and Degradation of Microencapsulated Spinosad and Emamectin Benzoate.

PubMed

Huang, Bin Bin; Zhang, Shao Fei; Chen, Peng Hao; Wu, Gang

2017-09-07

The dynamics of release and degradation of the microencapsulation formulation containing spinosad (SP) and emamectin benzoate (EM) were evaluated in the present study. SP and EM were microencapsulated using biodegradable poly-lactic acid (PLA) as the wall material. Their release from and degradation within the prepared SP and EM microspheres (SP-EM-microspheres) were studied. It was found that the encapsulation significantly prolonged the insecticide release. The release could be further extended if the external aqueous phase was pre-saturated with the insecticides and the microspheres were additionally coated with gelatin. On the other hand, increasing the water content of the emulsion or the hydrophilic polycaprolactone (PCL) content in the PLA/PCL mixture accelerated the release. Due to the photolysis and hydrolysis of SP and EM by sunlight, the toxicity of the non-encapsulated insecticides in water declined continuously from 0 through the 9 th day (d), and dissipated in 13 d. In contrast, an aqueous suspension containing 5% SP-EM-microspheres maintained a mostly constant toxicity to Plutella xylostella for 17 d. The biodegradable SP-EM-microspheres showed significantly higher long-term toxicity to P. xylostella due to lower release, reduced photolysis and hydrolysis of the encapsulated insecticides, which were affected by the varied preparation conditions.

A Randomized, Double-Blind, Double-Dummy Study to Evaluate the Intranasal Human Abuse Potential and Pharmacokinetics of a Novel Extended-Release Abuse-Deterrent Formulation of Oxycodone

PubMed Central

Kopecky, Ernest A.; Smith, Michael D.; Fleming, Alison B.

2016-01-01

Objective. Evaluate the human abuse potential (HAP) of an experimental, microsphere-in-capsule formulation of extended-release oxycodone (oxycodone DETERx®) (herein “DETERx”). Design. Randomized, double-blind, double-dummy, positive- and placebo-controlled, single-dose, four-phase, four-treatment, crossover study. Setting. Clinical research site. Subjects. There were 39 qualifying subjects (72% male, 85% white, mean age of 27 years) with 36 completing all four Double-blind Treatment Periods. Methods. The four phases encompassed: 1) Screening; 2) Drug Discrimination; 3) Double-blind Treatment; and 4) Follow-up. Drug Discrimination tests ensured that subjects could distinguish placebo from opioid. The four Double-blind Treatments compared DETERx—administered as either a crushed intranasal (IN) or an intact oral (PO) preparation—with immediate-release oxycodone IN (OXY-IR IN) and with an intact IN and PO placebo DETERx control. Results. For primary pharmacokinetic (PK) assessments, abuse quotient (Cmax/Tmax) was lower with DETERx IN than DETERx PO; both treatments were substantially lower than OXY-IR IN (6.24, 8.60, and 69.6 ng/mL/h, respectively). For drug liking, the primary subjective pharmacodynamic (PD) endpoint, both DETERx IN and DETERx PO produced significantly lower scores than OXY-IR IN (P ≤ 0.0001 for each); DETERx IN was less liked than DETERx PO (P ≤ 0.05), mirroring the PK relationships. Objectively assessed pupillometry corroborated the more rapid and significantly greater effect of OXY-IR IN than either DETERx IN or DETERx PO (P ≤ 0.007 for each). Overall safety profiles of DETERx and OXY-IR were comparable and both were well tolerated. Conclusions. Pharmacokinetic and pharmacodynamic outcomes suggest that DETERx IN has relatively low HAP; continued research in larger populations is suggested. PMID:26814256

A novel accelerated in vitro release method to evaluate the release of thymopentin from PLGA microspheres.

PubMed

Xie, Xiangyang; Li, Zhiping; Zhang, Ling; Chi, Qiang; Yang, Yanfang; Zhang, Hui; Yang, Yang; Mei, Xingguo

2015-01-01

A novel accelerated method of good correlations with "real-time" release to evaluate in vitro thymopentin release from poly (D, L-lactide-co-glycolide) (PLGA) microsphere was developed. Thymopentin-loaded microspheres were made from three types of PLGA, and peptide release was studied in various conditions. Incomplete release of peptide (<60%) from microspheres was found in accelerated testing with two typical release media. This problem was circumvented by adding organic solvents to the release media and varying the temperature in the media heating process. Release media containing three kinds of organic solvents at 50 °C were tested, respectively, and hydro-alcoholic solution was selected for further study. After the surfactant concentration (0.06%, W/V) and ethanol concentration (20%, V/V) were fixed, a gradient heating program, consisting of three stages and each stage with a different temperature, was introduced to enhance the correlations between the short- and long-term release. After adjusting the heating time of each stage, a good correlation (R(2) = 9896, formulation 8 K; R(2) = 0.9898, formulation 13 K; R(2) = 0.9886, formulation 28 K) between accelerated and "real-time" release was obtained. By optimizing the conditions as ethanol concentration and temperature gradients, this accelerated method may be appropriate for similar peptide formulations that not well correlate with "real-time" release.

Stomach specific polymeric low density microballoons as a vector for extended delivery of rabeprazole and amoxicillin for treatment of peptic ulcer.

PubMed

Choudhary, Sandeep; Jain, Ashay; Amin, Mohd Cairul Iqbal Mohd; Mishra, Vijay; Agrawal, Govind P; Kesharwani, Prashant

2016-05-01

The study was intended to develop a new intra-gastric floating in situ microballoons system for controlled delivery of rabeprazole sodium and amoxicillin trihydrate for the treatment of peptic ulcer disease. Eudragit S-100 and hydroxypropyl methyl cellulose based low density microballoons systems were fabricated by employing varying concentrations of Eudragit S-100 and hydroxypropyl methyl cellulose, to which varying concentrations of drug was added, and formulated by stirring at various speed and time to optimize the process and formulation variable. The formulation variables like concentration and ratio of polymers significantly affected the in vitro drug release from the prepared floating device. The validation of the gastro-retentive potential of the prepared microballoons was carried out in rabbits by orally administration of microballoons formulation containing radio opaque material. The developed formulations showed improved buoyancy and lower ulcer index as compared to that seen with plain drugs. Ulcer protective efficacies were confirmed in ulcer-bearing mouse model. In conclusion, greater compatibility, higher gastro-retention and higher anti-ulcer activity of the presently fabricated formulations to improve potential of formulation for redefining ulcer treatment are presented here. These learning exposed a targeted and sustained drug delivery potential of prepared microballoons in gastric region for ulcer therapeutic intervention as corroborated by in vitro and in vivo findings and, thus, deserves further attention for improved ulcer treatment. Copyright © 2016 Elsevier B.V. All rights reserved.

Undigested Pills in Stool Mimicking Parasitic Infection.

PubMed

Mir, Fazia; Achakzai, Ilyas; Ibdah, Jamal A; Tahan, Veysel

2017-01-01

Background . Orally ingested medications now come in both immediate release and controlled release preparations. Controlled release preparations were developed by pharmaceutical companies to improve compliance and decrease frequency of pill ingestion. Case Report . A 67-year-old obese male patient presented to our clinic with focal abdominal pain that had been present 3 inches below umbilicus for the last three years. This pain was not associated with any trauma or recent heavy lifting. Upon presentation, the patient reported that for the last two months he started to notice pearly oval structures in his stool accompanying his chronic abdominal pain. This had coincided with initiation of his nifedipine pills for his hypertension. He reported seeing these undigested pills daily in his stool. Conclusion . The undigested pills may pose a cause of concern for both patients and physicians alike, as demonstrated in this case report, because they can mimic a parasitic infection. This can result in unnecessary extensive work-up. It is important to review the medication list for extended release formulations and note that the outer shell can be excreted whole in the stool.

Release of Liposomal Contents by Cell-Secreted Matrix Metalloproteinase-9

PubMed Central

Banerjee, Jayati; Hanson, Andrea J.; Gadam, Bhushan; Elegbede, Adekunle I.; Tobwala, Shakila; Ganguly, Bratati; Wagh, Anil; Muhonen, Wallace W.; Law, Benedict; Shabb, John B.; Srivastava, D. K.; Mallik, Sanku

2011-01-01

Liposomes have been widely used as a drug delivery vehicle and currently, more than 10 liposomal formulations are approved by the Food and Drug Administration for clinical use. However, upon targeting, the release of the liposome-encapsulated contents is usually slow. We have recently demonstrated that contents from appropriately-formulated liposomes can be rapidly released by the cancer-associated enzyme matrix metalloproteinase-9 (MMP-9). Herein, we report our detailed studies to optimize the liposomal formulations. By properly selecting the lipopeptide, the major lipid component and their relative amounts, we demonstrate that the contents are rapidly released in the presence of cancer-associated levels of recombinant human MMP-9. We observed that the degree of lipid mismatch between the lipopepides and the major lipid component profoundly affects the release profiles from the liposomes. By utilizing the optimized liposomal formulations, we also demonstrate that cancer cells (HT-29) which secrete low levels of MMP-9 failed to release significant amount of the liposomal contents. Metastatic cancer cells (MCF7) secreting high levels of the enzyme rapidly release the encapsulated contents from the liposomes. PMID:19601658

Development and evaluation of in situ gel of pregabalin

PubMed Central

Madan, Jyotsana R; Adokar, Bhushan R; Dua, Kamal

2015-01-01

Aim and Background: Pregabalin (PRG), an analog of gamma-aminobutyric acid, reduces the release of many neurotransmitters, including glutamate, and noradrenaline. It is used for the treatment of epilepsy; simple and complex partial convulsion. The present research work aims to ensure a high drug absorption by retarding the advancement of PRG formulation through the gastrointestinal tract. The work aims to design a controlled release PRG formulation which is administered as liquid and further gels in the stomach and floats in gastric juice. Materials and Methods: In situ gelling formulations were prepared using sodium alginate, calcium chloride, sodium citrate, hydroxypropyl methylcellulose (HPMC) K100M, and sodium bicarbonate. The prepared formulations were evaluated for solution viscosity, drug content, in vitro gelling studies, gel strength, and in vitro drug release. The final formulation was optimized using a 32 full factorial design. Results: The formulation containing 2.5% w/v sodium alginate and 0.2% w/v calcium chloride were considered optimum since it showed minimum floating lag time (18 s), optimum viscosity (287.3 cps), and gel strength (4087.17 dyne/cm2). The optimized formulation follows Korsmeyer-Peppas kinetic model with n value 0.3767 representing Fickian diffusion mechanism of drug release. Conclusion: Floating in situ gelling system of PRG can be formulated using sodium alginate as a gelling polymer and calcium chloride as a complexing agent to control the drug release for about 12 h for the treatment of epilepsy. PMID:26682193

Prolonged release matrix tablet of pyridostigmine bromide: formulation and optimization using statistical methods.

PubMed

Bolourchian, Noushin; Rangchian, Maryam; Foroutan, Seyed Mohsen

2012-07-01

The aim of this study was to design and optimize a prolonged release matrix formulation of pyridostigmine bromide, an effective drug in myasthenia gravis and poisoning with nerve gas, using hydrophilic - hydrophobic polymers via D-optimal experimental design. HPMC and carnauba wax as retarding agents as well as tricalcium phosphate were used in matrix formulation and considered as independent variables. Tablets were prepared by wet granulation technique and the percentage of drug released at 1 (Y(1)), 4 (Y(2)) and 8 (Y(3)) hours were considered as dependent variables (responses) in this investigation. These experimental responses were best fitted for the cubic, cubic and linear models, respectively. The optimal formulation obtained in this study, consisted of 12.8 % HPMC, 24.4 % carnauba wax and 26.7 % tricalcium phosphate, had a suitable prolonged release behavior followed by Higuchi model in which observed and predicted values were very close. The study revealed that D-optimal design could facilitate the optimization of prolonged release matrix tablet containing pyridostigmine bromide. Accelerated stability studies confirmed that the optimized formulation remains unchanged after exposing in stability conditions for six months.

Galantamine-ER for the treatment of mild-to-moderate Alzheimer’s disease

PubMed Central

Seltzer, Ben

2010-01-01

An extended release form of the cholinesterase inhibitor (ChEI) drug galantamine (galantamine-ER) was developed, chiefly to increase adherence to medication regimes in patients with mild-to-moderate Alzheimer’s disease (AD). Except for predicted differences in (Cmax) and tmax, comparable doses of once daily galantamine-ER and regular, immediate release galantamine, (galantamine-IR), are pharmacologically equivalent. A 24-week randomized, double-blind, placebo-and active-controlled, multicenter phase III trial, which compared galantamine-IR, galantamine-ER and placebo in subjects with mild to moderate AD (mini-mental state examination [MMSE] score range, 10 to 24) showed that both formulations of galantamine were significantly better than placebo in terms of cognition, although not with regard to global change. There was no difference in drug-related adverse events between galantamine-ER and galantamine-IR. Since its release onto the market galantamine-ER has enjoyed wide popularity and a recent surveillance study suggests that it has the highest 1-year persistence rate of all the ChEIs. PMID:20169037

A morphological screening of protein crystals for interferon delivery by metal ion-chelate technology.

PubMed

Jiang, Yanbo; Shi, Kai; Wang, Shuo; Li, Xuefeng; Cui, Fude

2010-12-01

This study presents a preliminary exploration on extending the half-life of therapeutic proteins by crystallization strategy without new molecular entities generation. Recombinant human interferon (rhIFN) α-2b, a model protein drug in this case, was crystallized using a hanging-drop vapor diffusion method. A novel chelating technique with metal ions was employed to promote crystals formation. The effects of key factors such as seeding protein concentration, pH of the hanging drop, ionic strength of the equilibration solution, and precipitants were investigated. Size-exclusion liquid chromatography, antiviral activity determination, and enzyme-linked immunosorbent assay indicated that both the molecular integrity and biological potency of rhIFN were not significantly affected by crystallization process. In addition, the in vitro release behavior of rhIFN from crystal lattice was characterized by an initial fast release, followed by a sustained release up to 48 hour. The work described here suggested an exciting possibility of therapeutic protein crystals as a long-acting formulation.

Controlled release systems containing solid dispersions: strategies and mechanisms.

PubMed

Tran, Phuong Ha-Lien; Tran, Thao Truong-Dinh; Park, Jun Bom; Lee, Beom-Jin

2011-10-01

In addition to a number of highly soluble drugs, most new chemical entities under development are poorly water-soluble drugs generally characterized by an insufficient dissolution rate and a small absorption window, leading to the low bioavailability. Controlled-release (CR) formulations have several potential advantages over conventional dosage forms, such as providing a uniform and prolonged therapeutic effect to improve patient compliance, reducing the frequency of dosing, minimizing the number of side effects, and reducing the strength of the required dose while increasing the effectiveness of the drug. Solid dispersions (SD) can be used to enhance the dissolution rate of poorly water-soluble drugs and to sustain the drug release by choosing an appropriate carrier. Thus, a CR-SD comprises both functions of SD and CR for poorly water-soluble drugs. Such CR dosage forms containing SD provide an immediately available dose for an immediate action followed by a gradual and continuous release of subsequent doses to maintain the plasma concentration of poorly water-soluble drugs over an extended period of time. This review aims to summarize all currently known aspects of controlled release systems containing solid dispersions, focusing on the preparation methods, mechanisms of action and characterization of physicochemical properties of the system.

Effect of formulation and process variables on lipid based sustained release tablets via continuous twin screw granulation: A comparative study.

PubMed

Kallakunta, Venkata Raman; Tiwari, Roshan; Sarabu, Sandeep; Bandari, Suresh; Repka, Michael A

2018-05-14

The current study's aim is to prepare lipid based sustained release tablets via a twin-screw granulation technique and compare those dosage forms with conventional techniques, namely wet granulation and direct compression. The granules were successfully manufactured in a single-step, continuous twin-screw granulation process with a low proportion of binder (Klucel™ EF, HPC SSL) using Compritol® 888 ATO, Precirol® ATO 5 and Geleol™ as sustained release agents. The granules prepared showed good flow characteristics and compaction properties. DSC and XRD studies were conducted to characterize the granules prepared via a twin-screw granulation method and the results demonstrated the crystalline nature of lipids within the granules. FTIR data indicated that there were no interactions with the formulation components investigated. The formulations developed by all three methods were compressed into tablets with a mechanical strength of 14-16 KP. The tablets formulated were characterized for physicochemical properties, in vitro drug release studies, water uptake and erosion studies. These results showed that the drug was not completely released after 24 h for tablets developed by the wet granulation process using all three lipids. The tablets prepared by the direct compression method demonstrated a burst release within 8 to 10 h from Precirol ATO 5® and Geleol™ formulations compared to Compritol® 888 ATO. However, tablets prepared using twin-screw granulation exhibited sustained release of the drug over 24 h and the water uptake and erosion results were in accordance with dissolution data. Stability data for 45 days at accelerated conditions (40 °C/75% RH) showed similar release profiles with ƒ2 values above 50 for all of the twin screw granulation formulations, indicating the suitability of the process for formulating sustained release tablets. These findings of a single-step, continuous twin-screw granulation process are novel and demonstrate new opportunities for development of sustained release tablets. Copyright © 2017. Published by Elsevier B.V.

Evaluating Suspension Formulations of Theophylline Cocrystals With Artificial Sweeteners.

PubMed

Aitipamula, Srinivasulu; Wong, Annie B H; Kanaujia, Parijat

2018-02-01

Pharmaceutical cocrystals have garnered significant interest as potential solids to address issues associated with formulation development of drug substances. However, studies concerning the understanding of formulation behavior of cocrystals are still at the nascent stage. We present results of our attempts to evaluate suspension formulations of cocrystals of an antiasthmatic drug, theophylline, with 2 artificial sweeteners. Stability, solubility, drug release, and taste of the suspension formulations were evaluated. Suspension that contained cocrystal with acesulfame showed higher drug release rate, while a cocrystal with saccharin showed a significant reduction in drug release rate. The cocrystal with saccharin was found stable in suspension for over 9 weeks at accelerated test condition; in contrast, the cocrystal with acesulfame was found unstable. Taste analysis using an electronic taste-sensing system revealed improved sweetness of the suspension formulations with cocrystals. Theophylline has a narrow therapeutic index with a short half-life which necessitates frequent dosing. This adversely impacts patient compliance and enhances risk of gastrointestinal and cardiovascular adverse effects. The greater thermodynamic stability, sweetness, and sustained drug release of the suspension formulation of theophylline-saccharin could offer an alternative solution to the short half-life of theophylline and make it a promising formulation for treating asthmatic pediatric and geriatric patients. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Application of a Compact Magnetic Resonance Imaging System with 1.5 T Permanent Magnets to Visualize Release from and the Disintegration of Capsule Formulations in Vitro and in Vivo.

PubMed

Takeshita, Keizo; Okazaki, Shoko; Shinada, Kyosuke; Shibamoto, Yuma

2017-01-01

Although magnetic resonance imaging (MRI) has potential in assessments of formulations, few studies have been conducted because of the size and expense of the instrument. In the present study, the processes of in vitro and in vivo release in a gelatin capsule formulation model were visualized using a compact MRI system with 1.5 T permanent magnets, which is more convenient than the superconducting MRI systems typically used for clinical and experimental purposes. A Gd-chelate of diethylenetriamine-N,N,N',N″,N″-pentaacetic acid, a contrast agent that markedly enhances proton signals via close contact with water, was incorporated into capsule formulations as a marker compound. In vitro experiments could clearly demonstrate the preparation-dependent differences in the release/disintegration of the formulations. In some preparations, the penetration of water into the formulation and generation of bubbles in the capsule were also observed prior to the disintegration of the formulation. When capsule formulations were orally administered to rats, the release of the marker into the stomach and its transit to the duodenum were visualized. These results strongly indicate that the compact MRI system is a powerful tool for pharmaceutical studies.

Relationship between mono-hydroxy-carbazepine serum concentrations and adverse effects in patients on oxcarbazepine monotherapy.

PubMed

Sattler, Annika; Schaefer, Marion; May, Theodor W

2015-09-01

To evaluate the relationship between serum concentrations of mono-hydroxy-carbazepine (MHD), the main metabolite of oxcarbazepine (OXC), and the occurrence of adverse effects (AE) in a large group of patients on OXC monotherapy. An antiepileptic drug (AED) therapeutic drug monitoring (TDM) database was analyzed especially with regard to OXC dosage, MHD serum concentration, and the occurrence of AE. In total, 893 blood samples of 442 patients were included in this retrospective study. The statistical evaluation was performed by means of Kaplan-Meier estimates, log-rank tests and generalized estimating equations (GEE). At least one AE was reported in 78 (17.6%) of the 442 patients. At MHD serum concentrations of 30.0 μg/ml and 43.7 μg/ml and OXC dosages of 33.1 mg/kg and 62.3 mg/kg, 25% and 75% of patients, respectively, experienced at least one AE. Log-rank tests indicated that younger patients (<18 years) may be able to tolerate higher MHD serum levels (p = 0.006) and higher OXC dosages per body weight (p < 0.001) compared to adult patients (≥ 18 years). Furthermore, AEs occurred at higher body-weight adjusted OXC dosages of extended release formulations compared to immediate-release formulations (p = 0.010), whereas MHD serum levels at which AEs occurred did not differ significantly between formulations (p = 0.125). Multivariate GEE confirmed the results. The occurrence of AEs is significantly (and non-linearly) dependent on MHD serum level, whereas the dependence of OXC dosage is less distinctive. But, tolerability of OXC seems to depend on age of the patients as well as on pharmaceutical formulation of OXC. Copyright © 2015 British Epilepsy Association. Published by Elsevier Ltd. All rights reserved.

Ionic Hydrogel Based on Chitosan Cross-Linked with 6-Phosphogluconic Trisodium Salt as a Drug Delivery System.

PubMed

Martínez-Martínez, Mayte; Rodríguez-Berna, Guillermo; Gonzalez-Alvarez, Isabel; Hernández, Ma Jesús; Corma, Avelino; Bermejo, Marival; Merino, Virginia; Gonzalez-Alvarez, Marta

2018-04-09

In this work, 6-phosphogluconic trisodium salt (6-PG - Na + ) is introduced as a new aqueous and nontoxic cross-linking agent to obtain ionic hydrogels. Here, it is shown the formation of hydrogels based on chitosan cross-linked with 6-PG - Na + . This formulation is obtained by ionic interaction of cationic groups of polymer with anionic groups of the cross-linker. These hydrogels are nontoxic, do not cause dermal irritation, are easy to extend, and have an adequate adhesion force to be applied as polymeric film over the skin. This formulation exhibits a first order release kinetic and can be applied as drug vehicle for topical administration or as wound dressing for wound healing. The primary goal of this communication is to report the identification and utility of 6-phosphogluconic trisodium salt (6-PG - Na + ) as a nontoxic cross-linker applicable for cationic polymers.

Controlled release of glaucocalyxin - a self-nanoemulsifying system from osmotic pump tablets with enhanced bioavailability.

PubMed

Yanfei, Miao; Guoguang, Chen; Lili, Ren; Pingkai, Ouyang

2017-03-01

The purpose of this study was to develop a new formulation to enhance the bioavailability simultaneously with controlled release of glaucocalyxin A (GLA). In this study, controlled release of GLA was achieved by the osmotic release strategy taking advantage of the bioavailability enhancing capacity of self-nanoemulsifying drug delivery systems (SNEDDS). The formulation of GLA-SNEDDS was selected by the solubility and pseudoternary-phase diagrams studies. The prepared GLA-SNEDDS formulations were characterized for self-emulsification time, effect of pH and robustness to dilution, droplet size analysis and zeta potential. The optimized GLA-SNEDDS were used to prepare GLA-SNEDDS osmotic pump tablet via direct powder compression method. The effect of formulation variables on the release characteristic was investigated. GLA-SNEDDS osmotic pump tablets were administered to beagle dogs and their pharmacokinetics were compared to GLA and GLA-SNEDDS as a control. In vitro drug release studies indicated that the GLA-SNEDDS osmotic pump tablet showed sustained release profiles with 90% released within 12 h. Pharmacokinetic study showed steady blood GLA with prolonged T max and mean residence time (MRT), and enhanced bioavailability for GLA-SNEDDS osmotic pump tablet. It was concluded that simultaneous controlling on GLA release and enhanced bioavailability had been achieved by a combination of osmotic pump tablet and SNEDDS.

Optimizing novel implant formulations for the prolonged release of biopharmaceuticals using in vitro and in vivo imaging techniques.

PubMed

Beyer, Susanne; Xie, Li; Schmidt, Mike; de Bruin, Natasja; Ashtikar, Mukul; Rüschenbaum, Sabrina; Lange, Christian M; Vogel, Vitali; Mäntele, Werner; Parnham, Michael J; Wacker, Matthias G

2016-08-10

As a rapidly growing class of therapeutics, biopharmaceuticals have conquered the global market. Despite the great potential from a therapeutic perspective, such formulations often require frequent injections due to their short half-life. Aiming to establish a parenteral dosage form with prolonged release properties, a biodegradable implant was developed, based on a combination of nanoencapsulation of protein-heparin complexes, creation of a slow release matrix by freeze-drying, and compression using hyaluronan and methylcellulose. In order to investigate this novel delivery system, formulations containing IFN-β-1a and trypsinogen as model proteins were developed. No degradation of the proteins was observed at any stage of the formulation processing. The potential of the delivery system was evaluated in vivo and in vitro after fluorescence-labeling of the biopharmaceuticals. An optimized agarose gel was utilized as in vitro release medium to simulate the subcutaneous environment in a biorelevant manner. In addition, the formulations were administered to female SJL mice and release was innovatively tracked by fluorescence imaging, setting up an in vitro-in vivo correlation. A prolonged time of residence of approximately 12days was observed for the selected formulation design. Copyright © 2016 Elsevier B.V. All rights reserved.

Capsule shell material impacts the in vitro disintegration and dissolution behaviour of a green tea extract☆

PubMed Central

Glube, Natalie; Moos, Lea von; Duchateau, Guus

2013-01-01

Purpose In vitro disintegration and dissolution are routine methods used to assess the performance and quality of oral dosage forms. The purpose of the current work was to determine the potential for interaction between capsule shell material and a green tea extract and the impact it can have on the release. Methods A green tea extract was formulated into simple powder-in-capsule formulations of which the capsule shell material was either of gelatin or HPMC origin. The disintegration times were determined together with the dissolution profiles in compendial and biorelevant media. Results All formulations disintegrated within 30 min, meeting the USP criteria for botanical formulations. An immediate release dissolution profile was achieved for gelatin capsules in all media but not for the specified HPMC formulations. Dissolution release was especially impaired for HPMCgell at pH 1.2 and for both HPMC formulations in FeSSIF media suggesting the potential for food interactions. Conclusions The delayed release from studied HPMC capsule materials is likely attributed to an interaction between the catechins, the major constituents of the green tea extract, and the capsule shell material. An assessment of in vitro dissolution is recommended prior to the release of a dietary supplement or clinical trial investigational product to ensure efficacy. PMID:25755998

Capsule shell material impacts the in vitro disintegration and dissolution behaviour of a green tea extract.

PubMed

Glube, Natalie; Moos, Lea von; Duchateau, Guus

2013-01-01

In vitro disintegration and dissolution are routine methods used to assess the performance and quality of oral dosage forms. The purpose of the current work was to determine the potential for interaction between capsule shell material and a green tea extract and the impact it can have on the release. A green tea extract was formulated into simple powder-in-capsule formulations of which the capsule shell material was either of gelatin or HPMC origin. The disintegration times were determined together with the dissolution profiles in compendial and biorelevant media. All formulations disintegrated within 30 min, meeting the USP criteria for botanical formulations. An immediate release dissolution profile was achieved for gelatin capsules in all media but not for the specified HPMC formulations. Dissolution release was especially impaired for HPMCgell at pH 1.2 and for both HPMC formulations in FeSSIF media suggesting the potential for food interactions. The delayed release from studied HPMC capsule materials is likely attributed to an interaction between the catechins, the major constituents of the green tea extract, and the capsule shell material. An assessment of in vitro dissolution is recommended prior to the release of a dietary supplement or clinical trial investigational product to ensure efficacy.

Drug disposition and modelling before and after gastric bypass: immediate and controlled-release metoprolol formulations.

PubMed

Gesquiere, Ina; Darwich, Adam S; Van der Schueren, Bart; de Hoon, Jan; Lannoo, Matthias; Matthys, Christophe; Rostami, Amin; Foulon, Veerle; Augustijns, Patrick

2015-11-01

The aim of the present study was to evaluate the disposition of metoprolol after oral administration of an immediate and controlled-release formulation before and after Roux-en-Y gastric bypass (RYGB) surgery in the same individuals and to validate a physiologically based pharmacokinetic (PBPK) model for predicting oral bioavailability following RYGB. A single-dose pharmacokinetic study of metoprolol tartrate 200 mg immediate release and controlled release was performed in 14 volunteers before and 6-8 months after RYGB. The observed data were compared with predicted results from the PBPK modelling and simulation of metoprolol tartrate immediate and controlled-release formulation before and after RYGB. After administration of metoprolol immediate and controlled release, no statistically significant difference in the observed area under the curve (AUC(0-24 h)) was shown, although a tendency towards an increased oral exposure could be observed as the AUC(0-24 h) was 32.4% [95% confidence interval (CI) 1.36, 63.5] and 55.9% (95% CI 5.73, 106) higher following RYGB for the immediate and controlled-release formulation, respectively. This could be explained by surgery-related weight loss and a reduced presystemic biotransformation in the proximal gastrointestinal tract. The PBPK values predicted by modelling and simulation were similar to the observed data, confirming its validity. The disposition of metoprolol from an immediate-release and a controlled-release formulation was not significantly altered after RYGB; there was a tendency to an increase, which was also predicted by PBPK modelling and simulation. © 2015 The British Pharmacological Society.

Drug disposition and modelling before and after gastric bypass: immediate and controlled-release metoprolol formulations

PubMed Central

Gesquiere, Ina; Darwich, Adam S; Van der Schueren, Bart; de Hoon, Jan; Lannoo, Matthias; Matthys, Christophe; Rostami, Amin; Foulon, Veerle; Augustijns, Patrick

2015-01-01

Aims The aim of the present study was to evaluate the disposition of metoprolol after oral administration of an immediate and controlled-release formulation before and after Roux-en-Y gastric bypass (RYGB) surgery in the same individuals and to validate a physiologically based pharmacokinetic (PBPK) model for predicting oral bioavailability following RYGB. Methods A single-dose pharmacokinetic study of metoprolol tartrate 200 mg immediate release and controlled release was performed in 14 volunteers before and 6–8 months after RYGB. The observed data were compared with predicted results from the PBPK modelling and simulation of metoprolol tartrate immediate and controlled-release formulation before and after RYGB. Results After administration of metoprolol immediate and controlled release, no statistically significant difference in the observed area under the curve (AUC0–24 h) was shown, although a tendency towards an increased oral exposure could be observed as the AUC0–24 h was 32.4% [95% confidence interval (CI) 1.36, 63.5] and 55.9% (95% CI 5.73, 106) higher following RYGB for the immediate and controlled-release formulation, respectively. This could be explained by surgery-related weight loss and a reduced presystemic biotransformation in the proximal gastrointestinal tract. The PBPK values predicted by modelling and simulation were similar to the observed data, confirming its validity. Conclusions The disposition of metoprolol from an immediate-release and a controlled-release formulation was not significantly altered after RYGB; there was a tendency to an increase, which was also predicted by PBPK modelling and simulation. PMID:25917170

[Studies on preparation of sustained-release Shuxiong formulation, a traditional Chinese medicine compound recipe, using time-controlled release techniques].

PubMed

Song, Hong-Tao; Zhang, Qian; Jiang, Peng; Guo, Tao; Chen, Da-Wei; He, Zhong-Gui

2006-09-01

To prepare a sustained-release formulation of traditional Chinese medicine compound recipe by adopting time-controlled release techniques. Shuxiong tablets were chosen as model drug. The prescription and technique of core tablets were formulated with selecting disintegrating time and swelling volume of core tablets in water as index. The time-controlled release tablets were prepared by adopting press-coated techniques, using PEG6000, HCO and EVA as coating materials. The influences of compositions, preparation process and dissolution conditions in vitro on the lag time (T(lag)) of drug release were investigated. The composition of core tablets was as follow: 30% of drug, 50% MCC and 20% CMS-Na. The T(lag) of time-controlled release tablets was altered remarkably by PEG6000 content of the outer layer, the amount of outer layer and hardness of tablet. The viscosity of dissolution media and basket rotation had less influence on the T(lag) but more on rate of drug release. The core tablets pressed with the optimized composition had preferable swelling and disintegrating properties. The shuxiong sustained-release formulations which contained core tablet and two kinds of time-controlled release tablets with 3 h and 6 h of T(lag) could release drug successively at 0 h, 3 h and 6 h in vitro. The technique made it possible that various components with extremely different physicochemical properties in these preparations could release synchronously.

Formulation and evaluation of novel controlled release of topical pluronic lecithin organogel of mefenamic acid.

PubMed

Jhawat, Vikas; Gupta, Sumeet; Saini, Vipin

2016-11-01

In the present study, pluronic lecithin based organogels (PLO gels) were formulated as topical carrier for controlled delivery of mefenamic acid. Ten organogel formulations were prepared by a method employing lecithin as lipophilic phase and pluronic F-127 as hydrophilic phase in varying concentrations to study various parameters using in vitro diffusion study and in vivo studies. All formulations were found to be off-white, homogenous, and reluctant to be washed easily and have pH value within the range of 5.56-5.80 which is nonirritant. Polymer concentration increased in formulations of F1 to F5 (lecithin) and F6 to F10 (pluronic) resulted in decrease of the gelation temperature, increase of viscosity and reduction of spreadability of gels having polymer tendency to form rigid 3D network. Organogels with higher viscosity were found to be more stable and retard the drug release from the gel. The formulations of F2 and F3 were selected for kinetic studies and stability studies, as they found to have all physical parameters within acceptable limits, highest percent drug content and exhibited highest drug release in eight hours. The order of drug release from various formulations was found to be F2 > F3 > F10 > F4 > F1 > F9 > F8 > F5 > F7 > F6. The optimized formulation F2 was found to follow zero order rate kinetics showing controlled release of the drug from the formulations. In vivo anti-inflammatory activity of optimized mefenamic acid organogel (F2) against a standard marketed preparation (Volini gel) was found satisfactory and significant.

Liposomal Aloe vera trans-emulgel drug delivery of naproxen and nimesulide: A study

PubMed Central

Venkataharsha, Panuganti; Maheshwara, Ellutla; Raju, Y Prasanna; Reddy, Vayalpati Ashok; Rayadu, Bandugalla Sanjeev; Karisetty, Basappa

2015-01-01

Introduction: The present aim of this study was to formulate naproxen and nimesulide liposomal formulation for incorporation in Aloe vera transemulgel and to carry out in vitro and in vivo evaluation of the formulation. Material and Methods: A. vera gel was prepared and used as a gel base for formulation. Carbopol 934 is used as a gelling agent and Methyl paraben was used as a preservative for the formulation of the gel. Liposomes was formulated by using hydration method. The formulated naproxen and nimesulide liposomal formulation using A. vera trans-emul gel were evaluated for in vitro studies such as drug release, permeation study, and drug content and entrapment efficiency. Paw edema method in Wistar rats induced by carrageenan is used to study in vivo anti-inflammatory action. Result: From the in vitro studies such permeability drug release naproxen 65% (69.6), Nimesulide 65% (61.1), and commercial Nimsulide gel (60.82) at 240 min. In vivo data shows that formulated liposomal transemulgel formulation are superior in their efficacy compared to commercial and A. vera gel. The results are compared with the commercial formulations. Conclusion: From our results, it is concluded that the A. vera trans emul gel using nimesulide and naproxen liposomal formulation is stable and prepared gel base is effective for formulation with high drug release and drug content compared with commercial formulation with significant anti-inflammatory effect. PMID:25599030

Microphase separation in solid lipid dosage forms as the cause of drug release instability.

PubMed

Lopes, Diogo Gomes; Koutsamanis, Ioannis; Becker, Karin; Scheibelhofer, Otto; Laggner, Peter; Haack, Detlev; Stehr, Michael; Zimmer, Andreas; Salar-Behzadi, Sharareh

2017-01-30

Although lipid excipients are of increasing interest for development of taste-masked and modified release formulations, the drug release instability and the lack of mechanistic understanding in that regard still prevent their larger-scale application. In this work, we investigated the physical stability of a binary (tripalmitin/polysorbate 65) lipid coating formulation with a known stable polymorphism. The coating composition was characterized using DSC to construct the phase diagram of binary system and polarized light microscopy to display the microstructure organization. The water uptake and the erosion of slabs cast from the coating formulations were investigated post-production and after storage. Subsequently, N-acetylcysteine particles were coated with the selected formulations and the drug release stability was investigated. Additionally, microstructure characterization was performed via SEM and X-ray diffraction. The drug release instability was explained by polysorbate 65 and tripalmitin phase growth during storage, especially at 40°C, suggesting that polysorbate 65 can leak out of tripalmitin spherulitic structures, creating lipophilic and impermeable tripalmitin regions. The growth of polysorbate 65 phase leads to larger hydrophilic channels with reduced tortuosity. This work indicates that for obtaining stable drug release profiles from advanced lipid formulations, microphase separation should be prevented during storage. Copyright © 2016 Elsevier B.V. All rights reserved.

In vitro evaluation of suspoemulsions for in situ-forming polymeric microspheres and controlled release of progesterone.

PubMed

Turino, Ludmila N; Mariano, Rodolfo N; Mengatto, Luciano N; Luna, Julio A

2015-01-01

One possibility to obtain a higher dose of drug in a lower formulation volume can be by using of saturated quantity of drug in one of the phases of an emulsion. These formulations are called suspoemulsions (S/O/W). When a hydrophobic polymer is added to the organic phase of suspoemulsions, these formulations can be used to entrap the drug inside microspheres after in situ precipitation of the polymer-drug-excipients mix. In this work, performance and stability of progesterone suspensions in triacetin as organic phase of suspoemulsions were evaluated. These formulations were compared with O/W emulsions. Mathematical models were used to study in vitro release profiles. The results confirmed that S/O/W systems could be an attractive alternative to O/W formulations for the entrapment of progesterone inside poly(d,l-lactide-co-glycolide) microspheres. Diffusive-based models fit the in vitro release of progesterone from in situ-formed microspheres. For longer release periods, a time-dependent diffusion coefficient was successfully estimated.

Study on encapsulation of chlorine dioxide in gelatin microsphere for reducing release rate

PubMed Central

Ci, Ying; Wang, Lin; Guo, Yanchuan; Sun, Ruixue; Wang, Xijie; Li, Jinyou

2015-01-01

Objective: This study aims to explore the effects of encapsulation of chlorine dioxide in a hydrophilic biodegradable polymer gelatin to reduce its release rate. Methods: An emulsification-coacervation method was adopted. The characterizations of chlorine dioxide-gelatin microspheres were described. Using UV-vis spectrophotometer the λmax of chlorine dioxide was observed at 358 nm. The particle size and distribution of chlorine oxide-gelatin microspheres was measured by a dynamic light scattering (DLS) method, the diameter was (1400~1900) nm. The entrapment of chlorine dioxide-gelatin microspheres was confirmed by IR. The surface morphology, size, and shape of chlorine dioxide-gelatin microspheres were analyzed using Scanning electron microscope (SEM). Results: It showed that the encapsulated microspheres size was around 2000 nm with uniform distribution. The percentage entrapment of chlorine dioxide in the encapsulated samples was about 80~85%. A slow release study of chlorine dioxide from the encapsulated biopolymer (gelatin) in air was also carried out, which showed continuous release up to ten days. Conclusions: It can be concluded that it is possible to make a slow release formulation of ClO2 by entrapped in a hydrophilic biodegradable polymer gelatin. ClO2-gelatin microspheres can stable release low concentration ClO2 gas over an extended period. PMID:26550151

Granisetron Extended-Release Injection: A Review in Chemotherapy-Induced Nausea and Vomiting.

PubMed

Deeks, Emma D

2016-12-01

An extended-release (ER) subcutaneously injectable formulation of the first-generation 5-HT 3 receptor antagonist granisetron is now available in the USA (Sustol ® ), where it is indicated for the prevention of acute and delayed chemotherapy-induced nausea and vomiting (CINV) following moderately emetogenic chemotherapy (MEC) or anthracycline and cyclophosphamide combination chemotherapy regimens in adults. Granisetron ER is administered as a single subcutaneous injection and uses an erosion-controlled drug-delivery system to allow prolonged granisetron release. Primary endpoint data from phase III studies after an initial cycle of chemotherapy indicate that, when used as part of an antiemetic regimen, granisetron ER injection is more effective than intravenous ondansetron in preventing delayed CINV following highly emetogenic chemotherapy (HEC); is noninferior to intravenous palonosetron in preventing both acute CINV following MEC or HEC and delayed CINV following MEC; and is similar, but not superior, to palonosetron in preventing delayed CINV following HEC. The benefits of granisetron ER were seen in various patient subgroups, including those receiving anthracycline plus cyclophosphamide-based HEC, and (in an extension of one of the studies) over multiple MEC or HEC cycles. Granisetron ER injection is generally well tolerated, with an adverse event profile similar to that of ondansetron or palonosetron. Thus, granisetron ER injection expands the options for preventing both acute and delayed CINV in adults with cancer receiving MEC or anthracycline plus cyclophosphamide-based HEC.

Roller compaction of hydrophilic extended release tablets-combined effects of processing variables and drug/matrix former particle size.

PubMed

Heiman, Johanna; Tajarobi, Farhad; Gururajan, Bindhumadhavan; Juppo, Anne; Abrahmsén-Alami, Susanna

2015-04-01

The present study shows that roller compaction (RC) can successfully be used as a granulation method to prepare hydroxypropyl methylcellulose (HPMC)-based extended release matrix tablets containing a high drug load, both for materials deforming mainly by fragmentation (paracetamol) as for those having mainly plastic deformation (ibuprofen). The combined effect of RC process variables and composition on the manufacturability of HPMC tablets was investigated. Standard wet granulation grade HPMC was compared with a larger particle size direct compressible HPMC grade. Higher roll pressure was found to result in larger paracetamol granules and narrower granule particle size distributions, especially for formulations containing smaller size HPMC. However, for ibuprofen, no clear effect of roll pressure was observed. High roll pressure also resulted in denser ribbon and less bypass fines during RC. Loss of compactibility was observed for granules compared to powder blends, which was found to be related to differences in granule porosity and morphology. Using the large-sized HPMC grade did in some cases result in lower tensile strength tablets but had the advantage to improve the powder flow into the roller compactor. This work also indicates that when the HPMC level lies near the percolation threshold, significant changes can occur in the drug release rate due to changes in other factors (raw material characteristics and processing).

Conceptuation, formulation and evaluation of sustained release floating tablets of captopril compression coated with gastric dispersible hydrochlorothiazide using 23 factorial design

PubMed Central

Sirisha, Pathuri Lakshmi; Babu, Govada Kishore; Babu, Puttagunta Srinivasa

2014-01-01

Ambulatory blood pressure monitoring is regarded as the gold standard for hypertensive therapy in non-dipping hypertension patients. A novel compression coated formulation of captopril and hydrochlorothiazide (HCTZ) was developed in order to improve the efficacy of antihypertensive therapy considering the half-life of both drugs. The synergistic action using combination therapy can be effectively achieved by sustained release captopril (t1/2= 2.5 h) and fast releasing HCTZ (average t1/2= 9.5 h). The sustained release floating tablets of captopril were prepared by using 23 factorial design by employing three polymers i.e., ethyl cellulose (EC), carbopol and xanthan gum at two levels. The formulations (CF1-CF8) were optimized using analysis of variance for two response variables, buoyancy and T50%. Among the three polymers employed, the coefficients and P values for the response variable buoyancy and T50% using EC were found to be 3.824, 0.028 and 0.0196, 0.046 respectively. From the coefficients and P values for the two response variables, formulation CF2 was optimized, which contains EC polymer alone at a high level. The CF2 formulation was further compression coated with optimized gastric dispersible HCTZ layer (HF9). The compression coated tablet was further evaluated using drug release kinetics. The Q value of HCTZ layer is achieved within 20 min following first order release whereas the Q value of captopril was obtained at 6.5 h following Higuchi model, from which it is proved that rapid release HCTZ and slow release of captopril is achieved. The mechanism of drug release was analyzed using Peppas equation, which showed an n >0.90 confirming case II transportation mechanism for drug release. PMID:25006552

Hydrophobin-nanofibrillated cellulose stabilized emulsions for encapsulation and release of BCS class II drugs.

PubMed

Paukkonen, Heli; Ukkonen, Anni; Szilvay, Geza; Yliperttula, Marjo; Laaksonen, Timo

2017-03-30

The purpose of this study was to construct biopolymer-based oil-in-water emulsion formulations for encapsulation and release of poorly water soluble model compounds naproxen and ibuprofen. Class II hydrophobin protein HFBII from Trichoderma reesei was used as a surfactant to stabilize the oil/water interfaces of the emulsion droplets in the continuous aqueous phase. Nanofibrillated cellulose (NFC) was used as a viscosity modifier to further stabilize the emulsions and encapsulate protein coated oil droplets in NFC fiber network. The potential of both native and oxidized NFC were studied for this purpose. Various emulsion formulations were prepared and the abilities of different formulations to control the drug release rate of naproxen and ibuprofen, used as model compounds, were evaluated. The optimal formulation for sustained drug release consisted of 0.01% of drug, 0.1% HFBII, 0.15% oxidized NFC, 10% soybean oil and 90% water phase. By comparison, the use of native NFC in combination with HFBII resulted in an immediate drug release for both of the compounds. The results indicate that these NFC originated biopolymers are suitable for pharmaceutical emulsion formulations. The native and oxidized NFC grades can be used as emulsion stabilizers in sustained and immediate drug release applications. Furthermore, stabilization of the emulsions was achieved with low concentrations of both HFBII and NFC, which may be an advantage when compared to surfactant concentrations of conventional excipients traditionally used in pharmaceutical emulsion formulations. Copyright © 2017 Elsevier B.V. All rights reserved.

Press-coated tablets for time-programmed release of drugs.

PubMed

Conte, U; Maggi, L; Torre, M L; Giunchedi, P; La Manna, A

1993-10-01

A new dry-coated device for the release of drug after a programmable period of time is proposed. It is intended to be used mainly in the therapy of those diseases which depend on circadian rhythms. Some core formulations, characterized by different release rates and mechanisms (containing diltiazem hydrochloride or sodium diclofenac as model drugs), were coated by compression with different polymeric barrier layers (press-coated systems). The shell formulations tested contained either gellable or erodible polymers. The dissolution profiles of uncoated cores and press-coated devices were compared. The gellable and/or erodible characteristics (properties) of the barrier formulations were also examined by means of a penetrometer. The coatings prevent drug release from the core until the polymeric shell is completely eroded or swollen. This delay in release start is not influenced by the core composition and depends only on the shell formulation. Except for the time-lag, the release kinetics of the drug contained in the core are not significantly influenced by the presence of the erodible barrier, but can be widely modulated using a swellable polymeric shell.

A mathematical model for interpreting in vitro rhGH release from laminar implants.

PubMed

Santoveña, A; García, J T; Oliva, A; Llabrés, M; Fariña, J B

2006-02-17

Recombinant human growth hormone (rhGH), used mainly for the treatment of growth hormone deficiency in children, requires daily subcutaneous injections. The use of controlled release formulations with appropriate rhGH release kinetics reduces the frequency of medication, improving patient compliance and quality of life. Biodegradable implants are a valid alternative, offering the feasibility of a regular release rate after administering a single dose, though it exists the slight disadvantage of a very minor surgical operation. Three laminar implant formulations (F(1), F(2) and F(3)) were produced by different manufacture procedures using solvent-casting techniques with the same copoly(D,L-lactic) glycolic acid (PLGA) polymer (Mw=48 kDa). A correlation in vitro between polymer matrix degradation and drug release rate from these formulations was found and a mathematical model was developed to interpret this. This model was applied to each formulation. The obtained results where explained in terms of manufacture parameters with the aim of elucidate whether drug release only occurs by diffusion or erosion, or by a combination of both mechanisms. Controlling the manufacture method and the resultant changes in polymer structure facilitates a suitable rhGH release profile for different rhGH deficiency treatments.

[Study on sustained release preparations of Epimedium component].

PubMed

Yan, Hong-mei; Ding, Dong-mei; Zhang, Zhen-hai; Sun, E; Song, Jie; Jia, Xiao-bin

2015-04-01

The formulation for sustained release tablet of Epinedium component was selected and the evaluation equation of in vitro release was established. The liquidity of component was improved with the help of colloidal silica aided by spray drying, which would be the main drug in the sustained release tablets. Dissolution was selected as an evaluation index to investigate skeletal material type, fillers, impact porogen, lubricants and other materials on the quality of sustained release tablet. The sustained release tablets were prepared by dry compression. Formulation of sustained release preparations was main drug 35%, HPMC K(4M) 20% and HPMC K(15M) 10% as skeleton material, MCC 31% as filler, PEG6000 2% as porogen and magnesium stearate 2% as lubricant. The sustained release tablets released up to 80% in 8 h. The zero order equation, primary equation and Higuchi equation could simulate the release characteristics of sustained release tablets in vitro, the correlation coefficients r were larger than 0.96. The primary equation was most similar in vitro release characteristics and its correlation coefficient r was 0.9950. The preparation method is simple and the results of formulation selection are reliable. It can be used to guide the production of Epimedium component sustained release preparations.

In Vivo Formation of Cubic Phase in Situ after Oral Administration of Cubic Phase Precursor Formulation Provides Long Duration Gastric Retention and Absorption for Poorly Water-Soluble Drugs.

PubMed

Pham, Anna C; Hong, Linda; Montagnat, Oliver; Nowell, Cameron J; Nguyen, Tri-Hung; Boyd, Ben J

2016-01-04

Lipid-based liquid crystalline systems based on the combination of digestible and nondigestible lipids have been proposed as potential sustained release delivery systems for oral delivery of poorly water-soluble drugs. The potential for cubic phase liquid crystal formation to induce dramatically extended gastric retention in vivo has been shown previously to strongly influence the resulting pharmacokinetics of incorporated drug. In vitro studies showing the in situ formation of cubic phase from a disordered precursor comprising a mixture of digestible and nondigestible lipids under enzymatic digestion have also recently been reported. Combining both concepts, here we show the potential for such systems to form in vivo, increasing gastric retention, and providing a sustained release effect for a model poorly water-soluble drug cinnarizine. A mixture of phytantriol and tributyrin at an 85:15 mass ratio, shown previously to form cubic phase under the influence of digestion, induced a similar pharmacokinetic profile to that in the absence of tributyrin, but completely different from tributyrin alone. The gastric retention of the formulation, assessed using micro-X-ray CT imaging, was also consistent with the pharmacokinetic behavior, where phytantriol alone and with 15% tributyrin was greater than that of tributyrin in the absence of phytantriol. Thus, the concept of precursor lipid systems that form cubic phase in situ during digestion in vivo has been demonstrated and opens new opportunities for sustained release of poorly water-soluble drugs.

Physicochemical and pharmacological investigation of water/oil microemulsion of non-selective beta blocker for treatment of glaucoma.

PubMed

Hegde, Rahul Rama; Bhattacharya, Shiv Sankar; Verma, Anurag; Ghosh, Amitava

2014-02-01

Ocular drug delivery system always remained associated with lots of difficulties and faced issues of poor drug absorption and poor bioavailability. Timolol maleate is a nonspecific beta blocker used for reduction of elevated intraocular pressure in glaucoma. Timolol maleate is absorbed systemically and is contraindicated in asthmatic patients. This study is focused to deliver Timolol maleate by a water/oil microemulsion to extend the time of reduced intraocular pressure of glaucomatous rabbit's eye measured by using a Schoetz tonometer. The microemulsion is prepared by mixing the oily components with two nonionic surfactants, drug and water, and evaluated for the physicochemical, in vitro and in vivo parameters. The colloidal system demonstrates monodisperse distribution behavior and exhibits a uniform size distribution of finite width. In vitro drug release from microemulsion was found to follow Higuchi's pattern followed by a zero-order drug release by the emulsion. Ex vivo permeation through goat cornea revealed delayed release of Timolol maleate from microemulsion as compared with its aqueous solution. A reduction in intraocular pressure is seen lasting for 12 h compared to aqueous eye drop that lasted for only 5 h. CONCLUSION. In vivo reduction of intraocular pressure revealed a similar efficacy for once daily dosed 0.3% Timolol maleate in microemulsion formulation compared to 0.5% concentration in both microemulsion as well as aqueous formulation. The possible outcome of dose reduction will reduce the cardiovascular side effects generally reported with Timolol maleate eye drops.

Preparation and evaluation of a controlled drug release of repaglinide through matrix pellets: in vitro and in vivo studies.

PubMed

Tavakoli, Naser; Minaiyan, Mohsen; Tabbakhian, Majid; Pendar, Yaqub

2014-01-01

Repaglinide, an oral antidiabetic agent, has a rapid onset of action and short half-life of approximately 1 h. Designing a controlled release dosage form of the drug is required to maintain its therapeutic blood level and to eliminate its adverse effects, particularly the hypoglycaemia. Repaglinide sustained release matrix pellets consisting of Avicel, lactose and different polymers were prepared using extrusion-spheronisation method. The effect of different formulation components on in vitro drug release were evaluated using USP apparatus (paddle) for 12 h in phosphate buffer. The optimised formulation was orally administrated to normal and STZ induced diabetic rats. Most pellet formulations had acceptable physical properties with regard to size distribution, flowability and friability. Repaglinide pellets comprising Avicel 50%, lactose 47% and SLS 1% were released 94% of its drug content after 12 h. The optimised formulation was able to decrease blood glucose level in normal rats and those with diabetes throughout 8-12 h.

The effect of excipients on the release kinetics of diclofenac sodium and papaverine hydrochloride from composed tablets.

PubMed

Kasperek, Regina; Trebacz, Hanna; Zimmer, Łukasz; Poleszak, Ewa

2014-01-01

For increased analgesic effect, new composed tablets containing diclofenac sodium (DIC) with an addition of papaverine hydrochloride (PAP) were prepared to investigate the mechanism of release of the active substances from tablets with different excipients in eight different formulations. To detect the possible interactions between active substances and excipients differential scanning calorimetry (DSC) was used. A shift of the melting point and enthalpy values of the physical mixtures of tablets components suggested a kind of interaction between components in certain formulations, however, the tabletting process was not disturbed in any of them. Kinetics of drug release from formulations was estimated by zero order, first order and Higuchi and Korsmeyer-Peppas models using results of dissolution of DIC and PAP from tablets. The study revealed that the mechanism of release of active substances was dependent on the excipients contained in tablets and the best fitted kinetics models were obtained for formulations with potentially prolonged release of DIC and PAP.

In vivo biocompatibility, sustained-release and stability of triptorelin formulations based on a liquid, degradable polymer.

PubMed

Asmus, Lutz R; Tille, Jean-Christophe; Kaufmann, Béatrice; Melander, Louise; Weiss, Torsten; Vessman, Kerstin; Koechling, Wolfgang; Schwach, Grégoire; Gurny, Robert; Möller, Michael

2013-02-10

Hexylsubstituted poly(lactic acid) (hexPLA) is a viscous polymer, which degrades in the presence of water similar to the structure related poly(lactic acid). With hydrophilic active compounds, like Triptorelin acetate, the lipophilic polymer was formulated in form of parenterally injectable suspensions. This first in vivo study toward the biocompatibility of hexPLA implants in rats over 3 months in comparison to in situ forming poly(lactic-co-glycolic acid) (PLGA) formulations is presented here. The hexPLA implants showed only a mild acute inflammation at the injection site after application, which continuously regressed. In contrast to the PLGA formulations, hexPLA did not provoke an encapsulation of the implant with extracellular matrix. Prior to the formulation application, the stability of Triptorelin inside the hexPLA matrix was assessed under different storage conditions and in the presence of buffer to simulate a peptide degrading environment. At 5°C Triptorelin showed a stability of 98% inside the polymer for at least 6 months. The stability was still 78% at an elevated temperature of 40°C. HexPLA protected the incorporated peptide from the surrounding aqueous environment, which resulted in 20% less degradation inside the polymer compared to the solution. This protection effect supports the use of Triptorelin-hexPLA formulations for parenteral sustained-release formulations. In a second in vivo evaluation in Wistar Hannover rats, formulations containing 5% and 10% Triptorelin in the polymeric matrix released the active compound continuously for 6 months. The formulations showed a higher release during the initial 7 days, which is necessary for the clinical use to down-regulate all GnRH-receptors. Afterwards, a zero order drug release was observed over the first 3 months. After 3 months, the plasma levels decreased slowly but remained at effective concentrations for the total of 6 months. Furthermore, a qualitative in vitro-in vivo correlation was observed, possibly facilitating future optimization of the Triptorelin-hexPLA sustained-release formulations. Copyright © 2012 Elsevier B.V. All rights reserved.

Eco-friendly PEG-based controlled release nano-formulations of Mancozeb: Synthesis and bioefficacy evaluation against phytopathogenic fungi Alternaria solani and Sclerotium rolfsii.

PubMed

Majumder, Sujan; Shakil, Najam A; Kumar, Jitendra; Banerjee, Tirthankar; Sinha, Parimal; Singh, Braj B; Garg, Parul

2016-12-01

Controlled release (CR) nano-formulations of Mancozeb (manganese-zinc double salt of N,N-bisdithiocarbamic acid), a protective fungicide, have been prepared using laboratory-synthesized poly(ethylene glycols) (PEGs)-based functionalized amphiphilic copolymers without using any surfactants or external additives. The release kinetics of the developed Mancozeb CR formulations were studied and compared with that of commercially available 42% suspension concentrate and 75% wettable powder. Maximum amount of Mancozeb was released on 42nd day for PEG-600 and octyl chain, PEG-1000 and octyl chain, and PEG-600 and hexadecyl chain, on 35th day for PEG-1000 and hexadecyl chain, on 28th day for PEG-1500 and octyl chain, PEG-2000 and octyl chain, PEG-1500 and hexadecyl chain, and PEG-2000 and hexadecyl chain in comparison to both commercial formulations (15th day). The diffusion exponent (n value) of Mancozeb in water ranged from 0.42 to 0.62 in tested formulations. The half-release (t 1/2 ) values ranged from 17.35 to 35.14 days, and the period of optimum availability of Mancozeb ranged from 18.54 to 35.42 days. Further, the in vitro bioefficacy evaluation of developed formulations was done against plant pathogenic fungi Alternaria solani and Sclerotium rolfsii by poison food technique. Effective dose for 50% inhibition in mgL -1 (ED 50 ) values of developed formulations varied from 1.31 to 2.79 mg L -1 for A. solani, and 1.60 to 3.14 mg L -1 for S. rolfsii. The present methodology is simple, economical, and eco-friendly for the development of environment-friendly CR formulations of Mancozeb. These formulations can be used to optimize the release of Mancozeb to achieve disease control for the desired period depending upon the matrix of the polymer used. Importantly, the maximum amount of active ingredient remains available for a reasonable period after application. In addition, the developed CR formulations were found to be suitable for fungicidal applications, allowing use of Mancozeb in lower doses.

Formulation and development of pH-independent/dependent sustained release matrix tablets of ondansetron HCl by a continuous twin-screw melt granulation process.

PubMed

Patil, Hemlata; Tiwari, Roshan V; Upadhye, Sampada B; Vladyka, Ronald S; Repka, Michael A

2015-12-30

The objective of the present study was to develop pH-independent/dependent sustained release (SR) tablets of ondansetron HCl dihydrate (OND), a selective 5-HT3 receptor antagonist that is used for prevention of nausea and vomiting caused by chemotherapy, radiotherapy and postoperative treatment. The challenge with the OND API is its pH-dependent solubility and relatively short elimination half-life. Therefore, investigations were made to solve these problems in the current study. Formulations were prepared using stearic acid as a binding agent via a melt granulation process in a twin-screw extruder. The micro-environmental pH of the tablet was manipulated by the addition of fumaric acid to enhance the solubility and release of OND from the tablet. The in vitro release study demonstrated sustained release for 24h with 90% of drug release in formulations using stearic acid in combination with ethyl cellulose, whereas 100% drug release in 8h for stearic acid-hydroxypropylcellulose matrices. The formulation release kinetics was correlated to the Higuchi diffusion model and a non-Fickian drug release mechanism. The results of the present study demonstrated for the first time the pH dependent release from hydrophilic-lipid matrices as well as pH independent release from hydrophobic-lipid matrices for OND SR tablets manufactured by means of a continuous melt granulation technique utilizing a twin-screw extruder. Copyright © 2015 Elsevier B.V. All rights reserved.

An Accelerated Release Method of Risperidone Loaded PLGA Microspheres with Good IVIVC.

PubMed

Hu, Xiaoqin; Zhang, Jianwei; Tang, Xuemei; Li, Mingyuan; Ma, Siyu; Liu, Cheng; Gao, Yue; Zhang, Yue; Liu, Yan; Yu, Fanglin; Yang, Yang; Guo, Jia; Li, Zhiping; Mei, Xingguo

2018-01-01

A long release period lasting several days or several weeks is always needed and thereby it is tedious and time consuming to screen formulations of such microspheres with so long release period and evaluate their release profiles in vitro with conventional long-term or "real-time" release method. So, an accelerated release testing of such system is necessary for formulation design as well as quality control purpose. The purpose of this study is to obtain an accelerated release method of risperidone loaded poly(lactic-co-glycolic acid) (PLGA) microspheres with good in vitro/in vivo correlation (IVIVC). Two formulations of risperidone loaded PLGA microspheres used for evaluating IVIVC were prepared by O/W method. The accelerated release condition was optimized by investigating the effect of pH, osmotic pressure, temperature and ethanol concentration on the release of risperidone from microspheres and the in vitro accelerated release profiles of risperidone from PLGA microspheres were obtained under this optimized accelerated release condition. The plasma concentration of risperidone were also detected after subcutaneous injection of risperidone loaded microspheres to rats. The in vivo cumulative absorption profiles were then calculated using Wagner-Nelson model, Loo- Riegelman model and numerical convolution model, respectively. The correlation between in vitro accelerated release and in vivo cumulative absorption were finally evaluated with Least Square Method. It was shown that temperature and ethanol concentration significantly affected the release of risperidone from the microspheres while pH and osmotic pressure of release media slightly affected the release behavior of risperidone. The in vitro release of risperidone from microspheres were finally undergone in PBS (pH7.0, 300mosm) with 20% (V/V) ethanol at 45°C. The sustained and complete release of risperidone was observed in both formulations under the accelerated release condition although these two release profiles were dissimilar. The correlation coefficients (R2) of IVIVC were all above 0.95 and the slopes were all between 0.9564 and 1.1868 in spite of fitted model and microsphere formulation. An in vitro accelerated release method of risperidone microspheres with good IVIVC was established in this paper and this accelerated release method was supposed to have great potential in both in vivo performance prediction and quality control for risperidone loaded PLGA microspheres. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Formulation and In Vitro, In Vivo Evaluation of Effervescent Floating Sustained-Release Imatinib Mesylate Tablet

PubMed Central

Kadivar, Ali; Kamalidehghan, Behnam; Javar, Hamid Akbari; Davoudi, Ehsan Taghizadeh; Zaharuddin, Nurul Dhania; Sabeti, Bahareh; Chung, Lip Yong; Noordin, Mohamed Ibrahim

2015-01-01

Introduction Imatinib mesylate is an antineoplastic agent which has high absorption in the upper part of the gastrointestinal tract (GIT). Conventional imatinib mesylate (Gleevec) tablets produce rapid and relatively high peak blood levels and requires frequent administration to keep the plasma drug level at an effective range. This might cause side effects, reduced effectiveness and poor therapeutic management. Therefore, floating sustained-release Imatinib tablets were developed to allow the tablets to be released in the upper part of the GIT and overcome the inadequacy of conventional tablets. Methodology Floating sustained-release Imatinib mesylate tablets were prepared using the wet granulation method. Tablets were formulated using Hydroxypropyl Methylcellulose (HPMC K4M), with Sodium alginate (SA) and Carbomer 934P (CP) as release-retarding polymers, sodium bicarbonate (NaHCO3) as the effervescent agent and lactose as a filler. Floating behavior, in vitro drug release, and swelling index studies were conducted. Initial and total drug release duration was compared with a commercial tablet (Gleevec) in 0.1 N HCl (pH 1.2) at 37 ± 0.5°C for 24 hours. Tablets were then evaluated for various physical parameters, including weight variation, thickness, hardness, friability, and drug content. Consequently, 6 months of physical stability studies and in vitro gastro-retentive studies were conducted. Results and Discussion Statistical data analysis revealed that tablets containing a composition of 14.67% w/w HPMC K4M, 10.67%, w/w Na alginate, 1.33%, w/w Carbomer 934P and 9.33%, w/w NaHCO3 produced the most favorable formulation to develop 24-hour sustained-release tablets with optimum floating behavior and satisfactory physicochemical characteristics. Furthermore, in vitro release study revealed that the formulated SR tablet had significantly lower Cmax and higher Tmax compared to the conventional tablet (Gleevec). Thus, formulated SR tablets preserved persistent concentration of plasma up to 24 hours. Conclusion In conclusion, in order to suggest a better drug delivery system with constant favorable release, resulting in optimized absorption and less side effects, formulated CP-HPMC-SA based imatinib mesylate floating sustained-release tablets can be a promising candidate for cancer chemotherapy. PMID:26035710

Effect of crospovidone and hydroxypropyl cellulose on carbamazepine in high-dose tablet formulation.

PubMed

Flicker, Felicia; Betz, Gabriele

2012-06-01

The aim of this study was to develop a high-dose tablet formulation of the poorly soluble carbamazepine (CBZ) with sufficient tablet hardness and immediate drug release. A further aim was to investigate the influence of various commercial CBZ raw materials on the optimized tablet formulation. Hydroxypropyl cellulose (HPC-SL) was selected as a dry binder and crospovidone (CrosPVP) as a superdisintegrant. A direct compacted tablet formulation of 70% CBZ was optimized by a 3² full factorial design with two input variables, HPC (0--10%) and CrosPVP (0--5%). Response variables included disintegration time, amount of drug released at 15 and 60 min, and tablet hardness, all analyzed according to USP 31. Increasing HPC-SL together with CrosPVP not only increased tablet hardness but also reduced disintegration time. Optimal condition was achieved in the range of 5--9% HPC and 3--5% CrosPVP, where tablet properties were at least 70 N tablet hardness, less than 1 min disintegration, and within the USP requirements for drug release. Testing the optimized formulation with four different commercial CBZ samples, their variability was still observed. Nonetheless, all formulations conformed to the USP specifications. With the excipients CrosPVP and HPC-SL an immediate release tablet formulation was successfully formulated for high-dose CBZ of various commercial sources.

The relationship between functional sciatic nerve block duration and the rate of release of lidocaine from a controlled-release matrix.

PubMed

Gerner, Peter; Wang, Chi-Fei; Lee, Byung-Sang; Suzuki, Suzuko; Degirolami, Umberto; Gandhi, Ankur; Knaack, David; Strichartz, Gary

2010-07-01

Nerve blocks of long duration are often desirable in perioperative and postoperative situations. The relationship between the duration of such blocks and the rate at which a local anesthetic is released is important to know for developing a localized drug delivery system that will optimize block duration. Lidocaine concentration was varied in 1 series of formulations (OSB-L) containing a constant amount of release rate modifier. In another series (OST-R), the release rate modifier was varied while the lidocaine content was held constant. Release kinetics were measured in vitro and correlated to the in vivo duration of antinociceptive and motor block effects when the formulation was implanted next to the rat sciatic nerve. In parallel studies, rats receiving different formulations of slow-release lidocaine were fixed by intracardiac perfusion with 4% paraformaldehyde and nerve-muscle tissue taken for histopathological analysis. In this study, we have demonstrated that the most important variable for effecting functional nerve block, i.e., the blockade of impulses in the relevant fibers of the sciatic nerve, is the rate of lidocaine release at that time. For the OSB-L formulations (lidocaine concentrations of 1.875%, 3.75%, 7.5%, and 15% at a constant release rate modifier of 5%), the average in vitro release rates at 50% recovery of motor block and nociceptive block were 0.91 +/- 0.28 and 1.75 +/- 0.61 mg/h, respectively. For the OST-R formulations (16% lidocaine with release rate modifier concentrations of 1.875%, 3.75%, 7.5%, and 15%), the average in vitro release rates at 50% recovery of motor block and nociceptive block were 2.33 +/- 1.39 and 4.34 +/- 1.09 mg/h, respectively. The OSB-L formulations showed a dose-dependent increase in block duration proportional to an increase in initial lidocaine concentration, whereas the OST-R formulations showed a nonmonotonic relationship between release rate modifier concentration and block duration. The histopathological studies at 24 hours, 3, 5, or 7 days, and 4 weeks after the implantation revealed inflammatory reactions with degrees correlated with lidocaine content, but limited to the connective tissue and muscle immediately surrounding the implanted material. Despite these observed inflammatory reactions, nociceptive and motor block function returned to normal, preimplantation values in all animals. Increasing initial lidocaine content proportionately increased the duration of functional sciatic nerve block. However, decreasing the release rate per se does not give a proportional increase in block duration. Instead, there seems to be an optimal, intermediate release rate for achieving the maximum duration of block.

Alprazolam absorption kinetics affects abuse liability.

PubMed

Mumford, G K; Evans, S M; Fleishaker, J C; Griffiths, R R

1995-03-01

To evaluate the behavioral, subjective, and reinforcing effects of immediate-release (IR) alprazolam and extended-release (XR) alprazolam to assess the effect of release rate on laboratory measures of abuse liability. Fourteen healthy men with histories of sedative abuse participated as subjects in a double-blind crossover study. All subjects received placebo, 1 and 2 mg immediate-release alprazolam, and 2 and 3 mg extended-release alprazolam in random order. Behavioral performance, subjective effects, and alprazolam plasma concentrations were assessed repeatedly 1/2 hour before and 1/2, 1, 3, 5, 7, 9, 12, and 24 hours after drug administration. Mean peak alprazolam plasma concentrations occurred 1.7 and 9.2 hours after immediate-release alprazolam and extended-release alprazolam, respectively. Compared to placebo, 2 mg immediate-release alprazolam impaired all measures of psychomotor and cognitive performance (Digit Symbol Substitution Test), motor coordination (circular lights and balance), and memory (digit entry and recall); 2 mg extended-release alprazolam did not affect any of these measures and 3 mg extended-release alprazolam impaired circular lights only. Immediate-release alprazolam, 2 mg, increased all six measures of positive drug effects (e.g., ratings of liking or good effects); none of these measures were increased by 2 mg extended-release alprazolam and only three of the six measures were increased by 3 mg extended-release alprazolam. A drug versus money multiple-choice procedure designed to assess the relative reinforcing effects of each condition was administered 24 hour after the drug. The amount of money subjects were willing to "pay" to take the drug was significantly greater than placebo for both doses of immediate-release alprazolam but for neither dose of extended-release alprazolam. These data indicate that extended-release alprazolam has less potential for abuse than immediate-release alprazolam.

Formulation and characterization of sustained release dosage form of moisture sensitive drug

PubMed Central

Patel, Priya; Dave, Abhishek; Vasava, Amit; Patel, Paresh

2015-01-01

Objective: The purpose of this study was to prepare sustained release tablet of moisture sensitive drug like Ranitidine Hydrochloride for treatment of gastroesophageal reflux disease along with the improvement of moisture stability to get better therapeutic efficacy. Materials and Methods: Pan coating technique was used for coating of the tablet. Film coating was done using Eudragit RLPO and Eugragit EPO as coating polymer. 32 full factorial design was applied for optimization purpose, and 9 runs were conducted. In that Eudragit RLPO and Eudragit EPO taken as an independent variables and moisture gain and Cummulative Drug Release (CDR) were taken as dependent variables. Drug and excipient compatibility was done using differential scanning calorimetry and Fourier transform infrared spectroscopy study. The tablet was evaluated for precompression parameter and all postcompression parameter. Stability study was carried out at room temperature (30°C ± 2°C/65% ± 5% relative humidity). Final formulation was compared with marketed formulation RANTEC 300. Result: Tablets were passing out all precompression parameter along with postcompression parameter. Stability study shows that the parameter such as hardness, friability, and dissolution are in the range. Hence, there is no significant change shown after stability study. Our final formulation was compared with marketed formulation RANTEC 300 and result demonstrates that our final formulation have less moisture gain and give release up to 12 h. Conclusion: The result of present study demonstrates that final formulation has less moisture gain and getting desired CDR for sustained release of drug. On the basis of all study, it was concluded that the tablet was coated by combination of Eudragit RLPO 10% and Eudragit EPO 10% give better result. This formation provided promising approach for the drug release up to 12 h for moisture sensitive drug like ranitidine hydrochloride. PMID:25838994

Six-month, open-label study of hydrocodone extended release formulated with abuse-deterrence technology: Safety, maintenance of analgesia, and abuse potential.

PubMed

Hale, Martin E; Ma, Yuju; Malamut, Richard

2016-01-01

To evaluate long-term safety, maintenance of analgesia, and aberrant drug-related behaviors of hydrocodone extended release (ER) formulated with CIMA® Abuse-Deterrence Technology. Phase 3, multicenter, open-label extension. Fifty-six US centers. Adults with chronic low back pain completing a 12-week placebocontrolled study of abuse-deterrent hydrocodone ER were eligible. One hundred eighty-two patients enrolled and received ≥1 dose of study drug, 170 entered openlabel treatment, and 136 completed the study. Patients receiving hydrocodone ER in the 12-week, placebo-controlled study continued their previous dose unless adjustment was needed; those previously receiving placebo (n=78) underwent dose titration/adjustment to an analgesic dose (15-90 mg every 12 hours). Patients received 22 weeks of open-label treatment. adverse events (AEs). Maintenance of analgesia: worst pain intensity (WPI) and average pain intensity (API) at each study visit. Aberrant drug behavior: study drug loss and diversion. AEs were reported for 65/182 (36 percent) patients during dose titration/ adjustment and 88/170 (52 percent) during open-label treatment. No treatmentrelated serious AEs were reported. There were no clinically meaningful trends in other safety assessments, including physical examinations and pure tone audiometry. One patient receiving hydrocodone ER 30 mg twice daily experienced a severe AE of neurosensory deafness that was considered treatment related. Mean WPI and API remained steady throughout open-label treatment. Six (3 percent) patients reported medication loss, and 5 (3 percent) reported diversion. Abuse-deterrent hydrocodone ER was generally well tolerated in patients with chronic low back pain, maintained efficacy, and was associated with low rates of loss and diversion.

A comparison among tapentadol tamper-resistant formulations (TRF) and OxyContin® (non-TRF) in prescription opioid abusers

PubMed Central

Vosburg, Suzanne K.; Jones, Jermaine D.; Manubay, Jeanne M.; Ashworth, Judy B.; Shapiro, Douglas Y.; Comer, Sandra D.

2013-01-01

Aims To examine whether tamper-resistant formulations (TRFs) of tapentadol hydrochloride ER 50 mg (TAP50) and tapentadol hydrochloride 250 mg (TAP250) could be converted into forms amenable to intranasal (Study 1) or intravenous abuse (Study 2). Design Randomized, repeated-measures study designs were employed. A non-TRF of OxyContin® 40 mg (OXY40) served as a positive control. No drug was taken in either study. Setting The studies took place in an outpatient setting in New York, NY. Participants 25 experienced, healthy extended-release oxycodone abusers participated in each study. Measurements The primary outcome for Study 1 was percentage of participants who indicated they would snort the tampered tablets, while the primary outcome for Study 2 was percent yield of active drug in solution. Other descriptive variables such as time spent manipulating the tablets were also examined to better characterize tampering behaviors. Findings Tampered TRF tablets were less desirable than the tampered OXY40 tablets. Few individuals were willing to snort the TRF particles (TAP50: 24%, TAP250: 16%; OXY40: 100% p<.001). There was less drug extracted from the TAP50 tablet than from the OXY40 tablet (3.5% vs. 37.0%, p=.008), and no samples from the TAP250 tablets contained analyzable solutions of the drug. It took participants longer to tamper with the TAPs (Study 1: TAP50 vs. OXY40, p<.01; TAP250 vs. OXY40, p<.01; Study 2: TAP250 vs. OXY40, p<05). Conclusions Taptentadol TRF tablets were not well-liked by individuals who regularly tampered with extended-release oxycodone tablets. Employing tamper resistant technology may be a promising approach towards reducing the abuse potential of tapentadol ER. PMID:23316699

Development and characterisation of electrospun timolol maleate-loaded polymeric contact lens coatings containing various permeation enhancers.

PubMed

Mehta, Prina; Al-Kinani, Ali A; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G; Ahmad, Zeeshan

2017-10-30

Despite exponential growth in research relating to sustained and controlled ocular drug delivery, anatomical and chemical barriers of the eye still pose formulation challenges. Nanotechnology integration into the pharmaceutical industry has aided efforts in potential ocular drug device development. Here, the integration and in vitro effect of four different permeation enhancers (PEs) on the release of anti-glaucoma drug timolol maleate (TM) from polymeric nanofiber formulations is explored. Electrohydrodynamic (EHD) engineering, more specifically electrospinning, was used to engineer nanofibers (NFs) which coated the exterior of contact lenses. Parameters used for engineering included flow rates ranging from 8 to 15μL/min and a novel EHD deposition system was used; capable of hosting four lenses, masked template and a ground electrode to direct charged atomised structures. SEM analysis of the electrospun structures confirmed the presence of smooth nano-fibers; whilst thermal analysis confirmed the stability of all formulations. In vitro release studies demonstrated a triphasic release; initial burst release with two subsequent sustained release phases with most of the drug being released after 24h (86.7%) Biological evaluation studies confirmed the tolerability of all formulations tested with release kinetics modelling results showing drug release was via quasi-Fickian or Fickian diffusion. There were evident differences (p<0.05) in TM release dependant on permeation enhancer. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Preparation and characterization of cefditoren pivoxil-loaded liposomes for controlled in vitro and in vivo drug release

PubMed Central

Venugopalarao, Gojjala; Lakshmipathy, Rajasekhar; Sarada, Nallani Chakravarthula

2015-01-01

Background The application of antibiotics has been limited due to weak biodistribution and pharmacokinetics. Encapsulation of these drugs in lipid vesicles might be a good solution for obtaining the required properties. Liposomes are one of the most suitable drug-delivery systems to deliver the drug to the target organ and minimize the distribution of the drug to non-target tissues. Objective The study reported here aimed to develop cefditoren pivoxil liposomes by thin-film hydration, characterize them in terms of physical interactions, and undertake in vitro and in vivo release studies. Methodology The pre-formulation studies were carried out using Fourier-transform infrared spectroscopy and differential scanning calorimetry. Cefditoren pivoxil liposomal formulations were formulated by thin-film hydration using biomaterials ie, soya lecithin and cholesterol in different molar ratios. The best molar ratio was determined by in vitro studies such as entrapment efficacy, particle size distribution, and diffusion. Results From the in vitro release studies, it was found that the formulation that contained soya lecithin and cholesterol in a 1.0:0.6 molar ratio gave good entrapment of 72.33% and drug release of 92.5% at 36 hours. Further, the formulation’s zeta potential and surface morphology were examined and stability and in vivo studies were undertaken evaluating the pharmacokinetic parameters, which showed promising results. Conclusion Formulation CPL VI showed the maximum drug-loading capacity of 72.3% with good controlled release and acceptable stability when compared with the other formulations. In vivo studies in rabbits showed that the drug release from the liposomes was successfully retarded with good controlled release behavior which can be used to treat many bacterial infections with a minimal dose. PMID:26491316

In vitro evaluation of mucoadhesive vaginal tablets of antifungal drugs prepared with thiolated polymer and development of a new dissolution technique for vaginal formulations.

PubMed

Baloglu, Esra; Ay Senyıgıt, Zeynep; Karavana, Sinem Yaprak; Vetter, Anja; Metın, Dilek Yesim; Hilmioglu Polat, Suleyha; Guneri, Tamer; Bernkop-Schnurch, Andreas

2011-01-01

The main objective of this work was to develop antifungal matrix tablet for vaginal applications using mucoadhesive thiolated polymer. Econazole nitrate (EN) and miconazole nitrate (MN) were used as antifungal drugs to prepare the vaginal tablet formulations. Thiolated poly(acrylic acid)-cysteine (PAA-Cys) conjugate was synthesized by the covalent attachment of L-cysteine to PAA with the formation of amide bonds between the primary amino group of L-cysteine and the carboxylic acid group of the polymer. Vaginal mucoadhesive matrix tablets were prepared by direct compression technique. The investigation focused on the influence of modified polymer on water uptake behavior, mucoadhesive property and release rate of drug. Thiolated polymer increased the water uptake ratio and mucoadhesive property of the formulations. A new simple dissolution technique was developed to simulate the vaginal environment for the evaluation of release behavior of vaginal tablets. In this technique, daily production amount and rate of the vaginal fluid was used without any rotational movement. The drug release was found to be slower from PAA-Cys compared to that from PAA formulations. The similarity study results confirmed that the difference in particle size of EN and MN did not affect their release profile. The release process was described by plotting the fraction released drug versus time and n fitting data to the simple exponential model: M(t)/M(∞)=kt(n). The release kinetics were determined as Super Case II for all the formulations prepared with PAA or PAA-Cys. According to these results the mucoadhesive vaginal tablet formulations prepared with PAA-Cys represent good example for delivery systems which prolong the residence time of drugs at the vaginal mucosal surface.

Investigation of in situ gelling alginate formulations as a sustained release vehicle for co-precipitates of dextromethrophan and Eudragit S 100.

PubMed

El Maghraby, Gamal Mohamed; Elzayat, Ehab Mostafa; Alanazi, Fars Kaed

2014-03-01

Alginate vehicles are capable of forming a gel matrix in situ when they come into contact with gastric medium in the presence of calcium ions. However, the gel structure is pH dependent and can break after gastric emptying, leading to dose dumping. The aim of this work was to develop modified in situ gelling alginate formulations capable of sustaining dextromethorphan release throughout the gastrointestinal tract. Alginate solution (2 %, m/m) was used as a vehicle for the tested formulations. Solid matrix of the drug and Eudragit S 100 was prepared by dissolving the drug and polymer in acetone. The organic solvent was then evaporated and the deposited solid matrix was micronized, sieved and dispersed in alginate solution to obtain candidate formulations. The release behavior of dextromethorphan was monitored and evaluated in a medium simulating the gastric and intestinal pH. Drug-polymer compatibility and possible solid-state interactions suggested physical interaction through hydrogen bonding between the drug and the polymer. A significant decrease in the rate and extent of dextromethorphan release was observed with increasing Eudragit S 100 concentration in the prepared particles. Most formulations showed sustained release profiles similar to that of a commercial sustained-release liquid based on ion exchange resin. The release pattern indicated strict control of drug release both under gastric and intestinal conditions, suggesting the potential advantage of using a solid dispersion of drug-Eudragit S 100 to overcome the problem of dose dumping after the rupture of the pH dependent alginate gels.

78 FR 16685 - Impax Laboratories, Inc.; Withdrawal of Approval of Bupropion Hydrochloride Extended-Release...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-18

...] Impax Laboratories, Inc.; Withdrawal of Approval of Bupropion Hydrochloride Extended-Release Tablets... Administration (FDA) is withdrawing approval of Bupropion Hydrochloride (HCl) Extended-Release Tablets, 300 Milligrams (mg) (Bupropion HCl Extended-Release Tablets 300 mg), under Abbreviated New Drug Application (ANDA...

Lyophilization closures for protein based drugs.

PubMed

DeGrazio, F; Flynn, K

1992-01-01

Rubber stopper formulations which are currently used as lyophilization stoppers vary widely in their capacities to absorb and release moisture. Release of moisture from the stopper over the shelf life of the product may result in drug degradation for extremely low cake weight products. The degree to which rubber formulations absorb water is dependent upon the components of these formulations. Independently, polymers and fillers absorb water during autoclave cycles to varying levels depending upon such factors as the solubility, structure, possibility of chemical reactions and impurity levels of these materials. Once combined into a stopper formulation, the raw materials can react to form species which further promote absorption. Data is presented comparing the absorption characteristics of low versus high absorbent rubber formulations. The release of moisture from these formulas when stoppered on vials containing dry product is also discussed.

Positively Charged Nanostructured Lipid Carriers and Their Effect on the Dissolution of Poorly Soluble Drugs.

PubMed

Choi, Kyeong-Ok; Choe, Jaehyeog; Suh, Seokjin; Ko, Sanghoon

2016-05-20

The objective of this study is to develop suitable formulations to improve the dissolution rate of poorly water soluble drugs. We selected lipid-based formulation as a drug carrier and modified the surface using positively charged chitosan derivative (HTCC) to increase its water solubility and bioavailability. Chitosan and HTCC-coated lipid particles had higher zeta-potential values than uncoated one over the whole pH ranges and improved encapsulation efficiency. In vitro drug release showed that all NLC formulations showed higher in vitro release efficiency than drug particle at pH 7.4. Furthermore, NLC formulation prepared with chitosan or HTCC represented good sustained release property. The results indicate that chitosan and HTCC can be excellent formulating excipients of lipid-based delivery carrier for improving poorly water soluble drug delivery.

Development of near zero-order release dosage forms using three-dimensional printing (3-DP) technology.

PubMed

Wang, Chen-Chao; Tejwani Motwani, Monica R; Roach, Willie J; Kay, Jennifer L; Yoo, Jaedeok; Surprenant, Henry L; Monkhouse, Donald C; Pryor, Timothy J

2006-03-01

Three near zero-order controlled-release pseudoephedrine hydrochloride (PEH) formulations demonstrating proportional release rates were developed using 3-Dimensional Printing (3-DP) technology. Mixtures of Kollidon SR and hydroxypropylmethyl cellulose (HPMC) were used as drug carriers. The release rates were adjusted by varying the Kollidon SR-HPMC ratio while keeping fabrication parameters constant. The dosage forms were composed of an immediate release core and a release rate regulating shell, fabricated with an aqueous PEH and an ethanolic triethyl citrate (TEC) binder, respectively. The dosage form design called for the drug to be released via diffusional pathways formed by HPMC in the shell matrix. The release rate was shown to increase correspondingly with the fraction of HPMC contained in the polymer blend. The designed formulations resulted in dosage forms that were insensitive to changes in pH of the dissolution medium, paddle stirring rate, and the presence/absence of a sinker. The near zero-order release properties were unchanged regardless of the dissolution test being performed on either single cubes or on a group of eight cubes encased within a gelatin capsule shell. The chemical and dissolution properties of the three formulations remained unchanged following 1 month's exposure to 25 degrees C/60% RH or 40 degrees C/75% RH environment under open container condition. The in vivo performance of the three formulations was evaluated using a single-dose, randomized, open-label, four-way crossover clinical study composed of 10 fasted healthy volunteers. The pharmacokinetic parameters were analyzed using a noncompartmental model. Qualitative rank order linear correlations between in vivo absorption profiles and in vitro dissolution parameters (with slope and intercept close to unity and origin, respectively) were obtained for all three formulations, indicating good support for a Level A in vivo/in vitro correlation.

Variables that affect the mechanism of drug release from osmotic pumps coated with acrylate/methacrylate copolymer latexes.

PubMed

Jensen, J L; Appel, L E; Clair, J H; Zentner, G M

1995-05-01

The feasibility of using modified Eudragit acrylic latexes as microporous coatings for osmotic devices was investigated. Potassium chloride tablets were coated with mixtures of Eudragit RS30D and RL30D acrylic latexes that also contained a plasticizer (triethyl citrate or acetyl tributyl citrate) and a pore-forming agent (urea). A 2(5-1) fractional factorial experimental design was employed to determine the effect of five formulation variables (RS30D:RL30D polymer ratio plasticizer type, plasticizer level, urea level, and cure) on the in vitro release rate of KCl in deionized water (di water), lag time, and coat burst strength. The RS30D:RL30D polymer ratio had the greatest effect on the release rate, and both lag time and burst strength were most affected by the urea level. Statistical optimization was performed, and a coat formulation with predicted desirable in vitro performance was prepared and tested. The in vitro release rate (di water), lag time, and coat burst strength agreed well with the prediction. Dissolutions were also performed in phosphate buffered saline (PBS; pH 7.4); several formulations released markedly slower in PBS than in di water. This discrepancy was dependent on the type of plasticizer and the amount of pore former. Only those coat formulations containing acetyl tributyl citrate as the plasticizer and a 100% urea [(g urea/g polymer solids) x 100] level exhibited similar release rates in di water and PBS. The mechanism of release from these devices was primarily osmotic, whereas the release from devices coated with a formulation containing triethyl citrate and 50% urea was not dependent on the osmotic pressure difference. Devices with an osmotic release mechanism behaved similarly in vivo and in vitro.(ABSTRACT TRUNCATED AT 250 WORDS)

Development and evaluation of intestinal targeted mucoadhesive microspheres of Bacillus coagulans.

PubMed

Alli, Sk Md Athar; Ali, Sk Md Ajhar; Samanta, Amalesh

2011-11-01

Intestinal targeted mucoadhesive microsphere of probiotics may provide numerous associated health benefits. To develop mucoadhesive microspheres that will deliver viable probiotic cells into gut protectively against harsh environmental conditions of stomach for extended period. Core mucoadhesive microspheres of Bacillus coagulans were prepared using hypromellose, following coacervation and phase separation technique and were then coated with hypromellose phthalate to achieve their site-specific release. Microspheres were evaluated for percent yield, entrapment efficiency, surface morphology, particle size and size distribution, flow property, swelling property, mucoadhesion property by the in vitro wash-off and the ex vivo mucoadhesive strength tests, in vitro release profile and release kinetic, in vivo probiotic activity, and stability. The values for kinetic constant and regression coefficient of model-dependent approaches and the difference factor, the similarity factor, and the Rescigno index of model-independent approaches were determined for accessing and comparing in vitro performance. Microsphere formulation batches have percent yield value between 56.26% and 69.13% and entrapment efficiency value between 66.95% and 77.89%. Microspheres were coarser with spherical shape having mean particle size from 28.03 to 48.31 μm. In vitro B. coagulans release profile follows zero-order kinetics and depends on the grade of hypromellose and the B. coagulans-to-hypromellose ratio. Experimental microspheres rendered adequate stability to B. coagulans at room temperature. Microspheres had delivered B. coagulans in simulated intestinal condition following zero-order kinetics, protectively in simulated gastric condition, exhibiting appreciable mucoadhesion in intestinal condition, which could be useful to achieve site-specific delivery for extended period.

A pharmacokinetic and pharmacodynamic comparison of immediate-release metoprolol and extended-release metoprolol CR/XL in patients with suspected acute myocardial infarction: a randomized, open-label study.

PubMed

Karlson, Björn W; Dellborg, Mikael; Gullestad, Lars; Aberg, Jan; Sugg, Jennifer; Herlitz, Johan

2014-01-01

Previous metoprolol studies in myocardial infarction patients were performed with immediate-release (IR) metoprolol. This study aims to evaluate if extended-release metoprolol CR/XL once daily gives a similar β-blockade over 24 h compared to multiple dosing of metoprolol IR. After 2 days of routine metoprolol treatment, 27 patients with suspected acute myocardial infarction were randomized to open-label treatment with metoprolol IR (50 mg four times daily or 100 mg twice daily) or metoprolol CR/XL 200 mg once daily for 3 days. Metoprolol CR/XL 200 mg once daily gave more pronounced suppression of peak heart rate, with lower peak and less variation in peak to trough plasma levels. There were no differences in AUC between the CR/XL and IR formulations, although the trough plasma metoprolol levels were comparable for metoprolol CR/XL 200 mg once daily and metoprolol IR 50 mg four times daily, but lower for metoprolol IR 100 mg twice daily. Both treatments were well tolerated. Metoprolol CR/XL 200 mg once daily showed lower peak and less variation in peak to trough plasma levels compared to multiple dosing of metoprolol IR with the same AUC. This was accompanied by a more uniform β-blockade over time, which was reflected by heart rate, and a more pronounced suppression of peak heart rate with similar tolerability. This suggests metoprolol CR/XL may be used as an alternative to metoprolol IR in patients with myocardial infarction. © 2013 S. Karger AG, Basel.

Formulation and optimization of coated PLGA – Zidovudine nanoparticles using factorial design and in vitro in vivo evaluations to determine brain targeting efficiency

PubMed Central

Peter Christoper, G.V.; Vijaya Raghavan, C.; Siddharth, K.; Siva Selva Kumar, M.; Hari Prasad, R.

2013-01-01

In the current study zidovudine loaded PLGA nanoparticles were prepared, coated and further investigated for its effectiveness in brain targeting. IR and DSC studies were performed to determine the interaction between excipients used and to find out the nature of drug in the formulation. Formulations were prepared by adopting 23 factorial designs to evaluate the effects of process and formulation variables. The prepared formulations were subjected for in vitro and in vivo evaluations. In vitro evaluations showed particle size below 100 nm, entrapment efficiency of formulations ranges of 28–57%, process yield of 60–76% was achieved and drug release for the formulations were in the range of 50–85%. The drug release from the formulations was found to follow Higuchi release pattern, n–value obtained after Korsemeyer plot was in the range of 0.56–0.78. In vivo evaluations were performed in mice after intraperitoneal administration of zidovudine drug solution, uncoated and coated formulation. Formulation when coated with Tween 80 achieved a higher concentration in the brain than that of the drug in solution and of the uncoated formulation. Stability studies indicated that there was no degradation of the drug in the formulation after 90 days of preparation when stored in refrigerated condition. PMID:24648825

Preparation and characterization of poly(lactic acid) nanoparticles for sustained release of pyridostigmine bromide.

PubMed

Tan, Q Y; Xu, M L; Wu, J Y; Yin, H F; Zhang, J Q

2012-04-01

A novel pyridostigmine bromide poly (lactic acid) nanoparticles (PBPNPs) was prepared to obtain sustained release characteristics of PB. A central composite design approach was employed for process optimization. The in vitro release studies were carried out by dialysis method and conducted using four different dissolution media. Similar factor method was investigated for dissolution profile comparison. Multiple linear regression analysis for process optimization revealed that the optimal PBPNPs were obtained where the values of the amount of PB (X1, mg), PLA concentration (X2, % w:v), and PVA concentration (X3, % w:v) were 49.20 mg, 3.31% and 3.41%, respectively. The average particle size and zeta potential of PBPNPs with the optimized formulation were 722.9 +/- 4.3 nm, and -25.12 +/- 1.2 mV, respectively. PBPNPs provided an initial burst of drug release followed by a very slow release over an extended period of time (72 h). Compared with free PB, PBPNPs had a significantly lower release rate of PB in vitro. The in vitro release profile of the PBPNPs could be described by Weibull models, regardless of type of dissolution medium. Statistical significance of similarity between every two dissolution profiles of PBPNPs in different dissolution media was found, and the difference between the curves of PBPNPs and pure PB was statistically significant.

Evaluation of acetylated moth bean starch as a carrier for controlled drug delivery

PubMed Central

Singh, Akhilesh V.; Nath, Lila K.

2012-01-01

The present investigation concerns with the development of controlled release tablets of lamivudine using acetylated moth bean starch. The acetylated starch was synthesized with acetic anhydride in pyridine medium. The acetylated moth bean starch was tested for acute toxicity and drug–excipient compatibility study. The formulations were evaluated for physical characteristics like hardness, friability, % drug content and weight variations. The in vitro release study showed that the optimized formulation exhibited highest correlation (R) value in case of Higuchi kinetic model and the release mechanism study proved that the formulation showed a combination of diffusion and erosion process. There was a significant difference in the pharmacokinetic parameters (Tmax, Cmax, AUC, Vd, T1/2 and MDT) of the optimized formulation as compared to the marketed conventional tablet Lamivir®, which proved controlled release potential of acetylated moth bean starch. PMID:22210486

The EMEP MSC-W chemical transport model - technical description

NASA Astrophysics Data System (ADS)

Simpson, D.; Benedictow, A.; Berge, H.; Bergström, R.; Emberson, L. D.; Fagerli, H.; Flechard, C. R.; Hayman, G. D.; Gauss, M.; Jonson, J. E.; Jenkin, M. E.; Nyíri, A.; Richter, C.; Semeena, V. S.; Tsyro, S.; Tuovinen, J.-P.; Valdebenito, Á.; Wind, P.

2012-08-01

The Meteorological Synthesizing Centre-West (MSC-W) of the European Monitoring and Evaluation Programme (EMEP) has been performing model calculations in support of the Convention on Long Range Transboundary Air Pollution (CLRTAP) for more than 30 years. The EMEP MSC-W chemical transport model is still one of the key tools within European air pollution policy assessments. Traditionally, the model has covered all of Europe with a resolution of about 50 km × 50 km, and extending vertically from ground level to the tropopause (100 hPa). The model has changed extensively over the last ten years, however, with flexible processing of chemical schemes, meteorological inputs, and with nesting capability: the code is now applied on scales ranging from local (ca. 5 km grid size) to global (with 1 degree resolution). The model is used to simulate photo-oxidants and both inorganic and organic aerosols. In 2008 the EMEP model was released for the first time as public domain code, along with all required input data for model runs for one year. The second release of the EMEP MSC-W model became available in mid 2011, and a new release is targeted for summer 2012. This publication is intended to document this third release of the EMEP MSC-W model. The model formulations are given, along with details of input data-sets which are used, and a brief background on some of the choices made in the formulation is presented. The model code itself is available at www.emep.int, along with the data required to run for a full year over Europe.

The EMEP MSC-W chemical transport model - Part 1: Model description

NASA Astrophysics Data System (ADS)

Simpson, D.; Benedictow, A.; Berge, H.; Bergström, R.; Emberson, L. D.; Fagerli, H.; Hayman, G. D.; Gauss, M.; Jonson, J. E.; Jenkin, M. E.; Nyíri, A.; Richter, C.; Semeena, V. S.; Tsyro, S.; Tuovinen, J.-P.; Valdebenito, Á.; Wind, P.

2012-02-01

The Meteorological Synthesizing Centre-West (MSC-W) of the European Monitoring and Evaluation Programme (EMEP) has been performing model calculations in support of the Convention on Long Range Transboundary Air Pollution (CLRTAP) for more than 30 yr. The EMEP MSC-W chemical transport model is still one of the key tools within European air pollution policy assessments. Traditionally, the EMEP model has covered all of Europe with a resolution of about 50 × 50 km2, and extending vertically from ground level to the tropopause (100 hPa). The model has undergone substantial development in recent years, and is now applied on scales ranging from local (ca. 5 km grid size) to global (with 1 degree resolution). The model is used to simulate photo-oxidants and both inorganic and organic aerosols. In 2008 the EMEP model was released for the first time as public domain code, along with all required input data for model runs for one year. Since then, many changes have been made to the model physics, and input data. The second release of the EMEP MSC-W model became available in mid 2011, and a new release is targeted for early 2012. This publication is intended to document this third release of the EMEP MSC-W model. The model formulations are given, along with details of input data-sets which are used, and brief background on some of the choices made in the formulation are presented. The model code itself is available at www.emep.int, along with the data required to run for a full year over Europe.

Multi-kinetic release of benznidazole-loaded multiparticulate drug delivery systems based on polymethacrylate interpolyelectrolyte complexes.

PubMed

García, Mónica C; Martinelli, Marisa; Ponce, Nicolás E; Sanmarco, Liliana M; Aoki, María P; Manzo, Rubén H; Jimenez-Kairuz, Alvaro F

2018-07-30

Interpolyelectrolyte complexes (IPEC) formulated as multiparticulate drug delivery systems (MDDS) are interesting carriers to improve drug' performance. Benznidazole (BZ) is the first-line drug for Chagas treatment; however, it presents side effects and toxicity, conditioning its efficacy and safety. The goal of this work was to obtain novel MDDS composed by IPEC based on different polymethacrylate carriers loaded with BZ and to investigate in vitro drug delivery performance for oral administration. Physicochemical characterizations were studied and preclinical studies in a murine model of acute Chagas disease were also performed. The MDDS composed by BZ-loaded IPEC based on polymethacrylates were obtained by casting solvent followed by wet granulation methods with yields >83%. FT-IR demonstrated ionic interaction between the polyelectrolytes. Confocal microscopy, DSC and PXRD revealed a fraction uniformly distributed of free BZ on the multiparticles. The rheological evaluation of the MDDS showed adequate flow features for their formulation in hard gelatin-capsules. The type and composition of IPEC conditioned the modulation of BZ release and fluid uptake results. MDDS based on more hydrophylic Eudragit® showed very fast dissolution (Q 15min  > 85%), while an extended release (Q 120min  ≤ 40%) for the hydrophobic ones was observed. Capsules containing a combination of two MDDS with different release profile of BZ showed promising properties to improve Chagas disease pharmacotherapy in the preliminary in vivo assay performed, in which the BZ-loaded MDDS exhibited efficacy to reduce parasitemia, while decreasing the levels of liver injury markers in comparison to BZ conventional treatment. Multi-kinetic BZ delivery systems developed are interesting pharmaceutical alternatives to improve the treatment of Chagas disease. Copyright © 2018. Published by Elsevier B.V.

Pharmaceutical suspension containing both immediate/sustained-release amoxicillin-loaded gelatin nanoparticles: preparation and in vitro characterization.

PubMed

Harsha, Sree

2013-01-01

Pharmaceutical suspension containing oral dosage forms delivering both immediate-release and sustained-release amoxicillin was developed as a new dosage form to eradicate Helicobacter pylori. Amoxicillin-loaded gelatin nanoparticles are able to bind with the mucosal membrane after delivery to the stomach and could escalate the effectiveness of a drug, providing dual release. The objective of this study was to develop amoxicillin nanoparticles using innovative new technology--the Büchi Nano Spray Dryer B-90 - and investigate such features as drug content, particle morphology, yield, in vitro release, flow properties, and stability. The nanoparticles had an average particle size of 571 nm. The drug content and percentage yield was 89.2% ± 0.5% and 93.3% ± 0.6%, respectively. Angle of repose of nanoparticle suspension was 26.3° and bulk density was 0.59 g/cm(3). In vitro drug release of formulations was best fitted by first-order and Peppas models with R (2) of 0.9841 and 0.9837 respectively; release profile was 15.9%, while; for the original drug, amoxicillin, under the same conditions, 90% was released in the first 30 minutes. The nanoparticles used in this study enabled sustained release of amoxicillin over an extended period of time, up to 12 hours, and were stable for 12 months under accelerated storage conditions of 25 °C ± 2 °C and 60% ± 5% relative humidity.

Formation of nanoparticles of a hydrophilic drug using supercritical carbon dioxide and microencapsulation for sustained release.

PubMed

Thote, Amol J; Gupta, Ram B

2005-03-01

Our purpose was to produce nanoparticles of a hydrophilic drug with use of supercritical carbon dioxide (CO2), encapsulate the obtained nanoparticles into polymer microparticles with use of an anhydrous method and study their sustained in vitro drug release. The hydrophilic drug, dexamethasone phosphate, is dissolved in methanol and injected in supercritical CO2 with an ultrasonic field for enhanced molecular mixing (supercritical antisolvent technique with enhanced mass transfer [SAS-EM]). Supercritical CO2 rapidly extracts methanol leading to instantaneous precipitation of drug nanoparticles. The nanoparticles are then encapsulated in poly(lactide-co-glycolide) (PLGA) polymer by use of the anhydrous solid-oil-oil-oil technique. This results in a well-dispersed encapsulation of drug nanoparticles in polymer microspheres. In vitro drug release from these microparticles is studied. With supercritical CO2 used as an antisolvent, nanoparticles of dexamethasone phosphate were obtained in the range of 150 to 200 nm. On encapsulation in polylactide coglycolide, composite microspheres of approximately 70 microm were obtained. The in vitro drug release of these nanoparticles/microparticles composites shows sustained release of dexamethasone phosphate over a period of 700 hours with almost no initial burst release. Nanoparticles of dexamethasone phosphate can be produced with the SAS-EM technique. When microencapsulated, these particles can provide sustained drug release without initial burst release. Because the complete process is anhydrous, it can be easily extended to produce sustained release formulations of other hydrophilic drugs.

Semisolid matrix filled capsules: an approach to improve dissolution stability of phenytoin sodium formulation.

PubMed

El Massik, M A; Abdallah, O Y; Galal, S; Daabis, N A

2003-05-01

Seven semisolid fill bases were selected for the formulation of 24 capsule formulations, each containing 100 mg of phenytoin sodium. The fill materials were selected based on the water absorption capacity of their mixtures with phenytoin sodium. The fill matrices included lipophilic bases (castor oil, soya oil, and Gelucire (G) 33/01), amphiphilic bases (G 44/14 and Suppocire BP), and water-soluble bases (PEG 4000 and PEG 6000). The drug:base ratio was 1:2. Excipients such as lecithin, docusate sodium, and poloxamer 188 were added to some formulations. The dissolution rate study indicated that formulations containing lipophilic and amphiphilic bases showed the best release profiles. These are F4 (castor oil-1% docusate sodium); F10 (castor oil-3% poloxamer 188); F14 (G33/01-10% lecithin); F17 (G33/01-1% docusate sodium), and F20 (Suppocire BP). Further, the dissolution stability of the five formulations above was assessed by an accelerated stability study at 30 degrees C and 75% RH using standard Epanutin capsules for comparison. The study included the test and standard capsules either packed in the container of marketed Epanutin capsules (packed) or removed from their outer pack (unpacked). Release data indicated superior release rates of castor oil based formulations (F4 and F10) relative to standard capsules in both the unpacked and packed forms. For instance, the extent of drug release at 30 min after 1 month was 91% for F4 and F10 and 20% for standard capsules. Drug release from packed capsules after 6 months storage was 88% for both formulations F4 and F10 and 35% for standard capsules. In conclusion, the pharmaceutical quality of phenytoin sodium capsules can be improved by using a semisolid lipophilic matrix filled in hard gelatin capsules.

Bioequivalence of Dapagliflozin/Metformin Extended-release Fixed-combination Drug Product and Single-component Dapagliflozin and Metformin Extended-release Tablets in Healthy Russian Subjects.

PubMed

Khomitskaya, Yunona; Tikhonova, Nadezhda; Gudkov, Konstantin; Erofeeva, Svetlana; Holmes, Victoria; Dayton, Brian; Davies, Nigel; Boulton, David W; Tang, Weifeng

2018-04-01

Fixed-combination drug products (FCDPs) combining dapagliflozin and metformin extended release (XR) may provide patients with type 2 diabetes mellitus with an alternative antihyperglycemic treatment, which could improve adherence by reducing tablet burden. This study evaluated the bioequivalence of dapagliflozin/metformin XR FCDP versus the co-administration of the individual monotherapy tablets currently available for use in the Russian Federation. Healthy subjects aged 18 to 45 years were enrolled in this randomized, open-label, 2-period crossover study, conducted in a single Russian center. Pharmacokinetic parameters (AUC 0-t , C max , and C max /AUC 0-t ) were used to assess bioequivalence of dapagliflozin/metformin XR (10/1000 mg) FCDP to the individual component tablets (dapagliflozin [10 mg] plus metformin XR [2 × 500 mg]) under standard fed conditions. Safety and tolerability were also assessed. Forty healthy subjects were included (47.5% male; mean age, 30 years; and mean body mass index, 24.2 kg/m 2 ). Dapagliflozin and metformin XR in the FCDP were bioequivalent to the individual component tablets marketed in the Russian Federation, with the 90% CIs of the geometric least-squares mean ratios for all key pharmacokinetic parameters being contained within the 80% to 125% bioequivalence limits. Both FCDP and the individual component formulations were well tolerated, with no serious adverse events. Bioequivalence of dapagliflozin/metformin XR FCDP and the individual components was established without any new safety concerns, presenting a safe alternative for patients currently receiving regimens including each component individually. ClinicalTrials.gov identifier: NCT02722239. Copyright © 2018 Elsevier HS Journals, Inc. All rights reserved.

Novel swellable polymer of orchidaceae family for gastroretentive drug delivery of famotidine

PubMed Central

Razavi, Mahboubeh; Nyamathulla, Shaik; Karimian, Hamed; Noordin, Mohamed Ibrahim

2014-01-01

This study aimed to develop hydrophilic, gastroretentive matrix tablets of famotidine with good floating and swelling properties. A novel gastroretentive drug delivery formulation was designed using salep, also known as salepi, a flour obtained from grinding dried palmate tubers of Orchis morio var mascula (Orchidaceae family). The main polysaccharide content of salep is glucomannan, highly soluble in cold and hot water, which forms a viscous solution. Salep was characterized for physicochemical properties, thermal stability, chemical interaction, and surface morphology using X-ray diffraction analysis, differential scanning calorimetry, Fourier transform infrared spectroscopy, and scanning electron microscopy. Ten different formulations (S1–S10) were prepared using famotidine to salep ratios from 1:0.5 to 1:5. Results demonstrated that all formulations were able to sustain the drug release for more than 24 hours. The S5 formulation, with a famotidine to salep ratio of 1:2.5, had the shortest floating lag time of 35 seconds and 100% drug release within 24 hours. The dissolution data were fitted into popular mathematical models to assess the mechanism of drug release. S5 showed Zero order release (R=0.9746) with Higuchi diffusion (R=0.9428). We conclude that salep, a novel polymer, can be used in controlled release formulations to sustain release for 24 hours, due to inherent swelling and gelling properties. PMID:25246773

The release profiles of intact and enzymatically digested hyaluronic acid from semisolid formulations using multi-layer membrane system.

PubMed

Alkrad, Jamal Alyoussef; Mrestani, Yahya; Neubert, Reinhard H H

2003-07-01

A multi-layer membrane system was used to measure in vitro release of hydrophilic macromolecules such as hyaluronic acid (HA) from semisolid formulations. One enzymatically digested HA-derivative with molecular mass of 22 kDa (HA-D) and 1200 kDa intact HA (HA) were incorporated into three semisolid formulations: water-containing hydrophilic ointment (WHO), amphiphilic cream (AC) and water-containing wool wax alcohol ointment (WWO). Because of the high hydrophilic properties of HA-D and HA, the artificial model membranes consisted of collodion as the matrix and glycerol as the hydrophilic acceptor phase. The area under the concentration-time curve and the mean dissolution time were used as a quantitative parameter to characterise the rate and extent of release in vitro. This study showed that the HA-D and HA release as hydrophilic substances from WHO was higher than both from AC and WWO. It was observed that 83% of HA-D1 was released from WHO after 2 h; in contrast, only 10% was released from 2% HA from the same vehicle during the same time. In conclusion, the in vitro availability of enzymatically digested HA-D was higher for WHO than for the other formulations, AC and WWO. Similarly, the availability of HA-D was higher than that of HA from the same formulations.

Formulation and evaluation of floating tablet of H2-receptor antagonist.

PubMed

Kesarla, Rajesh S; Vora, Pratik Ashwinbhai; Sridhar, B K; Patel, Gunvant; Omri, Abdelwahab

2015-01-01

Conventional sustained dosage form of ranitidine hydrochloride (HCl) does not prevent frequent administration due to its degradation in colonic media and limited absorption in the upper part of GIT. Ranitidine HCl floating tablet was formulated with sublimation method to overcome the stated problem. Compatibility study for screening potential excipients was carried out using Fourier transform infrared spectroscopy (FT-IR) and differential scanning chromatography (DSC). Selected excipients were further evaluated for optimizing the formulation. Preliminary screening of binder, polymer and sublimating material was based on hardness and drug release, drug release with release kinetics and floating lag time with total floatation time, respectively. Selected excipients were subjected to 3(2) factorial design with polymer and sublimating material as independent factors. Matrix tablets were obtained by using 16/32" flat-faced beveled edges punches followed by sublimation. FT-IR and DSC indicated no significant incompatibility with selected excipients. Klucel-LF, POLYOX WSR N 60 K and l-menthol were selected as binder, polymer and sublimating material, respectively, for factorial design batches after preliminary screening. From the factorial design batches, optimum concentration to release the drug within 12 h was found to be 420 mg of POLYOX and 40 mg of l-menthol. Stability studies indicated the formulation as stable. Ranitidine HCl matrix floating tablets were formulated to release 90% of drug in stomach within 12 h. Hence, release of the drug could be sustained within narrow absorption site. Moreover, the dosage form was found to be floating within a fraction of second independent of the pH of media ensuring a robust formulation.

Model‐Informed Development and Registration of a Once‐Daily Regimen of Extended‐Release Tofacitinib

PubMed Central

Lamba, M; Hutmacher, MM; Furst, DE; Dikranian, A; Dowty, ME; Conrado, D; Stock, T; Nduaka, C; Cook, J

2017-01-01

Extended‐release (XR) formulations enable less frequent dosing vs. conventional (e.g., immediate release (IR)) formulations. Regulatory registration of such formulations typically requires pharmacokinetic (PK) and clinical efficacy data. Here we illustrate a model‐informed, exposure–response (E‐R) approach to translate controlled trial data from one formulation to another without a phase III trial, using a tofacitinib case study. Tofacitinib is an oral Janus kinase (JAK) inhibitor for the treatment of rheumatoid arthritis (RA). E‐R analyses were conducted using validated clinical endpoints from phase II dose–response and nonclinical dose fractionation studies of the IR formulation. Consistent with the delay in clinical response dynamics relative to PK, average concentration was established as the relevant PK parameter for tofacitinib efficacy and supported pharmacodynamic similarity. These evaluations, alongside demonstrated equivalence in total systemic exposure between IR and XR formulations, provided the basis for the regulatory approval of tofacitinib XR once daily by the US Food and Drug Administration. PMID:27859030

Formulation development of allopurinol suppositories and injectables.

PubMed

Lee, D K; Wang, D P

1999-11-01

Allopurinol was formulated into injectable and suppository dosage forms. The injectable formulation was prepared by dissolving allopurinol in a cosolvent system consisting of dimethyl sulfoxide (DMSO) and propylene glycol (v/v = 50/50). The stability of allopurinol in the cosolvent system was studied under accelerated storage conditions, and results indicate first-order degradation kinetics with an activation energy of 24.3 kcal/mol. The development of suppository dosage forms was performed by formulating allopurinol with polyethylene glycol (PEG) mixtures of different molecular weights. In vitro release profiles of suppositories formulated with different polyethylene bases were obtained in the pH 7.4 buffer solution using the USP 23 paddle method at 100 rpm. Results indicate that the release rate of the suppository formulations containing PEG 1500/PEG 4000 at the ratio (w/w) of 2.5/10 to 10/2.5 appeared to be similar. However, the addition of sodium lauryl sulfate in the suppository decreased the release rate of allopurinol significantly. A future study to establish in vitro/in vivo correlation (iv/ivc) is suggested.

Formulation and evaluation of floating matrix tablet of stavudine

PubMed Central

Prajapati, Pankaj H; Nakum, Vijay V; Patel, Chhagan N

2012-01-01

Background/Aim: The purpose of the study was to prolong the gastric residence time of stavudine by designing its floating tablets and to study the influence of different polymers on its release rate. Materials and Methods: The floating mix matrix tablets of stavudine were prepared by melt granulation method. Beeswax was used as hydrophobic meltable material. Hydroxypropyl methylcellulose (HPMC), sodium bicarbonate, and ethyl cellulose were used as matrixing agent, gas generating agent, and floating enhancer, respectively. The prepared tablets were evaluated for physicochemical parameters such as hardness, weight variation, friability, floating properties (floating lag time, total floating time), drug content, stability study, and in vitro drug release. The drug- polymer interaction was studied by Differential Scanning Calorimetry (DSC) thermal analysis and Fourier transform infared (FT-IR). Results: The floating lag time of all the formulations was within the prescribed limit (<3 min). All the formulations showed good matrix integrity and retarded the release of drug for 12 h except the formulation F5.The concentration of beeswax (X1), HPMC K4M (X2), and ethyl cellulose (X3) were selected as independent variables and drug release values at 1 (Q1), at 6 (Q6) and at 12 h (Q12) as dependent variables. Formulation F7 was selected as an optimum formulation as it showed more similarity in dissolution profile with theoretical profile (similarity factor, f2 = 70.91). The dissolution of batch F7 can be described by zero-order kinetics (R2 =0.9936) with anomalous (non-Fickian) diffusion as the release mechanism (n=0.545). There was no difference observed in release profile after temperature sensitivity study at 40°C/75% relative humidity (RH) for 1 month. Conclusion: It can be concluded from this study that the combined mix matrix system containing hydrophobic and hydrophilic polymer minimized the burst release of drug from the tablet and achieved a drug release by zero-order kinetics, which is practically difficult with only hydrophilic matrix. PMID:23119237

Nonclinical evaluation of the potential for mast cell activation by an erythropoietin analog

DOE Office of Scientific and Technical Information (OSTI.GOV)

Weaver, James L., E-mail: James.Weaver@fda.hhs.gov; Boyne, Michael, E-mail: mboyne@biotechlogic.com; Pang, Eric, E-mail: Eric.Pang@fda.hhs.gov

The erythropoietin analog peginesatide was withdrawn from marketing due to unexpected severe anaphylactic reactions associated with administration of the multi-use formulation. The adverse events occurred rapidly following the first ever administration of the drug with most affected patients becoming symptomatic in less than 30 min. This is most consistent with an anaphylactoid reaction due to direct activation of mast cells. Laboratory evaluation was undertaken using rat peritoneal mast cells as the model system. Initial studies showed that high concentrations of the formulated drug as well as formulated vehicle alone could cause mast cell degranulation as measured by histamine release. Themore » purified active drug was not able to cause histamine release whereas the vehicle filtrate and lab created drug vehicle were equally potent at causing histamine release. Individual formulations of vehicle leaving one component out showed that histamine release was due to phenol. Dose response studies with phenol showed a very sharp dose response curve that was similar in three buffer systems. Cellular analysis by flow cytometry showed that the histamine release was not due to cell death, and that changes in light scatter parameters consistent with degranulation were rapidly observed. Limited testing with primary human mast cells showed a similar dose response of histamine release with exposure to phenol. To provide in vivo confirmation, rats were injected with vehicle formulated with various concentrations of phenol via a jugular vein cannula. Significant release of histamine was detected in blood samples taken 2 min after dosing at the highest concentrations tested. - Highlights: • Peginesatide caused severe anaphylactoid reactions in 0.2% of patients. • Both formulated drug and vehicle cause degranulation of rat mast cells. • Phenol was identified as the vehicle component causing degranulation. • Human mast cells show similar dose response to phenol as rat mast cells. • Histamine release could be caused in vivo in rats by rapid phenol injection.« less

Development of a discriminative biphasic in vitro dissolution test and correlation with in vivo pharmacokinetic studies for differently formulated racecadotril granules.

PubMed

Deng, Jia; Staufenbiel, Sven; Hao, Shilei; Wang, Bochu; Dashevskiy, Andriy; Bodmeier, Roland

2017-06-10

The purpose of this study was to discriminate the release behavior from three differently formulated racecadotril (BCS II) granules and to establish an in vitro-in vivo correlation. Three granule formulations of the lipophilic drug were prepared with equivalent composition but prepared with different manufacturing processes (dry granulation, wet granulation with or without binder). In vitro release of the three granules was investigated using a biphasic dissolution system (phosphate buffer pH6.8 and octanol) and compared to the conventional single phase USP II dissolution test performed under sink and non-sink conditions. In vivo studies with each granule formulation were performed in rats. Interestingly, the granule formulations exhibited pronouncedly different behavior in the different dissolution systems depending on different wetting and dissolution conditions. Single phase USP II dissolution tests lacked discrimination. In contrast, remarkable discrimination between the granule formulations was observed in the octanol phase of biphasic dissolution system with a rank order of release from granules prepared by wet granulation with binder>wet granulation without binder>dry granulation. This release order correlated well with the wettability of these granules. An excellent correlation was also established between in vitro release in the octanol phase of the biphasic test and in vivo data (R 2 =0.999). Compared to conventional dissolution methods, the biphasic method provides great potential to discriminate between only minor formulation and process changes within the same dosage form for poorly soluble drugs. Copyright © 2017 Elsevier B.V. All rights reserved.

Analysis of in vitro release through reconstructed human epidermis and synthetic membranes of multi-vitamins from cosmetic formulations.

PubMed

Gabbanini, Simone; Matera, Riccardo; Beltramini, Claudia; Minghetti, Andrea; Valgimigli, Luca

2010-08-01

A convenient method for in vitro investigation of the release of lipid- and water-soluble vitamins from cosmetic formulations was developed. The permeation of (d)-alpha-tocopherol (vitamin E), retinyl acetate (pro-vitamin A), ascorbic acid (vitamin C) and pyridoxine (vitamin B6) through SkinEthic reconstructed human epidermis (RHE), and synthetic polyethersulfone and polycarbonate membranes was studied in vitro using a Franz-type diffusion apparatus, coupled either to a spectrophotometer for continuous reading (dynamic setting) or to HPLC-DAD analysis of the receptor medium (static setting). O/W and W/O emulsions were compared with simple aqueous solutions for their kinetic of vitamins release, to evaluate the influence of the cosmetic formulation on the bioavailability of active ingredients. Results indicate that synthetic membranes offer a limited barrier to the diffusion of vitamins, but may provide information on the release ability of the formulation. Penetration was more effective when water was the external phase of the formulation, i.e. W/O emulsions were less effective in the release of vitamins than O/W emulsion or aqueous solutions. RHE (17 days old) offered a significantly higher barrier to penetration of vitamins, as expected for native human epidermis. The relative ranking in coefficient of permeability (Ps (cm/h)) was: ascorbic acid>pyridoxine>retinyl acetate>alpha-tocopherol approximately 0, the absolute values depending on the formulation. The method herein described showed to be a practical and convenient tool for the quality-control and efficacy evaluation of cosmetic formulations. Copyright (c) 2010 Elsevier B.V. All rights reserved.

Regulating Drug Release Behavior and Kinetics from Matrix Tablets Based on Fine Particle-Sized Ethyl Cellulose Ether Derivatives: An In Vitro and In Vivo Evaluation

PubMed Central

Shah, Kifayat Ullah; Khan, Gul Majid

2012-01-01

The design and fabrication of sustained/controlled release dosage forms, employing new excipients capable of extending/controlling the release of drugs from the dosage forms over prolonged periods, has worked well in achieving optimally enhanced therapeutic levels of the drugs. In this sense, the objective of this study was to investigate the suitability of selected cellulose ether derivatives for use in direct compression (DC) and as efficient drug release controlling agents. Controlled release matrix tablets of ciprofloxacin were prepared at different drug-to-polymer (D : P) ratios by direct compression using a fine particle sized ethylcellulose ether derivative (ETHOCEL Standard Premium 7FP) as rate controlling polymer. The tablets obtained were evaluated for various physico-chemical characteristics and in-vitro drug release studies were conducted in phosphate buffer (pH 7.4) using PharmaTest dissolution apparatus at constant temperature of 37°C ± 0.1. Similarity factor f 2 was employed to the release profiles of test formulations and were compared with marketed ciprofloxacin conventional tablets. Drug release mechanism and the kinetics involved were investigated by fitting the release profile data to various kinetic models. It was found that with increasing the proportion of ethylcellulose ether derivative in the matrix, the drug release was significantly extended up to 24 hours. The tablets exhibited zero order or nearly zero order drug transport mechanism. In vivo drug release performance of the developed controlled release tablets and reference conventional tablets containing ciprofloxacin were determined in rabbit serum according to randomized two-way crossover study design using High Performance Liquid Chromatography. Several bioavailability parameters of both the test tablets and conventional tablets including C max⁡, T max⁡ and AUC0-t were compared which showed an optimized C max⁡ and T max⁡ (P < 0.05). A good correlation was obtained between in vitro drug release and in vivo drug absorption with correlation value (R 2 = 0.934). Relative bioavailability was found to be 93%. Reproducibility of manufacturing process and accelerated stability of the developed tablets were performed in stability chamber at 40 ± 2°C and 75 ± 5% relative humidity for a period of 6 months and were found to be stable throughout the stability period. PMID:22649325

A novel sustained-release formulation of recombinant human growth hormone and its pharmacokinetic, pharmacodynamic and safety profiles.

PubMed

Wei, Yi; Wang, Yuxia; Kang, Aijun; Wang, Wei; Ho, Sa V; Gao, Junfeng; Ma, Guanghui; Su, Zhiguo

2012-07-02

An effective and safe formulation of sustained-release rhGH for two months using poly(monomethoxypolyethylene glycol-co-D,L-lactide) (mPEG-PLA, PELA) microspheres was developed to reduce the frequency of medication. The rhGH-loaded PELA microspheres with a narrow size distribution were successfully prepared by a double emulsion method combined with a premix membrane emulsification technique without any exogenous stabilizing excipients. The narrow size distribution of the microspheres would guarantee repeatable productivity and release behavior. Moreover, the amphiphilic PELA improved the bioactivity retention of protein drugs since it prevented protein contact with the oil/water interface and the hydrophobic network, and modulated diffusion of acidic degradation products from the carrier system. These PELA microspheres were compared in vivo with commercial rhGH solution, conventional poly(D,L-lactic acid) (PLA) and poly(D,L-lactic-co-glycolic acid) (PLGA) microspheres. Administration of rhGH-PELA could extend the duration of rhGH release (for up to 56 days) and increase area under the curve (AUC) compared to rhGH solution, PLA or PLGA microspheres in Sprague-Dawley (SD) rats. In addition, rhGH-PELA microspheres induced a greater response in total insulin-like growth factor-1 (IGF-1) and insulin-like growth factor binding protein-3 (IGFBP-3) than other rhGH formulations. With a hypophysectomized SD rat model, the pharmacological efficacy of rhGH-PELA microspheres was shown to be better than that from daily administration of rhGH solutions over 6 days based on body weight gain and width of the tibial growth plate. Histological examination of the injection sites indicated a significantly milder inflammatory response than that observed after injection of PLA and PLGA microspheres. Neither anti-rhGH antibodies nor the toxic effects on heart, liver and kidney were detectable after administration of rhGH-PELA microspheres in SD rats. These results suggest that rhGH-PELA microspheres have the potential to be clinically effective and safe when administered only once every two months, a dose regimen for better patient acceptance and compliance.

Optimization of primaquine diphosphate tablet formulation for controlled drug release using the mixture experimental design.

PubMed

Duque, Marcelo Dutra; Kreidel, Rogério Nepomuceno; Taqueda, Maria Elena Santos; Baby, André Rolim; Kaneko, Telma Mary; Velasco, Maria Valéria Robles; Consiglieri, Vladi Olga

2013-01-01

A tablet formulation based on hydrophilic matrix with a controlled drug release was developed, and the effect of polymer concentrations on the release of primaquine diphosphate was evaluated. To achieve this purpose, a 20-run, four-factor with multiple constraints on the proportions of the components was employed to obtain tablet compositions. Drug release was determined by an in vitro dissolution study in phosphate buffer solution at pH 6.8. The polynomial fitted functions described the behavior of the mixture on simplex coordinate systems to study the effects of each factor (polymer) on tablet characteristics. Based on the response surface methodology, a tablet composition was optimized with the purpose of obtaining a primaquine diphosphate release closer to a zero order kinetic. This formulation released 85.22% of the drug for 8 h and its kinetic was studied regarding to Korsmeyer-Peppas model, (Adj-R(2) = 0.99295) which has confirmed that both diffusion and erosion were related to the mechanism of the drug release. The data from the optimized formulation were very close to the predictions from statistical analysis, demonstrating that mixture experimental design could be used to optimize primaquine diphosphate dissolution from hidroxypropylmethyl cellulose and polyethylene glycol matrix tablets.

Release kinetics of papaverine hydrochloride from tablets with different excipients.

PubMed

Kasperek, Regina; Polski, Andrzej; Zimmer, Łukasz; Poleszak, Ewa

2014-01-01

The influence of excipients on the disintegration times of tablets and the release of papaverine hydrochloride (PAP) from tablets were studied. Ten different formulations of tablets with PAP were prepared by direct powder compression. Different binders, disintegrants, fillers, and lubricants were used as excipients. The release of PAP was carried out in the paddle apparatus using 0.1 N HCl as a dissolution medium. The results of the disintegration times of tablets showed that six formulations can be classified as fast dissolving tablets (FDT). FDT formulations contained Avicel PH 101, Avicel PH 102, mannitol, (3-lactose, PVP K 10, gelatinized starch (CPharmGel), Prosolv Easy Tab, Prosolv SMCC 90, magnesium stearate, and the addition of disintegrants such as AcDiSol and Kollidon CL. Drug release kinetics were estimated by the zero- and first-order, Higuchi release rate, and Korsmeyer-Peppas models. Two formulations of the tablets containing PVP (K10) (10%), CPharmGel (10% and 25%), and Prosolv Easy Tab (44% and 60%) without the addition of a disintegrant were well-fitted to the kinetics models such as the Higuchi and zero-order, which are suitable for controlled- or sustained-release.

Release Kinetics of Papaverine Hydrochloride from Tablets with Different Excipients

PubMed Central

Kasperek, Regina; Polski, Andrzej; Zimmer, Łukasz; Poleszak, Ewa

2014-01-01

Abstract The influence of excipients on the disintegration times of tablets and the release of papaverine hydrochloride (PAP) from tablets were studied. Ten different formulations of tablets with PAP were prepared by direct powder compression. Different binders, disintegrants, fillers, and lubricants were used as excipients. The release of PAP was carried out in the paddle apparatus using 0.1 N HCl as a dissolution medium. The results of the disintegration times of tablets showed that six formulations can be classified as fast dissolving tablets (FDT). FDT formulations contained Avicel PH 101, Avicel PH 102, mannitol, (3-lactose, PVP K 10, gelatinized starch (CPharmGel), Prosolv Easy Tab, Prosolv SMCC 90, magnesium stearate, and the addition of disintegrants such as AcDiSol and Kollidon CL. Drug release kinetics were estimated by the zero- and first-order, Higuchi release rate, and Korsmeyer-Peppas models. Two formulations of the tablets containing PVP (K10) (10%), CPharmGel (10% and 25%), and Prosolv Easy Tab (44% and 60%) without the addition of a disintegrant were well-fitted to the kinetics models such as the Higuchi and zero-order, which are suitable for controlled- or sustained-release. PMID:25853076

Design and in vitro/in vivo evaluation of sustained-release floating tablets of itopride hydrochloride.

PubMed

Ahmed, Sayed M; Ahmed Ali, Adel; Ali, Ahmed Ma; Hassan, Omiya A

2016-01-01

The aim of the present study was to improve the bioavailability of itopride (ITO) and sustain its action by formulating as a floating dosage form. Sustained-release floating tablets of ITO hydrochloride (HCl) were prepared by direct compression using different hydrocolloid polymers such as hydroxypropyl methylcellulose and ethylcellulose and/or methacrylic acid polymers Eudragit RSPM and Carbopol 934P. The floating property was achieved using an effervescent mixture of sodium bicarbonate and anhydrous citric acid (1:1 mol/mol). Hardness, friability, content uniformity, and dissolution rate of the prepared floating tablets were evaluated. The formulation F 10 composed of 28.5% Eudragit RSPM, 3% NaHCO 3 , and 7% citric acid provided sustained drug release. In vitro results showed sustained release of F 10 where the drug release percentage was 96.51%±1.75% after 24 hours ( P =0.031). The pharmacokinetic results indicated that the area under the curve (AUC 0-∞ ) of the prepared sustained-release floating tablets at infinity achieved 93.69 µg·h/mL compared to 49.89 µg·h/mL for the reference formulation (Ganaton ® ) and the relative bioavailability of the sustained-release formulation F 10 increased to 187.80% ( P =0.022). The prepared floating tablets of ITO HCl (F 10 ) could be a promising drug delivery system with sustained-release action and enhanced drug bioavailability.

Extended‐Release Once‐Daily Formulation of Tofacitinib: Evaluation of Pharmacokinetics Compared With Immediate‐Release Tofacitinib and Impact of Food

PubMed Central

Wang, Rong; Fletcher, Tracey; Alvey, Christine; Kushner, Joseph; Stock, Thomas C.

2016-01-01

Abstract Tofacitinib is an oral Janus kinase inhibitor for the treatment of rheumatoid arthritis. An extended‐release (XR) formulation has been designed to provide a once‐daily (QD) dosing option to patients to achieve comparable pharmacokinetic (PK) parameters to the twice‐daily immediate‐release (IR) formulation. We conducted 2 randomized, open‐label, phase 1 studies in healthy volunteers. Study A characterized single‐dose and steady‐state PK of tofacitinib XR 11 mg QD and intended to demonstrate equivalence of exposure under single‐dose and steady‐state conditions to tofacitinib IR 5 mg twice daily. Study B assessed the effect of a high‐fat meal on the bioavailability of tofacitinib from the XR formulation. Safety and tolerability were monitored in both studies. In study A (N = 24), the XR and IR formulations achieved time to maximum plasma concentration at 4 hours and 0.5 hours postdose, respectively; terminal half‐life was 5.9 hours and 3.2 hours, respectively. Area under plasma concentration‐time curve (AUC) and maximum plasma concentration (Cmax) after single‐ and multiple‐dose administration were equivalent between the XR and IR formulations. In study B (N = 24), no difference in AUC was observed for fed vs fasted conditions. Cmax increased by 27% under the fed state. On repeat administration, negligible accumulation (<20%) of systemic exposures was observed for both formulations. Steady state was achieved within 48 hours of dosing with the XR formulation. Tofacitinib administration as an XR or IR formulation was generally well tolerated in these studies. PMID:26970526

Optimization of carboxylate-terminated poly(amidoamine) dendrimer-mediated cisplatin formulation.

PubMed

Kulhari, Hitesh; Pooja, Deep; Singh, Mayank K; Chauhan, Abhay S

2015-02-01

Abstract Cisplatin is mainly used in the treatment of ovarian, head and neck and testicular cancer. Poor solubility and non-specific interactions causes hurdles in the development of successful cisplatin formulation. There were few reports on poly(amidoamine) (PAMAM) dendrimer-cisplatin complexes for anticancer treatment. But the earlier research was mainly focused on therapeutic effect of PAMAM dendrimer-cisplatin complex, with less attention paid on the formulation development of these complexes. Objective of the present study is to optimize and validate the carboxylate-terminated, EDA core PAMAM dendrimer-based cisplatin formulation with respect to various variables such as dendrimer core, generation, drug entrapment, purification, yield, reproducibility, stability, storage and in-vitro release. Dendrimer-cisplatin complex was prepared by an efficient method which significantly increases the % platinum (Pt) content along with the product yield. Dendrimers showed reproducible (∼27%) platinum loading by weight. Variation in core and generations does not produce significant change in the % Pt content. Percentage Pt content of dendrimeric formulation increases with increase in drug/dendrimer mole ratio. Formulation with low drug/dendrimer mole ratio showed delayed release compared to the higher drug/dendrimer mole ratio; these dendrimer formulations are stable in room temperature. In vitro release profiles of the stored dendrimer-cisplatin samples showed comparatively slow release of cisplatin, which may be due to formation of strong bond between cisplatin and dendrimer. This study will contribute to create a fine print for the formulation development of PAMAM dendrimer-cisplatin complexes.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hoyle, Gary W., E-mail: Gary.Hoyle@louisville.edu; Chen, Jing; Schlueter, Connie F.

Chlorine is a commonly used, reactive compound to which humans can be exposed via accidental or intentional release resulting in acute lung injury. Formulations of rolipram (a phosphodiesterase inhibitor), triptolide (a natural plant product with anti-inflammatory properties), and budesonide (a corticosteroid), either neat or in conjunction with poly(lactic:glycolic acid) (PLGA), were developed for treatment of chlorine-induced acute lung injury by intramuscular injection. Formulations were produced by spray-drying, which generated generally spherical microparticles that were suitable for intramuscular injection. Multiple parameters were varied to produce formulations with a wide range of in vitro release kinetics. Testing of selected formulations in chlorine-exposedmore » mice demonstrated efficacy against key aspects of acute lung injury. The results show the feasibility of developing microencapsulated formulations that could be used to treat chlorine-induced acute lung injury by intramuscular injection, which represents a preferred route of administration in a mass casualty situation. - Highlights: • Chlorine causes lung injury when inhaled and is considered a chemical threat agent. • Countermeasures for treatment of chlorine-induced acute lung injury are needed. • Formulations containing rolipram, triptolide, or budesonide were produced. • Formulations with a wide range of release properties were developed. • Countermeasure formulations inhibited chlorine-induced lung injury in mice.« less

New release cell for NMR microimaging of tablets. Swelling and erosion of poly(ethylene oxide).

PubMed

Abrahmsén-Alami, Susanna; Körner, Anna; Nilsson, Ingvar; Larsson, Anette

2007-09-05

A small release cell, in the form of a rotating disc, has been constructed to fit into the MRI equipment. The present work show that both qualitative and quantitative information of the swelling and erosion behavior of hydrophilic extended release (ER) matrix tablets may be obtained using this release cell and non-invasive magnetic resonance imaging (MRI) studies at different time-points during matrix dissolution. The tablet size, core size and the gel layer thickness of ER matrix formulations based on poly(ethylene oxide) have been determined. The dimensional changes as a function of time were found to correspond well to observations made with texture analysis (TA) methodology. Most importantly, the results of the present study show that both the erosion (displacement of the gel-dissolution media interface) and the swelling (decrease of dry tablet core size) proceed with a faster rate in radial than in axial direction using the rotating disk set-up. This behavior was attributed to the higher shear forces experienced in the radial direction. The results also indicate that front synchronization (constant gel layer thickness) is associated with the formation of an almost constant polymer concentration profile through the gel layer at different time-points.

Development of an ANN optimized mucoadhesive buccal tablet containing flurbiprofen and lidocaine for dental pain.

PubMed

Hussain, Amjad; Syed, Muhammad Ali; Abbas, Nasir; Hanif, Sana; Arshad, Muhammad Sohail; Bukhari, Nadeem Irfan; Hussain, Khalid; Akhlaq, Muhammad; Ahmad, Zeeshan

2016-06-01

A novel mucoadhesive buccal tablet containing flurbiprofen (FLB) and lidocaine HCl (LID) was prepared to relieve dental pain. Tablet formulations (F1-F9) were prepared using variable quantities of mucoadhesive agents, hydroxypropyl methyl cellulose (HPMC) and sodium alginate (SA). The formulations were evaluated for their physicochemical properties, mucoadhesive strength and mucoadhesion time, swellability index and in vitro release of active agents. Release of both drugs depended on the relative ratio of HPMC:SA. However, mucoadhesive strength and mucoadhesion time were better in formulations, containing higher proportions of HPMC compared to SA. An artificial neural network (ANN) approach was applied to optimise formulations based on known effective parameters (i.e., mucoadhesive strength, mucoadhesion time and drug release), which proved valuable. This study indicates that an effective buccal tablet formulation of flurbiprofen and lidocaine can be prepared via an optimized ANN approach.

Advances in Nanotechnology for Efficacious and Stable Formulation Development

NASA Technical Reports Server (NTRS)

Putcha, Lakshimi

2012-01-01

Current operational medical kits aboard the International Space Station (ISS) include an array of medications intended for the treatment of minor ambulatory care symptoms, first aid, and basic life support. All medications contained in the flight kits are commercially available off-the-shelf formulations used for treatment of illnesses on Earth. However, transport and stowage of supplies including medications for space missions are exposed to adverse environmental conditions and extended shelf-life demands. Proposed missions to Mars and near-Earth objects such as asteroid 1999 AO10 will present crew health risk that is different both quantitatively and qualitatively from those encountered on ISS missions. Few drug options are available at the present time for mitigation of crew health risk of planned space exploration missions. Alternatives to standard oral formulations that include sustained and targeted delivery technologies for preventive healthcare in space will be a welcome addition to the space formulary and may include controlled release topical, sub-cutaneous, intranasal and inhalation dosage forms. An example of such a technology development endeavor can be nanotechnology-based multi-stage drug cocktail and vaccine delivery systems. Nanostructures also have the ability to protect drugs encapsulated within them from physiologic degradation, target their delivery with sustained release and are suitable for per oral routes of administration. The use of nanostructures such as polymeric nanoparticles offers a non-invasive approach for penetrating the blood brain barrier. Finally, nanotechnology offers great potential for the development of safe and efficacious drug delivery systems for preventive health care in space and on Earth.

Improved Bioavailability of Levodopa Using Floatable Spray-Coated Microcapsules for the Management of Parkinson's Disease.

PubMed

Baek, Jong-Suep; Tee, Jie Kai; Pang, Yi Yun; Tan, Ern Yu; Lim, Kah Leong; Ho, Han Kiat; Loo, Say Chye Joachim

2018-06-01

Oral administration of levodopa (LD) is the gold standard in managing Parkinson's disease (PD). Although LD is the most effective drug in treating PD, chronic administration of LD induces levodopa-induced dyskinesia. A continuous and sustained provision of LD to the brain could, therefore, reduce peak-dose dyskinesia. In commercial oral formulations, LD is co-administrated with an AADC inhibitor (carbidopa) and a COMT inhibitor (entacapone) to enhance its bioavailability. Nevertheless, patients are known to take up to five tablets a day because of poor sustained-releasing capabilities that lead to fluctuations in plasma concentrations. To achieve a prolonged release of LD with the aim of improving its bioavailability, floatable spray-coated microcapsules containing all three PD drugs were developed. This gastro-retentive delivery system showed sustained release of all PD drugs, at similar release kinetics. Pharmacokinetics study was conducted and this newly developed formulation showed a more plateaued delivery of LD that is void of the plasma concentration fluctuations observed for the control (commercial formulation). At the same time, measurements of LD and dopamine of mice administered with this formulation showed enhanced bioavailability of LD. This study highlights a floatable, sustained-releasing delivery system in achieving improved pharmacokinetics data compared to a commercial formulation.

Gamma scintigraphic evaluation of floating gastroretentive tablets of metformin HCl using a combination of three natural polymers in rabbits

PubMed Central

Razavi, Mahboubeh; Karimian, Hamed; Yeong, Chai Hong; Chung, Lip Yong; Nyamathulla, Shaik; Noordin, Mohamed Ibrahim

2015-01-01

The present research was aimed at formulating a metformin HCl sustained-release formulation from a combination of polymers, using the wet granulation technique. A total of 16 formulations (F1–F16) were produced using different combinations of the gel-forming polymers: tamarind kernel powder, salep (palmate tubers of Orchis morio), and xanthan. Post-compression studies showed that there were no interactions between the active drug and the polymers. Results of in vitro drug-release studies indicated that the F10 formulation which contained 5 mg of tamarind kernel powder, 33.33 mg of xanthan, and 61.67 mg of salep could sustain a 95% release in 12 hours. The results also showed that F2 had a 55% similarity factor with the commercial formulation (C-ER), and the release kinetics were explained with zero order and Higuchi models. The in vivo study was performed in New Zealand White rabbits by gamma scintigraphy; the F10 formulation was radiolabeled using samarium (III) oxide (153Sm2O3) to trace transit of the tablets in the gastrointestinal tract. The in vivo data supported the retention of F10 formulation in the gastric region for 12 hours. In conclusion, the use of a combination of polymers in this study helped to develop an optimal gastroretentive drug-delivery system with improved bioavailability, swelling, and floating characteristics. PMID:26273196

Development and evaluation of new multiple-unit levodopa sustained-release floating dosage forms.

PubMed

Goole, J; Vanderbist, F; Amighi, K

2007-04-04

This work relates to the development and the in vitro evaluation of sustained-release minitablets (MT), prepared by melt granulation and subsequent compression, which are designed to float over an extended period of time. Levodopa was used as a model drug. The importance of the composition and manufacturing parameters of the MT on their floating and dissolution properties was then examined. The investigation showed that MT composition and MT diameter had the greatest influence on drug release, which was sustained for more than 8h. By using the same formulation, the best floating properties were obtained with 3mm MT prepared at low compression forces ranging between 50 and 100N. Their resultant-weight (RW) values were always higher than those obtained with a marketed HBS dosage form within 13h. When they were filled into gelatin capsules, no sticking was observed. By evaluating the dissolution profiles of levodopa at different pH values, it was found that dissolution profiles depend more on the prolonged-release ability of Methocel K15M than on the pH-dependent solubility of levodopa. Finally, the robustness of the floating MT was assessed by testing the drug release variability in function of the stirring conditions during dissolution tests.

Development of sustained and dual drug release co-extrusion formulations for individual dosing.

PubMed

Laukamp, Eva Julia; Vynckier, An-Katrien; Voorspoels, Jody; Thommes, Markus; Breitkreutz, Joerg

2015-01-01

In personalized medicine and patient-centered medical treatment individual dosing of medicines is crucial. The Solid Dosage Pen (SDP) allows for an individual dosing of solid drug carriers by cutting them into tablet-like slices. The aim of the present study was the development of sustained release and dual release formulations with carbamazepine (CBZ) via hot-melt co-extrusion for the use in the SDP. The selection of appropriate coat- and core-formulations was performed by adapting the mechanical properties (like tensile strength and E-modulus) for example. By using different excipients (polyethyleneglycols, poloxamers, white wax, stearic acid, and carnauba wax) and drug loadings (30-50%) tailored dissolution kinetics was achieved showing cube root or zero order release mechanisms. Besides a biphasic drug release, the dose-dependent dissolution characteristics of sustained release formulations were minimized by a co-extruded wax-coated formulation. The dissolution profiles of the co-extrudates were confirmed during short term stability study (six months at 21.0 ± 0.2 °C, 45%r.h.). Due to a good layer adhesion of core and coat and adequate mechanical properties (maximum cutting force of 35.8 ± 2.0 N and 26.4 ± 2.8 N and E-modulus of 118.1 ± 8.4 and 33.9 ± 4.5 MPa for the dual drug release and the wax-coated co-extrudates, respectively) cutting off doses via the SDP was precise. While differences of the process parameters (like the barrel temperature) between the core- and the coat-layer resulted in unsatisfying content uniformities for the wax-coated co-extrudates, the content uniformity of the dual drug release co-extrudates was found to be in compliance with pharmacopoeial specification. Copyright © 2015 Elsevier B.V. All rights reserved.

Formulation development and optimization of sustained release matrix tablet of Itopride HCl by response surface methodology and its evaluation of release kinetics

PubMed Central

Bose, Anirbandeep; Wong, Tin Wui; Singh, Navjot

2012-01-01

The objective of this present investigation was to develop and formulate sustained release (SR) matrix tablets of Itopride HCl, by using different polymer combinations and fillers, to optimize by Central Composite Design response surface methodology for different drug release variables and to evaluate drug release pattern of the optimized product. Sustained release matrix tablets of various combinations were prepared with cellulose-based polymers: hydroxy propyl methyl cellulose (HPMC) and polyvinyl pyrolidine (pvp) and lactose as fillers. Study of pre-compression and post-compression parameters facilitated the screening of a formulation with best characteristics that underwent here optimization study by response surface methodology (Central Composite Design). The optimized tablet was further subjected to scanning electron microscopy to reveal its release pattern. The in vitro study revealed that combining of HPMC K100M (24.65 MG) with pvp(20 mg)and use of LACTOSE as filler sustained the action more than 12 h. The developed sustained release matrix tablet of improved efficacy can perform therapeutically better than a conventional tablet. PMID:23960836

Formulation development and optimization of sustained release matrix tablet of Itopride HCl by response surface methodology and its evaluation of release kinetics.

PubMed

Bose, Anirbandeep; Wong, Tin Wui; Singh, Navjot

2013-04-01

The objective of this present investigation was to develop and formulate sustained release (SR) matrix tablets of Itopride HCl, by using different polymer combinations and fillers, to optimize by Central Composite Design response surface methodology for different drug release variables and to evaluate drug release pattern of the optimized product. Sustained release matrix tablets of various combinations were prepared with cellulose-based polymers: hydroxy propyl methyl cellulose (HPMC) and polyvinyl pyrolidine (pvp) and lactose as fillers. Study of pre-compression and post-compression parameters facilitated the screening of a formulation with best characteristics that underwent here optimization study by response surface methodology (Central Composite Design). The optimized tablet was further subjected to scanning electron microscopy to reveal its release pattern. The in vitro study revealed that combining of HPMC K100M (24.65 MG) with pvp(20 mg)and use of LACTOSE as filler sustained the action more than 12 h. The developed sustained release matrix tablet of improved efficacy can perform therapeutically better than a conventional tablet.

Film-forming formulations containing porous silica for the sustained delivery of actives to the skin.

PubMed

Heck, Rouven; Hermann, Sabrina; Lunter, Dominique J; Daniels, Rolf

2016-11-01

The purpose of this study was to develop film-forming formulations facilitating long-term treatment of chronic pruritus with capsaicinoids. To this end, an oily solution of nonivamide was loaded into porous silica particles which were then suspended in the dispersion of a sustained release polymer. Such formulations form a film when applied to the skin and encapsulate the drug loaded silica particles in a dry polymeric matrix. Dermal delivery and permeation of the antipruritic drug nonivamide (NVA) are controlled by the matrix. The film-forming formulations were examined regarding homogeneity, storage stability, substantivity and ex vivo skin permeation. Confocal Raman spectral imaging proved the stability of silica-based film-forming formulations over a period of 6 months. Substantivity was found to be enhanced substantially compared to a conventional semisolid formulation. Permeation rates of nonivamide from film-forming formulations through the skin are much lower compared to those achieved with a conventional immediate release formulation with the same drug amount. Due to the drug reservoir in the polymer matrix, a sustained permeation is enabled. Film-forming formulations may therefore improve the treatment of chronic pruritus with capsaicinoids by enhancing patient compliance through a sustained release regime. Copyright © 2016 Elsevier B.V. All rights reserved.

The impact of manufacturing variables on in vitro release of clobetasol 17-propionate from pilot scale cream formulations.

PubMed

Fauzee, Ayeshah Fateemah Beebee; Khamanga, Sandile Maswazi; Walker, Roderick Bryan

2014-12-01

The purpose of the study was to evaluate the effect of different homogenization speeds and times, anchor speeds and cooling times on the viscosity and cumulative % clobetasol 17-propionate released per unit area at 72 h from pilot scale cream formulations. A 2(4) full factorial central composite design for four independent variables were investigated. Thirty pilot scale batches of cream formulations were manufactured using a Wintech® cream/ointment plant. The viscosity and in vitro release of CP were monitored and compared to an innovator product that is commercially available on the South African market, namely, Dermovate® cream. Contour and three-dimensional response surface plots were produced and the viscosity and cumulative % CP released per unit area at 72 h were found to be primarily dependent on the homogenization and anchor speeds. An increase in the homogenization and anchor speeds appeared to exhibit a synergistic effect on the resultant viscosity of the cream whereas an antagonistic effect was observed for the in vitro release of CP from the experimental cream formulations. The in vitro release profiles were best fitted to a Higuchi model and diffusion proved to be the dominant mechanism of drug release that was confirmed by use of the Korsmeyer-Peppas model. The research was further validated and confirmed by the high prognostic ability of response surface methodology (RSM) with a resultant mean percentage error of (±SD) 0.17 ± 0.093 suggesting that RSM may be an efficient tool for the development and optimization of topical formulations.

Formulation, in vitro evaluation and study of variables on tri-layered gastro-retentive delivery system of diltiazem HCl.

PubMed

Raut Desai, Shilpa; Rohera, Bhagwan D

2014-03-01

Tri-layered floating tablets using only one grade of polyethylene oxide (PEO) would enable easy manufacturing, reproducibility and controlled release for highly soluble drugs. To evaluate the potential of PEO as a sole polymer for the controlled release and to study the effect of formulation variables on release and gastric retention of highly soluble Diltiazem hydrochloride (DTZ). Tablets were compressed with middle layer consisting of drug and polymer while outer layers consisted of polymer with sodium bicarbonate. Design of formulation to obtain 12 h, zero-order release and rapid floatation was done by varying the grades, quantity of PEO and sodium bicarbonate. Dissolution data were fitted in drug release models and swelling/erosion studies were undertaken to verify the drug release mechanism. Effect of formulation variables and tablet surface morphology using scanning electron microscopy were studied. The optimized formula passed the criteria of USP dissolution test I and exhibited floating lag-time of 3-4 min. Drug release was faster from low molecular weight (MW) PEO as compared to high MW. With an increase in the amount of sodium bicarbonate, faster buoyancy was achieved due to the increased CO2 gas formation. Drug release followed zero-order and gave a good fit to the Korsmeyer-Peppas model, which suggested that drug release was due to diffusion through polymer swelling. Zero-order, controlled release profile with the desired buoyancy can be achieved by using optimum formula quantities of sodium bicarbonate and polymer. The tri-layered system shows promising delivery of DTZ, and possibly other water-soluble drugs.

Sustained Zero-Order Release of Intact Ultra-Stable Drug-Loaded Liposomes from an Implantable Nanochannel Delivery System

PubMed Central

Celia, Christian; Ferrati, Silvia; Bansal, Shyam; van de Ven, Anne L.; Ruozi, Barbara; Zabre, Erika; Hosali, Sharath; Paolino, Donatella; Sarpietro, Maria Grazia; Fine, Daniel; Fresta, Massimo; Ferrari, Mauro

2014-01-01

Metronomic chemotherapy supports the idea that long-term, sustained, constant administration of chemotherapeutics, currently not achievable, could be effective against numerous cancers. Particularly appealing are liposomal formulations, used to solubilize hydrophobic therapeutics and minimize side effects, while extending drug circulation time and enabling passive targeting. As liposome alone cannot survive in circulation beyond 48 hrs, sustaining their constant plasma level for many days is a challenge. To address this, we developed, as a proof of concept, an implantable nanochannel delivery system and ultra-stable PEGylated lapatinib loaded-liposomes, and we demonstrate the release of intact vesicles for over 18 days. Further, we investigate intravasation kinetics of subcutaneously delivered liposomes and verify their biological activity post nanochannel release on BT474 breast cancer cells. The key innovation of this work is the combination of two nanotechnologies to exploit the synergistic effect of liposomes, demonstrated as passive-targeting vectors and nanofluidics to maintain therapeutic constant plasma levels. In principle, this approach could maximize efficacy of metronomic treatments. PMID:23881575

Characteristics of platelet gels combined with silk

PubMed Central

Pallotta, Isabella; Kluge, Jonathan A.; Moreau, Jodie; Calabrese, Rossella

2014-01-01

Platelet gel, a fibrin network containing activated platelets, is widely used in regenerative medicine due the capacity of platelet-derived growth factors to accelerate and direct healing processes. However, limitations to this approach include poor mechanical properties, relatively rapid degradation, and the lack of control of release of growth factors at the site of injection. These issues compromise the ability of platelet gels for sustained function in regenerative medicine. In the present study, a combination of platelet gels with silk fibroin gel was studied to address the above limitations. Mixing sonicated silk gels with platelet gels extended the release of growth factors without inhibiting gel forming ability. The released growth factors were biologically active and their delivery was modified further by manipulation of the charge of the silk protein. Moreover, the silk gel augmented both the rheological properties and compressive stiffness of the platelet gel, tuned by the silk concentration and/or silk/platelet gel ratio. Silk-platelet gel injections in nude rats supported enhanced cell infiltration and blood vessel formation representing a step towards new platelet gel formulations with enhanced therapeutic impact. PMID:24480538

Gender differences in treatment and clinical characteristics among patients receiving extended release naltrexone.

PubMed

Herbeck, Diane M; Jeter, Kira E; Cousins, Sarah J; Abdelmaksoud, Reham; Crèvecoeur-MacPhail, Desirée

2016-01-01

Further research is needed to investigate real-world acceptability of extended-release naltrexone for alcohol and opioid use disorders, and potential gender differences. This study examines treatment and clinical characteristics among men and women receiving extended-release naltrexone in a large, publicly funded substance use disorder treatment system (N = 465; 52% female). Patient demographics, treatment characteristics, and the number of extended-release naltrexone doses received were collected from administrative data and treatment program staff. Additionally, patients provided information on experiences with extended-release naltrexone in an open-ended format at 1, 2, and 3 weeks following their first injection. For a subsample of patients (N = 220), alcohol/opioid cravings and specific adverse effects were also assessed. Compared to men, women reported experiencing a higher rate and mean number of adverse effects. Overall, craving scores showed substantial reductions over time. However, among patients taking extended-release naltrexone for alcohol use, women showed a significantly greater reduction in craving scores compared to men. No gender differences were observed in the number of extended-release naltrexone doses received. Although women may have a greater need for additional support in managing early adverse effects, extended-release naltrexone as an adjunct to psychosocial treatment may be an acceptable and promising treatment approach for both men and women, and particularly for women prescribed extended-release naltrexone for alcohol use. This study contributes further information on patients' experiences during the early course of extended-release naltrexone treatment in real-world settings. Understanding these experiences may assist policy makers and treatment providers in addressing challenges of implementing this treatment into wider practice.

Formulation and evaluation of different floating tablets containing metronidazole to target stomach.

PubMed

Loh, Zhiao C; Elkordy, Amal A

2015-01-01

The purpose of this study is to formulate and develop tablets dosage form containing Metronidazole which has swelling and floating properties as a gastroretentive controlled-release drug delivery system to improve drug bioavailability. Fifteen different formulations of effervescence-forming floating systems were designed using HPMC K15M, xanthan gum, co-povidone, Eudragit® RL PO, pluronic® F-127 and/or polypropylene foam powder as swelling agents and sodium bicarbonate with/ without citric acid as gas-forming agents at different compositions. Six out of these 15 formulations which have satisfactory tablet floating behaviour were further studied with the incorporation of Metronidazole. The tablets were evaluated based on tablet physicochemical properties, floating behaviour, swelling ability and drug dissolution studies which were carried out using 0.1M HCl at 37°C for 8 hours. Furthermore, evaluation of the powder mixtures using Fourier transform infrared (FT-IR) spectroscopy, differential scanning calorimetry (DSC) and scanning electron microscope (SEM) were investigated. Most of the tablets show good physicochemical properties except for F11 which contains pluronic® F-127 as its release-retarding matrix-forming polymer. Other formulations show high swelling capacity, ability to float for at least 8 hours in vitro and have sustained drug release characteristics. Data obtained indicated that F3 which contains HPMC (12.5%w/w), xanthan gum (25%w/w), co-povidone (12.5%w/w) and sodium bicarbonate (31.7%w/w) is a suitable formulation with short floating lag time, good floating behaviour and sustained drug release for at least 8 hours in vitro with a zero order kinetic. Combinations of HPMC K15M and xanthan gum as swelling agents show synergistic effect in retarding drug release and are suitable in providing the most sustained drug release system.

pH-independent immediate release polymethacrylate formulations--an observational study.

PubMed

Claeys, Bart; Vandeputte, Reinout; De Geest, Bruno G; Remon, Jean Paul; Vervaet, Chris

2016-01-01

Using Eudragit® E PO (EudrE) as a polymethacrylate carrier, the aim of the study was to develop a pH-independent dosage form containing ibuprofen (IBP) as an active compound via chemical modification of the polymer (i.e. quaternization of amine function) or via the addition of dicarboxylic acids (succinic, glutaric and adipic acid) to create a pH micro-environment during dissolution. Biconvex tablets (diameter: 10 mm; height: 5 mm) were produced via hot melt extrusion and injection molding. In vitro dissolution experiments revealed that a minimum of 25% of quaternization was sufficient to partially (up to pH 5) eliminate the pH-dependent effect of the EudrE/IBP formulation. The addition of dicarboxylic acids did not alter IBP release in a pH 1 and 3 medium as the dimethyl amino groups of EudrE are already fully protonated, while in a pH 5 solvent IBP release was significantly improved (cf. from 0% to 92% release after 1 h dissolution experiments upon the addition of 20 wt.% succinic acid). Hence, both approaches resulted in a pH-independent (up to pH 5) immediate release formulation. However, the presence of a positively charged polymer induced stability issues (recrystallization of API) and the formulations containing dicarboxylic acids were classified as mechanically unstable. Hence, further research is needed to obtain a pH-independent immediate release formulation while using EudrE as a polmethacrylate carrier.

Chronotherapeutically Modulated Pulsatile System of Valsartan Nanocrystals-an In Vitro and In Vivo Evaluation.

PubMed

Biswas, Nikhil; Kuotsu, Ketousetuo

2017-02-01

The objective was to improve the dissolution of valsartan by developing valsartan nanocrystals and design a pulsed release system for the chronotherapy of hypertension. Valsartan nanocrystals were prepared by sonication-anti-solvent precipitation method and lyophilized to obtain dry powder. Nanocrystals were directly compressed to minitablets and coated to achieve pulsatile valsartan release. Pharmacokinetic profiles of optimized and commercial formulations were compared in rabbit model. The mean particle size and PDI of the optimized nanocrystal batch V4 was reported as 211 nm and 0.117, respectively. DSC and PXRD analysis confirmed the crystalline nature of valsartan in nanocrystals. The dissolution extent of valsartan was markedly enhanced with both nanocrystals and minitablets as compared to pure valsartan irrespective of pH of the medium. Core minitablet V4F containing 5% w/w polyplasdone XL showed quickest release of valsartan, over 90% within 15 min. Coated formulation CV4F showed two spikes in release profile after successive lag times of 235 and 390 min. The pharmacokinetic study revealed that the bioavailability of optimized formulation (72.90%) was significantly higher than the commercial Diovan tablet (30.18%). The accelerated stability studies showed no significant changes in physicochemical properties, release behavior, and bioavialability of CV4F formulation. The formulation was successfully designed to achieve enhanced bioavailability and dual pulsatile release. Bedtime dosing will more efficiently control the circadian spikes of hypertension in the morning.

Carbamazepine

MedlinePlus

... a condition that causes facial nerve pain). Carbamazepine extended-release capsules (Equetro brand only) are also used ... comes as a tablet, a chewable tablet, an extended-release (long-acting) tablet, an extended-release capsule, ...

Effects of Extended Release Methylphenidate Treatment on Ratings of Attention-Deficit/Hyperactivity Disorder (ADHD) and Associated Behavior in Children with Autism Spectrum Disorders and ADHD Symptoms

PubMed Central

Santos, Cynthia W.; Aman, Michael G.; Arnold, L. Eugene; Casat, Charles D.; Mansour, Rosleen; Lane, David M.; Loveland, Katherine A.; Bukstein, Oscar G.; Jerger, Susan W.; Factor, Perry; Vanwoerden, Salome; Perez, Evelyn; Cleveland, Lynne A.

2013-01-01

Abstract Objective The purpose of this study was to examine the behavioral effects of four doses of psychostimulant medication, combining extended-release methylphenidate (MPH) in the morning with immediate-release MPH in the afternoon. Method The sample comprised 24 children (19 boys; 5 girls) who met American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV-TR) criteria for an autism spectrum disorder (ASD) on the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS), and had significant symptoms of attention-deficit/hyperactivity disorder (ADHD). This sample consisted of elementary school-age, community-based children (mean chronological age=8.8 years, SD=1.7; mean intelligence quotient [IQ]=85; SD=16.8). Effects of four dose levels of MPH on parent and teacher behavioral ratings were investigated using a within-subject, crossover, placebo-controlled design. Results MPH treatment was associated with significant declines in hyperactive and impulsive behavior at both home and school. Parents noted significant declines in inattentive and oppositional behavior, and improvements in social skills. No exacerbation of stereotypies was noted, and side effects were similar to those seen in typically developing children with ADHD. Dose response was primarily linear in the dose range studied. Conclusions The results of this study suggest that MPH formulations are efficacious and well-tolerated for children with ASD and significant ADHD symptoms. PMID:23782128

Effects of extended release methylphenidate treatment on ratings of attention-deficit/hyperactivity disorder (ADHD) and associated behavior in children with autism spectrum disorders and ADHD symptoms.

PubMed

Pearson, Deborah A; Santos, Cynthia W; Aman, Michael G; Arnold, L Eugene; Casat, Charles D; Mansour, Rosleen; Lane, David M; Loveland, Katherine A; Bukstein, Oscar G; Jerger, Susan W; Factor, Perry; Vanwoerden, Salome; Perez, Evelyn; Cleveland, Lynne A

2013-06-01

The purpose of this study was to examine the behavioral effects of four doses of psychostimulant medication, combining extended-release methylphenidate (MPH) in the morning with immediate-release MPH in the afternoon. The sample comprised 24 children (19 boys; 5 girls) who met American Psychiatric Association, Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV-TR) criteria for an autism spectrum disorder (ASD) on the Autism Diagnostic Interview-Revised (ADI-R) and the Autism Diagnostic Observation Schedule (ADOS), and had significant symptoms of attention-deficit/hyperactivity disorder (ADHD). This sample consisted of elementary school-age, community-based children (mean chronological age=8.8 years, SD=1.7; mean intelligence quotient [IQ]=85; SD=16.8). Effects of four dose levels of MPH on parent and teacher behavioral ratings were investigated using a within-subject, crossover, placebo-controlled design. MPH treatment was associated with significant declines in hyperactive and impulsive behavior at both home and school. Parents noted significant declines in inattentive and oppositional behavior, and improvements in social skills. No exacerbation of stereotypies was noted, and side effects were similar to those seen in typically developing children with ADHD. Dose response was primarily linear in the dose range studied. The results of this study suggest that MPH formulations are efficacious and well-tolerated for children with ASD and significant ADHD symptoms.

78 FR 73200 - Draft Guidance for Industry on Bioequivalence Recommendations for Paliperidone Palmitate Extended...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-12-05

... Paliperidone Palmitate Extended-Release Injectable Suspension; Availability AGENCY: Food and Drug...) studies to support abbreviated new drug applications (ANDAs) for paliperidone palmitate extended-release... the availability of revised draft BE recommendations for paliperidone palmitate extended-release...

New formulations of bupivacaine for the treatment of postoperative pain: liposomal bupivacaine and SABER-Bupivacaine.

PubMed

Skolnik, Aaron; Gan, Tong J

2014-08-01

Although generally considered both safe and effective, local anesthetics are often used in conjunction with opioids postoperatively in part because of the limited duration of drug action of local anesthetics. Much interest exists in extending the duration of local anesthetics' effects, which may reduce the requirement for opioid pain medications that are frequently associated with side effects, including nausea and vomiting, pruritus and respiratory depression. This article introduces liposomal bupivacaine and SABER®-Bupivacaine, two new formulations of bupivacaine that increase the duration of analgesia postoperatively through two novel slow-release technologies. The pharmacodynamics, pharmacokinetics, efficacy and safety of both preparations of bupivacaine are reviewed. An electronic database search conducted using the Cochrane Central Register of Controlled Trials and MEDLINE/PubMed with the following search terms: 'bupivacaine,' 'liposomal bupivacaine', 'liposome bupivacaine', 'Exparel', 'SABER-Bupivacaine', 'SABER Bupivacaine', and 'SABER' yielded 90 articles (no language or date of publication restrictions were imposed). Clinical trials involving liposomal bupivacaine and SABER-Bupivacaine indicate that both safely prolong analgesia, while decreasing opioid requirements when compared with placebo. However, additional clinical studies are necessary to better determine the efficacy and cost-effectiveness of these long-acting local anesthetic formulations.

A novel ropivacaine-loaded in situ forming implant prolongs the effect of local analgesia in rats

PubMed Central

Lu, Lei; Zhang, Wei; Wu, Xin; Wang, Xiaoyu; Zhang, Min; Zhu, Quangang; Ding, Xueying; Xu, Zhiyun

2012-01-01

Introduction Prolonged postoperative analgesia cannot be achieved by a single injection of local anesthetic solution. The objective of this study was to optimize the formulation of a ropivacaine hydrochloride (Ropi-HCl) loaded in situ forming implant (ISI) by addition of different co-solvents, and evaluate the in vitro release of Ropi-HCl, and the analgesic effect and toxicity of the optimized formulation in rats. Material and methods Triacetin (TA), benzyl benzoate (BB) and polyethylene glycol 400 (PEG 400) were used as additives and added to the solvent of N-methyl-2-pyrrolidone (NMP). Drug release to the surface and inner structural properties of the formed implant were evaluated by scanning electron microscopy (SEM). The analgesic effect was determined by injection near the rat sciatic nerve. Results The solvent system added with TA or BB significantly decreased the burst release, whereas PEG 400 increased the Ropi-HCl burst release from the formulation. Over 70% of the incorporated Ropi-HCl was released from all formulations in 14 days in the in vitro assay. The SEM showed that the surface of NMP-BB formulation was less porous and more homogeneous, compared with the other formulations. Compared with Ropi-HCl injection, the optimized formulation (NMP-BB) significantly prolonged the analgesic effect in 48 h (p < 0.05), with a mild degree of motor block from 3 h to 12 h. Histological evaluation of the injection site revealed only mild inflammatory infiltration without obvious pathological nerve alterations. Conclusions The biodegradable Ropi-HCl-loaded ISI system with NMP-BB may prove to be an attractive and safe alternative for the delivery of parenteral local anesthetics to prolong pain relief. PMID:24049519

Combining strategies to optimize a gel formulation containing miconazole: the influence of modified cyclodextrin on textural properties and drug release.

PubMed

Ribeiro, Andreza Maria; Figueiras, Ana; Freire, Cristina; Santos, Delfim; Veiga, Francisco

2010-06-01

Miconazol, an antimycotic drug, is commonly formulated into semisolid formulations designed to be applied in the oral cavity to treat oral candidiasis. However, given its limited aqueous solubility, permeation through the biological membranes is low and therefore its activity is also limited. Cyclodextrins (CDs) have been widely used to increase the solubility and stability of poorly water-soluble drugs. The aim of this study is to formulate a gel containing an inclusion complex between a modified CD, methyl-beta-cyclodextrin (MbetaCD), and miconazole (MCZ). The influence of the CD on the textural properties of the prepared gel and the drug release from formulation were evaluated. The gels were prepared using two polymers, Carbopol 71G and Pluronic F127, which were selected taking into account their bioadhesiveness and thermal-sensitive gelling properties, respectively. Texture profile analyses were performed at two different temperatures to ascertain the influence of the temperature on the gel texture properties. The in vitro MCZ release profiles from the prepared gel and the commercial gel formulations were evaluated and compared using modified Franz diffusion cells. The addition of MbetaCD to the gel resulted in a decrease of the gel adhesiveness and firmness, and the MCZ release profile through f1 and f2 proved to be similar to the commercial product. A gel comprising miconazol in the form of an inclusion complex with MbetaCD showed suitable textural properties to be applied to the buccal mucosa. The MbetaCD enhanced the solubility of the MCZ in the gel formulation resulting in adequate in vitro drug release profiles.

Effects of absorption enhancers in chloroquine suppository formulations: I. In vitro release characteristics.

PubMed

Onyeji, C O; Adebayo, A S; Babalola, C P

1999-12-01

The need to develop chloroquine suppository formulations that yield optimal bioavailability of the drug has been emphasized. This study demonstrates the effects of incorporation of known absorption-enhancing agents (nonionic surfactants and sodium salicylate) on the in vitro release characteristics of chloroquine from polyethylene glycol (1000:4000, 75:25%, w/w) suppositories. The release rates were determined using a modification of the continuous flow bead-bed dissolution apparatus for suppositories. Results showed that the extent of drug release from suppositories containing any of three surfactants (Tween 20, Tween 80 and Brij 35) was 100%, whereas 88% release was obtained with control formulation (without enhancer) (P<0.05). However, Tween 20 was more effective than Brij 35 and Tween 80 in improving the drug release rate. There was a concentration-dependent effect with Tween 20, and 4% (w/w) of this surfactant was associated with the highest increase in the rate of drug release from the suppositories. Sodium salicylate at a concentration of 25% (w/w) also significantly enhanced the drug release rate, but a higher concentration of the adjuvant markedly reduced both the rate and extent of drug release. Combined incorporation of Tween 20 and sodium salicylate did not significantly modify (P0.05) the rate of drug release when compared to the effect of the more effective single agent. Due to their effects in improving the drug release profiles coupled with their intrinsic absorption-promoting properties, it is suggested that incorporation of 4% (w/w) Tween 20 and/or 25% (w/w) sodium salicylate in the composite polyethylene glycol chloroquine suppository formulations, may result in enhancement of rectal absorption of the drug. This necessitates an in vivo validation.

Development of a reservoir type prolonged release system with felodipine via simplex methodology

PubMed Central

IOVANOV, RAREŞ IULIU; TOMUŢĂ, IOAN; LEUCUŢA, SORIN EMILIAN

2016-01-01

Background and aims Felodipine is a dihydropyridine calcium antagonist that presents good characteristics to be formulated as prolonged release preparations. The aim of the study was the formulation and in vitro characterization of a reservoir type prolonged release system with felodipine, over a 12 hours period using the Simplex method. Methods The first step of the Simplex method was to study the influence of the granules coating method on the felodipine release. Furthermore the influence of the coating polymer type, the percent of the coating polymer and the percent of pore forming agent in the coating on the felodipine release were studied. Afterwards these two steps of the experimental design the percent of Surelease applied on the felodipine loaded granules and the percent of pore former in the polymeric coating formulation variables were studied. The in vitro dissolution of model drug was performed in phosphate buffer solution (pH 6.5) with 1% sodium lauryl sulfate. The released drug quantification was done using an HPLC method. The release kinetics of felodipine from the final granules was assessed using different mathematical models. Results A 12 hours release was achieved using granules with the size between 315–500 μm coated with 45% Surelease with different pore former ratios in the coating via the top-spray method. Conclusion We have prepared prolonged release coated granules with felodipine using a fluid bed system based on the Simplex method. The API from the studied final formulations was released over a 12 hours period and the release kinetics of the model drug substance from the optimized preparations fitted best the Higuchi and Peppas kinetic models. PMID:27004036

Use of Microsphere Technology for Targeted Delivery of Rifampin to Mycobacterium tuberculosis-Infected Macrophages

PubMed Central

Barrow, Esther L. W.; Winchester, Gary A.; Staas, Jay K.; Quenelle, Debra C.; Barrow, William W.

1998-01-01

Microsphere technology was used to develop formulations of rifampin for targeted delivery to host macrophages. These formulations were prepared by using biocompatible polymeric excipients of lactide and glycolide copolymers. Release characteristics were examined in vitro and also in two monocytic cell lines, the murine J774 and the human Mono Mac 6 cell lines. Bioassay assessment of cell culture supernatants from monocyte cell lines showed release of bioactive rifampin during a 7-day experimental period. Treatment of Mycobacterium tuberculosis H37Rv-infected monocyte cell lines with rifampin-loaded microspheres resulted in a significant decrease in numbers of CFU at 7 days following initial infection, even though only 8% of the microsphere-loaded rifampin was released. The levels of rifampin released from microsphere formulations within monocytes were more effective at reducing M. tuberculosis intracellular growth than equivalent doses of rifampin given as a free drug. These results demonstrate that rifampin-loaded microspheres can be formulated for effective sustained and targeted delivery to host macrophages. PMID:9756777

Application of hydroxyapatite nanoparticles in development of an enhanced formulation for delivering sustained release of triamcinolone acetonide

PubMed Central

Koocheki, Saeid; Madaeni, Sayed Siavash; Niroomandi, Parisa

2011-01-01

We report an analysis of in vitro and in vivo drug release from an in situ formulation consisting of triamcinolone acetonide (TR) and poly(d,l-lactide-co-glycolide) (PLGA) and the additives glycofurol (GL) and hydroxyapatite nanoparticles (HA). We found that these additives enhanced drug release rate. We used the Taguchi method to predict optimum formulation variables to minimize the initial burst. This method decreased the burst rate from 8% to 1.3%. PLGA-HA acted as a strong buffer, thereby preventing tissue inflammation at the injection site caused by the acidic degradation products of PLGA. Characterization of the optimized formulation by a variety of techniques, including scanning electron microscopy, X-ray diffraction, differential scanning calorimetry, and Fourier transform near infrared spectroscopy, revealed that the crystalline structure of TR was converted to an amorphous form. Therefore, this hydrophobic agent can serve as an additive to modify drug release rates. Data generated by in vitro and in vivo experiments were in good agreement. PMID:21589650

Exploitation of novel gum Prunus cerasoides as mucoadhesive beads for a controlled-release drug delivery.

PubMed

Seelan, T Veenus; Kumari, Henry Linda Jeeva; Kishore, Narra; Selvamani, Palanisamy; Lalhlenmawia, H; Thanzami, K; Pachuau, Lalduhsanga; Ruckmani, Kandasamy

2016-04-01

The present study deals with the formulation of pH-sensitive mucoadhesive beads using natural gum isolated from Prunus cerasoides (PC) in combination with sodium alginate (SA) for the controlled release of diclofenac sodium (DS). PC and SA composite (PC-SA), DS loaded SA (DS-SA) and DS loaded PC-SA (DS-PC-SA) beads were prepared by ionotropic gelation method. The absence of interaction between DS and PC-SA was shown by FTIR, DSC and TGA analyses. The optimized DS-PC-SA formulation exhibited mucoadhesive property and the controlled release of DS was achieved 68% in 12h. The in vitro release kinetics follows zero order with anomalous diffusion mechanism. Therefore, the formulated mucoadhesive beads with the novel gum are preferable for the controlled release of DS by prolonging the residence time of the drug in the gastrointestinal tract, overcoming the problems associated with the immediate release dosage forms of DS. Copyright © 2016 Elsevier B.V. All rights reserved.

Formulation, in vitro evaluation and kinetic analysis of chitosan-gelatin bilayer muco-adhesive buccal patches of insulin nanoparticles.

PubMed

Mahdizadeh Barzoki, Zahra; Emam-Djomeh, Zahra; Mortazavian, Elaheh; Akbar Moosavi-Movahedi, Ali; Rafiee Tehrani, M

2016-11-01

The present study was performed to optimise the formulation of a muco-adhesive buccal patch for insulin nanoparticles (NPs) delivery. Insulin NPs were synthesised by an ionic gelation technique using N-di methyl ethyl chitosan cysteine (DMEC-Cys) as permeation enhancer biopolymer, tripolyphosphate (TPP) and insulin. Buccal patches were developed by solvent-casting technique using chitosan and gelatine as muco-adhesive polymers. Optimised patches were embedded with 3 mg of insulin-loaded NPs with a homogeneous distribution of NPs in the muco-adhesive matrix, which displayed adequate physico-mechanical properties. The drug release characteristics, release mechanism and kinetics were investigated. Data fitting to Peppas equation with a correlation coefficient indicated that the mechanism of drug release followed an anomalous transport that means drug release was afforded through drug diffusion along with polymer erosion. In vitro drug release, release kinetics, physical and mechanical studies for all patch formulations reflected the ideal characteristics of this buccal patch for the delivery of insulin NPs.

Pharmacokinetic analysis of modified-release metoprolol formulations: An interspecies comparison.

PubMed

De Thaye, Elien; Vervaeck, Anouk; Marostica, Eleonora; Remon, Jean Paul; Van Bocxlaer, Jan; Vervaet, Chris; Vermeulen, An

2017-01-15

In the current study, we investigated the metoprolol absorption kinetics of an in-house produced oral sustained-release formulation, matrices manufactured via prilling, and two commercially available formulations, ZOK-ZID ® (reservoir) and Slow-Lopresor ® (matrix) in both New Zealand White rabbits and Beagle dogs, using a population pharmacokinetic analysis approach. The aim of this study was to compare the in vivo pharmacokinetic (PK) profiles of different formulations based on metoprolol, a selective adrenergic β 1 -receptor antagonist, in dogs and rabbits and to contrast the observed differences. To that end, metoprolol (50 to 200mg) was administered to 6 Beagle dogs and 6 New Zealand White rabbits as a single intravenous (IV) bolus injection and to 8 dogs and 6 rabbits as an oral modified release formulation. To derive pharmacokinetic parameters from the data, a non-linear mixed-effects model was developed using NONMEM ® where the contribution of observations below the limit of detection (BDL, below detection limit) to the parameter estimates was taken into account in the parameter estimation procedure. In both species and for the three modified release formulations, different absorption models were tested to describe the PK of metoprolol following oral dosing. In Beagle dogs, plasma concentration-time profiles were best described using a sequential zero- and first-order absorption model. In rabbits though, the absorption phase was best described using a first-order process only. In both species, the reservoir formulation ZOK-ZID ® was behaving quite similarly. In contrast, the absorption properties of both matrix formulations were rather different between species. This study indicates that the PK of the reservoir formulation is similar in both species, even after accounting for the almost completely missed absorption phase in rabbits. The insights gained further illustrate that rabbits are not very well suited to study the PK of the current matrix formulations in view of their less optimal prolonged release characteristics and the resulting fast decline in metoprolol plasma levels. Copyright © 2016 Elsevier B.V. All rights reserved.

Application of a biphasic test for characterization of in vitro drug release of immediate release formulations of celecoxib and its relevance to in vivo absorption.

PubMed

Shi, Yi; Gao, Ping; Gong, Yuchuan; Ping, Haili

2010-10-04

A biphasic in vitro test method was used to examine release profiles of a poorly soluble model drug, celecoxib (CEB), from its immediate release formulations. Three formulations of CEB were investigated in this study, including a commercial Celebrex capsule, a solution formulation (containing cosolvent and surfactant) and a supersaturatable self-emulsifying drug delivery system (S-SEDDS). The biphasic test system consisted of an aqueous buffer and a water-immiscible organic solvent (e.g., octanol) with the use of both USP II and IV apparatuses. The aqueous phase provided a nonsink dissolution medium for CEB, while the octanol phase acted as a sink for CEB partitioning. For comparison, CEB concentration-time profiles of these formulations in the aqueous medium under either a sink condition or a nonsink condition were also explored. CEB release profiles of these formulations observed in the aqueous medium from either the sink condition test, the nonsink condition test, or the biphasic test have little relevance to the pharmacokinetic observations (e.g., AUC, C(max)) in human subjects. In contrast, a rank order correlation among the three CEB formulations is obtained between the in vitro AUC values of CEB from the octanol phase up to t = 2 h and the in vivo mean AUC (or C(max)) values. As the biphasic test permits a rapid removal of drug from the aqueous phase by partitioning into the organic phase, the amount of drug in the organic phase represents the amount of drug accumulated in systemic circulation in vivo. This hypothesis provides the scientific rationale for the rank order relationship among these CEB formulations between their CEB concentrations in the organic phase and the relative AUC or C(max). In addition, the biphasic test method permits differentiation and discrimination of key attributes among the three different CEB formulations. This work demonstrates that the biphasic in vitro test method appears to be useful as a tool in evaluating performance of formulations of poorly water-soluble drugs and to provide potential for establishing an in vitro-in vivo relationship.

New developments in the management of narcolepsy.

PubMed

Abad, Vivien C; Guilleminault, Christian

2017-01-01

Narcolepsy is a life-long, underrecognized sleep disorder that affects 0.02%-0.18% of the US and Western European populations. Genetic predisposition is suspected because of narcolepsy's strong association with HLA DQB1*06-02, and genome-wide association studies have identified polymorphisms in T-cell receptor loci. Narcolepsy pathophysiology is linked to loss of signaling by hypocretin-producing neurons; an autoimmune etiology possibly triggered by some environmental agent may precipitate hypocretin neuronal loss. Current treatment modalities alleviate the main symptoms of excessive daytime somnolence (EDS) and cataplexy and, to a lesser extent, reduce nocturnal sleep disruption, hypnagogic hallucinations, and sleep paralysis. Sodium oxybate (SXB), a sodium salt of γ hydroxybutyric acid, is a first-line agent for cataplexy and EDS and may help sleep disruption, hypnagogic hallucinations, and sleep paralysis. Various antidepressant medications including norepinephrine serotonin reuptake inhibitors, selective serotonin reuptake inhibitors, and tricyclic antidepressants are second-line agents for treating cataplexy. In addition to SXB, modafinil and armodafinil are first-line agents to treat EDS. Second-line agents for EDS are stimulants such as methylphenidate and extended-release amphetamines. Emerging therapies include non-hypocretin-based therapy, hypocretin-based treatments, and immunotherapy to prevent hypocretin neuronal death. Non-hypocretin-based novel treatments for narcolepsy include pitolisant (BF2.649, tiprolisant); JZP-110 (ADX-N05) for EDS in adults; JZP 13-005 for children; JZP-386, a deuterated sodium oxybate oral suspension; FT 218 an extended-release formulation of SXB; and JNJ-17216498, a new formulation of modafinil. Clinical trials are investigating efficacy and safety of SXB, modafinil, and armodafinil in children. γ-amino butyric acid (GABA) modulation with GABA A receptor agonists clarithromycin and flumazenil may help daytime somnolence. Other drugs investigated include GABA B agonists (baclofen), melanin-concentrating hormone antagonist, and thyrotropin-releasing hormone agonists. Hypocretin-based therapies include hypocretin peptide replacement administered either through an intracerebroventricular route or intranasal route. Hypocretin neuronal transplant and transforming stem cells into hypothalamic neurons are also discussed in this article. Immunotherapy to prevent hypocretin neuronal death is reviewed.

New developments in the management of narcolepsy

PubMed Central

Abad, Vivien C; Guilleminault, Christian

2017-01-01

Narcolepsy is a life-long, underrecognized sleep disorder that affects 0.02%–0.18% of the US and Western European populations. Genetic predisposition is suspected because of narcolepsy’s strong association with HLA DQB1*06-02, and genome-wide association studies have identified polymorphisms in T-cell receptor loci. Narcolepsy pathophysiology is linked to loss of signaling by hypocretin-producing neurons; an autoimmune etiology possibly triggered by some environmental agent may precipitate hypocretin neuronal loss. Current treatment modalities alleviate the main symptoms of excessive daytime somnolence (EDS) and cataplexy and, to a lesser extent, reduce nocturnal sleep disruption, hypnagogic hallucinations, and sleep paralysis. Sodium oxybate (SXB), a sodium salt of γ hydroxybutyric acid, is a first-line agent for cataplexy and EDS and may help sleep disruption, hypnagogic hallucinations, and sleep paralysis. Various antidepressant medications including norepinephrine serotonin reuptake inhibitors, selective serotonin reuptake inhibitors, and tricyclic antidepressants are second-line agents for treating cataplexy. In addition to SXB, modafinil and armodafinil are first-line agents to treat EDS. Second-line agents for EDS are stimulants such as methylphenidate and extended-release amphetamines. Emerging therapies include non-hypocretin-based therapy, hypocretin-based treatments, and immunotherapy to prevent hypocretin neuronal death. Non-hypocretin-based novel treatments for narcolepsy include pitolisant (BF2.649, tiprolisant); JZP-110 (ADX-N05) for EDS in adults; JZP 13-005 for children; JZP-386, a deuterated sodium oxybate oral suspension; FT 218 an extended-release formulation of SXB; and JNJ-17216498, a new formulation of modafinil. Clinical trials are investigating efficacy and safety of SXB, modafinil, and armodafinil in children. γ-amino butyric acid (GABA) modulation with GABAA receptor agonists clarithromycin and flumazenil may help daytime somnolence. Other drugs investigated include GABAB agonists (baclofen), melanin-concentrating hormone antagonist, and thyrotropin-releasing hormone agonists. Hypocretin-based therapies include hypocretin peptide replacement administered either through an intracerebroventricular route or intranasal route. Hypocretin neuronal transplant and transforming stem cells into hypothalamic neurons are also discussed in this article. Immunotherapy to prevent hypocretin neuronal death is reviewed. PMID:28424564

Injectable, in situ forming poly(propylene fumarate)-based ocular drug delivery systems.

PubMed

Ueda, H; Hacker, M C; Haesslein, A; Jo, S; Ammon, D M; Borazjani, R N; Kunzler, J F; Salamone, J C; Mikos, A G

2007-12-01

This study sought to develop an injectable formulation for long-term ocular delivery of fluocinolone acetonide (FA) by dissolving the anti-inflammatory drug and the biodegradable polymer poly(propylene fumarate) (PPF) in the biocompatible, water-miscible, organic solvent N-methyl-2-pyrrolidone (NMP). Upon injection of the solution into an aqueous environment, a FA-loaded PPF matrix is precipitated in situ through the diffusion/extraction of NMP into surrounding aqueous fluids. Fabrication of the matrices and in vitro release studies were performed in phosphate buffered saline at 37 degrees C. Drug loadings up to 5% were achieved. High performance liquid chromatography was employed to determine the released amount of FA. The effects of drug loading, PPF content of the injectable formulation, and additional photo-crosslinking of the matrix surface were investigated. Overall, FA release was sustained in vitro over up to 400 days. After an initial burst release of 22 to 68% of initial FA loading, controlled drug release driven by diffusion and bulk erosion was observed. Drug release rates in a therapeutic range were demonstrated. Release kinetics were found to be dependent on drug loading, formulation PPF content, and extent of surface crosslinking. The results suggest that injectable, in situ formed PPF matrices are promising candidates for the formulation of long-term, controlled delivery devices for intraocular drug delivery. Copyright 2007 Wiley Periodicals, Inc.

Gamma scintigraphic study of the hydrodynamically balanced matrix tablets of Metformin HCl in rabbits

PubMed Central

Razavi, Mahboubeh; Karimian, Hamed; Yeong, Chai Hong; Sarji, Sazilah Ahmad; Chung, Lip Yong; Nyamathulla, Shaik; Noordin, Mohamed Ibrahim

2015-01-01

The purpose of this study is to evaluate the in vitro and in vivo performance of gastro-retentive matrix tablets having Metformin HCl as model drug and combination of natural polymers. A total of 16 formulations were prepared by a wet granulation method using xanthan, tamarind seed powder, tamarind kernel powder and salep as the gel-forming agents and sodium bicarbonate as a gas-forming agent. All the formulations were evaluated for compendial and non-compendial tests and in vitro study was carried out on a USP-II dissolution apparatus at a paddle speed of 50 rpm. MOX2 formulation, composed of salep and xanthan in the ratio of 4:1 with 96.9% release, was considered as the optimum formulation with more than 90% release in 12 hours and short floating lag time. In vivo study was carried out using gamma scintigraphy in New Zealand White rabbits, optimized formulation was incorporated with 10 mg of 153Sm for labeling MOX2 formulation. The radioactive samarium oxide was used as the marker to trace transit of the tablets in the gastrointestinal tract. The in vivo data also supported retention of MOX2 formulation in the gastric region for 12 hours and were different from the control formulation without a gas and gel forming agent. It was concluded that the prepared floating gastro-retentive matrix tablets had a sustained-release effect in vitro and in vivo, gamma scintigraphy played an important role in locating the oral transit and the drug-release pattern. PMID:26124637

Formulation, functional evaluation and ex vivo performance of thermoresponsive soluble gels - A platform for therapeutic delivery to mucosal sinus tissue.

PubMed

Pandey, Preeti; Cabot, Peter J; Wallwork, Benjamin; Panizza, Benedict J; Parekh, Harendra S

2017-01-01

Mucoadhesive in situ gelling systems (soluble gels) have received considerable attention recently as effective stimuli-transforming vectors for a range of drug delivery applications. Considering this fact, the present work involves systematic formulation development, optimization, functional evaluation and ex vivo performance of thermosensitive soluble gels containing dexamethasone 21-phosphate disodium salt (DXN) as the model therapeutic. A series of in situ gel-forming systems comprising the thermoreversible polymer poloxamer-407 (P407), along with hydroxypropyl methyl cellulose (HPMC) and chitosan were first formulated. The optimized soluble gels were evaluated for their potential to promote greater retention at the mucosal surface, for improved therapeutic efficacy, compared to existing solution/suspension-based steroid formulations used clinically. Optimized soluble gels demonstrated a desirable gelation temperature with Newtonian fluid behaviour observed under storage conditions (4-8°C), and pseudoplastic fluid behaviour recorded at nasal cavity/sinus temperature (≈34°C). The in vitro characterization of formulations including rheological evaluation, textural analysis and mucoadhesion studies of the gel form were investigated. Considerable improvement in mechanical properties and mucoadhesion was observed with incorporation of HPMC and chitosan into the gelling systems. The lead poloxamer-based soluble gels, PGHC4 and PGHC7, which were carried through to ex vivo permeation studies displayed extended drug release profiles in conditions mimicking the human nasal cavity, which indicates their suitability for treating a range of conditions affecting the nasal cavity/sinuses. Copyright © 2016 Elsevier B.V. All rights reserved.

Design and in vitro/in vivo evaluation of sustained-release floating tablets of itopride hydrochloride

PubMed Central

Ahmed, Sayed M; Ahmed Ali, Adel; Ali, Ahmed MA; Hassan, Omiya A

2016-01-01

Purpose The aim of the present study was to improve the bioavailability of itopride (ITO) and sustain its action by formulating as a floating dosage form. Materials and methods Sustained-release floating tablets of ITO hydrochloride (HCl) were prepared by direct compression using different hydrocolloid polymers such as hydroxypropyl methylcellulose and ethylcellulose and/or methacrylic acid polymers Eudragit RSPM and Carbopol 934P. The floating property was achieved using an effervescent mixture of sodium bicarbonate and anhydrous citric acid (1:1 mol/mol). Hardness, friability, content uniformity, and dissolution rate of the prepared floating tablets were evaluated. The formulation F10 composed of 28.5% Eudragit RSPM, 3% NaHCO3, and 7% citric acid provided sustained drug release. Results In vitro results showed sustained release of F10 where the drug release percentage was 96.51%±1.75% after 24 hours (P=0.031). The pharmacokinetic results indicated that the area under the curve (AUC0–∞) of the prepared sustained-release floating tablets at infinity achieved 93.69 µg·h/mL compared to 49.89 µg·h/mL for the reference formulation (Ganaton®) and the relative bioavailability of the sustained-release formulation F10 increased to 187.80% (P=0.022). Conclusion The prepared floating tablets of ITO HCl (F10) could be a promising drug delivery system with sustained-release action and enhanced drug bioavailability. PMID:28008229

Controlled release of insect sex pheromones from paraffin wax and emulsions.

PubMed

Atterholt, C A; Delwiche, M J; Rice, R E; Krochta, J M

1999-02-22

Paraffin wax and aqueous paraffin emulsions can be used as controlled release carriers for insect sex pheromones for mating disruption of orchard pests. Paraffin can be applied at ambient temperature as an aqueous emulsion, adheres to tree bark or foliage, releases pheromone for an extended period of time, and will slowly erode from bark and biodegrade in soil. Pheromone emulsions can be applied with simple spray equipment. Pheromone release-rates from paraffin were measured in laboratory flow-cell experiments. Pheromone was trapped from an air stream with an adsorbent, eluted periodically, and quantified by gas chromatography. Pheromone release from paraffin was partition-controlled, providing a constant (zero-order) release rate. A typical paraffin emulsion consisted of 30% paraffin, 4% pheromone, 4% soy oil, 1% vitamin E, 2% emulsifier, and the balance water. Soy oil and vitamin E acted as volatility suppressants. A constant release of oriental fruit moth pheromone from paraffin emulsions was observed in the laboratory for more than 100 days at 27 degreesC, with release-rates ranging from 0.4 to 2 mg/day, depending on the concentration and surface area of the dried emulsion. The use of paraffin emulsions is a viable method for direct application of insect pheromones for mating disruption. Sprayable formulations can be designed to release insect pheromones to the environment at a rate necessary for insect control by mating disruption. At temperatures below 38 degreesC, zero-order release was observed. At 38 degreesC and higher, pheromone oxidation occurred. A partition-controlled release mechanism was supported by a zero-order pheromone release-rate, low air/wax partition coefficients, and pheromone solubility in paraffin.

Preparation and evaluation of novel metronidazole sustained release and floating matrix tablets.

PubMed

Asnaashari, Solmaz; Khoei, Nazaninossadat Seyed; Zarrintan, Mohammad Hosein; Adibkia, Khosro; Javadzadeh, Yousef

2011-08-01

In the present study, metronidazole was used for preparing floating dosage forms that are designed to retain in the stomach for a long time and have developed as a drug delivery system for better eradication of Helicobacter Pylori in peptic ulcer diseases. For this means, various formulations were designed using multi-factorial design. HPMC, psyllium and carbopol in different concentrations were used as floating agents, and sodium bicarbonate was added as a gas-forming agent. Hardness, friability, drug loading, floating ability and release profiles as well as kinetics of release were assessed. Formulations containing HPMC as filler showed prolonged lag times for buoyancy. Adding psyllium to these formulations had reduced relative lag times. Overall, selected formulations were able to float immediately and showed buoyancy for at least 8?h. Meanwhile, sustained profiles of drug release were also obtained. Kinetically, among the 10 assessed models, the release pattern of metronidazole from the tablets fitted best to Power law, Weibull and Higuchi models in respect overall to mean percentage error values of 3.8, 4.73 and 5.77, respectively, for calcium carbonate-based tablets and, 2.95, 6.39 and 3.9, respectively, for calcium silicate-based tablets. In general, these systems can float in the gastric condition and control the drug release from the tablets.

Laser-induced disruption of systemically administered liposomes for targeted drug delivery

NASA Astrophysics Data System (ADS)

Mackanos, Mark A.; Larabi, Malika; Shinde, Rajesh; Simanovskii, Dmitrii M.; Guccione, Samira; Contag, Christopher H.

2009-07-01

Liposomal formulations of drugs have been shown to enhance drug efficacy by prolonging circulation time, increasing local concentration and reducing off-target effects. Controlled release from these formulations would increase their utility, and hyperthermia has been explored as a stimulus for targeted delivery of encapsulated drugs. Use of lasers as a thermal source could provide improved control over the release of the drug from the liposomes with minimal collateral tissue damage. Appropriate methods for assessing local release after systemic delivery would aid in testing and development of better formulations. We use in vivo bioluminescence imaging to investigate the spatiotemporal distribution of luciferin, used as a model small molecule, and demonstrate laser-induced release from liposomes in animal models after systemic delivery. These liposomes were tested for luciferin release between 37 and 45 °C in PBS and serum using bioluminescence measurements. In vivo studies were performed on transgenic reporter mice that express luciferase constitutively throughout the body, thus providing a noninvasive readout for controlled release following systemic delivery. An Nd:YLF laser was used (527 nm) to heat tissues and induce rupture of the intravenously delivered liposomes in target tissues. These data demonstrate laser-mediated control of small molecule delivery using thermally sensitive liposomal formulations.

Repaglinide-loaded solid lipid nanoparticles: effect of using different surfactants/stabilizers on physicochemical properties of nanoparticles.

PubMed

Ebrahimi, Hossein Ali; Javadzadeh, Yousef; Hamidi, Mehrdad; Jalali, Mohammad Barzegar

2015-09-21

Repaglinide is an efficient anti-diabetic drug which is prescribed widely as multi-dosage oral daily regimens. Due to the low compliance inherent to each multi-dosage regimen, development of prolonged-release formulations could enhance the overall drug efficacy in patient populations. Repaglinide-loaded solid lipid nanoparticles (SLNs) were developed and characterized in vitro. Various surfactants were used in this study during the nanocarrier preparation procedure and their corresponding effects on some physicochemical properties of SLNs such as size, zeta potential; drug loading parameters and drug release profiles was investigated. Stearic acid and glyceryl mono stearate (GMS) were used as lipid phase and phosphatidylcholin, Tween80, Pluronic F127, poly vinyl alcohol (PVA) and polyvinyl pyrrolidone (PVP) were used as surfactant/stabilizer. The results showed some variations between formulations; where the Tween80-based SLNs showed smallest size, the phosphatidylcholin-based SLNs indicated most prolonged drug release time and the highest loading capacity. SEM images of these formulations showed morphological variations and also confirmed the nanoscale size of these particles. The FTIR and DSC results demonstrated no interaction between drug and excipients. The invitro release profiles of different formulations were studied and observed slow release of drug from all formulations. However significant differences were found among them in terms of their initial burst release as well as the whole drug release profile. From fitting these data to various statistical models, the Peppas model was proposed as the best model to describe the statistical indices and, therefore, mechanism of drug release. The results of this study confirmed the effect of surfactant type on SLNs physicochemical properties such as morphological features, loading parameters, particle sizes and drug release kinetic. With respect to the outcome data, the mixture of phosphatidylcholin/Pluronic F127 was selected as the best surfactant/stabilizer to coat the lipid core comprising stearic acid and GMS.

Effect of gellan gum on the thermogelation property and drug release profile of Poloxamer 407 based ophthalmic formulation.

PubMed

Dewan, Mitali; Sarkar, Gunjan; Bhowmik, Manas; Das, Beauty; Chattoapadhyay, Atis Kumar; Rana, Dipak; Chattopadhyay, Dipankar

2017-09-01

The effect of gellan gum on the gelation behavior and in-vitro release of a specific drug named pilocarpine hydrochloride from different ophthalmic formulations based on poloxamer 407 is examined. The mixture of 0.3wt% gellan gum and 18wt% poloxamer (PM) solutions show a considerable increase in gel strength in physiological condition. Gel dissolution rate from PM based formulation is significantly decreased due to the addition of gellan gum. FTIR spectra analysis witnesses an interaction in between OH groups of two polymers which accounts for lowering in gelation temperature of PM-gellan gum based formulations. It is also observed from the cryo-SEM study that the pore size of PM gel decreases with an addition of gellan gum and in-vitro release studies indicate that PM-gellan gum based formulation retain drug better than the PM solution alone. Therefore, the developed formulation has the potential to be utilized as an in-situ ophthalmic drug carrier. Copyright © 2017 Elsevier B.V. All rights reserved.

Long-Acting Phospholipid Gel of Exenatide for Long-Term Therapy of Type II Diabetes.

PubMed

Hu, Mei; Zhang, Yu; Xiang, Nanxi; Zhong, Ying; Gong, Tao; Zhang, Zhi-Rong; Fu, Yao

2016-06-01

This study aimed to develop a sustained-release formulation of exenatide (EXT) for the long-term therapeutic efficacy in the treatment of type II diabetes. In this study, we present an injectable phospholipid gel by mixing biocompatible phospholipid S100, medium chain triglyceride (MCT) with 85% (w/w) ethanol. A systemic pre-formulation study has been carried out to improve the stability of EXT during formulation fabrication. With the optimized formulation, the pharmacokinetic profiles in rats were studied and two diabetic animal models were employed to evaluate the therapeutic effect of EXT phospholipid gel via a single subcutaneous injection versus repeated injections of normal saline and EXT solution. With optimized formulation, sustained release of exenatide in vivo for over three consecutive weeks was observed after one single subcutaneous injection. Moreover, the pharmacodynamic study in two diabetic models justified that the gel formulation displayed a comparable hypoglycemic effect and controlled blood glucose level compared with exenatide solution treated group. EXT-loaded phospholipid gel represents a promising controlled release system for long-term therapy of type II diabetes.

Long-term safety and efficacy of budesonide in the treatment of ulcerative colitis

PubMed Central

Iborra, Marisa; Álvarez-Sotomayor, Diego; Nos, Pilar

2014-01-01

Ulcerative colitis (UC) is a chronic, relapsing, and remitting inflammatory disease involving the large intestine (colon). Treatment seeks to break recurrent inflammation episodes by inducing and maintaining remission. Historically, oral systemic corticosteroids played an important role in inducing remission of this chronic disease; however, their long-term use is limited and can lead to adverse events. Budesonide is a synthetic steroid with potent local anti-inflammatory effects and low systemic bioavailability due to high first-pass hepatic metabolism. Several studies have demonstrated oral budesonide’s usefulness in treating active mild to moderate ileocecal Crohn’s disease and microscopic colitis and in an enema formulation for left sided UC. However, there is limited information regarding oral budesonide’s efficacy in UC. A novel oral budesonide formulation using a multimatrix system (budesonide-MMX) to extend drug release throughout the colon has been developed recently and seems to be an effective treatment in active left sided UC patients. This article summarizes budesonide’s long-term safety and efficacy in treating UC. PMID:24523594

Efficacy of tebuconazole embedded in biodegradable poly-3-hydroxybutyrate to inhibit the development of Fusarium moniliforme in soil microecosystems.

PubMed

Volova, Tatiana G; Prudnikova, Svetlana V; Zhila, Natalia O; Vinogradova, Olga N; Shumilova, Anna A; Nikolaeva, Elena D; Kiselev, Evgeniy G; Shishatskaya, Ekaterina I

2017-05-01

An important line of research is the development of a new generation of formulations with targeted and controlled release of the pesticide, using matrices made from biodegradable materials. In this study, slow-release formulations of the fungicide tebuconazole (TEB) have been prepared by embedding it into the matrix of poly-3-hydroxybutyrate (P3HB) in the form of films, microgranules and pellets. The average rates of P3HB degradation were determined by the geometry of the formulation, reaching, for 63 days, 0.095-0.116, 0.081-0.083 and 0.030-0.055 mg day -1 for films, microgranules and pellets respectively. The fungicidal activity of P3HB/TEB against the plant pathogen Fusarium moniliforme was compared with that of the commercial formulation Raxil Ultra. A pronounced fungicidal effect of the experimental P3HB/TEB formulations was observed in 2-4 weeks after application, and it was retained for 8 weeks, without affecting significantly the development of soil aboriginal microflora. TEB release can be regulated by the process employed to fabricate the formulation and the fungicide loading, and the TEB accumulates in the soil gradually, as the polymer is degraded. The experimental forms of TEB embedded in the slowly degraded P3HB can be used as a basis for developing slow-release fungicide formulations. © 2016 Society of Chemical Industry. © 2016 Society of Chemical Industry.

Assessing the influence of media composition and ionic strength on drug release from commercial immediate-release and enteric-coated aspirin tablets.

PubMed

Karkossa, Frank; Klein, Sandra

2017-10-01

The objective of this test series was to elucidate the importance of selecting the right media composition for a biopredictive in-vitro dissolution screening of enteric-coated dosage forms. Drug release from immediate-release (IR) and enteric-coated (EC) aspirin formulations was assessed in phosphate-based and bicarbonate-based media with different pH, electrolyte composition and ionic strength. Drug release from aspirin IR tablets was unaffected by media composition. In contrast, drug release from EC aspirin formulations was affected by buffer species and ionic strength. In all media, drug release increased with increasing ionic strength, but in bicarbonate-based buffers was delayed when compared with that in phosphate-based buffers. Interestingly, the cation species in the dissolution medium had also a clear impact on drug release. Drug release profiles obtained in Blank CarbSIF, a new medium simulating pH and average ionic composition of small intestinal fluid, were different from those obtained in all other buffer compositions studied. Results from this study in which the impact of various media parameters on drug release of EC aspirin formulations was systematically screened clearly show that when developing predictive dissolution tests, it is important to simulate the ionic composition of intraluminal fluids as closely as possible. © 2017 Royal Pharmaceutical Society.

Formulation of unidirectional release buccal patches of carbamazepine and study of permeation through porcine buccal mucosa

PubMed Central

Govindasamy, Parthasarathy; Kesavan, Bhaskar Reddy; Narasimha, Jayaveera Korlakunta

2013-01-01

Objective To achieve transbuccal release of carbamazepine by loading in unidirectional release mucoadhesive buccal patches. Methods Buccal patches of carbamazepine with unidirectional drug release were prepared using hydroxypropyl methyl cellulose, polyvinyl alcohol, polyvinyl pyrrolidone and ethyl cellulose by solvent casting method. Water impermeable backing layer (Pidilite® Biaxially-oriented polypropylene film) of patches provided unidirectional drug release. They were evaluated for thickness, mass uniformity, surface pH and folding endurance. Six formulations FA2, FA8, FA10, FB1, FB14 and FB16 (folding endurance above 250) were evaluated further for swelling studies, ex vivo mucoadhesive strength, ex vivo mucoadhesion time, in vitro drug release, ex vivo permeation, accelerated stability studies and FTIR and XRD spectral studies. Results The ex vivo mucoadhesion time of patches ranged between 109 min (FA10) to 126 min (FB14). The ex vivo mucoadhesive force was in the range of 0.278 to 0.479 kg/m/s. The in vitro drug release studies revealed that formulation FA8 released 84% and FB16 released 99.01% of drug in 140 min. Conclusions The prepared unidirectional buccal patches of carbamazepine provided a maximum drug release within specified mucoadhesion period and it indicates a potential alternative drug delivery system for systemic delivery of carbamazepine. PMID:24093793

Local sustained delivery of bupivacaine HCl from a new castor oil-based nanoemulsion system.

PubMed

Rachmawati, Heni; Arvin, Yang Aryani; Asyarie, Sukmadjaja; Anggadiredja, Kusnandar; Tjandrawinata, Raymond Rubianto; Storm, Gert

2018-06-01

Bupivacaine HCl (1-butyl-2',6'-pipecoloxylidide hydrochloride), an amide local anesthetic compound, is a local anesthetic drug utilized for intraoperative local anesthesia, post-operative analgesia and in the treatment of chronic pain. However, its utility is limited by the relative short duration of analgesia after local administration (approximately 9 h after direct injection) and risk for side effects. This work is aimed to develop a nanoemulsion of bupivacaine HCl with sustained local anesthetics release kinetics for improved pain management, by exhibiting extended analgesic action and providing reduced peak levels in the circulation to minimize side effects. Herein, biodegradable oils were evaluated for use in nanoemulsions to enable sustained release kinetics of bupivacaine HCl. Only with castor oil, a clear and stable nanoemulsion was obtained without the occurrence of phase separation over a period of 3 months. High loading of bupivacaine HCl into the castor oil-based nanoemulsion system was achieved with about 98% entrapment efficiency and the resulting formulation showed high stability under stress conditions (accelerated stability test) regarding changes in visual appearance, drug content, and droplet size. We show herein that the in vitro release and in vivo pharmacokinetic profiles as well as pharmacodynamic outcome (pain relief test) after subcutaneous administration in rats correlate well and clearly demonstrate the prolonged release and extended duration of activity of our novel nanoformulation. In addition, the lower C max value achieved in the blood compartment suggests the possibility that the risk for systemic side effects is reduced. We conclude that castor oil-based nanomulsion represents an attractive pain treatment possibility to achieve prolonged local action of bupivacaine HCl.

Bioadhesive hydrogels for cosmetic applications.

PubMed

Parente, M E; Ochoa Andrade, A; Ares, G; Russo, F; Jiménez-Kairuz, Á

2015-10-01

The use of bioadhesive hydrogels for skin care presents important advantages such as long residence times on the application site and reduced product administration frequency. The aim of the present work was to develop bioadhesive hydrogels for skin application, using caffeine as a model active ingredient. Eight hydrogels were formulated using binary combinations of a primary polymer (carbomer homopolymer type C (Carbopol(®) 980) or kappa carrageenan potassium salt (Gelcarin(®) GP-812 NF)) and a secondary polymer (carbomer copolymer type B (Pemulen(™) TR-1), xanthan gum or guar gum). Hydrogels were characterized by means of physico-chemical (dynamic rheological measurements, spreadability and adhesion measurements) and sensory methods (projective mapping in combination with a check-all-that-apply (CATA) question). Caffeine hydrogels were formulated using two of the most promising formulations regarding adhesion properties and sensory characteristics. In vitro active ingredient release studies were carried out. Hydrogel formulations showed a prevalently elastic rheological behaviour. Complex viscosity of carbomer homopolymer type C hydrogels was higher than that of the kappa carrageenan hydrogels. Besides, complex viscosity values were dependent on the secondary polymer present in the formulation. Significant differences among hydrogels were found in detachment force, work of adhesion and spreading diameter results. Association of projective mapping with CATA allowed to determine similarities and dissimilarities among samples. Cluster analysis associated the samples in two groups. Two hydrogels were selected to study the release of caffeine. Both hydrogels presented similar release profiles which were well described by the Higuchi model. Caffeine release was exclusively controlled by a diffusive process. Physico-chemical and sensory techniques enabled the identification of bioadhesive hydrogel formulations with positive characteristics for cosmetic applications. Formulations which combined carbomer homopolymer type C with xanthan gum or with carbomer copolymer type B were the most promising for bioadhesive skin products. Caffeine release profiles of selected formulations were not statistically different. Both hydrogels gradually released the active ingredient, reaching approximately 80% within the first 5 h, and their profiles were well described by the Higuchi model. In this context, it could be concluded that the selected hydrogels are suitable bioadhesive hydrogel formulations for cosmetic application on the skin. © 2015 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Formulation and evaluation of controlled release matrix mucoadhesive tablets of domperidone using Salvia plebeian gum

PubMed Central

Arora, Gurpreet; Malik, Karan; Singh, Inderbir; Arora, Sandeep; Rana, Vikas

2011-01-01

The aim of study was to prepare controlled release matrix mucoadhesive tablets of domperidone using Salvia plebeian gum as natural polymer. Tablets were formulated by direct compression technology employing the natural polymer in different concentrations (5, 10, 15 and 20% w/w). The prepared batches were evaluated for drug assay, diameter, thickness, hardness and tensile strength, swelling index, mucoadhesive strength (using texture analyzer) and subjected to in vitro drug release studies. Real-time stability studies were also conducted on prepared batches. In vitro drug release data were fitted in various release kinetic models for studying the mechanism of drug release. Tensile strength was found to increase from 0.808 ± 0.098 to 1.527 ± 0.10 mN/cm2 and mucoadhesive strength increased from 13.673 ± 1.542 to 40.378 ± 2.345 N, with an increase in the polymer concentration from 5 to 20% (A1 to A4). Swelling index was reported to increase with both increase in the concentration of gum and the time duration. The in vitro drug release decreased from 97.76 to 83.4% (A1 to A4) with the increase in polymer concentration. The drug release from the matrix tablets was found to follow zero-order and Higuchi models, indicating the matrix-forming potential of natural polymer. The value of n was found to be between 0.5221 and 0.8992, indicating the involvement of more than one drug release mechanism from the formulation and possibly the combination of both diffusion and erosion. These research findings clearly indicate the potential of S. plebeian gum to be used as binder, release retardant and mucoadhesive natural material in tablet formulations. PMID:22171313

Formulation and in vitro evaluation of Hydrodynamically balanced system for theophylline delivery.

PubMed

Nayak, Amit Kumar; Malakar, Jadupati

2011-06-01

The objective of the present study was to formulate hydrodynamically balanced systems (HBSs) of theophylline as single unit capsules. They were formulated by physical blending of theophylline with hydroxypropyl methyl cellulose, polyethylene oxide, polyvinyl pyrrolidone, ethyl cellulose, liquid paraffin, and lactose in different ratios. These theophylline HBS capsules were evaluated for weight uniformity, drug content uniformity, in vitro floating behavior and drug release in simulated gastric fluids (pH 1.2). All these formulated HBS capsules containing theophylline were floated well over 6 hours with no floating lag time, and also showed sustained in vitro drug release in simulated gastric fluid over 6 hours. The theophylline release from these capsules was more sustained with the addition of release modifiers (ethyl cellulose and liquid paraffin). The drug release pattern from these capsules was correlated well with first order model (F-1 to F-5) and Korsmeyer-Peppas model (F-6 and F-7) with the non-Fickian (anomalous) diffusion mechanism. These experimental results clearly indicated that these theophylline HBS capsules were able to remain buoyant in the gastric juice for longer period, which may improve oral bioavailability of theophylline.

Extended-release, once-daily morphine (Avinza) for the treatment of chronic nonmalignant pain: effect on pain, depressive symptoms, and cognition.

PubMed

Panjabi, Sumeet S; Panjabi, Ravi S; Shepherd, Marvin D; Lawson, Kenneth A; Johnsrud, Michael; Barner, Jamie

2008-11-01

To evaluate the impact of an extended-release, once-daily morphine sulfate formulation on depressive symptoms and neurocognition in patients with chronic nonmalignant pain. Prospective, open-label, one-group trial with a pretest-posttest design. Outpatient pain management clinic. Chronic nonmalignant pain patients inadequately controlled with short-acting opioid analgesics and eligible for treatment with once-daily morphine sulfate were initiated on a dose at or near the morphine-equivalent dose of the short-acting regimen. The following assessments were made at baseline and 4 weeks after initiating intervention: pain intensity, pain unpleasantness, pain suffering, pain behaviors, Beck Depression Inventory, and cognitive function. Eighty-four patients provided usable data. Pain intensity, unpleasantness, and suffering scores were significantly reduced at follow-up (P = 0.001). The mean Beck Depression Inventory scores were significantly lower at follow-up (P = 0.001). Significant improvements were seen in scores at follow-up on the three validated neurocognitive tests: the digit span test, the digit symbol substitution test, and the paced auditory serial addition test (P = 0.001). Achieving adequate pain control with once-daily morphine was associated with a reduction in pain and improvements in depressive symptoms and cognitive functioning in the short term.

Optimization of novel pentablock copolymer based composite formulation for sustained delivery of peptide/protein in the treatment of ocular diseases

PubMed Central

Patel, Sulabh P.; Vaishya, Ravi; Patel, Ashaben; Agrahari, Vibhuti; Pal, Dhananjay; Mitra, Ashim K.

2016-01-01

This manuscript is focused on the development of pentablock (PB) copolymer based sustained release formulation for the treatment of posterior segment ocular diseases. We have successfully synthesized biodegradable and biocompatible PB copolymers for the preparation of nanoparticles (NPs) and thermosensitive gel. Achieving high drug loading with hydrophilic biotherapeutics (peptides /proteins) is a challenging task. Moreover, small intravitreal injection volume (≤100 μL) requires high loading to develop a long term (6 months) sustained release formulation. We have successfully investigated various formulation parameters to achieve maximum peptide/protein (octreotide, insulin, lysozyme, IgG-Fab, IgG, and catalase) loading in PB NPs. Improvement in drug loading can facilitate delivery of larger doses of therapeutic proteins via limited injection volume. A composite formulation comprised of NPs in gel system exhibited sustained release (without burst effect) of peptides and proteins, may serve as a platform technology for the treatment of posterior segment ocular diseases. PMID:26964498

The effect of additives on release and in vitro skin retention of flavonoids from emulsion and gel semisolid formulations.

PubMed

Dyja, R; Jankowski, A

2017-08-01

To assess the effect of two different additives (propylene glycol (PG) and polyethylene glycol 400 (PEG 400)) on release and in vitro skin retention of quercetin and chrysin from semisolid bases (amphiphilic creams and acidic carbomer gels). For obtaining semisolid formulations, flavonoids were pre-dissolved in the liquid (PG or PEG 400) or directly suspended in the semisolid base. Three chrysin formulations ('cream 0', 'PG-cream' and 'PEG 400-cream') and five quercetin formulations ('cream 0', 'PG cream', 'PEG 400 cream', 'gel 0' and 'PG gel') were prepared. The release studies were carried out in Franz diffusion cells by means of a cellulose membrane. The porcine ear skin was used in in vitro skin retention studies. The dissolution was a prerequisite to increase the release rates of tested flavonoids from obtained semisolid formulations. The cumulative amount of chrysin released after 6 h from 'PEG 400 cream' containing partly dissolved form of that flavonoid was higher than that from 'cream 0' or 'PG cream' containing its suspended form. The formulations containing quercetin dissolved in PG ('PG cream', 'PG gel') or PEG 400 ('PEG 400 cream') exhibited higher release rates of that flavonoid than corresponding semisolid suspensions ('cream 0' or 'gel 0'). The effects of both liquid additives (PG and PEG 400) on the cumulative amount of quercetin released after 6 h were comparable. However, there was no correlation between the release rate and the skin retention. The amounts of the flavonoids found in the skin were strongly affected by the type of the used solvent. While PG increased the skin retention of both flavonoids, PEG 400 had no effect on chrysin skin retention and delayed quercetin skin absorption. The proper choice of the solvent added to the semisolid base is crucial for enhanced skin delivery of the tested flavonoids. PG is more efficient absorption promoter than PEG 400 of both chrysin and quercetin. © 2017 Society of Cosmetic Scientists and the Société Française de Cosmétologie.

Accelerated in-vitro release testing methods for extended-release parenteral dosage forms.

PubMed

Shen, Jie; Burgess, Diane J

2012-07-01

This review highlights current methods and strategies for accelerated in-vitro drug release testing of extended-release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in-situ depot-forming systems and implants. Extended-release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, 'real-time' in-vitro release tests for these dosage forms are often run over a long time period. Accelerated in-vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in-vitro release methods using United States Pharmacopeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended-release parenteral dosage forms, along with the accelerated in-vitro release testing methods currently employed are discussed. Accelerated in-vitro release testing methods with good discriminatory ability are critical for quality control of extended-release parenteral products. Methods that can be used in the development of in-vitro-in-vivo correlation (IVIVC) are desirable; however, for complex parenteral products this may not always be achievable. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

Accelerated in vitro release testing methods for extended release parenteral dosage forms

PubMed Central

Shen, Jie; Burgess, Diane J.

2012-01-01

Objectives This review highlights current methods and strategies for accelerated in vitro drug release testing of extended release parenteral dosage forms such as polymeric microparticulate systems, lipid microparticulate systems, in situ depot-forming systems, and implants. Key findings Extended release parenteral dosage forms are typically designed to maintain the effective drug concentration over periods of weeks, months or even years. Consequently, “real-time” in vitro release tests for these dosage forms are often run over a long time period. Accelerated in vitro release methods can provide rapid evaluation and therefore are desirable for quality control purposes. To this end, different accelerated in vitro release methods using United States Pharmacopoeia (USP) apparatus have been developed. Different mechanisms of accelerating drug release from extended release parenteral dosage forms, along with the accelerated in vitro release testing methods currently employed are discussed. Conclusions Accelerated in vitro release testing methods with good discriminatory ability are critical for quality control of extended release parenteral products. Methods that can be used in the development of in vitro-in vivo correlation (IVIVC) are desirable, however for complex parenteral products this may not always be achievable. PMID:22686344

Hypnotics in insomnia: the experience of zolpidem.

PubMed

MacFarlane, James; Morin, Charles M; Montplaisir, Jacques

2014-11-01

One of the most commonly prescribed medications to treat insomnia is zolpidem, a nonbenzodiazepine compound that is available as an immediate-release oral tablet formulation, an extended-release oral formulation, an oral spray formulation, and as sublingual formulations. The purpose of this review was to summarize the data currently available on the efficacy and safety of zolpidem in the treatment of insomnia among adults. Published studies on the use of zolpidem in the treatment of insomnia were identified by using combinations of relevant search terms in PubMed and Google Scholar. Studies were included if they were placebo- or active comparator-controlled studies, with the exception of trials on the long-term use of zolpidem. Studies were limited to those conducted in adults. Studies were not included if the patient population was small, if the study was not designed or powered to assess the efficacy or safety of zolpidem, if insomniac patients had a medical condition in addition to insomnia (with the exception of comorbid depression or anxiety for studies on comorbid insomnia), or if zolpidem was given concomitantly with any other therapy (with the exception of selective serotonin reuptake inhibitors for studies on comorbid insomnia). Twenty-five studies designed to evaluate the efficacy of zolpidem in insomnia and 51 studies reporting the safety of zolpidem in insomnia were included in this review. The studies discussed in this review report the efficacy and safety of zolpidem in both young adults and the elderly. It can be used for either bedtime or middle-of-the-night administration, over the short or long term, with minimal risk of withdrawal or abuse. The use of zolpidem is associated with rebound insomnia, complex sleep-related behaviors, and next-day residual effects (after middle-of-the-night dosing) on driving ability, memory, and psychomotor performance. Copyright © 2014 Elsevier HS Journals, Inc. All rights reserved.

Development and characterization of controlled release polar lipid microparticles of candesartan cilexetil by solid dispersion

PubMed Central

Kamalakkannan, V; Puratchikody, A; Ramanathan, L

2013-01-01

Candesartan cilexetil (CC) is a newer class of angiotensin II receptor antagonist used for the treatment of hypertension. The solubility of the CC is very poor and its oral bioavailability is only 15%. The controlledrelease polar lipid microparticles of CC (formulations F1, F2, F3 and F4) were prepared using variable erodible lipophilic excipients like hydrogenated castor oil, stearic acid, cetostearyl alcohol and carnauba wax by fusion method. The particle sizes of polar lipid microparticles were less than 50 microns and they were irregular in shape. Drug content ranged between 98.96 ± 2.1 and 101.9 ± 1.6% were present in all the formulations. The formulation F3 showed better drug release throughout the study period in a controlled release manner. Moreover, the in vitro release showed that all the formulations were best fitted to Higuchi model. Accelerated stability studies indicated that there was no significant changes in the chemical and physical characteristics of the formulated drug product during initial and at the end of the study period. The FTIR and DSC studies showed that there was no interaction between the drug and lipophilic excipients and no polymorphic transitions in all formulations. The X-ray diffraction peak of solid dispersion indicated that the crystalline nature of CC disappeared and no new peaks could be observed, suggesting the absence of interaction between drug and excipients. PMID:24019822

Synthesis and evaluation of mesoporous carbon/lipid bilayer nanocomposites for improved oral delivery of the poorly water-soluble drug, nimodipine.

PubMed

Zhang, Yanzhuo; Zhao, Qinfu; Zhu, Wufu; Zhang, Lihua; Han, Jin; Lin, Qisi; Ai, Fengwei

2015-07-01

A novel mesoporous carbon/lipid bilayer nanocomposite (MCLN) with a core-shell structure was synthesized and characterized as an oral drug delivery system for poorly water-soluble drugs. The objective of this study was to investigate the potential of MCLN-based formulation to modulate the in vitro release and in vivo absorption of a model drug, nimodipine (NIM). NIM-loaded MCLN was prepared by a procedure involving a combination of thin-film hydration and lyophilization. Scanning electron microscopy (SEM), transmission electron microscopy (TEM), specific surface area analysis, differential scanning calorimetry (DSC) and X-ray diffraction (XRD) were employed to characterize the NIM-loaded MCLN formulation. The effect of MCLN on cell viability was assessed using the MTT assay. In addition, the oral bioavailability of NIM-loaded MCLN in beagle dogs was compared with that of the immediate-release formulation, Nimotop®. Our results demonstrate that the NIM-loaded MCLN formulation exhibited a typical sustained release pattern. The NIM-loaded MCLN formulation achieved a greater degree of absorption and longer lasting plasma drug levels compared with the commercial formulation. The relative bioavailability of NIM for NIM-loaded MCLN was 214%. MCLN exhibited negligible toxicity. The data reported herein suggest that the MCLN matrix is a promising carrier for controlling the drug release rate and improving the oral absorption of poorly water-soluble drugs.

Development of loteprednol etabonate-loaded cationic nanoemulsified in-situ ophthalmic gel for sustained delivery and enhanced ocular bioavailability.

PubMed

Patel, Nirav; Nakrani, Happy; Raval, Mihir; Sheth, Navin

2016-11-01

A novel cationic nanoemulsified in-situ ophthalmic gel of loteprednol etabonate (LE) was developed to improve the permeability and retention time of formulations for overall improvement of drug's ocular bioavability. Capryol 90 (oil phase), tween 80 (surfactant) and transcutol P (cosurfactant) was selected as formulation excipients to construct pseudoternary phase diagrams and nanoemulsion region was recognized from diagrams. Spontaneous emulsification method was used to manufacture LE nanoemulsion and it was optimized using 3 2 factorial design by considering the amount of oil and the ratio of surfactant to cosurfactant (S mix ) as independent variables and evaluated for various physicochemical properties. Optimized NE was dispersed in Poloxamer 407 and 188 solution to form nanoemulsified sols that were predictable to transform into in-situ gels at corneal temperature. Drug pharmacokinetics of sterilized optimized in situ NE gel, NE-ISG2 [0.69% w/w Capryol 90, 0.99%w/w S mix (3:1), 13% Poloxamer 407, 4% w/w Poloxamer 188] and marketed formulation were assessed in rabbit aqueous humor. The in-situ gels were clear, shear thinning in nature and displayed zero-order drug release kinetics. NE-ISG2 showed the minimum ocular irritation potential and significantly (p < 0.01) higher C max and AUC (0-10 h) , delayed T max , extended mean residence time and improved (2.54-fold times) bioavailability compared to marketed formulation.

Comparison of different models for the testing of pilocarpine eyedrops using conventional eyedrops and a novel depot formulation (nanoparticles).

PubMed

Diepold, R; Kreuter, J; Himber, J; Gurny, R; Lee, V H; Robinson, J R; Saettone, M F; Schnaudigel, O E

1989-01-01

An objective in the development of ophthalmic formulations is the use of in vitro or animal models that closely resemble the clinical situation. For this reason, experiments with conventional pilocarpine nitrate eyedrops and a depot formulation of pilocarpine nitrate sorbed to poly (butylcyanoacrylate) nanoparticles were carried out. In vitro, the diffusion of pilocarpine through bovine cornea was measured using Edelhauser cells. In vivo, the rabbit aqueous humor concentration of pilocarpine and miosis were determined after application of the above formulations. In addition, intraocular pressure was measured. Since pilocarpine has little influence on intraocular pressure in healthy rabbits, the pressure had to be increased artificially. Three models were employed that are described in the literature, namely, the betamethasone model, the alpha-chymotrypsin model, and the water-loading model. Pilocarpine could be loaded onto nanoparticles by 15% but was rapidly released from the nanoparticles based on the bovine corneal experiment. Nanoparticles only enhanced the aqueous humor concentration at 30 min; this increase, however, led to a considerably extended period of miosis as well as a reduction in intraocular pressure. The duration of the action and the intensity of the response were different among the three models tested. According to the present results, the betamethasone model seems to represent the best correlation to the clinical situation.

An efficient algorithm for the generalized Foldy-Lax formulation

NASA Astrophysics Data System (ADS)

Huang, Kai; Li, Peijun; Zhao, Hongkai

2013-02-01

Consider the scattering of a time-harmonic plane wave incident on a two-scale heterogeneous medium, which consists of scatterers that are much smaller than the wavelength and extended scatterers that are comparable to the wavelength. In this work we treat those small scatterers as isotropic point scatterers and use a generalized Foldy-Lax formulation to model wave propagation and capture multiple scattering among point scatterers and extended scatterers. Our formulation is given as a coupled system, which combines the original Foldy-Lax formulation for the point scatterers and the regular boundary integral equation for the extended obstacle scatterers. The existence and uniqueness of the solution for the formulation is established in terms of physical parameters such as the scattering coefficient and the separation distances. Computationally, an efficient physically motivated Gauss-Seidel iterative method is proposed to solve the coupled system, where only a linear system of algebraic equations for point scatterers or a boundary integral equation for a single extended obstacle scatterer is required to solve at each step of iteration. The convergence of the iterative method is also characterized in terms of physical parameters. Numerical tests for the far-field patterns of scattered fields arising from uniformly or randomly distributed point scatterers and single or multiple extended obstacle scatterers are presented.

Tailoring sub-micron PLGA particle release profiles via centrifugal fractioning

PubMed Central

Dutta, Dipankar; Salifu, Mariama; Sirianni, Rachael W.; Stabenfeldt, Sarah E.

2016-01-01

Poly(D,L-lactic-co-glycolic) acid (PLGA)-based submicron particles are uniquely posed to overcome limitations of conventional drug delivery systems. However, tailoring cargo/payload release profiles from PLGA micro/nanoparticles typically requires optimization of the multi-parameter formulation, where small changes may cause drastic shifts in the resulting release profiles. In this study, we aimed to establish whether refining the average diameter of submicron particle populations after formulation alters protein release profiles. PLGA particles were first produced via double emulsion-solvent evaporation method to encapsulate bovine serum albumin. Particles were then subjected to centrifugal fractioning protocols varying in both spin time and force to determine encapsulation efficiency and release profile of differently sized populations that originated from a single batch. We found the average particle diameter was related to marked alterations in encapsulation efficiencies (range: 36.4–49.4%), burst release (range: 15.8–49.1%), and time for total cargo release (range: 38–78 days). Our data corroborate previous reports relating PLGA particle size with such release characteristics, however, this is the first study, to our knowledge, to directly compare particle population size while holding all formulation parameters constant. In summary, centrifugal fractioning to selectively control the population distribution of sub-micron PLGA particles represents a feasible tool to tailor release characteristics. PMID:26517011

Influence of poloxamers on the dissolution performance and stability of controlled-release formulations containing Precirol ATO 5.

PubMed

Jannin, V; Pochard, E; Chambin, O

2006-02-17

Lipid excipients are usually used for the development of sustained-release formulations. When used in relatively high quantities, Precirol ATO 5 imparts sustained-release properties to solid oral dosage forms, by forming a lipid matrix. To control or adjust the drug release kinetics from such lipid matrix however, one must often resort to complementary ingredients or techniques. This study investigates the influence of poloxamers (Lutrol) included in lipid matrices composed of glyceryl palmitostearate (Precirol ATO 5) on their dissolution performance and their stability. The addition of these hydrophilic polymers in the lipid matrix increased the amount of theophylline released thanks to the swelling of the hydrophilic polymer and the creation of a porous network into the inert lipid matrix. The grade and the quantity of Lutrol could modulate the extent of drug release. Theophylline was released mainly by the matrix erosion but also by diffusion through the pores as suggested by the Peppas' model. Moreover, the addition of Lutrol enhanced the stability during storage. The theophylline release was quite steady after 6 months in different conditions (temperature and humidity). Thus, the mixture of glyceryl palmitostearate and poloxamers is an approach with many advantages for the development of controlled-release formulations by capsule molding.

Lyophilized mucoadhesive-dendrimer enclosed matrix tablet for extended oral delivery of albendazole.

PubMed

Mansuri, Shakir; Kesharwani, Prashant; Tekade, Rakesh Kumar; Jain, Narendra Kumar

2016-05-01

Dendrimers are multifunctional carriers widely employed for delivering drugs in a variety of disease conditions including HIV/AIDS and cancer. Albendazole (ABZ) is a commonly used anthelmintic drug in human as well as veterinary medicine. In this investigation, ABZ was formulated as a "muco-dendrimer" based sustained released tablet. The mucoadhesive complex was synthesized by anchoring chitosan to fifth generation PPI dendrimer (Muco-PPI) and characterized by UV, FTIR, (1)H NMR spectroscopy and electron microscopy. ABZ was entrapped inside Muco-PPI followed by lyophilization and tableting as matrix tablet. A half-life (t1/2) of 8.06±0.15, 8.17±0.47, 11.04±0.73, 11.49±0.92, 12.52±1.04 and 16.9±1.18h was noted for ABZ (free drug), conventional ABZ tablet (F1), conventional ABZ matrix tablet (F2), PPI-ABZ complex, PPI-ABZ matrix tablet (F3) and Muco-PPI-ABZ matrix tablet (F4), respectively. Thus the novel mucoadhesive-PPI based formulation of ABZ (F4) increased the t1/2 of ABZ significantly by almost twofold as compared to the administration of free drug. The in vivo drug release data showed that the Muco-PPI based formulations have a significantly higher Cmax (2.40±0.02μg/mL) compared with orally administered free ABZ (0.19±0.07μg/mL) as well as conventional tablet (0.20±0.05μg/mL). In addition, the Muco-PPI-ABZ matrix tablet displayed increased mean residence time (MRT) and is therefore a potential candidate to appreciably improve the pharmacokinetic profile of ABZ. Copyright © 2015 Elsevier B.V. All rights reserved.

Once-daily mesalamine granules for ulcerative colitis.

PubMed

Lawlor, Garrett; Ahmed, Awais; Moss, Alan C

2010-07-01

Mesalamine extended-release capsules (Apriso [Salix Pharmaceuticals, Raleigh, NC, USA]) are the first once-daily mesalamine preparation approved by the US FDA for the maintenance of remission of ulcerative colitis (UC). Each mesalamine extended-release capsule contains granules of a mesalamine-polymer matrix that are coated with a pH-sensitive resin. This design begins releasing mesalamine (0.375 g) once the pH is more than 6 in the ileum and colon. Two clinical trials have reported that mesalamine extended-release capsules (1.5 g/day) maintained remission in 79% of patients with UC who were in clinical remission. Reported adherence with mesalamine extended-release capsules once daily was high (>90%) in these studies. This article examines the efficacy and safety of mesalamine extended-release capsules in the maintenance of remission in patients with UC.

Design of sustained release pellets of ferrous fumarate using cow ghee as hot-melt coating agent.

PubMed

Sakarkar, Dinesh M; Dorle, Avinash K; Mahajan, Nilesh Manoharrao; Sudke, Suresh Gendappa

2013-07-01

The objective of the present study was to design ferrous fumarate (FF) sustained release (SR) pellets using of cow ghee (CG) as an important hot-melt coating (HMC) agent. The pellets were coated by HMC technique using CG and ethyl cellulose composition by conventional coating pan without the use of spray system. FF formulated as pellets and characterized with regard to the drug content and physico-chemical properties. Stability studies were carried out on the optimized formulation for a period of 6 months at 40 ± 2°C and 75 ± 5% relative humidity. Pellets with good surface morphology and smooth texture confirmed by stereo micrographs. HMC is easy, efficient, rapid and simple method since virtually no agglomeration seen during coating. In-vitro release from pellets at a given level of coating and for present pellet size was dependent upon the physico-chemical property of the drug and mostly aqueous solubility of the drug. The selection of optimized FF formulation was confirmed by comparing percent cumulative drug release with theoretical release profile. Formulation F2 had difference factor (f 1) and similarity factor (f 2) values was found to be 5 and 66 respectively. F2 showed SR of drug for 8 h with cumulative per cent release of 98.03 ± 4.49%. Release kinetics indicates approximately zero order release pattern. HMC pellets were stable during the course of stability study. By means of HMC using CG and ethyl cellulose, SR pellets containing FF were successfully prepared.

DEKFIS user's guide: Discrete Extended Kalman Filter/Smoother program for aircraft and rotorcraft data consistency

NASA Technical Reports Server (NTRS)

1979-01-01

The computer program DEKFIS (discrete extended Kalman filter/smoother), formulated for aircraft and helicopter state estimation and data consistency, is described. DEKFIS is set up to pre-process raw test data by removing biases, correcting scale factor errors and providing consistency with the aircraft inertial kinematic equations. The program implements an extended Kalman filter/smoother using the Friedland-Duffy formulation.

In vitro drug release behavior from a novel thermosensitive composite hydrogel based on Pluronic f127 and poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) copolymer

PubMed Central

Gong, Chang Yang; Shi, Shuai; Dong, Peng Wei; Zheng, Xiu Ling; Fu, Shao Zhi; Guo, Gang; Yang, Jing Liang; Wei, Yu Quan; Qian, Zhi Yong

2009-01-01

Background Most conventional methods for delivering chemotherapeutic agents fail to achieve therapeutic concentrations of drugs, despite reaching toxic systemic levels. Novel controlled drug delivery systems are designed to deliver drugs at predetermined rates for predefined periods at the target organ and overcome the shortcomings of conventional drug formulations therefore could diminish the side effects and improve the life quality of the patients. Thus, a suitable controlled drug delivery system is extremely important for chemotherapy. Results A novel biodegradable thermosensitive composite hydrogel, based on poly(ethylene glycol)-poly(ε-caprolactone)-poly(ethylene glycol) (PEG-PCL-PEG, PECE) and Pluronic F127 copolymer, was successfully prepared in this work, which underwent thermosensitive sol-gel-sol transition. And it was flowing sol at ambient temperature but became non-flowing gel at body temperature. By varying the composition, sol-gel-sol transition and in vitro drug release behavior of the composite hydrogel could be adjusted. Cytotoxicity of the composite hydrogel was conducted by cell viability assay using human HEK293 cells. The 293 cell viability of composite hydrogel copolymers were yet higher than 71.4%, even when the input copolymers were 500 μg per well. Vitamin B12 (VB12), honokiol (HK), and bovine serum albumin (BSA) were used as model drugs to investigate the in vitro release behavior of hydrophilic small molecular drug, hydrophobic small molecular drug, and protein drug from the composite hydrogel respectively. All the above-mentioned drugs in this work could be released slowly from composite hydrogel in an extended period. Chemical composition of composite hydrogel, initial drug loading, and hydrogel concentration substantially affected the drug release behavior. The higher Pluronic F127 content, lower initial drug loading amount, or lower hydrogel concentration resulted in higher cumulative release rate. Conclusion The results showed that composite hydrogel prepared in this paper were biocompatible with low cell cytotoxicity, and the drugs in this work could be released slowly from composite hydrogel in an extended period, which suggested that the composite hydrogel might have great potential applications in biomedical fields. PMID:19210779

Two release rates from monolithic carboxymethyl starch tablets: formulation, characterization, and in vitro/in vivo evaluation.

PubMed

Le, Tien Canh; Mateescu, Mircea Alexandru

2017-08-01

Most of non-steroidal anti-inflammatory drugs (NSAIDs) including ibuprofen at more than 1200 mg/day may generate gastrointestinal and cardiovascular side effects. Bilayer or multiparticulate devices have been developed for controlled release in order to prevent undesired side effects. A new "two release rate (2RR) monolithic tablets" approach is now proposed for controlled release of poorly soluble drugs, particularly NSAIDs. Ibuprofen was used as model drug. This concept is based on a calcium carboxymethyl-starch (CaCMS) complex as a novel, low-cost excipient for monolithic dosage forms easy to manufacture by direct compaction. The in vitro dissolution from CaCMS formulations (tablets containing 400 or 600 mg active principle) showed two distinct release rates: (i) an initial fast release (for 30 min in simulated gastric fluid) of about 200 mg ibuprofen, an amount similar to the dosage of conventional immediate-release form (Motrin® 200 mg), and (ii) a slow release of remaining about 200 or 400 mg for a period of 12 h. A preliminary in vivo study (beagle dogs) showed pharmacokinetic parameters of one single controlled-release dosage of ibuprofen (400 mg) formulated with CaCMS, near equivalence with multiple doses (three tablets of 200 mg ibuprofen) of conventional Motrin®. A marked reduction (with 33%) of administered dose (400 instead 600 mg) was achieved by the new formulation with equivalent therapeutic effects. This dose reduction may be beneficial and is expected to minimize side damage risks. Although the present study was limited to NSAIDs, the 2RR concept can be applied for other drugs, particularly for subjects unable to follow frequent administrations.

Electrospun matrices for localised controlled drug delivery: release of tetracycline hydrochloride from layers of polycaprolactone and poly(ethylene-co-vinyl acetate).

PubMed

Alhusein, Nour; Blagbrough, Ian S; De Bank, Paul A

2012-12-01

We report the controlled release of tetracycline (Tet) HCl from a three-layered electrospun matrix for the first time. Five formulations of electrospun poly-ε-caprolactone (PCL) and poly(ethylene-co-vinyl acetate) (PEVA) have been designed, prepared as micro/nanofibre layers, and assayed for the controlled release of the clinically useful antibiotic Tet HCl with potential applications in wound healing and especially in complicated skin and skin-structure infections. Tet HCl was also chosen as a model drug possessing a good ultraviolet (UV) chromophore and capable of fluorescence together with limited stability. Tet HCl was successfully incorporated (essentially quantitatively at 3 %, w/w) and provided controlled release from multilayered electrospun matrices. The Tet HCl release test was carried out by a total immersion method on 2 × 2 cm(2) electrospun fibrous mats in Tris or phosphate-buffered saline heated to 37 °C. The formulation PCL/PEVA/PCL with Tet HCl in each layer gave a large initial (burst) release followed by a sustained release. Adding a third layer to the two-layered formulations led to release being sustained from 6 days to more than 15 days. There was no detectable loss of Tet chemical stability (as shown by UV and NMR) or bioactivity (as shown by a modified Kirby-Bauer disc assay). Using Tet HCl-sensitive bacteria, Staphylococcus aureus (ATCC 25923), the Tet HCl-loaded three-layered matrix formulations were still showing significantly higher antibacterial effects on days 4 and 5 than commercially available Antimicrobial Susceptibility Test Discs of Tet HCl. Electrospinning provides good encapsulation efficiency of Tet HCl within PCL/PEVA/PCL polymers in micro/nanofibre layers which display sustained antibiotic release.

Comparison of the efficacy of extended-release clarithromycin tablets and amoxicillin/clavulanate tablets in the treatment of acute exacerbation of chronic bronchitis.

PubMed

Anzueto, A; Fisher, C L; Busman, T; Olson, C A

2001-01-01

Clarithromycin has established efficacy and safety in the treatment of respiratory infections. This study examined the efficacy and safety of a new extended-release formulation of clarithromycin compared with amoxicillin/clavulanate in the treatment of acute exacerbation of chronic bronchitis (AECB). This phase IIIB, multicenter, randomized, parallel-group, investigator-blinded study in patients with AECB and productive cough with purulent sputum compared treatment with extended-release clarithromycin (two 500-mg tablets once daily for 7 days) and amoxicillin/clavulanate (one 875-mg tablet twice daily for 10 days). Assessments were performed before treatment, between study days 10 and 12 (or within 48 hours after premature discontinuation), and between study days 17 and 21 (test of cure). Of 287 patients randomized and treated, 270 were clinically evaluable (137 clarithromycin, 133 amoxicillin/clavulanate). Treatment groups were well matched in terms of demographic characteristics, medical condition, and history. Among clinically evaluable patients at test of cure, 85% and 87% of clarithromycin- and amoxicillin/clavulanate-treated patients, respectively, demonstrated clinical cure (as defined in 1998 draft US Food and Drug Administration guidelines); among clinically and bacteriologically evaluable patients, 92% versus 89%, respectively, demonstrated bacteriologic cure. Overall pathogen eradication rates were similar in the 2 groups (88% clarithromycin, 89% amoxicillin/clavulanate). Rates of premature discontinuation of study drug for any reason differed between treatments: 3% (4/142) of clarithromycin-treated patients versus 12% (17/145) of amoxicillin/clavulanate-treated patients (P = 0.005). One percent (2/142) and 6% (8/145) of the respective treatment groups discontinued study drug because of adverse events. Adverse events generally occurred with a similar frequency in the 2 groups; however, taste alteration was more common with clarithromycin (9/142 [6%]) than with amoxicillin/clavulanate (1/145 [1%]; P = 0.01). Mean severity scores for gastrointestinal adverse events showed a significant difference between groups (1.16 for clarithromycin-treated patients and 1.58 for amoxicillin/clavulanate-treated patients: P = 0.016). The results of this study demonstrate the clinical and bacteriologic equivalence and improved gastrointestinal tolerability of a 7-day course of once-daily extended-release clarithromycin relative to a 10-day course of twice-daily amoxicillin/clavulanate in the treatment of AECB.

Innovation of novel 'Tab in Tab' system for release modulation of milnacipran HCl: optimization, formulation and in vitro investigations.

PubMed

Parejiya, Punit B; Barot, Bhavesh S; Patel, Hetal K; Shelat, Pragna K; Shukla, Arunkumar

2013-11-01

The study was aimed toward development of modified release oral drug delivery system for highly water soluble drug, Milnacipran HCl (MH). Novel Tablet in Tablet system (TITs) comprising immediate and extended release dose of MH in different parts was fabricated. The outer shell was composed of admixture of MH, lactose and novel herbal disintegrant obtained from seeds of Lepidium sativum. In the inner core, MH was matrixed with blend of hydrophilic (Benecel®) and hydrophobic (Compritol®) polymers. 3² full factorial design and an artificial neuron network (ANN) were employed for correlating effect of independent variables on dependent variables. The TITs were characterized for pharmacopoeial specifications, in vitro drug release, SEM, drug release kinetics and FTIR study. The release pattern of MH from batch A10 containing 25.17% w/w Benecel® and 8.21% w/w of Compritol® exhibited drug release pattern close proximal to the ideal theoretical profile (t(50%) = 5.92 h, t(75%) = 11.9 h, t(90%) = 18.11 h). The phenomenon of drug release was further explained by concept of percolation and the role of Benecel® and Compritol® in drug release retardation was studied. The normalized error obtained from ANN was less, compared with the multiple regression analysis, and exhibits the higher accuracy in prediction. The results of short-term stability study revealed stable chataracteristics of TITs. SEM study of TITs at different dissolution time points confirmed both diffusion and erosion mechanisms to be operative during drug release from the batch A10. Novel TITs can be a succesful once a day delivery system for highly water soluble drugs.

Trigger chemistries for better industrial formulations.

PubMed

Wang, Hsuan-Chin; Zhang, Yanfeng; Possanza, Catherine M; Zimmerman, Steven C; Cheng, Jianjun; Moore, Jeffrey S; Harris, Keith; Katz, Joshua S

2015-04-01

In recent years, innovations and consumer demands have led to increasingly complex liquid formulations. These growing complexities have provided industrial players and their customers access to new markets through product differentiation, improved performance, and compatibility/stability with other products. One strategy for enabling more complex formulations is the use of active encapsulation. When encapsulation is employed, strategies are required to effect the release of the active at the desired location and time of action. One particular route that has received significant academic research effort is the employment of triggers to induce active release upon a specific stimulus, though little has translated for industrial use to date. To address emerging industrial formulation needs, in this review, we discuss areas of trigger release chemistries and their applications specifically as relevant to industrial use. We focus the discussion on the use of heat, light, shear, and pH triggers as applied in several model polymeric systems for inducing active release. The goal is that through this review trends will emerge for how technologies can be better developed to maximize their value through industrial adaptation.

Investigation on influence of Wurster coating process parameters for the development of delayed release minitablets of Naproxen.

PubMed

Shah, Neha; Mehta, Tejal; Aware, Rahul; Shetty, Vasant

2017-12-01

The present work aims at studying process parameters affecting coating of minitablets (3 mm in diameter) through Wurster coating process. Minitablets of Naproxen with high drug loading were manufactured using 3 mm multi-tip punches. The release profile of core pellets (published) and minitablets was compared with that of marketed formulation. The core formulation of minitablets was found to show similarity in dissolution profile with marketed formulation and hence was further carried forward for functional coating over it. Wurster processing was implemented to pursue functional coating over core formulation. Different process parameters were screened and control strategy was applied for factors significantly affecting the process. Modified Plackett Burman Design was applied for studying important factors. Based on the significant factors and minimum level of coating required for functionalization, optimized process was executed. Final coated batch was evaluated for coating thickness, surface morphology, and drug release study.

Evaluation of Influence of Various Polymers on Dissolution and Phase Behavior of Carbamazepine-Succinic Acid Cocrystal in Matrix Tablets.

PubMed

Ullah, Majeed; Ullah, Hanif; Murtaza, Ghulam; Mahmood, Qaisar; Hussain, Izhar

2015-01-01

The aim of current study was to explore the influence of three commonly used polymers, that is, cellulosics and noncellulosics, for example, Methocel K4M, Kollidon VA/64, and Soluplus, on the phase disproportionation and drug release profile of carbamazepine-succinic acid (CBZ-SUC) cocrystal at varying drug to polymer ratios (1 : 1 to 1 : 0.25) in matrix tablets. The polymorphic phase disproportionation during in-depth dissolution studies of CBZ-SUC cocrystals and its crystalline properties were scrutinized by X-ray powder diffractrometry and Raman spectroscopy. The percent drug release from HPMC formulations (CSH) showed inverse relation with the concentration of polymer; that is, drug release increased with decrease in polymer concentration. On contrary, direct relation was observed between percent drug release and polymer concentrations of Kollidon VA 64/Soluplus (CSK, CSS). At similar polymer concentration, drug release from pure carbamazepine was slightly lower with HPMC formulations than that of cocrystal; however, opposite trend in release rate was observed with Kollidon VA/64 and Soluplus. The significant increase in dissolution rate of cocrystal occurred with Kollidon VA/64 and Soluplus at higher polymer concentration. Moreover, no phase change took place in Methocel and Kollidon formulations. No tablet residue was left for Soluplus formulation so the impact of polymer on cocrystal integrity cannot be predicted.

Evaluation of Influence of Various Polymers on Dissolution and Phase Behavior of Carbamazepine-Succinic Acid Cocrystal in Matrix Tablets

PubMed Central

Ullah, Majeed; Ullah, Hanif; Mahmood, Qaisar; Hussain, Izhar

2015-01-01

The aim of current study was to explore the influence of three commonly used polymers, that is, cellulosics and noncellulosics, for example, Methocel K4M, Kollidon VA/64, and Soluplus, on the phase disproportionation and drug release profile of carbamazepine-succinic acid (CBZ-SUC) cocrystal at varying drug to polymer ratios (1 : 1 to 1 : 0.25) in matrix tablets. The polymorphic phase disproportionation during in-depth dissolution studies of CBZ-SUC cocrystals and its crystalline properties were scrutinized by X-ray powder diffractrometry and Raman spectroscopy. The percent drug release from HPMC formulations (CSH) showed inverse relation with the concentration of polymer; that is, drug release increased with decrease in polymer concentration. On contrary, direct relation was observed between percent drug release and polymer concentrations of Kollidon VA 64/Soluplus (CSK, CSS). At similar polymer concentration, drug release from pure carbamazepine was slightly lower with HPMC formulations than that of cocrystal; however, opposite trend in release rate was observed with Kollidon VA/64 and Soluplus. The significant increase in dissolution rate of cocrystal occurred with Kollidon VA/64 and Soluplus at higher polymer concentration. Moreover, no phase change took place in Methocel and Kollidon formulations. No tablet residue was left for Soluplus formulation so the impact of polymer on cocrystal integrity cannot be predicted. PMID:26380301

Bioavailability enhancement of baclofen by gastroretentive floating formulation: statistical optimization, in vitro and in vivo pharmacokinetic studies.

PubMed

Thakar, Krishna; Joshi, Garima; Sawant, Krutika K

2013-06-01

The study was aimed to improve bioavailability of baclofen by developing gastroretentive floating drug delivery system (GFDDS). Preliminary optimization was done to select various release retardants to obtain minimum floating lag time, maximum floating duration and sustained release. Optimization by 3(2) factorial design was done using Polyox WSR 303 (X1) and HPMC K4M (X2) as independent variables and cumulative percentage drug released at 6 h (Q6h) as dependent variable. Optimized formulation showed floating lag time of 4-5 s, floated for more than 12 h and released the drug in sustained manner. In vitro release followed zero ordered kinetics and when fitted to Korsemeyer Peppas model, indicated drug release by combination of diffusion as well as chain relaxation. In vivo floatability study confirmed floatation for more than 6 h. In vivo pharmacokinetic studies in rabbits showed Cmax of 189.96 ± 13.04 ng/mL and Tmax of 4 ± 0.35 h for GFDDS. The difference for AUC(0-T) and AUC(0-∞) between the test and reference formulation was statistically significant (p > 0.05). AUC(0-T) and AUC(0-∞) for GFDDS was 2.34 and 2.43 times greater than the marketed formulation respectively. GFDDS provided prolonged gastric residence and showed significant increase in bioavailability of baclofen.

Impact of formulation and process variables on solid-state stability of theophylline in controlled release formulations.

PubMed

Korang-Yeboah, Maxwell; Rahman, Ziyaur; Shah, Dhaval; Mohammad, Adil; Wu, Suyang; Siddiqui, Akhtar; Khan, Mansoor A

2016-02-29

Understanding the impact of pharmaceutical processing, formulation excipients and their interactions on the solid-state transitions of pharmaceutical solids during use and in storage is critical in ensuring consistent product performance. This study reports the effect of polymer viscosity, diluent type, granulation and granulating fluid (water and isopropanol) on the pseudopolymorphic transition of theophylline anhydrous (THA) in controlled release formulations as well as the implications of this transition on critical quality attributes of the tablets. Accordingly, 12 formulations were prepared using a full factorial screening design and monitored over a 3 month period at 40 °C and 75%. Physicochemical characterization revealed a drastic drop in tablet hardness accompanied by a very significant increase in moisture content and swelling of all formulations. Spectroscopic analysis (ssNMR, Raman, NIR and PXRD) indicated conversion of THA to theophylline monohydrate (TMO) in all formulations prepared by aqueous wet granulation in as early as two weeks. Although all freshly prepared formulations contained THA, the hydration-dehydration process induced during aqueous wet granulation hastened the pseudopolymorphic conversion of theophylline during storage through a cascade of events. On the other hand, no solid state transformation was observed in directly compressed formulations and formulations in which isopropanol was employed as a granulating fluid even after the twelve weeks study period. The transition of THA to TMO resulted in a decrease in dissolution while an increase in dissolution was observed in directly compressed and IPA granulated formulation. Consequently, the impact of pseudopolymorphic transition of theophylline on dissolution in controlled release formulations may be the net result of two opposing factors: swelling and softening of the tablets which tend to favor an increase in drug dissolution and hydration of theophylline which decreases the drug dissolution. Published by Elsevier B.V.

Formulation and in vitro evaluation of xanthan gum-based bilayered mucoadhesive buccal patches of zolmitriptan.

PubMed

Shiledar, Rewathi R; Tagalpallewar, Amol A; Kokare, Chandrakant R

2014-01-30

A novel bilayered mucoadhesive buccal patch of zolmitriptan was prepared using xanthan gum (XG) as mucoadhesive polymer. Hydroxypropyl methylcellulose E-15 was used as film-former and polyvinyl alcohol (PVA) was incorporated, to increase the tensile strength of the patches. To study the effect of independent variables viz. concentrations of XG and PVA, on various dependent variables like in vitro drug release, ex vivo mucoadhesive strength and swelling index, 3(2) factorial design was employed. In vitro drug release studies of optimized formulation showed initially, rapid drug release; 43.15% within 15 min, followed by sustained release profile over 5h. Incorporation of 4% dimethyl sulfoxide enhanced drug permeability by 3.29 folds, transported 29.10% of drug after 5h and showed no buccal mucosal damage after histopathological studies. In conclusion, XG can be used as a potential drug release modifier and mucoadhesive polymer for successful formulation of zolmitriptan buccal patches. Copyright © 2013 Elsevier Ltd. All rights reserved.

Characterization of new functionalized calcium carbonate-polycaprolactone composite material for application in geometry-constrained drug release formulation development.

PubMed

Wagner-Hattler, Leonie; Schoelkopf, Joachim; Huwyler, Jörg; Puchkov, Maxim

2017-10-01

A new mineral-polymer composite (FCC-PCL) performance was assessed to produce complex geometries to aid in development of controlled release tablet formulations. The mechanical characteristics of a developed material such as compactibility, compressibility and elastoplastic deformation were measured. The results and comparative analysis versus other common excipients suggest efficient formation of a complex, stable and impermeable geometries for constrained drug release modifications under compression. The performance of the proposed composite material has been tested by compacting it into a geometrically altered tablet (Tablet-In-Cup, TIC) and the drug release was compared to commercially available product. The TIC device exhibited a uniform surface, showed high physical stability, and showed absence of friability. FCC-PCL composite had good binding properties and good compactibility. It was possible to reveal an enhanced plasticity characteristic of a new material which was not present in the individual components. The presented FCC-PCL composite mixture has the potential to become a successful tool to formulate controlled-release dosage solid forms.

Development of taste masked caffeine citrate formulations utilizing hot melt extrusion technology and in vitro-in vivo evaluations

PubMed Central

Pimparade, Manjeet. B.; Morott, Joseph T.; Park, Jun-Bom; Kulkarni, Vijay I.; Majumdar, Soumyajit; Murthy, S. N.; Lian, Zhuoyang; Pinto, Elanor; Bi, Vivian; Durig, Thomas; Murthy, Reena; Shivakumar, H.N; Vanaja, K.; Kumar, C. P; Repka, Michael A.

2015-01-01

The objective of this study was to develop caffeine citrate orally disintegrating tablet (ODT) formulations utilizing hot-melt extrusion technology and evaluate the ability of the formulation composition to mask the unpleasant bitter taste of the drug using in vitro and in vivo methods. Ethylcellulose, along with a suitable plasticizer, was used as a polymeric carrier. Pore forming agents were incorporated into the extruded matrix to enhance drug release. A modified screw configuration was applied to improve the extrusion processability and to preserve the crystallinity of the API. The milled extrudates were subjected to dissolution testing in an artificial salivary fluid and investigations using e-tongue, to assess the extent of masking of bitter taste of the API. There was an insignificant amount of drug released from the formulation in the salivary medium while over 80% of drug released within 30 min in 0.1 N HCl. ODTs were also developed with the extrudate mixed with mannitol and crospovidone. The quality properties such as friability and disintegration time of the ODTs met the USP specifications. The lead extrudate formulations and the ODTs prepared using this formulation were subjected to human gustatory evaluation. The formulations were found to mask the unpleasant taste of caffeine citrate significantly. PMID:25888797

Pharmacokinetic variability of long-acting stimulants in the treatment of children and adults with attention-deficit hyperactivity disorder.

PubMed

Ermer, James C; Adeyi, Ben A; Pucci, Michael L

2010-12-01

Methylphenidate- and amfetamine-based stimulants are first-line pharmacotherapies for attention-deficit hyperactivity disorder, a common neurobehavioural disorder in children and adults. A number of long-acting stimulant formulations have been developed with the aim of providing once-daily dosing, employing various means to extend duration of action, including a transdermal delivery system, an osmotic-release oral system, capsules with a mixture of immediate- and delayed-release beads, and prodrug technology. Coefficients of variance of pharmacokinetic measures can estimate the levels of pharmacokinetic variability based on the measurable variance between different individuals receiving the same dose of stimulant (interindividual variability) and within the same individual over multiple administrations (intraindividual variability). Differences in formulation clearly impact pharmacokinetic profiles. Many medications exhibit wide interindividual variability in clinical response. Stimulants with low levels of inter- and intraindividual variability may be better suited to provide consistent levels of medication to patients. The pharmacokinetic profile of stimulants using pH-dependent bead technology can vary depending on food consumption or concomitant administration of medications that alter gastric pH. While delivery of methylphenidate with the transdermal delivery system would be unaffected by gastrointestinal factors, intersubject variability is nonetheless substantial. Unlike the beaded formulations and, to some extent (when considering total exposure) the osmotic-release formulation, systemic exposure to amfetamine with the prodrug stimulant lisdexamfetamine dimesylate appears largely unaffected by such factors, likely owing to its dependence on systemic enzymatic cleavage of the precursor molecule, which occurs primarily in the blood involving red blood cells. The high capacity but as yet unidentified enzymatic system for conversion of lisdexamfetamine dimesylate may contribute to its consistent pharmacokinetic profile. The reasons underlying observed differential responses to stimulants are likely to be multifactorial, including pharmacodynamic factors. While the use of stimulants with low inter- and intrapatient pharmacokinetic variability does not obviate the need to titrate stimulant doses, stimulants with low intraindividual variation in pharmacokinetic parameters may reduce the likelihood of patients falling into subtherapeutic drug concentrations or reaching drug concentrations at which the risk of adverse events increases. As such, clinicians are urged both to adjust stimulant doses based on therapeutic response and the risk for adverse events and to monitor patients for potential causes of pharmacokinetic variability.

Statistical optimization of tretinoin-loaded penetration-enhancer vesicles (PEV) for topical delivery.

PubMed

Bavarsad, Neda; Akhgari, Abbas; Seifmanesh, Somayeh; Salimi, Anayatollah; Rezaie, Annahita

2016-02-29

The aim of this study was to develop and optimize deformable liposome for topical delivery of tretinoin. Liposomal formulations were designed based on the full factorial design and prepared by fusion method. The influence of different ratio of soy phosphatidylcholine and transcutol (independent variables) on incorporation efficiency and drug release in 15 min and 24 h (responses) from liposomal formulations was evaluated. Liposomes were characterized for their vesicle size and Differential Scanning Calorimetry (DSC) was used to investigate changes in their thermal behavior. The penetration and retention of drug was determined using mouse skin. Also skin histology study was performed. Particle size of all formulations was smaller than 20 nm. Incorporation efficiency of liposomes was 79-93 %. Formulation F7 (25:5) showed maximum drug release. Optimum formulations were selected based on the contour plots resulted by statistical equations of drug release in 15 min and 24 h. Solubility properties of transcutol led to higher skin penetration for optimum formulations compared to tretinoin cream. There was no significant difference between the amount of drug retained in the skin by applying optimum formulations and cream. Histopatological investigation suggested optimum formulations could decrease the adverse effect of tretinoin in liposome compared to conventional cream. According to the results of the study, it is concluded that deformable liposome containing transcutol may be successfully used for dermal delivery of tretinoin.

Isotretinoin Oil-Based Capsule Formulation Optimization

PubMed Central

Tsai, Pi-Ju; Huang, Chi-Te; Lee, Chen-Chou; Li, Chi-Lin; Huang, Yaw-Bin; Tsai, Yi-Hung; Wu, Pao-Chu

2013-01-01

The purpose of this study was to develop and optimize an isotretinoin oil-based capsule with specific dissolution pattern. A three-factor-constrained mixture design was used to prepare the systemic model formulations. The independent factors were the components of oil-based capsule including beeswax (X 1), hydrogenated coconut oil (X 2), and soybean oil (X 3). The drug release percentages at 10, 30, 60, and 90 min were selected as responses. The effect of formulation factors including that on responses was inspected by using response surface methodology (RSM). Multiple-response optimization was performed to search for the appropriate formulation with specific release pattern. It was found that the interaction effect of these formulation factors (X 1 X 2, X 1 X 3, and X 2 X 3) showed more potential influence than that of the main factors (X 1, X 2, and X 3). An optimal predicted formulation with Y 10 min, Y 30 min, Y 60 min, and Y 90 min release values of 12.3%, 36.7%, 73.6%, and 92.7% at X 1, X 2, and X 3 of 5.75, 15.37, and 78.88, respectively, was developed. The new formulation was prepared and performed by the dissolution test. The similarity factor f 2 was 54.8, indicating that the dissolution pattern of the new optimized formulation showed equivalence to the predicted profile. PMID:24068886

Extending antigen release from particulate vaccines results in enhanced antitumor immune response.

PubMed

Kapadia, Chintan H; Tian, Shaomin; Perry, Jillian L; Sailer, David; Christopher Luft, J; DeSimone, Joseph M

2018-01-10

Tumor-specific CD8 + cytotoxic T lymphocytes (CTLs) play a critical role in an anti-tumor immune response. However, vaccination intended to elicit a potent CD8 + T cell responses employing tumor-associated peptide antigens, are typically ineffective due to poor immunogenicity. Previously, we engineered a polyethylene glycol (PEG) hydrogel-based subunit vaccine for the delivery of an antigenic peptide and CpG (adjuvant) to elicit potent CTLs. In this study, we further examined the effect of antigen release kinetics on their induced immune responses. A CD8 + T cell epitope peptide from OVA (CSIINFEKL) and CpG were co-conjugated to nanoparticles utilizing either a disulfide or a thioether linkage. Subsequent studies comparing peptide release rates as a function of linker, determined that the thioether linkage provided sustained release of peptide over 72h. Ability to control the release of peptide resulted in both higher and prolonged antigen presentation when compared to disulfide-linked peptide. Both NP vaccine formulations resulted in activation and maturation of bone marrow derived dendritic cells (BMDCs) and induced potent CD8 + T cell responses when compared to soluble antigen and soluble CpG. Immunization with either disulfide or thioether linked vaccine constructs effectively inhibited EG7-OVA tumor growth in mice, however only treatment with the thioether linked vaccine construct resulted in enhanced survival. Copyright © 2017. Published by Elsevier B.V.

Preparation, characterization and evaluation of ranitidine hydrochloride-loaded mucoadhesive microspheres.

PubMed

Dhankar, Vandana; Garg, Garima; Dhamija, Koushal; Awasthi, Rajendra

2014-01-01

Mucoadhesion enables localization of drugs to a defined region of the gastrointestinal tract through attractive interactions between polymers composing the drug delivery devices and the mucin layer of the intestinal epithelium. Thus, this approach can be used for enhancement of the oral bioavailability of the drug. The current communication deals with the development of ranitidine hydrochloride-loaded chitosan-based mucoadhesive microspheres. Microspheres were prepared by water-in-oil emulsion technique, using glutaraldehyde as a cross-linking agent. The effect of independent variables like stirring speed and polymer-to-drug ratio on dependent variables, i.e. percentage mucoadhesion, percentage drug loading, particle size and swelling index, was examined using a 3(2); factorial design. The microspheres were discrete, spherical, free-flowing and also showed high percentage drug entrapment efficiency (43-70%). An in vitro mucoadhesion test showed that the microspheres adhered strongly to the mucous layer for an extended period of time. The RC 4 batch exhibited a high percentage of drug encapsulation (70%) and mucoadhesion (75%). The drug release was sustained for more than 12 h. The drug release kinetics were found to follow Peppas' kinetics for all the formulations and the drug release was diffusion controlled. The preliminary results of this study suggest that the developed microspheres containing ranitidine hydrochloride could enhance drug entrapment efficiency, reduce the initial burst release and modulate the drug release.

Pulmonary sustained release of insulin from microparticles composed of polyelectrolyte layer-by-layer assembly.

PubMed

Amancha, Kiran Prakash; Balkundi, Shantanu; Lvov, Yuri; Hussain, Alamdar

2014-05-15

The present study tests the hypothesis that layer-by-layer (LbL) nanoassembly of thin polyelectrolyte films on insulin particles provides sustained release of the drug after pulmonary delivery. LbL insulin microparticles were formulated using cationic and anionic polyelectrolytes. The microparticles were characterized for particle size, particle morphology, zeta potential and in vitro release. The pharmacokinetics and pharmacodynamics of drug were assessed by measuring serum insulin and glucose levels after intrapulmonary administration in rats. Bronchoalveolar lavage (BAL) and evans blue (EB) extravasation studies were performed to investigate the cellular or biochemical changes in the lungs caused by formulation administration. The mass median aerodynamic diameter (MMAD) of the insulin microparticles was 2.7 μm. Confocal image of the formulation particles confirmed the polyelectrolyte deposition around the insulin particles. Zeta potential measurements showed that there was charge reversal after each layering. Pulmonary administered LbL insulin formulation resulted in sustained serum insulin levels and concomitant decrease in serum glucose levels. The BAL and EB extravasation studies showed that the LbL insulin formulation did not elicit significant increase in marker enzymes activities compared to control group. These results demonstrate that the sustained release of insulin could be achieved using LbL nanoassembly around the insulin particles. Copyright © 2014 Elsevier B.V. All rights reserved.

Technology of stable, prolonged-release eye-drops containing Cyclosporine A, distributed between lipid matrix and surface of the solid lipid microspheres (SLM).

PubMed

Wolska, Eliza; Sznitowska, Małgorzata

2013-01-30

The aim of this study was to prepare solid lipid microspheres (SLM) with incorporated Cyclosporine A (Cs), suitable for ocular application. For this purpose, SLM were formulated by using different lipids and three different nonionic surfactants. The SLM were produced using a hot emulsification method. The SLM dispersions contained 10, 20 or 30% of lipid (w/w) and up to 2% (w/w) of Cs. The size of the microspheres with Cs ranged from 1 to 15 μm. Physically stable SLM with Cs were prepared using Compritol, as a lipid matrix, and Tween 80, as a surfactant. In contrast, dispersion with Precirol alone, formed semi-solid gels during storage, while in formulations with Precirol and Miglyol, crystals of Cs were observed. In vitro release profile of Compritol formulations showed that 40% of Cs is released within 1h, while the release of the following 40% takes more time, depending on lipid content in the formulations. The large part of Cs, added to SLM formulations (from 45 to 80%), was found on the surface of microparticles, but no drug crystallization occurred during a long-term storage. Copyright © 2012 Elsevier B.V. All rights reserved.

Localized In Situ Nanoemulgel Drug Delivery System of Quercetin for Periodontitis: Development and Computational Simulations.

PubMed

Aithal, Gururaj C; Nayak, Usha Yogendra; Mehta, Chetan; Narayan, Reema; Gopalkrishna, Pratibha; Pandiyan, Sudharsan; Garg, Sanjay

2018-06-06

This study was aimed at formulating a bioabsorbable, controlled-release, nanoemulgel of Quercetin, a potent antimicrobial and anti-inflammatory agent for the treatment of periodontitis that could improve its solubility and bioavailability. Screening of components was carried out based on the solubility studies. Nanoemulsion containing cinnamon oil as the oil phase, tween 80 and Carbitol ® as the surfactant-cosurfactant mixture (S mix ) and water as the aqueous phase containing 125 µg/200 µL of Quercetin was prepared by using spontaneous emulsification method. Nanoemulgel was prepared using 23% w / v poloxamer 407 as gel base. Comprehensive evaluation of the formulated nanoemulgel was carried out, and the optimized formulation was studied for drug release using Franz vertical diffusion cells. The formulated nanoemulgelexhibited a remarkable release of 92.4% of Quercetin at the end of 6 h, as compared to that of pure Quercetin-loaded gel (<3% release). The viscosity of the prepared nanoemulgel was found to be 30,647 ± 0.32 cPs at 37 °C. Also, molecular dynamics (MD) simulation was utilized to understand the gelation process and role of each component in the formulation. The present study revealed that the developed nanoemulgel of Quercetin could be a potential delivery system for clinical testing in periodontitis.

Design and In-vitro Evaluation of Sustained Release Floating Tablets of Metformin HCl Based on Effervescence and Swelling

PubMed Central

Senjoti, Faria Gias; Mahmood, Syed; Jaffri, Juliana Md; Mandal, Uttam Kumar

2016-01-01

An oral sustained-release floating tablet formulation of metformin HCl was designed and developed. Effervescence and swelling properties were attributed on the developed tablets by sodium bicarbonate and HPMC-PEO polymer combination, respectively. Tablet composition was optimized by response surface methodology (RSM). Seventeen (17) trial formulations were analyzed according to Box-Behnken design of experiment where polymer content of HPMC and PEO at 1: 4 ratio (A), amount of sodium bi-carbonate (B), and amount of SSG (C) were adopted as independent variables. Floating lag time in sec (Y1), cumulative percent drug released at 1 h (Y2) and 12 h (Y3) were chosen as response variables. Tablets from the optimized formulation were also stored at accelerated stability condition (40°C and 75% RH) for 3 months to assess their stability profile. RSM could efficiently optimize the tablet composition with excellent prediction ability. In-vitro drug release until 12 h, floating lag time, and duration of floating were dependent on the amount of three selected independent variables. Optimized tablets remained floating for more than 24 h with a floating lag time of less than 4 min. Based on best fitting method, optimized formulation was found to follow Korsmeyer-Peppas release kinetic. Accelerated stability study revealed that optimized formulation was stable for three months without any major changes in assay, dissolution profile, floating lag time and other physical properties. PMID:27610147

High-amylose sodium carboxymethyl starch matrices for oral, sustained drug-release: formulation aspects and in vitro drug-release evaluation.

PubMed

Brouillet, F; Bataille, B; Cartilier, L

2008-05-22

High-amylose sodium carboxymethyl starch (HASCA), produced by spray-drying (SD), was previously shown to have interesting properties as a promising pharmaceutical sustained drug-release tablet excipient for direct compression, including ease of manufacture and high crushing strength. This study describes the effects of some important formulation parameters, such as compression force (CF), tablet weight (TW), drug-loading and electrolyte particle size, on acetaminophen-release performances from sustained drug-release matrix tablets based on HASCA. An interesting linear relationship between TW and release time was observed for a typical formulation of the system consisting of 40% (w/w) acetaminophen as model drug and 27.5% NaCl as model electrolyte dry-mixed with HASCA. Application of the Peppas and Sahlin model gave a better understanding of the mechanisms involved in drug-release from the HASCA matrix system, which is mainly controlled by surface gel layer formation. Indeed, augmenting TW increased the contribution of the diffusion mechanism. CFs ranging from 1 to 2.5 tonnes/cm(2) had no significant influence on the release properties of tablets weighing 400 or 600 mg. NaCl particle size did not affect the acetaminophen-release profile. Finally, these results prove that the new SD process developed for HASCA manufacture is suitable for obtaining similar-quality HASCA in terms of release and compression performances.

Thermoplastic polyurethanes for the manufacturing of highly dosed oral sustained release matrices via hot melt extrusion and injection molding.

PubMed

Claeys, Bart; Vervaeck, Anouk; Hillewaere, Xander K D; Possemiers, Sam; Hansen, Laurent; De Beer, Thomas; Remon, Jean Paul; Vervaet, Chris

2015-02-01

This study evaluated thermoplastic polyurethanes (TPUR) as matrix excipients for the production of oral solid dosage forms via hot melt extrusion (HME) in combination with injection molding (IM). We demonstrated that TPURs enable the production of solid dispersions - crystalline API in a crystalline carrier - at an extrusion temperature below the drug melting temperature (Tm) with a drug content up to 65% (wt.%). The release of metoprolol tartrate was controlled over 24h, whereas a complete release of diprophylline was only possible in combination with a drug release modifier: polyethylene glycol 4000 (PEG 4000) or Tween 80. No burst release nor a change in tablet size and geometry was detected for any of the formulations after dissolution testing. The total matrix porosity increased gradually upon drug release. Oral administration of TPUR did not affect the GI ecosystem (pH, bacterial count, short chain fatty acids), monitored via the Simulator of the Human Intestinal Microbial Ecosystem (SHIME). The high drug load (65 wt.%) in combination with (in vitro and in vivo) controlled release capacity of the formulations, is noteworthy in the field of formulations produced via HME/IM. Copyright © 2014 Elsevier B.V. All rights reserved.

Formulation and evaluation of diclofenac controlled release matrix tablets made of HPMC and Poloxamer 188 polymer: An assessment on mechanism of drug release.

PubMed

Al-Hanbali, Othman A; Hamed, Rania; Arafat, Mosab; Bakkour, Youssef; Al-Matubsi, Hisham; Mansour, Randa; Al-Bataineh, Yazan; Aldhoun, Mohammad; Sarfraz, Muhammad; Dardas, Abdel Khaleq Yousef

2018-01-01

In this study, hydrophilic hydroxypropyl methylcellulose matrices with various concentrations of Poloxamer 188 were used in the development of oral controlled release tablets containing diclofenac sodium. Four formulations of hydrophilic matrix tablets containing 16.7% w/w HPMC and 0, 6.7, 16.7 and 25.0% w/w Poloxamer 188, respectively, were developed. Tablets were prepared by direct compression and characterized for diameter, hardness, thickness, weight and uniformity of content. The influence of various blends of hydroxypropyl methylcellulose and Poloxamer 188 on the in vitro dissolution profile and mechanism of drug release of was investigated. In the four formulations, the rate of drug release decreased with increasing the concentration of Poloxamer 188 at the initial dissolution stages due to the increase in the apparent viscosity of the gel diffusion layer. However, in the late dissolution stages, the rate of drug release increased with increasing Poloxamer 188 concentration due to the increase in wettability and dissolution of the matrix. The kinetic of drug release from the tablets followed non-Fickian mechanism, as predicted by Korsmeyer-Peppas model, which involves diffusion through the gel layer and erosion of the matrix system.

Controlling protein release using biodegradable microparticles

NASA Astrophysics Data System (ADS)

Kline, Benjamin Patrick

Research in the field of protein therapeutics has exploded over the past decade and continues to grow in both academia and in industry. Protein drugs have advantages of being highly specific and highly active making them coveted targets for high profile disease states like cancer and multiple sclerosis. Unfortunately, their many advantages are complemented by their obstacles. Because proteins are highly active and highly specific, the window between efficacy and toxicity is very narrow and drug development can be long and arduous. In addition, protein activity is dependent on its specific folding conformation that is easily disrupted by a variety of development processes. This research aimed to identify microparticle formulations to control protein release and also to determine which formulation parameters affected burst release, encapsulation, and steady-state release the most. It was found that polymer type and composition were two of the most important factors. Long-term controlled release of bovine serum albumin (BSA) was achieved as well as a wide variety of release profiles. A method was identified for micronizing protein at low cost to retain activity and coacervation was evaluated as a method for preparing protein loaded microspheres. This research provides a basis from which researchers can create better controlled release formulations for future protein therapeutics.

Fabrication of controlled-release budesonide tablets via desktop (FDM) 3D printing.

PubMed

Goyanes, Alvaro; Chang, Hanah; Sedough, Daniel; Hatton, Grace B; Wang, Jie; Buanz, Asma; Gaisford, Simon; Basit, Abdul W

2015-12-30

The aim of this work was to explore the feasibility of using fused deposition modelling (FDM) 3D printing (3DP) technology with hot melt extrusion (HME) and fluid bed coating to fabricate modified-release budesonide dosage forms. Budesonide was sucessfully loaded into polyvinyl alcohol filaments using HME. The filaments were engineered into capsule-shaped tablets (caplets) containing 9mg budesonide using a FDM 3D printer; the caplets were then overcoated with a layer of enteric polymer. The final printed formulation was tested in a dynamic dissolution bicarbonate buffer system, and two commercial budesonide products, Cortiment® (Uceris®) and Entocort®, were also investigated for comparison. Budesonide release from the Entocort® formulation was rapid in conditions of the upper small intestine while release from the Cortiment® product was more delayed and very slow. In contrast, the new 3D printed caplet formulation started to release in the mid-small intestine but release then continued in a sustained manner throughout the distal intestine and colon. This work has demonstrated the potential of combining FDM 3DP with established pharmaceutical processes, including HME and film coating, to fabricate modified release oral dosage forms. Copyright © 2015. Published by Elsevier B.V.

Influence of Differing Analgesic Formulations of Aspirin on Pharmacokinetic Parameters.

PubMed

Kanani, Kunal; Gatoulis, Sergio C; Voelker, Michael

2015-08-03

Aspirin has been used therapeutically for over 100 years. As the originator and an important marketer of aspirin-containing products, Bayer's clinical trial database contains numerous reports of the pharmacokinetics of various aspirin formulations. These include evaluations of plain tablets, effervescent tablets, granules, chewable tablets, and fast-release tablets. This publication seeks to expand upon the available pharmacokinetic information concerning aspirin formulations. In the pre-systemic circulation, acetylsalicylic acid (ASA) is rapidly converted into its main active metabolite, salicylic acid (SA). Therefore, both substances are measured in plasma and reported in the results. The 500 mg strength of each formulation was chosen for analysis as this is the most commonly used for analgesia. A total of 22 studies were included in the analysis. All formulations of 500 mg aspirin result in comparable plasma exposure to ASA and SA as evidenced by AUC. Tablets and dry granules provide a consistently lower Cmax compared to effervescent, granules in suspension and fast release tablets. Effervescent tablets, fast release tablets, and granules in suspension provide a consistently lower median Tmax compared to dry granules and tablets for both ASA and SA. This report reinforces the importance of formulation differences and their impact on pharmacokinetic parameters.

Influence of Differing Analgesic Formulations of Aspirin on Pharmacokinetic Parameters

PubMed Central

Kanani, Kunal; Gatoulis, Sergio C.; Voelker, Michael

2015-01-01

Aspirin has been used therapeutically for over 100 years. As the originator and an important marketer of aspirin-containing products, Bayer’s clinical trial database contains numerous reports of the pharmacokinetics of various aspirin formulations. These include evaluations of plain tablets, effervescent tablets, granules, chewable tablets, and fast-release tablets. This publication seeks to expand upon the available pharmacokinetic information concerning aspirin formulations. In the pre-systemic circulation, acetylsalicylic acid (ASA) is rapidly converted into its main active metabolite, salicylic acid (SA). Therefore, both substances are measured in plasma and reported in the results. The 500 mg strength of each formulation was chosen for analysis as this is the most commonly used for analgesia. A total of 22 studies were included in the analysis. All formulations of 500 mg aspirin result in comparable plasma exposure to ASA and SA as evidenced by AUC. Tablets and dry granules provide a consistently lower Cmax compared to effervescent, granules in suspension and fast release tablets. Effervescent tablets, fast release tablets, and granules in suspension provide a consistently lower median Tmax compared to dry granules and tablets for both ASA and SA. This report reinforces the importance of formulation differences and their impact on pharmacokinetic parameters. PMID:26247959

Preparation and pharmaceutical evaluation of glibenclamide slow release mucoadhesive buccal film

PubMed Central

Bahri-Najafi, R.; Tavakoli, N.; Senemar, M.; Peikanpour, M.

2014-01-01

Buccal mucoadhesive systems among novel drug delivery systems have attracted great attention in recent years due to their ability to adhere and remain on the oral mucosa and to release their drug content gradually. Buccal mucoadhesive films can improve the drug therapeutic effect by enhancement of drug absorption through oral mucosa increasing the drug bioavailability via reducing the hepatic first pass effect. The aim of the current study was to formulate the drug as buccal bioadhesive film, which releases the drug at sufficient concentration with a sustain manner reducing the frequency of the dosage form administration. One of the advantagees of this formulation is better patient compliances due to the ease of administration with no water to swallow the product. The mucoadhesive films of glibenclamide were prepared using hydroxypropyl methylcellulose (HPMC) K4M, K15M and Eudragit RL100 polymers and propylene glycol as plasticizer and co-solvent. Films were prepared using solvent casting method, and were evaluated with regard to drug content, thickness, weight variations, swelling index, tensile strength, ex vivo adhesion force and percentage of in vitro drug release. Films with high concentrations of HPMC K4M and K15M did not have favorable appearance and uniformity. The formulations prepared from Eudragit were transparent, uniform, flexible, and without bubble. The highest and the lowest percentages of swelling were observed for the films containing HPMC K15M and Eudragit RL100, respectively. Films made of HPMC K15M had adhesion force higher than those containing Eudragit RL100. Formulations with Eudragit RL100 showed the highest mean dissolution time (MDT). Drug release kinetics of all formulations followed Higuchi's model and the mechanism of diffusion was considered non-Fickian type. It was concluded that formulations containing Eudragit RL100 were more favorable than others with regard to uniformity, flexibility, rate and percentage of drug release. PMID:25657792

Two Formulations of Venlafaxine are Bioequivalent when Administered as Open Capsule Mixed with Applesauce to Healthy Subjects.

PubMed

Jain, Renu T; Panda, J; Srivastava, A

2011-09-01

Venlafaxine is a unique antidepressant approved for treatment of various depressive disorders. A single dose, cross-over bioequivalence study was performed with two different formulations of venlafaxine 150 mg extended-release capsules in which the contents of capsule were mixed with applesauce and administered to healthy subjects under fed condition. A total of 24 healthy adult male subjects participated in this randomized, single-dose, non-blinded, two-way crossover study conducted at a single centre and 23 subjects completed the study as per the study protocol. After an overnight fast of 10 h, a high-fat and high-calorie breakfast was served 30 min before dosing. The subjects then received a single dose of either formulation administered with apple sauce followed by 240 ml of water as per randomized schedule in each period separated by a washout period of 7 days. A series of blood samples were collected upto 72 h for estimation of venlafaxine and its active metabolite, O-desmethylvenlafaxine. The quantification of venlafaxine and O-desmethylvenlafaxine was done by LC-MS/MS method and pharmacokinetic and statistical analysis by WinNonlin(®) 5.2 and SAS(®) 9.1.3. The results of the study demonstrated bioequivalence of two formulations as the 90% confidence interval for the intra-individual mean ratio of log-transformed C(max), AUC(0-t) and AUC(0-inf) of the test to the reference formulation were found within the defined bioequivalence range of 80.00%-125.00%. Both the formulations were well tolerated. This alternative mode of administration may provide benefits to patients who have difficulty in swallowing the capsule as a whole.

Two Formulations of Venlafaxine are Bioequivalent when Administered as Open Capsule Mixed with Applesauce to Healthy Subjects

PubMed Central

Jain, Renu T.; Panda, J.; Srivastava, A.

2011-01-01

Venlafaxine is a unique antidepressant approved for treatment of various depressive disorders. A single dose, cross-over bioequivalence study was performed with two different formulations of venlafaxine 150 mg extended-release capsules in which the contents of capsule were mixed with applesauce and administered to healthy subjects under fed condition. A total of 24 healthy adult male subjects participated in this randomized, single-dose, non-blinded, two-way crossover study conducted at a single centre and 23 subjects completed the study as per the study protocol. After an overnight fast of 10 h, a high-fat and high-calorie breakfast was served 30 min before dosing. The subjects then received a single dose of either formulation administered with apple sauce followed by 240 ml of water as per randomized schedule in each period separated by a washout period of 7 days. A series of blood samples were collected upto 72 h for estimation of venlafaxine and its active metabolite, O-desmethylvenlafaxine. The quantification of venlafaxine and O-desmethylvenlafaxine was done by LC-MS/MS method and pharmacokinetic and statistical analysis by WinNonlin® 5.2 and SAS® 9.1.3. The results of the study demonstrated bioequivalence of two formulations as the 90% confidence interval for the intra-individual mean ratio of log-transformed Cmax, AUC0-t and AUC0-inf of the test to the reference formulation were found within the defined bioequivalence range of 80.00%-125.00%. Both the formulations were well tolerated. This alternative mode of administration may provide benefits to patients who have difficulty in swallowing the capsule as a whole. PMID:22923863

Electrically atomised formulations of timolol maleate for direct and on-demand ocular lens coatings.

PubMed

Mehta, Prina; Al-Kinani, Ali A; Haj-Ahmad, Rita; Arshad, Muhammad Sohail; Chang, Ming-Wei; Alany, Raid G; Ahmad, Zeeshan

2017-10-01

Advances in nanotechnology have enabled solutions for challenging drug delivery targets. While the eye presents numerous emerging opportunities for delivery, analysis and sensing; issues persist for conventional applications. This includes liquid phase formulation localisation on the ocular surface once administered as formulated eye-drops; with the vast majority of dosage (>90%) escaping from the administered site due to tear production and various drainage mechanisms. The work presented here demonstrates a single needle electrohydrodynamic (EHD) engineering process to nano-coat (as an on demand and controllable fiber depositing method) the surface of multiple contact lenses rendering formulations to be stationary on the lens and at the bio-interface. The coating process was operational based on ejected droplet charge and glaucoma drug timolol maleate (TM) was used to demonstrate surface coating optimisation, bio-surface permeation properties (flux, using a bovine model) and various kinetic models thereafter. Polymers PVP, PNIPAM and PVP:PNIPAM (50:50%w/w) were used to encapsulate the active. Nano-fibrous and particulate samples were characterised using SEM, FTIR, DSC and TGA to confirm structural and thermal stability of surface coated formulations. More than 52% of nano-structured coatings (for all formulations) were <200nm in diameter. In vitro studies show coatings to exhibit biphasic release profiles; an initial burst release followed by sustained release; with TM-loaded PNIPAM coating releasing most drug after 24h (89.8%). Kinetic modelling (Higuchi, Korsmeyer-Peppas) was indicative of quasi-Fickian diffusion whilst biological evaluation demonstrates adequate ocular tolerability. Results from permeation studies indicate coated lenses are ideal to reduce dosing regimen, which in turn will reduce systemic drug absorption. Florescent microscopy demonstrated probe and probe embedded coating behaviour from lens surface in vitro. The multiple lens surface coating method demonstrates sustained drug release yielding promising results; suggesting both novel device and method to enhance drug activity at the eyes surface which will reduce formulation drainage. Crown Copyright © 2017. Published by Elsevier B.V. All rights reserved.

Direct comparison of two different mesalamine formulations for the induction of remission in patients with ulcerative colitis: A double-blind, randomized study

PubMed Central

Ito, Hiroaki; Iida, Mitsuo; Matsumoto, Takayuki; Suzuki, Yasuo; Sasaki, Hidetaka; Yoshida, Toyomitsu; Takano, Yuichi; Hibi, Toshifumi

2010-01-01

Background: Mesalamine is the first-line drug for the treatment of ulcerative colitis (UC). We directly compared the efficacy and safety of two mesalamine formulations for the induction of remission in patients with UC. Methods: In a multicenter, double-blind, randomized study, 229 patients with mild-to-moderate active UC were assigned to 4 groups: 66 and 65 received a pH-dependent release formulation of 2.4 g/day (pH-2.4 g) or 3.6 g/day (pH-3.6 g), respectively; 65 received a time-dependent release formulation of 2.25 g/day (Time-2.25 g), and 33 received placebo (Placebo). The drugs were administered three times daily for eight weeks. The primary endpoint was a decrease in the UC disease activity index (UC-DAI). Results: In the full analysis set (n = 225) the decrease in UC-DAI in each group was 1.5 in pH-2.4 g, 2.9 in pH-3.6 g, 1.3 in Time-2.25 g and 0.3 in Placebo, respectively. These results demonstrate the superiority of pH-3.6 g over Time-2.25 g (P = 0.003) and the noninferiority of pH-2.4 g to Time-2.25 g. Among the patients with proctitis-type UC, a significant decrease in UC-DAI was observed in pH-2.4 g and pH-3.6 g as compared to Placebo, but not in Time-2.25 g. No differences were observed in the safety profiles. Conclusions: Higher dose of the pH-dependent release formulation was more effective for induction of remission in patients with mild-to-moderate active UC. Additionally, the pH-dependent release formulation was preferable to the time-dependent release formulation for patients with proctitis-type UC (UMIN Clinical Trials Registry, no. C000000288). (Inflamm Bowel Dis 2010) PMID:20049950

Formulation and In-vitro Evaluation of Tretinoin Microemulsion as a Potential Carrier for Dermal Drug Delivery

PubMed Central

Mortazavi, Seyed Alireza; Pishrochi, Sanaz; Jafari azar, Zahra

2013-01-01

In this study, tretinoin microemulsion has been formulated based on phase diagram studies by changing the amounts and proportions of inactive ingredients, such as surfactants, co-surfactants and oils. The effects of these variables have been determined on microemulsion formation, particle size of the dispersed phase and release profile of tretinoin from microemulsion through dialysis membrane. In released studies, static Franz diffusion cells mounted with dialysis membrane were used. Sampling was conducted every 3 h at room temperature over a period of 24 h. The amount of released drug was measured with UV-spectrophotometer and the percentage of drug released was calculated. Based on the results obtained, the oil phase concentration had a proportional effect on particle size which can consequently influence on drug release. The particle size and the amount of released drug were affected by the applied surfactants. The components of the optimized microemulsion formulation were 15% olive oil, 12% propylene glycol (as co-surfactant), 33% Tween®80 (as surfactant) and 40% distilled water, which was tested for viscosity and rheological behavior. The prepared tretinoin microemulsion showed pseudoplastic-thixotropic behavior. The profile of drug release follows zero order kinetics. The optimized tretinoin microemulsion showed enhanced in-vitro release profile compared to the commercial gels and creams. PMID:24523740

Pharmaceutical quality of "party pills" raises additional safety concerns in the use of illicit recreational drugs.

PubMed

Young, Simon A; Thrimawithana, Thilini R; Antia, Ushtana; Fredatovich, John D; Na, Yonky; Neale, Peter T; Roberts, Amy F; Zhou, Huanyi; Russell, Bruce

2013-06-14

To determine the content and release kinetics of 1-benzylpiperazine (BZP) and 1-(3-trifluoromethyl-phenyl)piperazine (TFMPP) from "party pill" formulations. From these data, the possible impact of pharmaceutical quality upon the safety of such illicit formulations may be inferred. The amount of BZP and TFMPP in party pill formulations was determined using a validated HPLC method. The in-vitro release kinetics of selected party pill brands were determined using a USP dissolution apparatus (75 rpm, 37.5 degrees Celsius). The release data were then fitted to a first order release model using PLOT software and the time taken to achieve 90% release reported. Many of the tested party pill brands contained amounts of BZP and TFMPP that varied considerably from that stated on the packaging; including considerable TFMPP content in some brands not labelled to contain this drug. Dissolution studies revealed that there was considerable variability in the release kinetics between brands; in one case 90% release required >30 minutes. Lack of quality control in party pill manufacture may have led to the toxic effects reported by users unaware of the true content and release of drug from pills. More stringent regulation in the manufacture and quality control of "new generation party pills" is essential to the harm reduction campaign.

Control-release microcapsule of famotidine loaded biomimetic synthesized mesoporous silica nanoparticles: Controlled release effect and enhanced stomach adhesion in vitro.

PubMed

Li, Jing; Wang, Hongyu; Yang, Baixue; Xu, Lu; Zheng, Nan; Chen, Hongtao; Li, Sanming

2016-01-01

In the present work, control-release microcapsule of famotidine (FMT) loaded biomimetic synthesized mesoporous silica nanoparticles (B-MSNs) was developed, and controlled release effect and stomach adhesion of this formulation in vitro were mainly investigated. B-MSN was previously synthesized and it was amorphous mesoporous nanoparticles with helical channels. Cytotoxicity of B-MSN was studied using human breast cancer cells (MCF-7) and the result indicated that cytotoxicity of B-MSN can be neglected. After loading FMT into B-MSN, specific surface area, pore volume and pore diameter of B-MSN were obviously reduced. In vitro dissolution test showed that B-MSN had the ability to slow down FMT release for 15 min. In order to prolong controlled release effect and remained the advantage of B-MSN (improve drug stability due to its rigid silica framework), the combined application of control-release microcapsule (using cellulose and hydroxypropyl methylcellulose K15M as excipients) with B-MSN was designed. It was obvious that newly designed formulation significantly controlled FMT release with Fickian diffusion mechanism and showed enhanced stomach adhesion in vitro, which has significant value in widening the application of B-MSN in formulation design. Copyright © 2015 Elsevier B.V. All rights reserved.

Formulation and In-vitro Evaluation of Tretinoin Microemulsion as a Potential Carrier for Dermal Drug Delivery.

PubMed

Mortazavi, Seyed Alireza; Pishrochi, Sanaz; Jafari Azar, Zahra

2013-01-01

In this study, tretinoin microemulsion has been formulated based on phase diagram studies by changing the amounts and proportions of inactive ingredients, such as surfactants, co-surfactants and oils. The effects of these variables have been determined on microemulsion formation, particle size of the dispersed phase and release profile of tretinoin from microemulsion through dialysis membrane. In released studies, static Franz diffusion cells mounted with dialysis membrane were used. Sampling was conducted every 3 h at room temperature over a period of 24 h. The amount of released drug was measured with UV-spectrophotometer and the percentage of drug released was calculated. Based on the results obtained, the oil phase concentration had a proportional effect on particle size which can consequently influence on drug release. The particle size and the amount of released drug were affected by the applied surfactants. The components of the optimized microemulsion formulation were 15% olive oil, 12% propylene glycol (as co-surfactant), 33% Tween(®)80 (as surfactant) and 40% distilled water, which was tested for viscosity and rheological behavior. The prepared tretinoin microemulsion showed pseudoplastic-thixotropic behavior. The profile of drug release follows zero order kinetics. The optimized tretinoin microemulsion showed enhanced in-vitro release profile compared to the commercial gels and creams.

Prescribing practices amid the OxyContin crisis: examining the effect of print media coverage on opioid prescribing among physicians.

PubMed

Borwein, Alexandra; Kephart, George; Whelan, Emma; Asbridge, Mark

2013-12-01

The pain medication OxyContin (hereafter referred to as oxycodone extended release) has been the subject of sustained, and largely negative, media attention in recent years. We sought to determine whether media coverage of oxycodone extended release in North American newspapers has led to changes in prescribing of the drug in Nova Scotia, Canada. An interrupted time-series design examined the effect of media attention on physicians' monthly prescribing of opioids. The outcome measures were, for each physician, the monthly proportions of all opioids prescribed and the proportion of strong opioids prescribed that were for oxycodone extended release. The exposure of interest was media attention defined as the number of articles published each month in 27 North American newspapers. Variations in media effects by provider characteristics (specialty, prescribing volume, and region) were assessed. Within-provider changes in the prescribing of oxycodone extended release in Nova Scotia were observed, and they followed changes in media coverage. Oxycodone extended release prescribing rose steadily prior to receiving media attention. Following peak media attention in the United States, the prescribing of oxycodone extended release slowed. Likewise, following peak coverage in Canadian newspapers, the prescribing of oxycodone extended release declined. These patterns were observed across prescriber specialties and by prescriber volume, though the magnitude of change in prescribing varied. This study demonstrates that print media reporting of oxycodone extended release in North American newspapers, and its continued portrayal as a social problem, coincided with reductions in the prescribing of oxycodone extended release by physicians in Nova Scotia. Copyright © 2013 American Pain Society. Published by Elsevier Inc. All rights reserved.

Synthesis and characterization of antibacterial dental monomers and composites

PubMed Central

Xu, Xiaoming; Wang, Yapin; Liao, Sumei; Wen, Zezhang T.; Fan, Yuwei

2012-01-01

The objective of this study is to synthesize antibacterial methacrylate and methacrylamide monomers and formulate antibacterial fluoride-releasing dental composites. Three antibacterial methacrylate or methacrylamide monomers containing long-chain quaternary ammonium fluoride, 1,2-methacrylamido-N,N,N-trimethyldodecan-1-aminium fluoride (monomer I), N-benzyl-11-(methacryloyloxy)-N,N-dimethylundecan-1-aminium fluoride (monomer II), and methacryloxyldecylpyridinium fluoride (monomer III) have been synthesized and analyzed by nuclear magnetic resonance (NMR) and mass spectrometry (MS). The cytotoxicity test and bactericidal test against Streptococcus mutans indicate that antibacterial monomer II is superior to monomers I and III. A series of dental composites containing 0–6% of antibacterial monomer II have been formulated and tested for degree of conversion (DC), flexure strength, water sorption, solubility, and inhibition of S. mutans biofilms. An antibacterial fluoride-releasing dental composite has also been formulated and tested for flexure strength and fluoride release. The dental composite containing 3% of monomer II has a significant effect against S. mutans biofilm formation without major adverse effects on its physical and mechanical properties. The new antibacterial monomers can be used together with the fluoride-releasing monomers containing a ternary zirconiun- fluoride chelate to formulate a new antibacterial fluoride- releasing dental composite. Such a new dental composite is expected to have higher anticaries efficacy and longer service life. PMID:22447582

Controlled drug delivery systems: past forward and future back.

PubMed

Park, Kinam

2014-09-28

Controlled drug delivery technology has progressed over the last six decades. This progression began in 1952 with the introduction of the first sustained release formulation. The 1st generation of drug delivery (1950-1980) focused on developing oral and transdermal sustained release systems and establishing controlled drug release mechanisms. The 2nd generation (1980-2010) was dedicated to the development of zero-order release systems, self-regulated drug delivery systems, long-term depot formulations, and nanotechnology-based delivery systems. The latter part of the 2nd generation was largely focused on studying nanoparticle formulations. The Journal of Controlled Release (JCR) has played a pivotal role in the 2nd generation of drug delivery technologies, and it will continue playing a leading role in the next generation. The best path towards a productive 3rd generation of drug delivery technology requires an honest, open dialog without any preconceived ideas of the past. The drug delivery field needs to take a bold approach to designing future drug delivery formulations primarily based on today's necessities, to produce the necessary innovations. The JCR provides a forum for sharing the new ideas that will shape the 3rd generation of drug delivery technology. Copyright © 2014 Elsevier B.V. All rights reserved.

Preparation and In vitro Evaluation of Naproxen Suppositories

PubMed Central

Hargoli, S.; Farid, J.; Azarmi, S. H.; Ghanbarzadeh, S.; Zakeri-Milani, P.

2013-01-01

The aim of this work was to develop the best formulations for naproxen suppositories. The effects of different bases and surfactants on the physicochemical characteristics of the suppositories were determined by several tests such as weight variation, melting point, assay, hardness, and release rate. All formulations met the standard criteria for tested physicochemical parameters; weight variation (97-112%), content uniformity (97-105%), melting point (4.66-8.7 min) and hardness tests (>5400 g). Based on release rate studies, hydrophilic, and lipophilic bases without surfactants were not suitable bases for naproxen suppository. Amongst the formulations containing surfactants only Witepsol H15 with 0.5% w/w of Tween 80 and Witepsol W35 with 0.5% of cetylpyridinium chloride were suitable and released nearly complete drug during 30 and 60 min, respectively. This study demonstrates the effects of incorporation of known agents on the in vitro release characteristics of naproxen suppository. PMID:24019561