A mathematical analysis of drug dissolution in the USP flow through apparatus

NASA Astrophysics Data System (ADS)

McDonnell, David; D'Arcy, D. M.; Crane, L. J.; Redmond, Brendan

2018-03-01

This paper applies boundary layer theory to the process of drug dissolution in the USP (United States Pharmacopeia) Flow Through Apparatus. The mass transfer rate from the vertical planar surface of a compact within the device is examined. The theoretical results obtained are then compared with those of experiment. The paper also examines the effect on the dissolution process caused by the interaction between natural and forced convection within the apparatus and the introduction of additional boundaries.

Influence of dissolution media pH and USP1 basket speed on erosion and disintegration characteristics of immediate release metformin hydrochloride tablets.

PubMed

Desai, Divyakant; Wong, Benjamin; Huang, Yande; Tang, Dan; Hemenway, Jeffrey; Paruchuri, Srinivasa; Guo, Hang; Hsieh, Daniel; Timmins, Peter

2015-01-01

To investigate the influence of the pH of the dissolution medium on immediate release 850 mg metformin hydrochloride tablets. A traditional wet granulation method was used to manufacture metformin hydrochloride tablets with or without a disintegrant. Tablet dissolution was conducted using the USP apparatus I at 100 rpm. In spite of its pH-independent high solubility, metformin hydrochloride tablets dissolved significantly slower in 0.1 N HCl (pH 1.2) and 50 mM pH 4.5 acetate buffer compared with 50 mM pH 6.8 phosphate buffer, the dissolution medium in the USP. Metformin hydrochloride API compressed into a round 1200 mg disk showed a similar trend. When basket rotation speed was increased from 100 to 250 rpm, the dissolution of metformin hydrochloride tablets was similar in all three media. Incorporation of 2% w/w crospovidone in the tablet formulation improved the dissolution although the pH-dependent trend was still evident, but incorporation of 2% w/w croscarmellose sodium resulted in rapid pH-independent tablet dissolution. In absence of a disintegrant in the tablet formulation, the dissolution was governed by the erosion-diffusion process. Even for a highly soluble drug, a super-disintegrant was needed in the formulation to overcome the diffusion layer limitation and change the dissolution mechanism from erosion-diffusion to disintegration.

Development and validation of a discriminating in vitro dissolution method for a poorly soluble drug, olmesartan medoxomil: comparison between commercial tablets.

PubMed

Bajerski, Lisiane; Rossi, Rochele Cassanta; Dias, Carolina Lupi; Bergold, Ana Maria; Fröehlich, Pedro Eduardo

2010-06-01

A dissolution test for tablets containing 40 mg of olmesartan medoxomil (OLM) was developed and validated using both LC-UV and UV methods. After evaluation of the sink condition, dissolution medium, and stability of the drug, the method was validated using USP apparatus 2, 50 rpm rotation speed, and 900 ml of deaerated H(2)O + 0.5% sodium lauryl sulfate (w/v) at pH 6.8 (adjusted with 18% phosphoric acid) as the dissolution medium. The model-independent method using difference factor (f(1)) and similarity factor (f(2)), model-dependent method, and dissolution efficiency were employed to compare dissolution profiles. The kinetic parameters of drug release were also investigated. The obtained results provided adequate dissolution profiles. The developed dissolution test was validated according to international guidelines. Since there is no monograph for this drug in tablets, the dissolution method presented here can be used as a quality control test for OLM in this dosage form, especially in a batch to batch evaluation.

Digitizing Medicines for Remote Capture of Oral Medication Adherence Using Co‐encapsulation

PubMed Central

Peloquin, C; Santillo, F; Haubrich, R; Muttera, L; Moser, K; Savage, GM; Benson, CA; Blaschke, TF

2017-01-01

High‐resolution measurement of medication adherence is essential to personalized drug therapy. A US Food and Drug Administration (FDA)‐cleared device, using an edible ingestion sensor (IS), external wearable patch, and paired mobile device can detect and record ingestion events. Oral medications must be combined with an IS to generate precise “digitized‐medication” ingestion records. We developed a Good Manufacturing Practice protocol to repackage oral medications with the IS within certified Capsugel capsules, termed co‐encapsulation (CoE). A randomized bioequivalence study of CoE‐IS‐Rifamate (Isoniazid/Rifampin 150/300 mg) vs. native‐Rifamate was conducted in 12 patients with active Mycobacterium tuberculosis and demonstrated bioequivalence using the population method ratio test (95% confidence interval). Subsequently, CoE‐IS‐medications across all biopharmaceutical classes underwent in vitro dissolution testing utilizing USP and FDA guidelines. CoE‐IS medications tested met USP dissolution specifications and were equivalent to their native formulations. CoE combines oral medications with the IS without altering the quality of the native formulation, generating “digitized” medications for remote capture of dosing histories. PMID:28597911

Magnetic resonance imaging of tablet dissolution.

PubMed

Nott, Kevin P

2010-01-01

Magnetic resonance imaging (MRI) is the technique of choice for measuring hydration, and its effects, during dissolution of tablets since it non-invasively maps (1)H nuclei associated with 'mobile' water. Although most studies have used MRI systems with high-field superconducting magnets, low-field laboratory-based instruments based on permanent magnet technology are being developed that provide key data for the formulation scientist. Incorporation of dissolution hardware, in particular the United States Pharmacopeia (USP) apparatus 4 flow-through cell, allows measurements under controlled conditions for comparison against other dissolution methods. Furthermore, simultaneous image acquisition and measurement of drug concentration allow direct comparison of the drug release throughout the hydration process. The combination of low-field MRI with USP-4 apparatus provides another tool to aid tablet formulation. Copyright 2009 Elsevier B.V. All rights reserved.

Assessment of oral bioavailability enhancing approaches for SB-247083 using flow-through cell dissolution testing as one of the screens.

PubMed

Perng, Cherng-Yih; Kearney, Albert S; Palepu, Nagesh R; Smith, Brian R; Azzarano, Leonard M

2003-01-02

SB-247083 is a potent, nonpeptidic, orally active, ETA-selective, endothelin receptor antagonist. The diacid form and three salts (monoarginine, diarginine and disodium) of SB-247083 were evaluated during the pre-clinical phase of development. The developability attributes (i.e. hygroscopicity, thermal behavior, aqueous solubility, and drug-excipient compatibility) of these compounds were evaluated. In addition to these attributes, the flow-through cell (FTC) dissolution testing (using USP Apparatus 4) was used as a screening technique to evaluate several SB-247083 formulations of the diacid and its salts. FTC dissolution testing offers two distinct advantages over the more traditional static-condition dissolution testing: (1) maintenance of sink conditions; and (2) the ability to change the dissolution medium during a dissolution run. The former advantage is especially important for poorly aqueous soluble drugs having associated dissolution-rate-limitations, and the latter advantage allows one to more closely simulate the pH gradient associated with transit through the GI tract. Based on the comparative dissolution data, three formulations were chosen for oral dosing in dogs. The reasonable correlation found between the FTC dissolution results and the oral bioavailability data demonstrate that FTC dissolution testing can be a valuable tool for aiding in salt (solid-state form) and formulation selection in the early stages of development of drug candidates.

Substandard Antimalarials Available in Afghanistan: A Case for Assessing the Quality of Drugs in Resource Poor Settings

PubMed Central

Lalani, Mirza; Kaur, Harparkash; Mohammed, Nader; Mailk, Naiela; van Wyk, Albert; Jan, Sakhi; Kakar, Rishtya Meena; Mojadidi, Mohammed Khalid; Leslie, Toby

2015-01-01

Good-quality antimalarials are crucial for the effective treatment and control of malaria. A total of 7,740 individual and packaged tablets, ampoules, and syrups were obtained from 60 randomly selected public (N = 35) and private outlets (N = 25) in Afghanistan. Of these, 134 samples were screened using the Global Pharma Health Fund (GPHF) MiniLab® in Kabul with 33/126 (26%) samples failing the MiniLab® disintegration test. The quality of a subsample (N = 37) of cholorquine, quinine, and sulfadoxine/pyrimethamine tablets was assessed by in vitro dissolution testing following U.S. Pharmacopeia (USP) monographs at a bioanalytical laboratory in London, United Kingdom. Overall, 12/32 (32%) samples of sulfadoxine/pyrimethamine and quinine were found not to comply with the USP tolerance limits. Substandard antimalarials were available in Afghanistan demonstrating that continuous monitoring of drug quality is warranted. However, in Afghanistan as in many low-income countries, capacity to determine and monitor drug quality using methods such as dissolution testing needs to be established to empower national authorities to take appropriate action in setting up legislation and regulation. PMID:25897070

The Properties of HPMC:PEO Extended Release Hydrophilic Matrices and their Response to Ionic Environments.

PubMed

Hu, Anran; Chen, Chen; Mantle, Michael D; Wolf, Bettina; Gladden, Lynn F; Rajabi-Siahboomi, Ali; Missaghi, Shahrzad; Mason, Laura; Melia, Colin D

2017-05-01

Investigate the extended release behaviour of compacts containing mixtures of hydrophilic HPMC and PEO in hydrating media of differing ionic strengths. The extended release behaviour of various HPMC:PEO compacts was investigated using dissolution testing, confocal microscopy and magnetic resonance imaging, with respect to polymer ratio and ionic strength of the hydrating media. Increasing HPMC content gave longer extended release times, but a greater sensitivity to high ionic dissolution environments. Increasing PEO content reduced this sensitivity. The addition of PEO to a predominantly HPMC matrix reduced release rate sensitivity to high ionic environments. Confocal microscopy of early gel layer development showed the two polymers appeared to contribute independently to gel layer structure whilst together forming a coherent and effective diffusion barrier. There was some evidence that poorly swollen HPMC particles added a tortuosity barrier to the gel layer in high ionic strength environments, resulting in prolonged extended release. MRI provides unique, non-invasive spatially resolved information from within the HPMC:PEO compacts that furthers our understanding of USP 1 and USP 4 dissolution data. Confocal microscopy and MRI data show that combinations of HPMC and PEO have advantageous extended release properties, in comparison with matrices containing a single polymer.

The use of ordered mixtures for improving the dissolution rate of low solubility compounds.

PubMed

Nyström, C; Westerberg, M

1986-03-01

The dissolution rate of micronized griseofulvin has been investigated, both for the agglomerated raw material and the material formulated as an ordered mixture, by means of the USP XX paddle method. During the experiments, which were performed at sink condition and constant temperature, the effects of adding a surfactant and of agitation were tested. The ordered mixture with sodium chloride gave a fast dissolution rate, practically independent of the test parameters. Micronized griseofulvin alone gave dissolution profiles that were improved by adding polysorbate 80 and by increased agitation, but the dissolution rates obtained were much lower than those for the ordered mixture. It was concluded that the rate limiting step in the dissolution of griseofulvin as the raw material is the penetration of the dissolution medium into the agglomerates. With an ordered mixture, these agglomerates were deaggregated during the mixing process, producing a system in which the entire external surface area of the primary particles was exposed to the dissolution medium. This conclusion was supported by calculation of the contact surface areas taking part in the dissolution process for the systems tested. The procedure developed in this study could be applied to preformulation work where a cohesive, low solubility drug of hydrophobic nature is to be formulated.

Development and Validation of Discriminating and Biorelevant Dissolution Test for Lornoxicam Tablets

PubMed Central

Anumolu, P. D.; Sunitha, G.; Bindu, S. Hima; Satheshbabu, P. R.; Subrahmanyam, C. V. S.

2015-01-01

The establishment of biorelevant and discriminating dissolution procedure for drug products with limited water solubility is a useful technique for qualitative forecasting of the in vivo behavior of formulations. It also characterizes the drug product performance in pharmaceutical development. Lornoxicam, a BCS class-II drug is a nonsteroidal antiinflammatory drug of the oxicam class, has no official dissolution media available in the literature. The objective of present work was to develop and validate a discriminating and biorelevant dissolution test for lornoxicam tablet dosage forms. To quantify the lornoxicam in dissolution samples, UV spectrophotometric method was developed using 0.01M sodium hydroxide solution as solvent at λma×376 nm. After evaluation of saturation solubility, dissolution, sink conditions and stability of lornoxicam bulk drug in different pH solutions and biorelevant media, the dissolution method was optimized using USP paddle type apparatus at 50 rpm rotation speed and 500 ml simulated intestinal fluid as discriminating and biorelevant dissolution medium. The similarity factor (f2) were investigated for formulations with changes in composition and manufacturing variations, values revealed that dissolution method having discriminating power and method was validated as per standard guidelines. The proposed dissolution method can be effectively applied for routine quality control in vitro dissolution studies of lornoxicam in tablets and helpful to pharmacopoeias. PMID:26180277

Development and Validation of Discriminating and Biorelevant Dissolution Test for Lornoxicam Tablets.

PubMed

Anumolu, P D; Sunitha, G; Bindu, S Hima; Satheshbabu, P R; Subrahmanyam, C V S

2015-01-01

The establishment of biorelevant and discriminating dissolution procedure for drug products with limited water solubility is a useful technique for qualitative forecasting of the in vivo behavior of formulations. It also characterizes the drug product performance in pharmaceutical development. Lornoxicam, a BCS class-II drug is a nonsteroidal antiinflammatory drug of the oxicam class, has no official dissolution media available in the literature. The objective of present work was to develop and validate a discriminating and biorelevant dissolution test for lornoxicam tablet dosage forms. To quantify the lornoxicam in dissolution samples, UV spectrophotometric method was developed using 0.01M sodium hydroxide solution as solvent at λma×376 nm. After evaluation of saturation solubility, dissolution, sink conditions and stability of lornoxicam bulk drug in different pH solutions and biorelevant media, the dissolution method was optimized using USP paddle type apparatus at 50 rpm rotation speed and 500 ml simulated intestinal fluid as discriminating and biorelevant dissolution medium. The similarity factor (f2) were investigated for formulations with changes in composition and manufacturing variations, values revealed that dissolution method having discriminating power and method was validated as per standard guidelines. The proposed dissolution method can be effectively applied for routine quality control in vitro dissolution studies of lornoxicam in tablets and helpful to pharmacopoeias.

Development of a Suitable Dissolution Method for the Combined Tablet Formulation of Atorvastatin and Ezetimibe by RP-LC Method.

PubMed

Ozkan Cansel, Kose; Ozgur, Esim; Sevinc, Kurbanoglu; Ayhan, Savaser; Ozkan, Sibel A; Yalcin, Ozkan

2016-01-01

Pharmaceutical preparations of ezetimibe and atorvastatin are generally used to regulate the lipid level in blood. It decreases the secondary events for patients with high cholesterol and clinical cardiovascular disease such as non-fatal or fatal heart attack. There is no any pharmacopoeia method available for the dissolution testing recommended by the FDA. Development of dissolution tests method is very critical parameter especially for the pharmaceutical preparations that contain Class II drugs (slightly soluble, good permeable). In the proposed method, the effects of pH and surfactant on the dissolution of poorly water soluble combined drug therapy with a different pKa values in an in vitro environment is investigated. The content of our study was designed to answer these open-ended questions. The optimized test conditions achieved under sink conditions with USP apparatus 2 at a paddle rotation speed of 75 rpm and 900 ml in 0.01 M Acetate buffer (pH= 6.8) containing 0.45% SDS as a dissolution medium. Quantification of dissolution samples were analyzed with a new fully validated RP-LC method with UV detection at 242 nm.

Effects of Pump Pulsation on Hydrodynamic Properties and Dissolution Profiles in Flow-Through Dissolution Systems (USP 4).

PubMed

Yoshida, Hiroyuki; Kuwana, Akemi; Shibata, Hiroko; Izutsu, Ken-Ichi; Goda, Yukihiro

2016-06-01

To clarify the effects of pump pulsation and flow-through cell (FTC) dissolution system settings on the hydrodynamic properties and dissolution profiles of model formulations. Two FTC systems with different cell temperature control mechanisms were used. Particle image velocimetry (PIV) was used to analyze the hydrodynamic properties of test solutions in the flow-through dissolution test cell. Two pulsation pumps (semi-sine, full-sine) and a non-pulsatile pump were used to study the effects of varied flows on the dissolution profiles of United States Pharmacopeia standard tablets. PIV analysis showed periodic changes in the aligned upward fluid flow throughout the dissolution cell that was designed to reduce the temperature gradient during pump pulsation (0.5 s/pulse). The maximum instantaneous flow from the semi-sine pump was higher than that of the full-sine pump under all conditions. The flow from the semi-sine wave pump showed faster dissolution of salicylic acid and prednisone tablets than those from other pumps. The semi-sine wave pump flow showed similar dissolution profiles in the two FTC systems. Variations in instantaneous fluid flow caused by pump pulsation that meets the requirements of pharmacopoeias are a factor that affects the dissolution profiles of tablets in FTC systems.

Understanding and predicting the impact of critical dissolution variables for nifedipine immediate release capsules by multivariate data analysis.

PubMed

Mercuri, A; Pagliari, M; Baxevanis, F; Fares, R; Fotaki, N

2017-02-25

In this study the selection of in vivo predictive in vitro dissolution experimental set-ups using a multivariate analysis approach, in line with the Quality by Design (QbD) principles, is explored. The dissolution variables selected using a design of experiments (DoE) were the dissolution apparatus [USP1 apparatus (basket) and USP2 apparatus (paddle)], the rotational speed of the basket/or paddle, the operator conditions (dissolution apparatus brand and operator), the volume, the pH, and the ethanol content of the dissolution medium. The dissolution profiles of two nifedipine capsules (poorly soluble compound), under conditions mimicking the intake of the capsules with i. water, ii. orange juice and iii. an alcoholic drink (orange juice and ethanol) were analysed using multiple linear regression (MLR). Optimised dissolution set-ups, generated based on the mathematical model obtained via MLR, were used to build predicted in vitro-in vivo correlations (IVIVC). IVIVC could be achieved using physiologically relevant in vitro conditions mimicking the intake of the capsules with an alcoholic drink (orange juice and ethanol). The multivariate analysis revealed that the concentration of ethanol used in the in vitro dissolution experiments (47% v/v) can be lowered to less than 20% v/v, reflecting recently found physiological conditions. Copyright © 2016 Elsevier B.V. All rights reserved.

Drug formulations intended for the global market should be tested for stability under tropical climatic conditions.

PubMed

Risha, P G; Vervaet, C; Vergote, G; Bortel, L Van; Remon, J P

2003-06-01

The quality of drugs imported into developing countries having a tropical climate may be adversely affected if their formulations have not been optimized for stability under these conditions. The present study investigated the influence of tropical climate conditions (class IV: 40 degrees C, 75% relative humidity) on the drug content, in vitro dissolution and oral bioavailability of different formulations of two essential drugs marketed in Tanzania: diclofenac sodium and ciprofloxacin tablets. Before and after 3 and 6 months storage under class IV conditions the drug content and in vitro dissolution were evaluated using United States Pharmacopoeia (USP) 24 methods. Following a randomized four-period cross-over study, the pharmacokinetic parameters of drug formulations stored for 3 months under class IV conditions were compared with those stored at ambient conditions. Drug content and drug release from all tested ciprofloxacin formulations were within USP-24 requirements and remained stable during storage at simulated tropical conditions. Oral bioavailability was also not influenced by tropical conditions. The dissolution rate of two diclofenac formulations (Diclo 50 manufactured by Camden and Dicloflame 50 manufactured by Intas) reduced significantly during storage under class IV conditions. After oral administration Camden tablets stored for 3 months under class IV conditions showed a reduction in C(max) (90% CI of C(max) ratio: 0.59 - 0.76). This reduction was smaller than expected based on the in vitro tests. Some drug formulations imported into Tanzania are not optimized for stability in a tropical climate. Manufacturers and regulatory authorities should pay more attention to the WHO recommendations for testing the stability of drugs under tropical climate conditions. Efforts should be made to improve the in vitro tests to better predict the bioavailability.

Use of bicarbonate buffer systems for dissolution characterization of enteric-coated proton pump inhibitor tablets.

PubMed

Shibata, Hiroko; Yoshida, Hiroyuki; Izutsu, Ken-Ichi; Goda, Yukihiro

2016-04-01

The aim of this study was to assess the effects of buffer systems (bicarbonate or phosphate at different concentrations) on the in vitro dissolution profiles of commercially available enteric-coated tablets. In vitro dissolution tests were conducted using an USP apparatus II on 12 enteric-coated omeprazole and rabeprazole tablets, including innovator and generic formulations in phosphate buffers, bicarbonate buffers and a media modified Hanks (mHanks) buffer. Both omeprazole and rabeprazole tablets showed similar dissolution profiles among products in the compendial phosphate buffer system. However, there were large differences between products in dissolution lag time in mHanks buffer and bicarbonate buffers. All formulations showed longer dissolution lag times at lower concentrations of bicarbonate or phosphate buffers. The dissolution rank order of each formulation differed between mHanks buffer and bicarbonate buffers. A rabeprazole formulation coated with a methacrylic acid copolymer showed the shortest lag time in the high concentration bicarbonate buffer, suggesting varied responses depending on the coating layer and buffer components. Use of multiple dissolution media during in vitro testing, including high concentration bicarbonate buffer, would contribute to the efficient design of enteric-coated drug formulations. © 2016 Royal Pharmaceutical Society, Journal of Pharmacy and Pharmacology.

Development and validation of a discriminative dissolution method for atorvastatin calcium tablets using in vivo data by LC and UV methods.

PubMed

Machado, J C; Lange, A D; Todeschini, V; Volpato, N M

2014-02-01

A dissolution method to analyze atorvastatin tablets using in vivo data for RP and test pilot (PB) was developed and validated. The appropriate conditions were determined after solubility tests using different media, and sink conditions were established. The conditions used were equipment paddle at 50 rpm and 900 mL of potassium phosphate buffer pH 6.0 as dissolution medium. In vivo release profiles were obtained from the bioequivalence study of RP and the generic candidate PB. The fraction of dose absorbed was calculated using the Loo-Riegelman method. It was necessary to use a scale factor of time similar to 6.0, to associate the values of absorbed fraction and dissolved fraction, obtaining an in vivo-in vitro correlation level A. The dissolution method to quantify the amount of drug dissolved was validated using high-performance liquid chromatography and ultraviolet spectrophotometry, and validated according to the USP protocol. The discriminative power of dissolution conditions was assessed using two different pilot batches of atorvastatin tablets (PA and PB) and RP. The dissolution test was validated and may be used as a discriminating method in quality control and in the development of the new formulations.

Development and application of a validated HPLC method for the analysis of dissolution samples of levothyroxine sodium drug products.

PubMed

Collier, J W; Shah, R B; Bryant, A R; Habib, M J; Khan, M A; Faustino, P J

2011-02-20

A rapid, selective, and sensitive gradient HPLC method was developed for the analysis of dissolution samples of levothyroxine sodium tablets. Current USP methodology for levothyroxine (L-T(4)) was not adequate to resolve co-elutants from a variety of levothyroxine drug product formulations. The USP method for analyzing dissolution samples of the drug product has shown significant intra- and inter-day variability. The sources of method variability include chromatographic interferences introduced by the dissolution media and the formulation excipients. In the present work, chromatographic separation of levothyroxine was achieved on an Agilent 1100 Series HPLC with a Waters Nova-pak column (250 mm × 3.9 mm) using a 0.01 M phosphate buffer (pH 3.0)-methanol (55:45, v/v) in a gradient elution mobile phase at a flow rate of 1.0 mL/min and detection UV wavelength of 225 nm. The injection volume was 800 μL and the column temperature was maintained at 28°C. The method was validated according to USP Category I requirements. The validation characteristics included accuracy, precision, specificity, linearity, and analytical range. The standard curve was found to have a linear relationship (r(2)>0.99) over the analytical range of 0.08-0.8 μg/mL. Accuracy ranged from 90 to 110% for low quality control (QC) standards and 95 to 105% for medium and high QC standards. Precision was <2% at all QC levels. The method was found to be accurate, precise, selective, and linear for L-T(4) over the analytical range. The HPLC method was successfully applied to the analysis of dissolution samples of marketed levothyroxine sodium tablets. Published by Elsevier B.V.

Development and application of a validated HPLC method for the analysis of dissolution samples of levothyroxine sodium drug products

PubMed Central

Collier, J.W.; Shah, R.B.; Bryant, A.R.; Habib, M.J.; Khan, M.A.; Faustino, P.J.

2011-01-01

A rapid, selective, and sensitive gradient HPLC method was developed for the analysis of dissolution samples of levothyroxine sodium tablets. Current USP methodology for levothyroxine (l-T4) was not adequate to resolve co-elutants from a variety of levothyroxine drug product formulations. The USP method for analyzing dissolution samples of the drug product has shown significant intra- and inter-day variability. The sources of method variability include chromatographic interferences introduced by the dissolution media and the formulation excipients. In the present work, chromatographic separation of levothyroxine was achieved on an Agilent 1100 Series HPLC with a Waters Nova-pak column (250mm × 3.9mm) using a 0.01 M phosphate buffer (pH 3.0)–methanol (55:45, v/v) in a gradient elution mobile phase at a flow rate of 1.0 mL/min and detection UV wavelength of 225 nm. The injection volume was 800 µL and the column temperature was maintained at 28 °C. The method was validated according to USP Category I requirements. The validation characteristics included accuracy, precision, specificity, linearity, and analytical range. The standard curve was found to have a linear relationship (r2 > 0.99) over the analytical range of 0.08–0.8 µg/mL. Accuracy ranged from 90 to 110% for low quality control (QC) standards and 95 to 105% for medium and high QC standards. Precision was <2% at all QC levels. The method was found to be accurate, precise, selective, and linear for l-T4 over the analytical range. The HPLC method was successfully applied to the analysis of dissolution samples of marketed levothyroxine sodium tablets. PMID:20947276

A novel dissolution media for testing drug release from a nanostructured polysaccharide-based colon specific drug delivery system: an approach to alternative colon media.

PubMed

Kotla, Niranjan G; Singh, Sima; Maddiboyina, Balaji; Sunnapu, Omprakash; Webster, Thomas J

2016-01-01

The aim of this study was to develop a novel microbially triggered and animal-sparing dissolution method for testing of nanorough polysaccharide-based micron granules for colonic drug delivery. In this method, probiotic cultures of bacteria present in the colonic region were prepared and added to the dissolution media and compared with the performance of conventional dissolution methodologies (such as media with rat cecal and human fecal media). In this study, the predominant species (such as Bacteroides, Bifidobacterium, Lactobacillus species, Eubacterium and Streptococcus) were cultured in 12% w/v skimmed milk powder and 5% w/v grade "A" honey. Approximately 10(10)-10(11) colony forming units m/L of probiotic culture was added to the dissolution media to test the drug release of polysaccharide-based formulations. A USP dissolution apparatus I/II using a gradient pH dissolution method was used to evaluate drug release from formulations meant for colonic drug delivery. Drug release of guar gum/Eudragit FS30D coated 5-fluorouracil granules was assessed under gastric and small intestine conditions within a simulated colonic environment involving fermentation testing with the probiotic culture. The results with the probiotic system were comparable to those obtained from the rat cecal and human fecal-based fermentation model, thereby suggesting that a probiotic dissolution method can be successfully applied for drug release testing of any polysaccharide-based oral formulation meant for colonic delivery. As such, this study significantly adds to the nanostructured biomaterials' community by elucidating an easier assay for colonic drug delivery.

The Relationship Between the Evolution of an Internal Structure and Drug Dissolution from Controlled-Release Matrix Tablets.

PubMed

Kulinowski, Piotr; Hudy, Wiktor; Mendyk, Aleksander; Juszczyk, Ewelina; Węglarz, Władysław P; Jachowicz, Renata; Dorożyński, Przemysław

2016-06-01

In the last decade, imaging has been introduced as a supplementary method to the dissolution tests, but a direct relationship of dissolution and imaging data has been almost completely overlooked. The purpose of this study was to assess the feasibility of relating magnetic resonance imaging (MRI) and dissolution data to elucidate dissolution profile features (i.e., kinetics, kinetics changes, and variability). Commercial, hydroxypropylmethyl cellulose-based quetiapine fumarate controlled-release matrix tablets were studied using the following two methods: (i) MRI inside the USP4 apparatus with subsequent machine learning-based image segmentation and (ii) dissolution testing with piecewise dissolution modeling. Obtained data were analyzed together using statistical data processing methods, including multiple linear regression. As a result, in this case, zeroth order release was found to be a consequence of internal structure evolution (interplay between region's areas-e.g., linear relationship between interface and core), which eventually resulted in core disappearance. Dry core disappearance had an impact on (i) changes in dissolution kinetics (from zeroth order to nonlinear) and (ii) an increase in variability of drug dissolution results. It can be concluded that it is feasible to parameterize changes in micro/meso morphology of hydrated, controlled release, swellable matrices using MRI to establish a causal relationship between the changes in morphology and drug dissolution. Presented results open new perspectives in practical application of combined MRI/dissolution to controlled-release drug products.

Testing lyoequivalency for three commercially sustained-release tablets containing diltiazem hydrochloride.

PubMed

Maswadeh, Hamzah A; Al-Hanbali, Othman A; Kanaan, Reem A; Shakya, Ashok K; Maraqa, Anwar

2010-01-01

In vitro release kinetics of three commercially available sustained release tablets (SR) diltiazem hydrochloride were studied at pH 1.1 for 2 h and for another 6 h at pH 6.8 using the USP dissolution apparatus with the paddle assemble. The kinetics of the dissolution process was studied by analyzing the dissolution data using five kinetic equations: the zero-order equation, the first-order equation, the Higuchi square root equation, the Hixson-Crowell cube root law and the Peppas equation. Analyses of the dissolution kinetic data for diltiazem hydrochloride commercial SR tablets showed that both Dilzacard and Dilzem SR tablets released drug by Non-Fickian (Anomalous transport) release with release exponent (n) equal to 0.59 and 0.54, respectively, which indicate the summation of both diffusion and dissolution controlled drug release. Bi-Tildiem SR tablets released drug by super case II (n = 1.29) which indicate zero-order release due to the dissolution of polymeric matrix and relaxation of the polymer chain. This finding was also in agreement with results obtained from application of zero-order and Hixson-Crowell equations. A dissolution profile comparative study was done to test the lyoequivelancy of the three products by using the mean dissolution time (MDT), dissimilarity factor f1 and similarity factor f2. Results showed that the three products are different and not lyoequivalent.

Assessment of pharmaceutical quality of furosemide tablets from multinational markets.

PubMed

Qureshi, S A; McGilveray, I J

1998-11-01

This report describes results of a collaborative study in which samples of the 40-mg strength of furosemide tablets were evaluated following a common protocol based on British (BP), European (Ph. Eur.), and US Pharmacopoeial (USP) specifications. Several tests, including identification, uniformity of mass, and dissolution, were performed. In total, excluding Lasix lots, results for 162 lots obtained from 115 manufacturers or suppliers were submitted. Also, 23 laboratories identified and submitted data for 34 lots of Lasix products available in their countries. There were no reported abnormalities in the physical test requirements of the products analyzed. The summaries (n, mean, and 95% CI) of the assay results for the "standard sample" (a common sample), Lasix lots from participating countries, and for all other furosemide products, respectively, are as follows: 30, 99.8%, 96-104; 33, 100.0%, 94-106; and 162, 99.6, 94-105. About half (approximately 62%) of the reported uniformity of mass results based on tablet weights were in the range 150-175 mg/tablet. However, there appears to be notable variability in tablet weights that would result in significant differences in the ratios (0.14 to 0.40) of active ingredient to excipient. The reported disintegration times ranged from 0 (instantaneous) to 18 min, with most less than 1 min. The drug dissolution testing was conducted with phosphate buffer at pH 5.8 (USP recommended). Another test was conducted with acetate buffer at pH 4.6 (noncompendial). There appears to be remarkable similarity in overall percentage of drug release from the three types of products (standard sample, Lasix lots, and other products). Although apparently there is a very wide spread in dissolution characteristics of the products tested, the analyses of variance did not detect differences among the products tested and, to this extent, would not indicate differences in bioavailability characteristics for most of these products. It is observed that about 20-38% of the variability in dissolution testing is not product related (i.e., it is from the dissolution testing itself), while the remaining 62-80% variability is product related (manufacturing, formulation, etc). The results of this multinational collaborative study showed that most of the furosemide products available in different countries met the required pharmaceutical quality standards, including drug-release characteristics. Based on an extensive statistical analysis, the main concern from the study was that the high variability in drug dissolution testing would require wide tolerance standards (e.g., pharmacopoeial standards). This may result in lack of needed discriminating ability of the test in revealing the impacts of formulation and manufacturing changes on in vitro, and perhaps in vivo, drug-release characteristics.

Physiological Parameters for Oral Delivery and In vitro Testing

PubMed Central

Mudie, Deanna M.; Amidon, Gordon L.; Amidon, Gregory E.

2010-01-01

Pharmaceutical solid oral dosage forms must undergo dissolution in the intestinal fluids of the gastrointestinal tract before they can be absorbed and reach the systemic circulation. Therefore, dissolution is a critical part of the drug-delivery process. The rate and extent of drug dissolution and absorption depend on the characteristics of the active ingredient as well as properties of the dosage form. Just as importantly, characteristics of the physiological environment such as buffer species, pH, bile salts, gastric emptying rate, intestinal motility, and hydrodynamics can significantly impact dissolution and absorption. While significant progress has been made since 1970 when the first compendial dissolution test was introduced (USP Apparatus 1), current dissolution testing does not take full advantage of the extensive physiologic information that is available. For quality control purposes, where the question is one of lot-to-lot consistency in performance, using nonphysiologic test conditions that match drug and dosage form properties with practical dissolution media and apparatus may be appropriate. However, where in vitro – in vivo correlations are desired, it is logical to consider and utilize knowledge of the in vivo condition. This publication critically reviews the literature that is relevant to oral human drug delivery. Physiologically relevant information must serve as a basis for the design of dissolution test methods and systems that are more representative of the human condition. As in vitro methods advance in their physiological relevance, better in vitro - in vivo correlations will be possible. This will, in turn, lead to in vitro systems that can be utilized to more effectively design dosage forms that have improved and more consistent oral bioperformance. PMID:20822152

The effect of formulation additives on in vitro dissolution-absorption profile and in vivo bioavailability of telmisartan from brand and generic formulations.

PubMed

Borbás, Enikő; Nagy, Zsombor K; Nagy, Brigitta; Balogh, Attila; Farkas, Balázs; Tsinman, Oksana; Tsinman, Konstantin; Sinkó, Bálint

2018-03-01

In this study, brand and four generic formulations of telmisartan, an antihypertensive drug, were used in in vitro simultaneous dissolution-absorption, investigating the effect of different formulation additives on dissolution and on absorption through an artificial membrane. The in vitro test was found to be sensitive enough to show even small differences between brand and generic formulations caused by the use of different excipients. By only changing the type of filler from sorbitol to mannitol in the formulation, the flux through the membrane was reduced by approximately 10%. Changing the salt forming agent as well resulted in approximately 20% of flux reduction compared to the brand formulation. This significant difference was clearly shown in the published in vivo results as well. The use of additional lactose monohydrate in the formulation also leads to approximately 10% reduction in flux. The results show that by changing excipients, the dissolution of telmisartan was not altered significantly, but the flux through the membrane was found to be significantly changed. These results pointed out the limitations of traditional USP dissolution tests and emphasized the importance of simultaneously measuring dissolution and absorption, which allows the complex effect of formulation excipients on both processes to be measured. Moreover, the in vivo predictive power of the simultaneous dissolution-absorption test was demonstrated by comparing the in vitro fluxes to in vivo bioequivalence study results. Copyright © 2018 Elsevier B.V. All rights reserved.

Ubiquitin-specific Protease 11 (USP11) Deubiquitinates Hybrid Small Ubiquitin-like Modifier (SUMO)-Ubiquitin Chains to Counteract RING Finger Protein 4 (RNF4)*

PubMed Central

Hendriks, Ivo A.; Schimmel, Joost; Eifler, Karolin; Olsen, Jesper V.; Vertegaal, Alfred C. O.

2015-01-01

Ring finger protein 4 (RNF4) is a SUMO-targeted ubiquitin E3 ligase with a pivotal function in the DNA damage response (DDR). SUMO interaction motifs (SIMs) in the N-terminal part of RNF4 tightly bind to SUMO polymers, and RNF4 can ubiquitinate these polymers in vitro. Using a proteomic approach, we identified the deubiquitinating enzyme ubiquitin-specific protease 11 (USP11), a known DDR-component, as a functional interactor of RNF4. USP11 can deubiquitinate hybrid SUMO-ubiquitin chains to counteract RNF4. SUMO-enriched nuclear bodies are stabilized by USP11, which functions downstream of RNF4 as a counterbalancing factor. In response to DNA damage induced by methyl methanesulfonate, USP11 could counteract RNF4 to inhibit the dissolution of nuclear bodies. Thus, we provide novel insight into cross-talk between ubiquitin and SUMO and uncover USP11 and RNF4 as a balanced SUMO-targeted ubiquitin ligase/protease pair with a role in the DDR. PMID:25969536

In vitro disintegration and dissolution studies of once-weekly copies of alendronate sodium tablets (70 mg) and in vivo implications.

PubMed

Dansereau, Richard J; Crail, Debbie J; Perkins, Alan C

2008-04-01

The aim of this study was to evaluate the in vitro disintegration and dissolution of 26 alendronic acid tablets (70 mg) on the market in Canada, Germany, the Netherlands, and the United Kingdom compared to the branded product (Fosamax). The disintegration and dissolution times were determined using the methods described in the United States Pharmacopeia 30 (USP 30). The disintegration of four orally disintegrating tablets (non-bisphosphonates) and branded film-coated risedronate sodium tablets were included for comparison. The mean disintegration times of the alendronic acid tablets ranged from 14 s for Pharmachemie (Netherlands) to 342 s (5.7 min) for Betapharm (Germany). The mean disintegration time of the branded product tablets ranged from 43 to 78 s. Six of the 26 companies market alendronic acid tablets with very rapid disintegration times which are similar to those of orally disintegrating tablets (non-bisphosphonates). The alendronic acid tablets with very rapid mean disintegration times are as follows: Pharmachemie (Netherlands), 14 s; Novopharm (Canada), 13-24 s; GRY-Pharma (Germany), 21 s; Juta Pharma (Germany), 30 s; APS/Teva (United Kingdom), 26 and 37 s; and Teva (UK), 14-29 s. Since there is no established disintegration time for alendronic acid tablets there can be no assurance that the copy tablets are equivalent to the branded product in terms of esophageal drug exposure. However, the in vitro disintegration times have not been correlated with in vivo disintegration and performance. The dissolution of all the bisphosphonate tablets was rapid with greater than 80% dissolved in 15 min and all products conformed to the USP 30 specification. The dissolution of all alendronic acid tablets was rapid and complete and conformed to the established USP 30 specifications which should ensure adequate drug absorption from the copy products. However, copies of alendronic acid tablets are approved based on the results of single-dose bioavailability studies in healthy subjects and this is not adequate to establish similar disintegration characteristics.

Broadband Acoustic Resonance Dissolution Spectroscopy (BARDS): A rapid test for enteric coating thickness and integrity of controlled release pellet formulations.

PubMed

Alfarsi, Anas; Dillon, Amy; McSweeney, Seán; Krüse, Jacob; Griffin, Brendan; Devine, Ken; Sherry, Patricia; Henken, Stephan; Fitzpatrick, Stephen; Fitzpatrick, Dara

2018-06-10

There are no rapid dissolution based tests for determining coating thickness, integrity and drug concentration in controlled release pellets either during production or post-production. The manufacture of pellets requires several coating steps depending on the formulation. The sub-coating and enteric coating steps typically take up to six hours each followed by additional drying steps. Post production regulatory dissolution testing also takes up to six hours to determine if the batch can be released for commercial sale. The thickness of the enteric coating is a key factor that determines the release rate of the drug in the gastro-intestinal tract. Also, the amount of drug per unit mass decreases with increasing thickness of the enteric coating. In this study, the coating process is tracked from start to finish on an hourly basis by taking samples of pellets during production and testing those using BARDS (Broadband Acoustic Resonance Dissolution Spectroscopy). BARDS offers a rapid approach to characterising enteric coatings with measurements based on reproducible changes in the compressibility of a solvent due to the evolution of air during dissolution. This is monitored acoustically via associated changes in the frequency of induced acoustic resonances. A steady state acoustic lag time is associated with the disintegration of the enteric coatings in basic solution. This lag time is pH dependent and is indicative of the rate at which the coating layer dissolves. BARDS represents a possible future surrogate test for conventional USP dissolution testing as its data correlates directly with the thickness of the enteric coating, its integrity and also with the drug loading as validated by HPLC. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparative stability of repackaged metoprolol tartrate tablets.

PubMed

Yang, Yongsheng; Gupta, Abhay; Carlin, Alan S; Faustino, Patrick J; Lyon, Robbe C; Ellison, Christopher D; Rothman, Barry; Khan, Mansoor A

2010-01-29

The stability of metoprolol tartrate tablets packaged in original high density polyethylene containers and repackaged in USP Class A unit-dose blister packs was investigated. Studies were conducted at 25 degrees C/60% relative humidity (RH) for 52 weeks and at 40 degrees C/75% RH for 13 weeks. The potency, dissolution, water content, loss on drying and hardness of the drug products were analyzed. Results indicated no differences in the stability between the tablets in both packages stored under 25 degrees C/60% RH. No difference in potency was found in both packages under either condition. However, a significant weight increase due to moisture uptake was observed for the repackaged tablets stored under 40 degrees C/75% RH. The weight increase was accompanied by a decrease in tablet hardness (6.5-0 kp) and a increase in dissolution rate (51-92%) in 5 min. Near-infrared (NIR) chemical imaging also monitored moisture uptake of the tablet non-invasively through the package. The observed changes in product stability may adversely affect the products bioavailability profile, even though the potency of the active drug remained within USP specification range of 90-110%. Study results suggest product quality can be negatively impacted even when using USP Class A repackaging materials. Published by Elsevier B.V.

Toward an In Vivo Dissolution Methodology: A Comparison of Phosphate and Bicarbonate Buffers

PubMed Central

Sheng, Jennifer J.; McNamara, Daniel P.; Amidon, Gordon L.

2011-01-01

Purpose To evaluate the difference between the pharmaceutical phosphate buffers and the gastrointestinal bicarbonates in dissolution of ketoprofen and indomethacin, to illustrate the dependence of buffer differential on biopharmaceutical properties of BCS II weak acids, and to recommend phosphate buffers equivalent to bicarbonates. Methods The intrinsic dissolution rates of, ketoprofen and indomethacin, were experimentally measured using rotating disk method at 37°C in USP SIF/FaSSIF and various concentrations of bicarbonates. Theoretical models including an improved reaction plane model and a film model were applied to estimate the surrogate phosphate buffers equivalent to the bicarbonates. Results Experimental results show that the intrinsic dissolution rates of ketoprofen and indomethacin, in USP and FaSSIF phosphate buffers are 1.5–3.0 times of that in the 15 mM bicarbonates. Theoretical analysis demonstrates that the buffer differential is largely dependent on the drug pKa and secondly on solubility, and weakly dependent on the drug diffusivity. Further, in accordance with the drug pKa, solubility and diffusivity, simple phosphate surrogate was proposed to match an average bicarbonate value (15 mM) of the upper gastrointestinal region. Specifically, phosphate buffers of 13–15 mM and 3–4 mM were recommended for ketoprofen and indomethacin, respectively. For both ketoprofen and indomethacin, the intrinsic dissolution using the phosphate surrogate buffers closely approximated the 15 mM bicarbonate buffer. Conclusions This work demonstrates the substantial difference between pharmaceutical phosphates and physiological bicarbonates in determining the drug intrinsic dissolution rates of BCS II weak acids, such as ketoprofen and indomethacin. Surrogate phosphates were recommended in order to closely reflect the in vivo dissolution of ketoprofen and indomethacin in gastrointestinal bicarbonates, which has significant implications for defining buffer systems for BCS II weak acids in developing in vitro bioequivalence dissolution methodology. PMID:19183104

Oral bioavailability enhancement of β-lapachone, a poorly soluble fast crystallizer, by cocrystal, amorphous solid dispersion, and crystalline solid dispersion.

PubMed

Liu, Chengyu; Liu, Zhengsheng; Chen, Yuejie; Chen, Zhen; Chen, Huijun; Pui, Yipshu; Qian, Feng

2018-03-01

The aim of this paper was to compare the in vitro dissolution and in vivo bioavailability of three solubility enhancement technologies for β-lapachone (LPC), a poorly water soluble compound with extremely high crystallization propensity. LPC cocrystal was prepared by co-grinding LPC with resorcinol. LPC crystalline and amorphous solid dispersions (CSD and ASD) were obtained by spray drying with Poloxamer 188 and HPMC-AS, respectively. The cocrystal structure was solved by single crystal x-ray diffraction. All formulations were characterized by WAXRD, DSC, POM and SEM. USP II and intrinsic dissolution studies were used to compare the in vitro dissolution of these formulations, and a crossover dog pharmacokinetic study was used to compare their in vivo bioavailability. An 1:1 LPC-resorcinol cocrystal with higher solubility and faster dissolution rate was obtained, yet it converted to LPC crystal rapidly in solution. LPC/HPMC-AS ASD was confirmed to be amorphous and uniform, while the crystal and crystallite sizes of LPC in CSD were found to be ∼1-3 μm and around 40 nm, respectively. These formulations performed similarly during USP II dissolution, while demonstrated dramatically different oral bioavailability of ∼32%, ∼5%, and ∼1% in dogs, for CSD, co-crystal, and ASD, respectively. CSD showed the fastest intrinsic dissolution rate among the three. The three formulations showed poor IVIVC which could be due to rapid and unpredictable crystallization kinetics. Considering all the reasons, we conclude that for molecules with extremely high crystallization tendency that cannot be inhibited by any pharmaceutical excipients, size-reduction technologies such as CSD could be advantageous for oral bioavailability enhancement in vivo than technologies only generating transient but not sustained supersaturation. Copyright © 2018 Elsevier B.V. All rights reserved.

Consumer vinegar test for determining calcium disintegration.

PubMed

Mason, N A; Patel, J D; Dressman, J B; Shimp, L A

1992-09-01

A consumer test and standardized methods were compared for measuring the disintegration of calcium tablets, and the disintegration results were compared with results of dissolution testing to determine the ability of the consumer test of disintegration to predict bioavailability of calcium. Disintegration of 17 calcium supplement products, in tablet form, was studied in Simulated Gastric Fluid Test Solution, USP, without pepsin (GF), in distilled water, and in white distilled vinegar. For disintegration testing with GF and with distilled water, six tablets of each product were placed in an apparatus and immersed in the solution at 37 degrees C for 60 minutes. Six tablets of each product were tested in 200 mL of vinegar at room temperature for 30 minutes. Disintegration was determined by visual observation. Seven products were tested for dissolution in GF or water. Three samples of each product were tested at intervals over 120 minutes for calcium content. Results of testing with an ion-selective electrode were converted to milligrams and compared with the calcium content of the tablets (as claimed on the package label). The mean disintegration times of various calcium products in vinegar ranged from 1.8 to greater than 30 minutes. The mean time in distilled water and GF ranged from 1.6 to greater than 60 minutes and from 1.0 to greater than 60 minutes, respectively. Results were in agreement in 87% to 93% of cases between the consumer vinegar test and the standardized disintegration test methods, a significant correlation. No correlation was found between disintegration time and the extent of dissolution. The disintegration and dissolution of commercially available calcium tablets was highly variable.(ABSTRACT TRUNCATED AT 250 WORDS)

In vitro dissolution of generic immediate-release solid oral dosage forms containing BCS class I drugs: comparative assessment of metronidazole, zidovudine, and amoxicillin versus relevant comparator pharmaceutical products in South Africa and India.

PubMed

Reddy, Nallagundla H S; Patnala, Srinivas; Löbenberg, Raimar; Kanfer, Isadore

2014-10-01

Biowaivers are recommended for immediate-release solid oral dosage forms using dissolution testing as a surrogate for in vivo bioequivalence studies. Several guidance are currently available (the World Health Organization (WHO), the US FDA, and the EMEA) where the conditions are described. In this study, definitions, criteria, and methodologies according to the WHO have been applied. The dissolution performances of immediate-release metronidazole, zidovudine, and amoxicillin products purchased in South African and Indian markets were compared to the relevant comparator pharmaceutical product (CPP)/reference product. The dissolution performances were studied using US Pharmacopeia (USP) apparatus 2 (paddle) set at 75 rpm in each of three dissolution media (pH1.2, 4.5, and 6.8). Concentrations of metronidazole, zidovudine, and amoxicillin in each dissolution media were determined by HPLC. Of the 11 metronidazole products tested, only 8 could be considered as very rapidly dissolving products as defined by the WHO, whereas 2 of those products could be considered as rapidly dissolving products but did not comply with the f 2 acceptance criteria in pH 6.8. All 11 zidovudine products were very rapidly dissolving, whereas in the case of the 14 amoxicillin products tested, none of those products met any of the WHO criteria. This study indicates that not all generic products containing the same biopharmaceutics classification system (BCS) I drug and in similar strength and dosage form are necessarily in vitro equivalent. Hence, there is a need for ongoing market surveillance to determine whether marketed generic products containing BCS I drugs meet the release requirements to confirm their in vitro bioequivalence to the respective reference product.

EFFECT OF HYDROPHILIC AND HYDROPHOBIC POLYMER ON IN VITRO DISSOLUTION AND PERMEATION OF BISOPROLOL FUMARATE THROUGH TRANSDERMAL PATCH.

PubMed

Shabbir, Maryam; Ali, Sajid; Raza, Moosa; Sharif, Ali; Akhtar, Furoan Muhammad; Manan, Abdul; Fazli, Ali Raza; Younas, Neelofar; Manzoor, Iqra

2017-01-01

A matrix transdermal patch of bisoprolol fumarate was formulated with different concentrations of Eudragit RS 100 and Methocel E5 with PEG 400 as plasticizer by solvent evaporation technique. Tween 80 was added to the optimized patch to evaluate the effect of permeation enhancer at different concentration through the excised rabbit's skin. The patches were analyzed for weight variation, drug content, swelling index, erosion studies, moisture content, moisture uptake, water vapor transmission rate (WVTR) and water vapor permeability (WVP). In vitro dissolution test was carried out in USP dissolution apparatus V to select the optimized formulation. In vitr skin permeation studies were done in Franz diffusion cell using rabbit skin as a model membrane. The cumulative drug release and flux were determined to compare the result of test patches with a control patch. The greatest enhancement ratio (ER) was obtained in F03-PE with 30% Tween 80. F03-PE seemed to follow zero order kinetics with super case II mechanism of drug release. Statistical ANOVA suggested that there was a significant difference in formulations, steady flux and cumulative permeation rate at different Tween 80 concentrations.

In vitro quantitative ((1))H and ((19))F nuclear magnetic resonance spectroscopy and imaging studies of fluvastatin™ in Lescol® XL tablets in a USP-IV dissolution cell.

PubMed

Zhang, Qilei; Gladden, Lynn; Avalle, Paolo; Mantle, Michael

2011-12-20

Swellable polymeric matrices are key systems in the controlled drug release area. Currently, the vast majority of research is still focused on polymer swelling dynamics. This study represents the first quantitative multi-nuclear (((1))H and ((19))F) fast magnetic resonance imaging study of the complete dissolution process of a commercial (Lescol® XL) tablet, whose formulation is based on the hydroxypropyl methylcellulose (HPMC) polymer under in vitro conditions in a standard USP-IV (United States Pharmacopeia apparatus IV) flow-through cell that is incorporated into high field superconducting magnetic resonance spectrometer. Quantitative RARE ((1))H magnetic resonance imaging (MRI) and ((19))F nuclear magnetic resonance (NMR) spectroscopy and imaging methods have been used to give information on: (i) dissolution media uptake and hydrodynamics; (ii) active pharmaceutical ingredient (API) mobilisation and dissolution; (iii) matrix swelling and dissolution and (iv) media activity within the swelling matrix. In order to better reflect the in vivo conditions, the bio-relevant media Simulated Gastric Fluid (SGF) and Fasted State Simulated Intestinal Fluid (FaSSIF) were used. A newly developed quantitative ultra-fast MRI technique was applied and the results clearly show the transport dynamics of media penetration and hydrodynamics along with the polymer swelling processes. The drug dissolution and mobility inside the gel matrix was characterised, in parallel to the ((1))H measurements, by ((19))F NMR spectroscopy and MRI, and the drug release profile in the bulk solution was recorded offline by UV spectrometer. We found that NMR spectroscopy and 1D-MRI can be uniquely used to monitor the drug dissolution/mobilisation process within the gel layer, and the results from ((19))F NMR spectra indicate that in the gel layer, the physical mobility of the drug changes from "dissolved immobilised drug" to "dissolved mobilised drug". Copyright © 2011 Elsevier B.V. All rights reserved.

A novel coating concept for ileo-colonic drug targeting: proof of concept in humans using scintigraphy.

PubMed

Varum, F J O; Hatton, G B; Freire, A C; Basit, A W

2013-08-01

The in vivo proof of concept of a novel double-coating system, based on enteric polymers, which accelerated drug release in the ileo-colonic region, was investigated in humans. Prednisolone tablets were coated with a double-coating formulation by applying an inner layer composed of EUDRAGIT S neutralised to pH 8.0 and a buffer salt (10% KH₂PO₄), which was overcoated with layer of standard EUDRAGIT S organic solution. For comparison, a single coating system was produced by applying the same amount of EUDRAGIT S organic solution on the tablet cores. Dissolution tests on the tablets were carried out using USP II apparatus in 0.1N HCl for 2 h and subsequently in pH 7.4 Krebs bicarbonate buffer. For comparison, tablets were also tested under the USP method established for modified release mesalamine formulations. Ten fasted volunteers received the double-coated and single-coated tablets in a two-way crossover study. The formulations were radiolabelled and followed by gamma scintigraphy; the disintegration times and positions were recorded. There was no drug release from the single-coated or double-coated tablets in 0.1N HCl for 2h. The single-coated tablets showed slow release in subsequent Krebs bicarbonate buffer with a lag time of 120 min, while in contrast drug release from the double-coated tablets was initiated at 60 min. In contrast, using the USP dissolution method, normally employed for modified release mesalamine products, no discrimination was attained. The in vivo disintegration of the single-coated EUDRAGIT S tablets in the large intestine was erratic. Furthermore, in 2 volunteers, the single-coated tablet was voided intact. Double-coated tablets disintegrated in a more consistent way, mainly in the ileo-caecal junction or terminal ileum. The accelerated in vivo disintegration of the double-coating EUDRAGIT S system can overcome the limitations of conventional enteric coatings targeting the colon and avoid the pass-through of intact tablets. Moreover, Krebs bicarbonate buffer has the ability to discriminate between formulations designed to target the ileo-colonic region. Copyright © 2013 Elsevier B.V. All rights reserved.

Improvements in soft gelatin capsule sample preparation for USP-based simethicone FTIR analysis.

PubMed

Hargis, Amy D; Whittall, Linda B

2013-02-23

Due to the absence of a significant chromophore, Simethicone raw material and finished product analysis is achieved using a FTIR-based method that quantifies the polydimethylsiloxane (PDMS) component of the active ingredient. The method can be found in the USP monographs for several dosage forms of Simethicone-containing pharmaceutical products. For soft gelatin capsules, the PDMS assay values determined using the procedure described in the USP method were variable (%RSDs from 2 to 9%) and often lower than expected based on raw material values. After investigation, it was determined that the extraction procedure used for sample preparation was causing loss of material to the container walls due to the hydrophobic nature of PDMS. Evaluation revealed that a simple dissolution of the gelatin capsule fill in toluene provided improved assay results (%RSDs≤0.5%) as well as a simplified and rapid sample preparation. Copyright © 2012 Elsevier B.V. All rights reserved.

Are multisource levothyroxine sodium tablets marketed in Egypt interchangeable?

PubMed

Abou-Taleb, Basant A; Bondok, Maha; Nounou, Mohamed Ismail; Khalafallah, Nawal; Khalil, Saleh

2018-02-01

A clinical study was initiated in response to patients' complaints, supported by the treating physicians, of suspected differences in efficacy among multisource levothyroxine sodium tablets marketed in Egypt. The study design was a multiple dose (100μg levothyroxine sodium tablet once daily for 6 months) and involved 50 primary hypothyroidism female patients (5 equal groups). Tablets administered included five tablet batches (two brands, three origin locations) purchased from local pharmacies in Alexandria. Assessment parameters (measured on consecutive visits) included the thyroid stimulating hormone, total and free levothyroxine. Tablet dissolution rate was determined (BP/EP 2014 & USP 2014). In vitro vs in vivovs correlations were developed. Clinical and pharmaceutical data confirmed inter-brand and inter-source differences in efficacy. Correlations examined indicated potential usefulness of in vitro dissolution test in detecting poor performing levothyroxine sodium tablets during shelf life. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Nanosuspension delivery of paclitaxel to xenograft mice can alter drug disposition and anti-tumor activity

NASA Astrophysics Data System (ADS)

Chiang, Po-Chang; Gould, Stephen; Nannini, Michelle; Qin, Ann; Deng, Yuzhong; Arrazate, Alfonso; Kam, Kimberly R.; Ran, Yingqing; Wong, Harvey

2014-04-01

Paclitaxel is a common chemotherapeutic agent that is effective against various cancers. The poor aqueous solubility of paclitaxel necessitates a large percentage of Cremophor EL:ethanol (USP) in its commercial formulation which leads to hypersensitivity reactions in patients. We evaluate the use of a crystalline nanosuspension versus the USP formulation to deliver paclitaxel to tumor-bearing xenograft mice. Anti-tumor efficacy was assessed following intravenous administration of three 20 mg/kg doses of paclitaxel. Paclitaxel pharmacokinetics and tissue distribution were evaluated, and differences were observed between the two formulations. Plasma clearance and tissue to plasma ratio of mice that were dosed with the nanosuspension are approximately 33- and 11-fold higher compared to those of mice that were given the USP formulation. Despite a higher tumor to plasma ratio for the nanosuspension treatment group, absolute paclitaxel tumor exposure was higher for the USP group. Accordingly, a higher anti-tumor effect was observed in the xenograft mice that were dosed with the USP formulation (90% versus 42% tumor growth inhibition). This reduction in activity of nanoparticle formulation appeared to result from a slower than anticipated dissolution in vivo. This study illustrates a need for careful consideration of both dose and systemic solubility prior utilizing nanosuspension as a mode of intravenous delivery.

In vitro dissolution of proton-pump inhibitor products intended for paediatric and geriatric use in physiological bicarbonate buffer.

PubMed

Liu, Fang; Shokrollahi, Honaz

2015-05-15

Proton-pump inhibitor (PPI) products based on enteric coated multiparticulates are design to meet the needs of patients who cannot swallow tablets such as children and older adults. Enteric coated PPI preparations exhibit delays in in vivo absorption and onset of antisecretory effects, which is not reflected by the rapid in vitro dissolution in compendial pH 6.8 phosphate buffer commonly used for assessment of these products. A more representative and physiological medium, pH 6.8 mHanks bicarbonate buffer, was used in this study to evaluate the in vitro dissolution of enteric coated multiparticulate-based PPI products. Commercially available omeprazole, lansoprazole and esomeprazole products were subject to dissolution tests using USP-II apparatus in pH 4.5 phosphate buffer saline for 45 min (acid stage) followed by pH 6.8 phosphate buffer or pH 6.8 mHanks bicarbonate buffer. In pH 6.8 phosphate buffer, all nine tested products displayed rapid and comparable dissolution profiles meeting the pharmacopeia requirements for delayed release preparations. In pH 6.8 mHanks buffer, drug release was delayed and failed the pharmacopeia requirements from most enteric coated preparations. Despite that the same enteric polymer, methacrylic acid-ethyl acrylate copolymer (1:1), was applied to all commercial multiparticulate-based products, marked differences were observed between dissolution profiles of these preparations. The use of pH 6.8 physiological bicarbonate (mHanks) buffer can serve as a useful tool to provide realistic and discriminative in vitro release assessment of enteric coated PPI preparations and to assist rational formulation development of these products. Copyright © 2015 Elsevier B.V. All rights reserved.

Enhancement of in-vitro drug dissolution of ketoconazole for its optimal in-vivo absorption using Nanoparticles and Solid Dispersion forms of the drug

NASA Astrophysics Data System (ADS)

Syed, Mohammed Irfan

Ketoconazole is one of the most widely prescribed oral antifungal drugs for the systemic treatment of various fungal infections. However, due its hydrophobic nature and poor solubility profiles in the gastro-intestinal fluids, variations in its bioavailability have been documented. Therefore, to enhance its dissolution in the biological fluids, this study was initiated to develop and evaluate Nanoparticles and Solid Dispersion forms of the drug. Nanoparticles of ketoconazole were developed by Wet Bead Milling technique using PVP-10k as the stabilizing material at a weight ratio of (2:1). Solid dispersion powder was prepared by Hot Melt method using PEG-8000 at a weight ratio of (1:2). A commercial product containing 200mg of ketoconazole tablet and pure drug powder were used as the control for comparison purposes. The dissolution studies were carried out in SGF, SIF, USP; and SIF with 0.2% sodium lauryl sulfate using the USP-II method for a 2 hours period. Physical characterizations were carried out using SEM, DSC, XRD and FTIR studies. Wet Bead Milling method yielded nanoparticles in the particles size range of (100-300nm.). First all samples were evaluated for their in-vitro dissolution in SGF at pH=1.2. After 15 minutes, the amounts of drug dissolved were observed to be 27% from both the pure powder and commercial tablet (control), 29% from solid dispersion and 100% from the Nanoparticles dosage form. This supports the fact that Nanoparticles had a strong influence on the dissolution rate of the drug and exhibited much faster dissolution of ketoconazole. When the same formulations were studied in the SIF, USP medium, the control formulation gave 3%, solid dispersion 8% and Nanoparticles 8% drug dissolution after 2 hours period. This could be because the weakly basic ketoconazole drug remained un-dissociated in the alkaline medium. Since this medium was unable to clearly distinguish the dissolution profiles from different formulation of the drug, the SIF solution was modified to include 0.02%, 0.05% and 0.1% sodium lauryl sulfate. Here, after 2 hours, the amount of drug dissolved was calculated to be 10% from controls, 21% from solid dispersion and 36% from nanoparticles in SIF with 0.02% SLS. Drug release was 20% from controls, 41% from solid dispersion and 52% from nanoparticle formulation in SIF with 0.05% SLS. Whereas amount of drug released in SIF with 0.1% SLS showed 21% from the control, 62% from solid dispersion and 85% from Nanoparticles respectively. This data supports that the ketoconazole Nanoparticles and its solid-dispersion exhibit many fold increase in dissolution of the drug, which could lead to a less variable and enhanced in-vivo drug absorption profiles. In addition, the data from the Physical Characterization (DSC, XRD and FTIR) supports that there were no interaction within the ingredients occurred in Nanoparticles and solid-dispersion formulations of the drug sample. Wet Bead Milling and Hot Melt methods proved useful in developing the Nanoparticles and solid dispersion form of ketoconazole. Results from particle size analysis were in correlation with data obtained from Scanning electron Microscopy and size of the nanoparticles was below 100nm. The dissolution studies with the modified simulated intestinal fluid (SIF) exhibited several fold increase in the dissolution of the drug compared to the pure drug powder and the commercial products used as the control. Also, the results from the physical characterization studies clearly support the stability of ketoconazole in both of these formulations.

In vitro dissolution kinetic study of theophylline from hydrophilic and hydrophobic matrices.

PubMed

Maswadeh, Hamzah M; Semreen, Mohammad H; Abdulhalim, Abdulatif A

2006-01-01

Oral dosage forms containing 300 mg theophylline in matrix type tablets, were prepared by direct compression method using two kinds of matrices, glycerylbehenate (hydrophobic), and (hydroxypropyl)methyl cellulose (hydrophilic). The in vitro release kinetics of these formulations were studied at pH 6.8 using the USP dissolution apparatus with the paddle assemble. The kinetics of the dissolution process were studied by analyzing the dissolution data using four kinetic equations, the zero-order equation, the first-order equation, the Higuchi square root equation and the Hixson-Crowell cube root law. The analysis of the dissolution kinetic data for the theophylline preparations in this study shows that it follows the first order kinetics and the release process involves erosion / diffusion and an alteration in the surface area and diameter of the matrix system, as well as in the diffusion path length from the matrix drug load during the dissolution process. This relation is best described by the use of both the first-order equation and the Hixson-Crowell cube root law.

Disintegration/dissolution profiles of copies of Fosamax (alendronate).

PubMed

Epstein, S; Cryer, B; Ragi, S; Zanchetta, J R; Walliser, J; Chow, J; Johnson, M A; Leyes, A E

2003-01-01

Poor quality has been reported for some generics and other copies of original products. We performed a pilot study to compare the disintegration/dissolution profiles of FOSAMAX (alendronate) 70 mg tablets with those of copies of FOSAMAX that were manufactured outside the United States. We used the standard United States Pharmacopeia (USP) disintegration method to evaluate FOSAMAX 70 mg tablets and 13 copies. At least 12 (n = 12) dosage units were tested for each product (except Fosmin, n = 10). The dissolution profiles of FOSAMAX and one representative copy were also compared. Nine copies (Osteomax, Defixal, Fosmin, Endronax, Osteomix, Genalmen, Fixopan, Osteoplus, and Fosval) disintegrated two- to ten-fold faster than FOSAMAX. Three other copies (Neobon, Regenesis, and Ostenan) disintegrated at least five-fold slower than FOSAMAX. Neobon is a softgel capsule, so special consideration was given to this different dosage form. One copy (Arendal) did not fall into either category but exhibited potentially large inter- and intra-lot variability. Dissolution of alendronate from Regenesis lagged behind that from FOSAMAX. Slower disintegration may reduce efficacy because bisphosphonates must be taken in the fasting state and contact with food or even certain beverages severely reduces bioavailability. Faster disintegration (or the use of gel-caps or other alterations to the drug formulation) could increase the risk of esophagitis, an adverse event associated with prolonged contact of the esophagus with bisphosphonates. These disintegration and dissolution results suggest that important differences may exist between FOSAMAX and its copies with regard to bioavailability, pharmacokinetics, and clinical efficacy and safety profiles. Additional testing is warranted to evaluate the pharmacokinetics and clinical safety of these copies.

In Vitro Dissolution of Fluconazole and Dipyridamole in Gastrointestinal Simulator (GIS), Predicting in Vivo Dissolution and Drug-Drug Interaction Caused by Acid-Reducing Agents.

PubMed

Matsui, Kazuki; Tsume, Yasuhiro; Amidon, Gregory E; Amidon, Gordon L

2015-07-06

Weakly basic drugs typically exhibit pH-dependent solubility in the physiological pH range, displaying supersaturation or precipitation along the gastrointestinal tract. Additionally, their oral bioavailabilities may be affected by coadministration of acid-reducing agents that elevate gastric pH. The purpose of this study was to assess the feasibility of a multicompartmental in vitro dissolution apparatus, Gastrointestinal Simulator (GIS), in predicting in vivo dissolution of certain oral medications. In vitro dissolution studies of fluconazole, a BCS class I, and dipyridamole, a BCS class II weak bases (class IIb), were performed in the GIS as well as United States Pharmacopeia (USP) apparatus II and compared with the results of clinical drug-drug interaction (DDI) studies. In both USP apparatus II and GIS, fluconazole completely dissolved within 60 min regardless of pH, reflecting no DDI between fluconazole and acid-reducing agents in a clinical study. On the other hand, seven-fold and 15-fold higher concentrations of dipyridamole than saturation solubility were observed in the intestinal compartments in GIS with gastric pH 2.0. Precipitation of dipyridamole was also observed in the GIS, and the percentage of dipyridamole in solution was 45.2 ± 7.0%. In GIS with gastric pH 6.0, mimicking the coadministration of acid-reducing agents, the concentration of dipyridamole was equal to its saturation solubility, and the percentage of drug in solution was 9.3 ± 2.7%. These results are consistent with the clinical DDI study of dipyridamole with famotidine, which significantly reduced the Cmax and area under the curve. An In situ mouse infusion study combined with GIS revealed that high concentration of dipyridamole in the GIS enhanced oral drug absorption, which confirmed the supersaturation of dipyridamole. In conclusion, GIS was shown to be a useful apparatus to predict in vivo dissolution for BCS class IIb drugs.

Dissolution of fine particle fraction from truncated Anderson cascade impactor with an enhancer cell.

PubMed

Tay, Justin Yong Soon; Liew, Celine Valeria; Heng, Paul Wan Sia

2018-04-22

Dissolution testing for inhalers were previously conducted either on unfractionated drug-carrier powders or drug of specific aerodynamic particle size. In this study, the collection of the full fine particle fraction (FPF) was attempted on a single stage. Capsules containing 30 mg of 2% salbutamol sulfate (SS) was tested to have a FPF of 9 ± 1% using the full set of Andersen cascade impactor (ACI) and a modified Rotahaler® capable of achieving 4.0 kPa pressure drop at 60 L/min air flow rate. A truncated ACI comprising the USP throat, pre-separator, stage 0, stage 4, stage F, polytetrafluoroethylene funnel (TF) and small collection plate (sCP) was found to be capable of achieving a FPF of 9% collected on TF and sCP. An adhesive tape was used to collect the FPF from the TF and sCP and held in place by an enhancer cell in a 200 mL round bottom vessel containing 50 mL Gamble's solution with 0.2 v/v, % Tween 80. Dissolution testing of SS and Seretide® showed burst release of SS and salmeterol while sustained release of fluticasone. This study demonstrated a reproducible method which may be used for evaluation of the full FPF of orally inhaled products. Copyright © 2018 Elsevier B.V. All rights reserved.

Formulation and in-vitro evaluation of directly compressed controlled release matrices of Losartan Potassium using Ethocel Grade 100 as rate retarding agent.

PubMed

Khan, Kamran Ahmad; Khan, Gul Majid; Zeeshan Danish, Muhammad; Akhlaq; Khan, Haroon; Rehman, Fazal; Mehsud, Saifullah

2015-12-30

Current study was aimed to develop 200mg controlled release matrix tablets of Losartan Potassium using Ethocel 100 Premium and Ethocel 100 FP Premium as rate controlling polymer. In-vitro studies were performed according to USP Method-I in phosphate buffer (PH 6.8) using pharma test dissolution apparatus. The temperature of the dissolution medium was kept constant at 37±0.5°C at 100rpm. Flow properties, physical quality control tests, effect of polymer size and drug-to-polymers ratios were studied using different kinetics models such as 1st-order, zero-order, Hixon Crowell model, Highuchi model and Power law. Difference factor f1 and similarity factor f2 were applied for dissolution profiles against Cardaktin® tablets used as a reference formulation. The matrices with polymer ethocel 100 FP Premiums have prolonged the drug release rate as compared to polymer ethocel 100 Premiums. The n values matrices with polymer ethocel grade 100 ranged from 0.603 to 0.857 indicating that the drug release occurred by anomalous non fickian diffusion kinetics while then value of reference Cardaktin® tablet was measured as 0.125 indicating that these tablets do not follow power law. The dissolution profiles of test formulations were different than that of reference Cardaktin®. This suggests the polymer Ethocel grade 100 can be proficiently incorporated in fabrication and development of once a day controlled release matrix tablets. Copyright © 2015. Published by Elsevier B.V.

In vitro-in vivo correlation for wet-milled tablet of poorly water-soluble cilostazol.

PubMed

Jinno, Jun-ichi; Kamada, Naoki; Miyake, Masateru; Yamada, Keigo; Mukai, Tadashi; Odomi, Masaaki; Toguchi, Hajime; Liversidge, Gary G; Higaki, Kazutaka; Kimura, Toshikiro

2008-08-25

The purpose of the present study was to investigate oral bioavailability of an immediate release tablet containing wet-milled crystals of a poorly water-soluble drug, cilostazol, and to establish in vitro-in vivo correlation. Sub-micron sized cilostazol (median diameter: 0.26 microm) was successfully prepared using a beads-mill in water in the presence of a hydrophilic polymer and an anionic surfactant. The milled suspension was solidified with a sugar alcohol as a water-soluble carrier by spray-drying method. The co-precipitate was compressed into an immediate release tablet with common excipients. Oral bioavailability of the wet-milled cilostazol tablet in male beagle dogs was 13-fold higher than the hammer-milled commercial tablet in fasted condition. Food did not increase the oral bioavailability of the wet-milled tablet, while 4-fold increase was found for the commercial tablet. Irrespective to the bioavailability enhancement, in vitro dissolution rate of the wet-milled tablet was even slower than the commercial tablet by the compendial method (USP Apparatus 2). On the other hand, a good correlation was found between the dissolution profiles obtained by a flow-through cell method (USP Apparatus 4, closed-loop system without outlet filter) using a large volume of water and sodium lauryl sulfate (SLS) solution at the concentration lower than the critical micellar concentration (cmc) as dissolution media corresponding to the fasted and fed conditions, respectively.

Effect of sodium lauryl sulfate in dissolution media on dissolution of hard gelatin capsule shells.

PubMed

Zhao, Fang; Malayev, Vyacheslav; Rao, Venkatramana; Hussain, Munir

2004-01-01

Sodium lauryl sulfate (SLS) is a commonly used surfactant in dissolution media for poorly water soluble drugs. However, it has occasionally been observed that SLS negatively impacts the dissolution of drug products formulated in gelatin capsules. This study investigated the effect of SLS on the dissolution of hard gelatin capsule shells. The USP paddle method was used with online UV monitoring at 214 nm (peptide bond). Empty size #0 capsule shells were held to the bottom of the dissolution vessel by magnetic three-prong sinkers. SLS significantly slowed down the dissolution of gelatin shells at pH < 5. Visually, the gelatin shells transformed into some less-soluble precipitate under these conditions. This precipitate was found to contain a higher sulfur content than the gelatin control sample by elemental analysis, indicating that SLS is part of the precipitate. Additionally, the slowdown of capsule shell dissolution was shown to be dependent on the SLS concentration and the ionic strength of the media. SLS interacts with gelatin to form a less-soluble precipitate at pH < 5. The use of SLS in dissolution media at acidic pH should be carefully evaluated for gelatin capsule products.

Caffeine: a potential complexing agent for solubility and dissolution enhancement of celecoxib.

PubMed

Shakeel, Faiyaz; Faisal, Mohammed S

2010-01-01

Complexation of caffeine with the drug celecoxib was used to enhance its solubility as well as in vitro dissolution in the present investigation. Caffeine was extracted from tea leaves using the sublimation method. A molecular complex (1:1) of caffeine-celecoxib was prepared using the solubility method. The solubility of celecoxib in distilled water and the caffeine complex was determined using a HPLC method at a wavelength of 250 nm. Dissolution studies of pure celecoxib, a marketed capsule (Celebrex), and the complex were performed using USP dissolution apparatus I for pure celecoxib and the complex and apparatus II for the capsule in distilled water. The highest solubility (48.32 mg/mL) as well as percent dissolution (90.54%) of celecoxib was obtained with the caffeine-celecoxib complex. The results for solubility and dissolution were highly significant as compared to pure celecoxib and the marketed capsule (p < 0.01). These results suggest that caffeine is a promising complexing agent for solubility as well as dissolution enhancement of the poorly soluble drug celecoxib.

On-line monitoring of in-vitro oral bioaccessibility tests as front-end to liquid chromatography for determination of chlorogenic acid isomers in dietary supplements.

PubMed

Kremr, Daniel; Cocovi-Solberg, David J; Bajerová, Petra; Ventura, Karel; Miró, Manuel

2017-05-01

A novel fully automated in-vitro oral dissolution test assay as a front-end to liquid chromatography has been developed and validated for on-line chemical profiling and monitoring of temporal release profiles of three caffeoylquinic acid (CQA) isomers, namely, 3-CQA,4-CQA and 5-CQA, known as chlorogenic acids, in dietary supplements. Tangential-flow filtration is harnessed as a sample processing approach for on-line handling of CQA containing extracts of hard gelatin capsules and introduction of protein-free samples into the liquid chromatograph. Oral bioaccessibility/dissolution test assays were performed at 37.0±0.5°C as per US Pharmacopeia recommendations using pepsin with activity of ca. 749,000 USP units/L in 0.1mol/L HCl as the extraction medium and a paddle apparatus stirred at 50rpm. CQA release rates and steady-state dissolution conditions were determined accurately by fitting the chromatographic datasets, namely, the average cumulative concentrations of bioaccessible pools of every individual isomer monitored during 200min, with temporal resolutions of ≥10min, to a first-order dissolution kinetic model. Distinct solid-to-liquid phase ratios in the mimicry of physiological extraction conditions were assessed. Relative standard deviations for intra-day repeatability and inter-day intermediate precision of 5-CQA within the 5-40µg/mL concentration range were <3.4% and <5.5%, respectively. Trueness of the automatic flow method for determination of 5-CQA released from dietary supplements in gastric fluid surrogate was demonstrated by spike recoveries, spanning from 91.5-104.0%, upon completion of the dissolution process. The proposed hyphenated setup was resorted for evaluating potential differences in dissolution profiles and content of the three most abundant chlorogenic acid isomers in dietary supplements from varied manufacturers. Copyright © 2016 Elsevier B.V. All rights reserved.

Behavioral Characteristics of Ubiquitin-Specific Peptidase 46-Deficient Mice

PubMed Central

Imai, Saki; Kano, Makoto; Nonoyama, Keiko; Ebihara, Shizufumi

2013-01-01

We have previously identified Usp46, which encodes for ubiquitin-specific peptidase 46, as a quantitative trait gene affecting the immobility time of mice in the tail suspension test (TST) and forced swimming test. The mutation that we identified was a 3-bp deletion coding for lysine (Lys 92), and mice with this mutation (MT mice), as well as Usp46 KO mice exhibited shorter TST immobility times. Behavioral pharmacology suggests that the gamma aminobutyric acid A (GABAA) receptor is involved in regulating TST immobility time. In order to understand how far Usp46 controls behavioral phenotypes, which could be related to mental disorders in humans, we subjected Usp46 MT and KO mice to multiple behavioral tests, including the open field test, ethanol preference test, ethanol-induced loss of righting reflex test, sucrose preference test, novelty-suppressed feeding test, marble burying test, and novel object recognition test. Although behavioral phenotypes of the Usp46 MT and KO mice were not always identical, deficiency of Usp46 significantly affected performance in all these tests. In the open field test, activity levels were lower in Usp46 KO mice than wild type (WT) or MT mice. Both MT and KO mice showed lower ethanol preference and shorter recovery times after ethanol administration. Compared to WT mice, Usp46 MT and KO mice exhibited decreased sucrose preference, took longer latency periods to bite pellets, and buried more marbles in the sucrose preference test, novelty-suppressed feeding test, and marble burying test, respectively. In the novel object recognition test, neither MT nor KO mice showed an increase in exploration of a new object 24 hours after training. These findings indicate that Usp46 regulates a wide range of behavioral phenotypes that might be related to human mental disorders and provides insight into the function of USP46 deubiquitinating enzyme in the neural system. PMID:23472206

Effect of hydrophobic inclusions on polymer swelling kinetics studied by magnetic resonance imaging.

PubMed

Gajdošová, Michaela; Pěček, Daniel; Sarvašová, Nina; Grof, Zdeněk; Štěpánek, František

2016-03-16

The rate of drug release from polymer matrix-based sustained release formulations is often controlled by the thickness of a gel layer that forms upon contact with dissolution medium. The effect of formulation parameters on the kinetics of elementary rate processes that contribute to gel layer formation, such as water ingress, polymer swelling and erosion, is therefore of interest. In the present work, gel layer formation has been investigated by magnetic resonance imaging (MRI), which is a non-destructive method allowing direct visualization of effective water concentration inside the tablet and its surrounding. Using formulations with Levetiracetam as the active ingredient, HPMC as a hydrophilic matrix former and carnauba wax (CW) as a hydrophobic component in the matrix system, the effect of different ratios of these two ingredients on the kinetics of gel formation (MRI) and drug release (USP 4 like dissolution test) has been investigated and interpreted using a mathematical model. Copyright © 2016 Elsevier B.V. All rights reserved.

Evaluation of various dissolution media for predicting in vivo performance of class I and II drugs.

PubMed

Galia, E; Nicolaides, E; Hörter, D; Löbenberg, R; Reppas, C; Dressman, J B

1998-05-01

In this paper we seek to verify the differences in dissolution behavior between class I and class II drugs and to evaluate the suitability of two new physiologically based media, of Simulated Gastric Fluid (SGF) and of milk for their ability to forecast trends in the in vivo performance of class II compounds and their formulations. Dissolution behavior of two class I drugs, i.e. acetaminophen and metoprolol, and of three class II drugs, i.e. danazol, mefenamic acid and ketoconazole, was studied with USP Apparatus 2 in water, SGF, milk, Simulated Intestinal Fluid without pancreatin (SIFsp) and in two media simulating the small intestinal contents in the fed (FeSSIF) and fasted (FaSSIF) states, respectively. Class I powders dissolved rapidly in all media tested. Acetaminophen dissolution in milk was slow from one tablet formulation, in all other cases dissolution was more than 85% complete in 15 minutes. The dissolution rate of metoprolol was shown to be dependent on formulation and manufacturing method, and one of the three tablet formulations did not meet compendial specifications (80%/30 minutes). Dissolution behavior of class II drugs was greatly affected by choice of medium. Dissolution from a capsule formulation of danazol proved to be dependent on the concentration of solubilizing agents, with a the 30-fold increase in percentage dissolved within 90 minutes upon changing from aqueous media without surfactants to FaSSIF. Use of FeSSIF or milk as the dissolution medium resulted in an even greater increase in percentage dissolved, 100 and 180-fold respectively. Dissolution of the weak acid mefenamic acid from a capsule formulation is dependent on both pH and bile salt concentration, which leads to an offset between increased bile salt concentration and lower pH in the fed state compared to the fasted state medium. The weak base ketoconazole showed complete dissolution from a tablet formulation in Simulated Gastric Fluid without pepsin (SGFsp) within 30 minutes, 70% dissolution in 2 hours under fed state simulated upper jejunal conditions but only 6% dissolution in 2 hours under fasted state conditions. As predicted, dissolution of class II drugs proved to be in general much more dependent on the medium than class I drugs. With the array of compendial and physiological media available, it should be possible to design a suitable set of tests to predict the in vivo dissolution of both class I and II drugs from immediate release formulations.

Terahertz Pulsed Imaging and Magnetic Resonance Imaging as Tools to Probe Formulation Stability

PubMed Central

Zhang, Qilei; Gladden, Lynn F.; Avalle, Paolo; Zeitler, J. Axel; Mantle, Michael D.

2013-01-01

Dissolution stability over the entire shelf life duration is of critical importance to ensure the quality of solid dosage forms. Changes in the drug release profile during storage may affect the bioavailability of drug products. This study investigated the stability of a commercial tablet (Lescol® XL) when stored under accelerated conditions (40 °C/75% r.h.). Terahertz pulsed imaging (TPI) was used to investigate the structure of the tablet coating before and after the accelerated aging process. The results indicate that the coating was reduced in thickness and exhibited a higher density after being stored under accelerated conditions for four weeks. In situ magnetic resonance imaging (MRI) of the water penetration processes during tablet dissolution in a USP-IV dissolution cell equipped with an in-line UV-vis analyzer was carried out to study local differences in water uptake into the tablet matrix between the stressed and unstressed state. The drug release profiles of the Lescol® XL tablet before and after the accelerated storage stability testing were compared using a “difference” factor f1 and a “similarity” factor f2. The results reveal that even though the physical properties of the coating layers changed significantly during the stress testing, the coating protected the tablet matrix and the densification of the coating polymer had no adverse effect on the drug release performance. PMID:24300564

Biorelevant Dissolution Models for a Weak Base To Facilitate Formulation Development and Overcome Reduced Bioavailability Caused by Hypochlordyria or Achlorhydria.

PubMed

Kou, Dawen; Dwaraknath, Sudharsan; Fischer, Yannick; Nguyen, Daniel; Kim, Myeonghui; Yiu, Hiuwing; Patel, Preeti; Ng, Tania; Mao, Chen; Durk, Matthew; Chinn, Leslie; Winter, Helen; Wigman, Larry; Yehl, Peter

2017-10-02

In this study, two dissolution models were developed to achieve in vitro-in vivo relationship for immediate release formulations of Compound-A, a poorly soluble weak base with pH-dependent solubility and low bioavailability in hypochlorhydric and achlorhydric patients. The dissolution models were designed to approximate the hypo-/achlorhydric and normal fasted stomach conditions after a glass of water was ingested with the drug. The dissolution data from the two models were predictive of the relative in vivo bioavailability of various formulations under the same gastric condition, hypo-/achlorhydric or normal. Furthermore, the dissolution data were able to estimate the relative performance under hypo-/achlorhydric and normal fasted conditions for the same formulation. Together, these biorelevant dissolution models facilitated formulation development for Compound-A by identifying the right type and amount of key excipient to enhance bioavailability and mitigate the negative effect of hypo-/achlorhydria due to drug-drug interaction with acid-reducing agents. The dissolution models use readily available USP apparatus 2, and their broader utility can be evaluated on other BCS 2B compounds with reduced bioavailability caused by hypo-/achlorhydria.

Evaluation and selection of bio-relevant dissolution media for a poorly water-soluble new chemical entity.

PubMed

Tang, L; Khan, S U; Muhammad, N A

2001-11-01

The purpose of this work is to develop a bio-relevant dissolution method for formulation screening in order to select an enhanced bioavailable formulation for a poorly water-soluble drug. The methods used included a modified rotating disk apparatus for measuring intrinsic dissolution rate of the new chemical entity (NCE) and the USP dissolution method II for evaluating dissolution profiles of the drug in three different dosage forms. The in vitro dissolution results were compared with the in vivo bioavailability for selecting a bio-relevant medium. The results showed that the solubility of the NCE was proportional to the concentration of sodium lauryl sulfate (SLS) in the media. The apparent intrinsic dissolution rate of the NCE was linear to the rotational speed of the disk, which indicated that the dissolution of the drug is a diffusion-controlled mechanism. The apparent intrinsic dissolution rate was also linear to the surfactant concentration in the media, which was interpreted using the Noyes and Whitney Empirical Theory. Three formulations were studied in three different SLS media using the bulk drug as a reference. The dissolution results were compared with the corresponding bioavailability results in dogs. In the 1% SLS--sink conditions--the drug release from all the formulations was complete and the dissolution results were discriminative for the difference in particle size of the drug in the formulations. However, the data showed poor IVIV correlation. In the 0.5% SLS medium--non-sink conditions--the dissolution results showed the same rank order among the tested formulations as the bioavailability. The best IVIV correlation was obtained from the dissolution in 0.25% SLS medium, an over-saturated condition. The conclusions are: a surfactant medium increases the apparent intrinsic dissolution rate of the NCE linearly due to an increase in solubility. A low concentration of surfactant in the medium (0.25%) is more bio-relevant than higher concentrations of surfactant in the media for the poorly water-soluble drug. Creating sink conditions (based on bulk drug solubilities) by using a high concentration of a surfactant in the dissolution medium may not be a proper approach in developing a bio-relevant dissolution method for a poorly water-soluble drug.

Fenofibrate Nanocrystals Embedded in Oral Strip-Films for Bioavailability Enhancement

PubMed Central

Barvaliya, Manish; Zhang, Lu; Anovadiya, Ashish; Brahmbhatt, Harshad; Paul, Parimal; Tripathi, Chandrabhanu

2018-01-01

The aim of the present study was to make a fenofibrate (FNB) nanocrystal (NC) by wet media milling, characterizations and formulates into oral strip-films (OSFs). Mechanical properties, redispersion study, and solid-state characterizations results suggested that reduction of drug crystal size at nanoscale and incorporation into OSFs does not affect the solid-state properties of the drug. In vitro dissolution kinetics showed enhanced dissolution rate was easily manipulated by changing the thickness of the OSF. In situ UV-imaging was used to monitor drug dissolution qualitatively and quantitatively in real time. Results confirm that the intrinsic dissolution rates and surface drug concentration measured with this device were in agreement with the USP-IV dissolution profiles. In vivo pharmacokinetics in rabbits showed a significant difference in the pharmacokinetics parameter (1.4 fold increase bioavailability) of FNB NC-loaded OSFs as compared to the marketed formulation “Tricor” and as-received (pristine) drug. This approach of drug nanocrystallization and incorporation into OSFs may have significant applications in cost-effective tools for bioavailability enhancement of FNB. PMID:29438297

Formulation and Evaluation of Fast-Disintegrating Sublingual Tablets of Atropine Sulfate: the Effect of Tablet Dimensions and Drug Load on Tablet Characteristics.

PubMed

Aodah, Alhussain; Bafail, Rawan S; Rawas-Qalaji, Mutasem

2017-07-01

In this study, we formulated and evaluated the effects of tablet dimensions and drug load on the characteristics of atropine sulfate (AS) fast-disintegrating sublingual tablets (FDSTs). We aim to develop AS FDSTs as an alternative non-invasive and portable dosage form for the emergency treatment of organophosphate (OP) toxicity. AS autoinjector, AtroPen®, is the only self-administered dosage form available as an antidote for-out-of-hospital emergency use, but it is associated with several limitations and drawbacks. Seven FDST formulations of two tablet sizes, 150 mg (A) and 50 mg (B), and of several AS loads, 0 mg (A1, B1), 2 mg (A2, B2), 4 mg (B3), and 8 mg (B4a, B4b), were formulated and manufactured by direct compression. AS FDST characteristics were evaluated using USP and non-USP tests. Results were statistically compared at p < 0.05. All FDSTs passed the USP content uniformity and friability tests, disintegrated and released AS in ≤30 and 60 s. B1 and B2 were significantly harder than A1 and A2. Water uptake of A1 was significantly the highest. However, B1 and B2 had shorter disintegration and wetting times and higher amounts of AS dissolved than did A1 and A2 (p < 0.05). Increasing AS negatively affected FDST tensile strength (p < 0.05 for B4a) and water uptake (p < 0.05 for B3, B4a and B4b), however, without affecting AS dissolution. Formulation of AS up to 16% into smaller FDSTs was successful. Smaller FDSTs were harder and disintegrated more quickly. These AS FDSTS have the potential for further in vivo testing to evaluate their OP antidote potential.

3D extrusion printing of high drug loading immediate release paracetamol tablets.

PubMed

Khaled, Shaban A; Alexander, Morgan R; Wildman, Ricky D; Wallace, Martin J; Sharpe, Sonja; Yoo, Jae; Roberts, Clive J

2018-03-01

The manufacture of immediate release high drug loading paracetamol oral tablets was achieved using an extrusion based 3D printer from a premixed water based paste formulation. The 3D printed tablets demonstrate that a very high drug (paracetamol) loading formulation (80% w/w) can be printed as an acceptable tablet using a method suitable for personalisation and distributed manufacture. Paracetamol is an example of a drug whose physical form can present challenges to traditional powder compression tableting. Printing avoids these issues and facilitates the relatively high drug loading. The 3D printed tablets were evaluated for physical and mechanical properties including weight variation, friability, breaking force, disintegration time, and dimensions and were within acceptable range as defined by the international standards stated in the United States Pharmacopoeia (USP). X-ray Powder Diffraction (XRPD) was used to identify the physical form of the active. Additionally, XRPD, Attenuated Total Reflectance Fourier Transform Infrared spectroscopy (ATR-FTIR) and differential scanning calorimetry (DSC) were used to assess possible drug-excipient interactions. The 3D printed tablets were evaluated for drug release using a USP dissolution testing type I apparatus. The tablets showed a profile characteristic of the immediate release profile as intended based upon the active/excipient ratio used with disintegration in less than 60 s and release of most of the drug within 5 min. The results demonstrate the capability of 3D extrusion based printing to produce acceptable high-drug loading tablets from approved materials that comply with current USP standards. Copyright © 2018 Elsevier B.V. All rights reserved.

Direct visualization of in vitro drug mobilization from Lescol XL tablets using two-dimensional (19)F and (1)H magnetic resonance imaging.

PubMed

Chen, Chen; Gladden, Lynn F; Mantle, Michael D

2014-02-03

This article reports the application of in vitro multinuclear ((19)F and (1)H) two-dimensional magnetic resonance imaging (MRI) to study both dissolution media ingress and drug egress from a commercial Lescol XL extended release tablet in a United States Pharmacopeia Type IV (USP-IV) dissolution cell under pharmacopoeial conditions. Noninvasive spatial maps of tablet swelling and dissolution, as well as the mobilization and distribution of the drug are quantified and visualized. Two-dimensional active pharmaceutical ingredient (API) mobilization and distribution maps were obtained via (19)F MRI. (19)F API maps were coregistered with (1)H T2-relaxation time maps enabling the simultaneous visualization of drug distribution and gel layer dynamics within the swollen tablet. The behavior of the MRI data is also discussed in terms of its relationship to the UV drug release behavior.

Interaction between fed gastric media (Ensure Plus®) and different hypromellose based caffeine controlled release tablets: comparison and mechanistic study of caffeine release in fed and fasted media versus water using the USP dissolution apparatus 3.

PubMed

Franek, Frans; Holm, Per; Larsen, Frank; Steffansen, Bente

2014-01-30

The aim of the study was to investigate caffeine release in fed and fasted state media from three controlled release matrix tablets containing different HPMC viscosity grades. The biorelevant in vitro dissolution methods utilize the USP 3 dissolution apparatus and biorelevant media to simulate fed and fasted gastro-intestinal dissolution conditions. The effect of tablet reciprocation rate (dip speed) in dissolution media (10 and 15 dips per minute) and media (water, fed and fasted) on caffeine release rate from - and erosion rate of - 100, 4000 and 15,000 mPa s HPMC viscosity tablets was investigated using factorial designed experiments. Furthermore, the mechanism of release in Ensure Plus(®), a nutrition drink similar in composition to the FDA standard meal, was investigated by studying tablet swelling using texture analysis. Altering dip speed has negligible effect on release and erosion rates. Using fasted media instead of water slightly decreases caffeine release from 100 and 4000 mPa s HPMC viscosity tablets as well as erosion rates, while 15,000 mPa s tablets remain unaffected. Fed compared to fasted media decreases caffeine release rate, and the food effect is greater for the 100 mPa s viscosity tablets compared to the 4000 and 15,000 mPa s viscosity tablets. The investigation using texture analysis indicates that Ensure Plus(®) becomes rate-limiting for caffeine release from HPMC tablets by forming a hydrophobic barrier around the tablets. The barrier decreases tablet water permeation, which decreases erosion rate in 100 mPa s viscosity tablets, swelling in 15,000 mPa s viscosity tablets and caffeine release from both tablets. This observed interaction between Ensure Plus(®) and the HPMC tablets may translate into decreased drug release rate in the fed stomach, which may decrease the amount of drug available for absorption in the small intestine and thus reduce systemic drug exposure and maximum plasma concentration. Copyright © 2013 Elsevier B.V. All rights reserved.

IDENTIFICATION OF PHARMACEUTICAL EXCIPIENT BEHAVIOR OF CHICKPEA (CICER ARIETINUM) STARCH IN GLICLAZIDE IMMEDIATE RELEASE TABLETS.

PubMed

Meka, Venkata Srikanth; Yee, Phung; Sheshala, Ravi

2016-01-01

In the past few years, there are number of researchers carrying out their research on the excipients derived from polysaccharides and some of these researches show that natural excipients are comparable and can serve as an alternative to the synthetic excipients. Hence, the objectives of this research are to characterize the naturally sourced chickpea starch powder and to study the pharmaceutical excipient behavior of chickpea starch in gliclazide immediate release (IR) tablets. In this research, the binding properties of chickpea starch were compared to that of povidone, whereas the disintegrant properties of chickpea starch were compared to those of crospovidone, croscarmellose sodium and sodium starch glycolate. Flow property of chickpea starch was assessed with the measurement of bulk density, tapped density, compressibility index and angle of repose. Calibration curve for gliclazide in phosphate buffer pH 7.4 was developed. Gliclazide IR tablets were then produced with direct compression method. Physicochemical characteristics of the tablets, including thickness, tablet weight uniformity, hardness, disintegration time and friability were evaluated. Then, in vitro dissolution studies were performed by following United States Pharmacopeia (USP) dissolution method. The dissolution results were analyzed and compared with t30, t50, dissolution efficiency (DE). Lastly, drug-excipient compatibility studies, including Fourier transform infrared (FTIR) spectroscopic analysis and differential scanning calorimetric (DSC) analysis were carried out. Fair flow property was observed in the chickpea starch powder. Furthermore, the tablets produced passed all the tests in physicochemical characteristics evaluation except hardness and disintegration test. Additionally, in vitro dissolution studies show that chickpea starch acted as a disintegrant instead of a binder in gliclazide IR tablets and its disintegrant properties were comparable to those of crospovidone, croscarmellose sodium and sodium starch glycolate. Besides that, gliclazide was also compatible with the excipients used. Chickpea starch acted as a disintegrant in gliclazide IR tablets, instead of a binder. Therefore, chickpea starch can be a promising disintegrant in gliclazide IR tablets.

Understanding and optimizing the dual excipient functionality of sodium lauryl sulfate in tablet formulation of poorly water soluble drug: wetting and lubrication.

PubMed

Aljaberi, Ahmad; Chatterji, Ashish; Dong, Zedong; Shah, Navnit H; Malick, Waseem; Singhal, Dharmendra; Sandhu, Harpreet K

2013-01-01

To evaluate and optimize sodium lauryl sulfate (SLS) and magnesium stearate (Mg.St) levels, with respect to dissolution and compaction, in a high dose, poorly soluble drug tablet formulation. A model poorly soluble drug was formulated using high shear aqueous granulation. A D-optimal design was used to evaluate and model the effect of granulation conditions, size of milling screen, SLS and Mg.St levels on tablet compaction and ejection. The compaction profiles were generated using a Presster(©) compaction simulator. Dissolution of the kernels was performed using a USP dissolution apparatus II and intrinsic dissolution was determined using a stationary disk system. Unlike kernels dissolution which failed to discriminate between tablets prepared with various SLS contents, the intrinsic dissolution rate showed that a SLS level of 0.57% was sufficient to achieve the required release profile while having minimal effect on compaction. The formulation factors that affect tablet compaction and ejection were identified and satisfactorily modeled. The design space of best factor setting to achieve optimal compaction and ejection properties was successfully constructed by RSM analysis. A systematic study design helped identify the critical factors and provided means to optimize the functionality of key excipient to design robust drug product.

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.

Development of the antimicrobial effectiveness test as USP chapter <51>.

PubMed

Sutton, Scott V W; Porter, David

2002-01-01

The antimicrobial effectiveness test first appeared as a USP General Chapter in the 18th revision, official September 1, 1970. This chapter, at the beginning, was designed to evaluate the performance of antimicrobials added to inhibit the growth of microorganisms that might be introduced during or subsequent to the manufacturing process. As Good Manufacturing Practices (GMPs) became a governing principal in pharmaceutical manufacturing, the purpose of the test was refined to focus on activity of the preservative system as a protection against inadvertent contamination during storage and usage of the product. This article will review the history of the antimicrobial test; its function, technique, and the background discussions that resulted in the changes from the test that appeared in USP XVIII to that of the current USP 25.

Preparation and characterization of fast dissolving pullulan films containing BCS class II drug nanoparticles for bioavailability enhancement.

PubMed

Krull, Scott M; Ma, Zhelun; Li, Meng; Davé, Rajesh N; Bilgili, Ecevit

2016-01-01

The aim of this study is to assess pullulan as a novel steric stabilizer during the wet-stirred media milling (WSMM) of griseofulvin, a model poorly water-soluble drug, and as a film-former in the preparation of strip films via casting-drying the wet-milled drug suspensions for dissolution and bioavailability enhancement. To this end, pullulan films, with xanthan gum (XG) as thickening agent and glycerin as plasticizer, were loaded with griseofulvin nanoparticles prepared by WSMM using pullulan in combination with sodium dodecyl sulfate (SDS) as an ionic stabilizer. The effects of drug loading and milling time on the particle size and suspension stability were investigated, as well as XG concentration and casting thickness on film properties and dissolution rate. The nanosuspensions prepared with pullulan-SDS combination were relatively stable over 7 days; hence, this combination was used for the film preparation. All pullulan-based strip films exhibited excellent content uniformity (most <3% RSD) despite containing only 0.3-1.3 mg drug, which was ensured by the use of precursor suspensions with >5000 cP viscosity. USP IV dissolution tests revealed fast/immediate drug release (t80 < 30 min) from films <120 μm thick. Thinner films, films with lower XG loading, or smaller drug particles led to faster drug dissolution, while drug loading had no discernible effect. Overall, these results suggest that pullulan may serve as an acceptable stabilizer for media milling in combination with surfactant as well as a fast-dissolving film former for the fast release of poorly water-soluble drug nanoparticles.

Chemometrics-assisted spectrophotometric green method for correcting interferences in biowaiver studies: Application to assay and dissolution profiling study of donepezil hydrochloride tablets

NASA Astrophysics Data System (ADS)

Korany, Mohamed A.; Mahgoub, Hoda; Haggag, Rim S.; Ragab, Marwa A. A.; Elmallah, Osama A.

2018-06-01

A green, simple and cost effective chemometric UV-Vis spectrophotometric method has been developed and validated for correcting interferences that arise during conducting biowaiver studies. Chemometric manipulation has been done for enhancing the results of direct absorbance, resulting from very low concentrations (high incidence of background noise interference) of earlier points in the dissolution timing in case of dissolution profile using first and second derivative (D1 & D2) methods and their corresponding Fourier function convoluted methods (D1/FF& D2/FF). The method applied for biowaiver study of Donepezil Hydrochloride (DH) as a representative model was done by comparing two different dosage forms containing 5 mg DH per tablet as an application of a developed chemometric method for correcting interferences as well as for the assay and dissolution testing in its tablet dosage form. The results showed that first derivative technique can be used for enhancement of the data in case of low concentration range of DH (1-8 μg mL-1) in the three different pH dissolution media which were used to estimate the low drug concentrations dissolved at the early points in the biowaiver study. Furthermore, the results showed similarity in phosphate buffer pH 6.8 and dissimilarity in the other 2 pH media. The method was validated according to ICH guidelines and USP monograph for both assays (HCl of pH 1.2) and dissolution study in 3 pH media (HCl of pH 1.2, acetate buffer of pH 4.5 and phosphate buffer of pH 6.8). Finally, the assessment of the method greenness was done using two different assessment techniques: National Environmental Method Index label and Eco scale methods. Both techniques ascertained the greenness of the proposed method.

Chemometrics-assisted spectrophotometric green method for correcting interferences in biowaiver studies: Application to assay and dissolution profiling study of donepezil hydrochloride tablets.

PubMed

Korany, Mohamed A; Mahgoub, Hoda; Haggag, Rim S; Ragab, Marwa A A; Elmallah, Osama A

2018-06-15

A green, simple and cost effective chemometric UV-Vis spectrophotometric method has been developed and validated for correcting interferences that arise during conducting biowaiver studies. Chemometric manipulation has been done for enhancing the results of direct absorbance, resulting from very low concentrations (high incidence of background noise interference) of earlier points in the dissolution timing in case of dissolution profile using first and second derivative (D1 & D2) methods and their corresponding Fourier function convoluted methods (D1/FF& D2/FF). The method applied for biowaiver study of Donepezil Hydrochloride (DH) as a representative model was done by comparing two different dosage forms containing 5mg DH per tablet as an application of a developed chemometric method for correcting interferences as well as for the assay and dissolution testing in its tablet dosage form. The results showed that first derivative technique can be used for enhancement of the data in case of low concentration range of DH (1-8μgmL -1 ) in the three different pH dissolution media which were used to estimate the low drug concentrations dissolved at the early points in the biowaiver study. Furthermore, the results showed similarity in phosphate buffer pH6.8 and dissimilarity in the other 2pH media. The method was validated according to ICH guidelines and USP monograph for both assays (HCl of pH1.2) and dissolution study in 3pH media (HCl of pH1.2, acetate buffer of pH4.5 and phosphate buffer of pH6.8). Finally, the assessment of the method greenness was done using two different assessment techniques: National Environmental Method Index label and Eco scale methods. Both techniques ascertained the greenness of the proposed method. Copyright © 2018 Elsevier B.V. All rights reserved.

Official USP Reference Standards: metrology concepts, overview, and scientific issues and opportunities.

PubMed

Williams, Roger L

2006-01-23

The United States Pharmacopeia (USP) is a private standards-setting body created in 1820 by practitioners who wished to promote the quality of therapeutic products in commerce. The principal product of USP, then and now, is the United StatesPharmacopeia (USP), to which was added the National Formulary (NF) in 1975. The two compendia are published as a combined text annually (USP-NF). Originally a book of process standards, USP-NF evolved over time into compendia containing primarily product standards that are expressed in monographs for therapeutic ingredients, products, and excipients. As a public health service, USP supplies official USP Reference Standards to manufacturers and others who wish to test an article according to selected procedures of a monograph or General Chapter. During the past decade, understanding of USP monographs and official USP Reference Standards as a means of controlling the quality of a therapeutic article has evolved, based on advances in metrology, on activities in the International Conference on Harmonization of Technical Requirements for the Registration of Pharmaceuticals for Human Use (ICH), and on considerations by the USP Council of Experts and its Expert Committees and USP staff. This article discusses the evolution of this understanding, focusing on drug substances and excipients for well-characterized small molecules and their corresponding dosage forms.

A New Test Unit for Disintegration End-Point Determination of Orodispersible Films.

PubMed

Low, Ariana; Kok, Si Ling; Khong, Yuet Mei; Chan, Sui Yung; Gokhale, Rajeev

2015-11-01

No standard time or pharmacopoeia disintegration test method for orodispersible films (ODFs) exists. The USP disintegration test for tablets and capsules poses significant challenges for end-point determination when used for ODFs. We tested a newly developed disintegration test unit (DTU) against the USP disintegration test. The DTU is an accessory to the USP disintegration apparatus. It holds the ODF in a horizontal position, allowing top-view of the ODF during testing. A Gauge R&R study was conducted to assign relative contributions of the total variability from the operator, sample or the experimental set-up. Precision was compared using commercial ODF products in different media. Agreement between the two measurement methods was analysed. The DTU showed improved repeatability and reproducibility compared to the USP disintegration system with tighter standard deviations regardless of operator or medium. There is good agreement between the two methods, with the USP disintegration test giving generally longer disintegration times possibly due to difficulty in end-point determination. The DTU provided clear end-point determination and is suitable for quality control of ODFs during product developmental stage or manufacturing. This may facilitate the development of a standardized methodology for disintegration time determination of ODFs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Toward Biopredictive Dissolution for Enteric Coated Dosage Forms.

PubMed

Al-Gousous, J; Amidon, G L; Langguth, P

2016-06-06

The aim of this work was to develop a phosphate buffer based dissolution method for enteric-coated formulations with improved biopredictivity for fasted conditions. Two commercially available enteric-coated aspirin products were used as model formulations (Aspirin Protect 300 mg, and Walgreens Aspirin 325 mg). The disintegration performance of these products in a physiological 8 mM pH 6.5 bicarbonate buffer (representing the conditions in the proximal small intestine) was used as a standard to optimize the employed phosphate buffer molarity. To account for the fact that a pH and buffer molarity gradient exists along the small intestine, the introduction of such a gradient was proposed for products with prolonged lag times (when it leads to a release lower than 75% in the first hour post acid stage) in the proposed buffer. This would allow the method also to predict the performance of later-disintegrating products. Dissolution performance using the accordingly developed method was compared to that observed when using two well-established dissolution methods: the United States Pharmacopeia (USP) method and blank fasted state simulated intestinal fluid (FaSSIF). The resulting dissolution profiles were convoluted using GastroPlus software to obtain predicted pharmacokinetic profiles. A pharmacokinetic study on healthy human volunteers was performed to evaluate the predictions made by the different dissolution setups. The novel method provided the best prediction, by a relatively wide margin, for the difference between the lag times of the two tested formulations, indicating its being able to predict the post gastric emptying onset of drug release with reasonable accuracy. Both the new and the blank FaSSIF methods showed potential for establishing in vitro-in vivo correlation (IVIVC) concerning the prediction of Cmax and AUC0-24 (prediction errors not more than 20%). However, these predictions are strongly affected by the highly variable first pass metabolism necessitating the evaluation of an absorption rate metric that is more independent of the first-pass effect. The Cmax/AUC0-24 ratio was selected for this purpose. Regarding this metric's predictions, the new method provided very good prediction of the two products' performances relative to each other (only 1.05% prediction error in this regard), while its predictions for the individual products' values in absolute terms were borderline, narrowly missing the regulatory 20% prediction error limits (21.51% for Aspirin Protect and 22.58% for Walgreens Aspirin). The blank FaSSIF-based method provided good Cmax/AUC0-24 ratio prediction, in absolute terms, for Aspirin Protect (9.05% prediction error), but its prediction for Walgreens Aspirin (33.97% prediction error) was overwhelmingly poor. Thus it gave practically the same average but much higher maximum prediction errors compared to the new method, and it was strongly overdiscriminating as for predicting their performances relative to one another. The USP method, despite not being overdiscriminating, provided poor predictions of the individual products' Cmax/AUC0-24 ratios. This indicates that, overall, the new method is of improved biopredictivity compared to established methods.

Computational Fluid Dynamics Simulation of Hydrodynamics and Stresses in the PhEur/USP Disintegration Tester Under Fed and Fasted Fluid Characteristics.

PubMed

Kindgen, Sarah; Wachtel, Herbert; Abrahamsson, Bertil; Langguth, Peter

2015-09-01

Disintegration of oral solid dosage forms is a prerequisite for drug dissolution and absorption and is to a large extent dependent on the pressures and hydrodynamic conditions in the solution that the dosage form is exposed to. In this work, the hydrodynamics in the PhEur/USP disintegration tester were investigated using computational fluid dynamics (CFD). Particle image velocimetry was used to validate the CFD predictions. The CFD simulations were performed with different Newtonian and non-Newtonian fluids, representing fasted and fed states. The results indicate that the current design and operating conditions of the disintegration test device, given by the pharmacopoeias, are not reproducing the in vivo situation. This holds true for the hydrodynamics in the disintegration tester that generates Reynolds numbers dissimilar to the reported in vivo situation. Also, when using homogenized US FDA meal, representing the fed state, too high viscosities and relative pressures are generated. The forces acting on the dosage form are too small for all fluids compared to the in vivo situation. The lack of peristaltic contractions, which generate hydrodynamics and shear stress in vivo, might be the major drawback of the compendial device resulting in the observed differences between predicted and in vivo measured hydrodynamics. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

USP7 promotes cell proliferation through the stabilization of Ki-67 protein in non-small cell lung cancer cells.

PubMed

Zhang, Chao; Lu, Jing; Zhang, Quan-Wu; Zhao, Wei; Guo, Jia-Hui; Liu, Shan-Ling; Wu, Ying-Li; Jiang, Bin; Gao, Feng-Hou

2016-10-01

The Ki-67 antigen (Ki-67) is the most reliable immunohistochemical marker for evaluation of cell proliferation in non-small cell lung cancer. However, the mechanisms underlying the regulation of protein levels of Ki-67 in non-small cell lung cancer have remained elusive. In this study, we found that Ki-67 and ubiquitin-specific processing protease 7 (USP7) protein were highly expressed in the nucleus of non-small cell lung cancer cells. Furthermore, statistical analysis uncovered the existence of a strong correlation between Ki-67 and USP7 levels. We could also show that the protein levels of Ki-67 in non-small cell lung cancer cells significantly decreased after treatment with P22077, a selective chemical inhibitor of USP7, while the Ki-67 mRNA levels were unperturbed. Similar results were obtained by knocking down USP7 using short hairpin RNA (shRNA) in lung cancer cells. Interestingly, we noticed that ubiquitination levels of Ki-67 increased dramatically in USP7-silenced cells. The tests in vitro and vivo showed a significant delay in tumor cell growth upon knockdown of USP7. Additionally, drug sensitivity tests indicated that USP7-silenced A549 cells had enhanced sensitivity to paclitaxel and docetaxel, while there was no significant change in sensitivity toward carboplatin and cisplatin. Taken together, these data strongly suggest that the overexpression of USP7 might promote cell proliferation by deubiquitinating Ki-67 protein, thereby maintaining its high levels in the non-small cell lung cancer. Our study also hints potential for the development of deubiquitinase-based therapies, especially those targeting USP7 to improve the condition of patients diagnosed with non-small cell lung cancer. Copyright © 2016 Elsevier Ltd. All rights reserved.

Pharmaceutics, Drug Delivery and Pharmaceutical Technology: A New Test Unit for Disintegration End-Point Determination of Orodispersible Films.

PubMed

Low, Ariana; Kok, Si Ling; Khong, Yuetmei; Chan, Sui Yung; Gokhale, Rajeev

2015-11-01

No standard time or pharmacopoeia disintegration test method for orodispersible films (ODFs) exists. The USP disintegration test for tablets and capsules poses significant challenges for end-point determination when used for ODFs. We tested a newly developed disintegration test unit (DTU) against the USP disintegration test. The DTU is an accessory to the USP disintegration apparatus. It holds the ODF in a horizontal position, allowing top-view of the ODF during testing. A Gauge R&R study was conducted to assign relative contributions of the total variability from the operator, sample or the experimental set-up. Precision was compared using commercial ODF products in different media. Agreement between the two measurement methods was analysed. The DTU showed improved repeatability and reproducibility compared to the USP disintegration system with tighter standard deviations regardless of operator or medium. There is good agreement between the two methods, with the USP disintegration test giving generally longer disintegration times possibly due to difficulty in end-point determination. The DTU provided clear end-point determination and is suitable for quality control of ODFs during product developmental stage or manufacturing. This may facilitate the development of a standardized methodology for disintegration time determination of ODFs. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association J Pharm Sci 104:3893-3903, 2015. Copyright © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Structural and Functional Investigations of the N-Terminal Ubiquitin Binding Region of Usp25.

PubMed

Yang, Yuanyuan; Shi, Li; Ding, Yiluan; Shi, Yanhong; Hu, Hong-Yu; Wen, Yi; Zhang, Naixia

2017-05-23

Ubiquitin-specific protease 25 (Usp25) is a deubiquitinase that is involved in multiple biological processes. The N-terminal ubiquitin-binding region (UBR) of Usp25 contains one ubiquitin-associated domain, one small ubiquitin-like modifier (SUMO)-interacting motif and two ubiquitin-interacting motifs. Previous studies suggest that the covalent sumoylation in the UBR of Usp25 impairs its enzymatic activity. Here, we raise the hypothesis that non-covalent binding of SUMO, a prerequisite for efficient sumoylation, will impair Usp25's catalytic activity as well. To test our hypothesis and elucidate the underlying molecular mechanism, we investigated the structure and function of the Usp25 N-terminal UBR. The solution structure of Usp25 1-146 is obtained, and the key residues responsible for recognition of ubiquitin and SUMO2 are identified. Our data suggest inhibition of Usp25's catalytic activity upon the non-covalent binding of SUMO2 to the Usp25 SUMO-interacting motif. We also find that SUMO2 can competitively block the interaction between the Usp25 UBR and its ubiquitin substrates. Based on our findings, we have proposed a working model to depict the regulatory role of the Usp25 UBR in the functional display of the enzyme. Copyright © 2017 Biophysical Society. Published by Elsevier Inc. All rights reserved.

PHARMACEUTICAL QUALITY OF GENERIC ATORVASTATIN PRODUCTS COMPARED WITH THE INNOVATOR PRODUCT: A NEED FOR REVISING PRICING POLICY IN PALESTINE.

PubMed

Shawahna, Ramzi; Hroub, Abdel Kareem; Abed, Eliama; Jibali, Sondos; Al-Saghir, Ruba; Zaid, Abdel Naser

2016-01-01

Atorvastatin reduces morbidity and mortality due to cardiovascular events. This study was conducted to assess the prices and pharmaceutical quality of innovator atorvastatin 20 mg with its locally available generics in Palestine and to assess the suitability of their interchangeability. The prices of innovator and generic atorvastatin 20 mg were determined and compared. Innovator atorvastatin and four generic products were tested for their pharmaceutical quality. Tablets were tested for their drug contents, weight uniformity, hardness, disintegration and dissolution. Three out of four generics were less expensive than the innovator. Pharmaceutical quality assessments were satisfactory and within limits for all atorvastatin tested products. The average weight ranged from 206.6 ± 8.40 to 330 ± 3.92 mg and the %RSDs were within the permitted limits as per USP. Tablet hardness ranged from 102 ± 1.41 to 197.4 ± 6.88 kg and drug contents ranged from 92.2% to 105.3%. All products disintegrated within permitted time limits and showed very rapid dissolution. Products released more than 85% of their drug contents in less than 15 min. Our results showed that all tested innovator and generic atorvastatin products were of good pharmaceutical quality. Despite the lack of in vivo evaluation, our results indicate that these products are equivalent in vitro. Considering the in vitro release characteristics, these products might be used interchangeably. However, regulatory authorities permit the use of in vitro data in establishing similarity between immediate release oral dosage forms containing biopharmaceutical classification system class I and III drugs only.

Enhanced dissolution and oral bioavailability of valsartan solid dispersions prepared by a freeze-drying technique using hydrophilic polymers.

PubMed

Xu, Wei-Juan; Xie, Hong-Juan; Cao, Qing-Ri; Shi, Li-Li; Cao, Yue; Zhu, Xiao-Yin; Cui, Jing-Hao

2016-01-01

This study aimed to improve the dissolution rate and oral bioavailability of valsartan (VAL), a poorly soluble drug using solid dispersions (SDs). The SDs were prepared by a freeze-drying technique with polyethylene glycol 6000 (PEG6000) and hydroxypropylmethylcellulose (HPMC 100KV) as hydrophilic polymers, sodium hydroxide (NaOH) as an alkalizer, and poloxamer 188 as a surfactant without using any organic solvents. In vitro dissolution rate and physicochemical properties of the SDs were characterized using the USP paddle method, differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and Fourier transform-infrared (FT-IR) spectroscopy, respectively. In addition, the oral bioavailability of SDs in rats was evaluated by using VAL (pure drug) as a reference. The dissolution rates of the SDs were significantly improved at pH 1.2 and pH 6.8 compared to those of the pure drug. The results from DSC, XRD showed that VAL was molecularly dispersed in the SDs as an amorphous form. The FT-IR results suggested that intermolecular hydrogen bonding had formed between VAL and its carriers. The SDs exhibited significantly higher values of AUC 0-24 h and Cmax in comparison with the pure drug. In conclusion, hydrophilic polymer-based SDs prepared by a freeze-drying technique can be a promising method to enhance dissolution rate and oral bioavailability of VAL.

Solid dispersions of the penta-ethyl ester prodrug of diethylenetriaminepentaacetic acid (DTPA): Formulation design and optimization studies

PubMed Central

Yang, Yu-Tsai; Di Pasqua, Anthony J.; Zhang, Yong; Sueda, Katsuhiko; Jay, Michael

2015-01-01

The penta-ethyl ester prodrug of diethylenetriaminepentaacetic acid (DTPA), which exists as an oily liquid, was incorporated into a solid dispersion for oral administration by the solvent evaporation method using blends of polyvinylpyrrolidone (PVP), Eudragit® RL PO and α-tocopherol. D-optimal mixture design was used to optimize the formulation. Formulations that had a high concentration of both Eudragit® RL PO and α-tocopherol exhibited low water absorption and enhanced stability of the DTPA prodrug. Physicochemical properties of the optimal formulation were evaluated using Fourier transform infrared (FTIR) spectroscopy and differential scanning calorimetry (DSC). In vitro release of the prodrug was evaluated using the USP Type II apparatus dissolution method. DSC studies indicated that the matrix had an amorphous structure, while FTIR spectrometry showed that DTPA penta-ethyl ester and excipients did not react with each other during formation of the solid dispersion.. Dissolution testing showed that the optimized solid dispersion exhibited a prolonged release profile, which could potentially result in a sustained delivery of DTPA penta-ethyl to enhance bioavailability. In conclusion, DTPA penta-ethyl ester was successfully incorporated into a solid matrix with high drug loading and improved stability compared to prodrug alone. PMID:24047113

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.

Influence of formulation parameters on dissolution rate enhancement of glyburide using liquisolid technique.

PubMed

Singh, Sachin Kumar; Srinivasan, K K; Gowthamarajan, K; Prakash, Dev; Gaikwad, Narayan B; Singare, Dhananjay S

2012-08-01

The aim of this study was to investigate the use of liquisolid technique in improving the dissolution of glyburide in a solid dosage form. This study was designed to evaluate the effects of different formulation variables, i.e. type of non-volatile liquid vehicles and drug concentrations, on drug dissolution rates. The liquisolid tablets were formulated with Propylene glycol, as liquid vehicle. Microcrystalline cellulose was used as a carrier material, silica as a coating material and croscaremellose as a disintegrant. In vitro drug dissolution profiles of the liquisolid formulations were studied and compared with direct compressed non-micronized and micronized tablets of glyburide using USP II, paddle apparatus at 50 rpm for 60 min using 900 ml of 0.05 M Phosphate Buffer, pH 7.5. The stability studies showed that the dissolution profiles of liquisolid tablets prepared with propylene glycol were not affected by ageing significantly, as f2 value found between aged and fresh samples was 51.92. Differential scanning calorimetry revealed that the drug has got solubilized in the liquid vehicle. This was further supported by the powder X-ray diffraction studies of pure drug and the liquisolid powder system. It can be concluded that it is possible to load poorly soluble drug into liquisolid tablets by addition of PVP to the liquid vehicle. This is valuable for the preparation of liquisolid tablets of poorly soluble drugs. The liquisolid tablets prepared with PVP showed a remarkably improved dissolution rate in comparison with DC tablet and other formulations.

Absence of a Metallicity Effect for Ultra-short-period Planets

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

Winn, Joshua N.; Sanchis-Ojeda, Roberto; Isaacson, Howard

Ultra-short-period (USP) planets are a newly recognized class of planets with periods shorter than one day and radii smaller than about 2  R {sub ⊕}. It has been proposed that USP planets are the solid cores of hot Jupiters that have lost their gaseous envelopes due to photo-evaporation or Roche lobe overflow. We test this hypothesis by asking whether USP planets are associated with metal-rich stars, as has long been observed for hot Jupiters. We find the metallicity distributions of USP-planet and hot-Jupiter hosts to be significantly different ( p = 3 × 10{sup −4}) based on Keck spectroscopy ofmore » Kepler stars. Evidently, the sample of USP planets is not dominated by the evaporated cores of hot Jupiters. The metallicity distribution of stars with USP planets is indistinguishable from that of stars with short-period planets with sizes between 2 and 4  R {sub ⊕}. Thus, it remains possible that the USP planets are the solid cores of formerly gaseous planets that are smaller than Neptune.« less

Novel mesalamine-loaded beads in tablets for delayed release of drug to the colon.

PubMed

Nguyen, Chien; Christensen, J Mark; Ayres, James W

2012-01-01

Novel 'beads-in-a-tablet' formulations (total weight ∼740-780 mg) have been prepared that meet USP 31 requirements for Delayed Release of mesalamine. Several methods are presented that overcome breakage of beads during tablet compaction were explored. Bead formulations comprise a combination of extrusion and spheronization to produce a relatively high drug load (80%), followed by coating (25%) with a colonic-targeted drug release polymer (polymethacrylates, Eudragit(®) S100), overcoated (3%) with hydroxypropyl methylcellulose (Opadry(®)) to improve bead binding and compactability, and using 20% coat of lactose/sodium starch glycolate (Explotab(®)) as binder/disintegrant/cushioning agent, thus allowing a sufficiently thick coating to be uniform and without being broken during tablet compaction. Then, the aforementioned beads were compressed into tablets at 1500 pounds of pressure containing 400 mg of mesalamine, and finally coating the compressed tablets with Surelease(®) (ethylcellulose):Opadry(®) = 1:0.5 ranging from 1.5-2.5% weight gain; the resulting tablets met USP 31 dissolution requirements for delayed release tablets.

Inhibition of Ubiquitin-specific Peptidase 8 Suppresses Adrenocorticotropic Hormone Production and Tumorous Corticotroph Cell Growth in AtT20 Cells

PubMed Central

Jian, Fang-Fang; Li, Yun-Feng; Chen, Yu-Fan; Jiang, Hong; Chen, Xiao; Zheng, Li-Li; Zhao, Yao; Wang, Wei-Qing; Ning, Guang; Bian, Liu-Guan; Sun, Qing-Fang

2016-01-01

Background: Two recent whole-exome sequencing researches identifying somatic mutations in the ubiquitin-specific protease 8 (USP8) gene in pituitary corticotroph adenomas provide exciting advances in this field. These mutations drive increased epidermal growth factor receptor (EGFR) signaling and promote adrenocorticotropic hormone (ACTH) production. This study was to investigate whether the inhibition of USP8 activity could be a strategy for the treatment of Cushing's disease (CD). Methods: The anticancer effect of USP8 inhibitor was determined by testing cell viability, colony formation, apoptosis, and ACTH secretion. The immunoblotting and quantitative reverse transcription polymerase chain reaction were conducted to explore the signaling pathway by USP8 inhibition. Results: Inhibition of USP8-induced degradation of receptor tyrosine kinases including EGFR, EGFR-2 (ERBB2), and Met leading to a suppression of AtT20 cell growth and ACTH secretion. Moreover, treatment with USP8 inhibitor markedly induced AtT20 cells apoptosis. Conclusions: Inhibition of USP8 activity could be an effective strategy for CD. It might provide a novel pharmacological approach for the treatment of CD. PMID:27569239

Accelerating the dissolution of enteric coatings in the upper small intestine: evolution of a novel pH 5.6 bicarbonate buffer system to assess drug release.

PubMed

Varum, Felipe J O; Merchant, Hamid A; Goyanes, Alvaro; Assi, Pardis; Zboranová, Veronika; Basit, Abdul W

2014-07-01

Despite rapid dissolution in compendial phosphate buffers, gastro resistant (enteric coated) products can take up to 2 h to disintegrate in the human small intestine, which clearly highlights the inadequacy of the in vitro test method to predict in vivo behaviour of these formulations. The aim of this study was to establish the utility of a novel pH 5.6 bicarbonate buffer, stabilized by an Auto pH™ System, as a better surrogate of the conditions of the proximal small intestine to investigate the dissolution behaviour of standard and accelerated release enteric double coating formulations. Prednisolone tablets were coated with 3 or 5 mg/cm(2) of partially neutralized EUDRAGIT(®) L 30 D-55, HP-55 or HPMC adjusted to pH 6 or 8. An outer layer of EUDRAGIT(®) L 30 D-55 was applied at 5mg/cm(2). For comparison purposes, a standard single layer of EUDRAGIT(®) L 30 D-55 was applied to the tablets. Dissolution was carried out using USP II apparatus in 0.1 M HCl for 2 h, followed by pH 5.6 bicarbonate buffer. EUDRAGIT(®) L 30 D-55 single-coated tablets showed a slow drug release with a lag time of 75 min in buffer, whereas release from the EUDRAGIT(®) L 30 D-55 double-coated tablets was accelerated. These in vitro lag times closely match the in vivo disintegration times for these coated tablets reported previously. Drug release was further accelerated from modified double coatings, particularly in the case of coatings with a thinner inner layer of HP-55 or HPMC (pH 8 and KH2PO4). This study confirms that the pH 5.6 bicarbonate buffer system offers significant advantages during the development of dosage forms designed to release the drug in the upper small intestine. Copyright © 2014. Published by Elsevier B.V.

Accelerated in vitro release testing method for naltrexone loaded PLGA microspheres.

PubMed

Andhariya, Janki V; Choi, Stephanie; Wang, Yan; Zou, Yuan; Burgess, Diane J; Shen, Jie

2017-03-30

The objective of the present study was to develop a discriminatory and reproducible accelerated release testing method for naltrexone loaded parenteral polymeric microspheres. The commercially available naltrexone microsphere product (Vivitrol ® ) was used as the testing formulation in the in vitro release method development, and both sample-and-separate and USP apparatus 4 methods were investigated. Following an in vitro drug stability study, frequent media replacement and addition of anti-oxidant in the release medium were used to prevent degradation of naltrexone during release testing at "real-time" (37°C) and "accelerated" (45°C), respectively. The USP apparatus 4 method was more reproducible than the sample-and-separate method. In addition, the accelerated release profile obtained using USP apparatus 4 had a shortened release duration (within seven days), and good correlation with the "real-time" release profile. Lastly, the discriminatory ability of the developed accelerated release method was assessed using compositionally equivalent naltrexone microspheres with different release characteristics. The developed accelerated USP apparatus 4 release method was able to detect differences in the release characteristics of the prepared naltrexone microspheres. Moreover, a linear correlation was observed between the "real-time" and accelerated release profiles of all the formulations investigated, suggesting that the release mechanism(s) may be similar under both conditions. These results indicate that the developed accelerated USP apparatus 4 method has the potential to be an appropriate fast quality control tool for long-acting naltrexone PLGA microspheres. Copyright © 2017 Elsevier B.V. All rights reserved.

Lipid globule size in total nutrient admixtures prepared in three-chamber plastic bags.

PubMed

Driscoll, David F; Thoma, Andrea; Franke, Rolf; Klütsch, Karsten; Nehne, Jörg; Bistrian, Bruce R

2009-04-01

The stability of injectable lipid emulsions in three-chamber plastic (3CP) bags, applying the globule-size limits established by United States Pharmacopeia ( USP ) chapter 729, was studied. A total of five premixed total nutrient admixture (TNA) products packaged in 3CP bags from two different lipid manufacturers containing either 20% soybean oil or a mixture of soybean oil and medium-chain-triglyceride oil as injectable lipid emulsions were tested. Two low-osmolarity 3CP bags and three high-osmolarity 3CP bags were studied. All products were tested with the addition of trace elements and multivitamins. All additive conditions (with and without electrolytes) were tested in triplicate at time 0 (immediately after mixing) and at 6, 24, 30, and 48 hours after mixing; the bags were stored at 24-26 degrees C. All additives were equally distributed in each bag for comparative testing, applying both globule sizing methods outlined in USP chapter 729. Of the bags tested, all bags from one manufacturer were coarse emulsions, showing signs of significant growth in the large-diameter tail when mixed as a TNA formulation and failing the limits set by method II of USP chapter 729 from the outset and throughout the study, while the bags from the other manufacturer were fine emulsions and met these limits. Of the bags that failed, significant instability was noted in one series containing additional electrolytes. Injectable lipid emulsions provided in 3CP bags that did not meet the globule-size limits of USP chapter 729 produced coarser TNA formulations than emulsions that met the USP limits.

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.

Improvement of physicomechanical properties of carbamazepine by recrystallization at different pH values.

PubMed

Javadzadeh, Yousef; Mohammadi, Ameneh; Khoei, Nazaninossadat Seyed; Nokhodchi, Ali

2009-06-01

The morphology of crystals has an appreciable impact role on the physicochemical properties of drugs. Drug properties such as flowability, dissolution, hardness and bioavailability may be affected by crystallinity behaviours of drugs. The objective of this study was to achieve an improved physicomechanical property of carbamazepine powder through recrystallization from aqueous solutions at different pH values. For this purpose, carbamazapine was recrystallized from aqueous solutions at different pH values (1, 7, 11). The morphology of crystals was investigated using scanning electron microscopy; X-ray powder diffraction (XRPD) was used to identify polymorphism; thermodynamic properties were analyzed using differential scanning calorimetery (DSC). Dissolution rate was determined using USP dissolution apparatus. Mechanical behavior of recrystallized carbamazepine powders was investigated by making tablets under different compaction pressure and measuring their hardness. SEM studies showed that the carbamazepine crystallization in different media affected the morphology and size of carbamazepine crystals. The shape of carbamazepine crystals changed from flaky or thin plate-like to needle shape. XRPD and DSC results ruled out any crystallinity changes occurring due to the temperature during recrystallization procedure or pH of crystallization media. The crushing strength of tablets indicated that all of the recrystallized carbamazepine samples had better compactiblity than the original carbamazepine powder. In vitro dissolution studies of carbamazepine samples showed a higher dissolution rate for carbamazepine crystals obtained from media with pH 11 and 1. Carbamazepine particles recrystallized from aqueous solutions of different pH values (all media) appeared to have superior mechanical properties to those of the original carbamazepine sample.

Absence of a Metallicity Effect for Ultra-short-period Planets

NASA Astrophysics Data System (ADS)

Winn, Joshua N.; Sanchis-Ojeda, Roberto; Rogers, Leslie; Petigura, Erik A.; Howard, Andrew W.; Isaacson, Howard; Marcy, Geoffrey W.; Schlaufman, Kevin C.; Cargile, Phillip; Hebb, Leslie

2017-08-01

Ultra-short-period (USP) planets are a newly recognized class of planets with periods shorter than one day and radii smaller than about 2 R ⊕. It has been proposed that USP planets are the solid cores of hot Jupiters that have lost their gaseous envelopes due to photo-evaporation or Roche lobe overflow. We test this hypothesis by asking whether USP planets are associated with metal-rich stars, as has long been observed for hot Jupiters. We find the metallicity distributions of USP-planet and hot-Jupiter hosts to be significantly different (p = 3 × 10-4) based on Keck spectroscopy of Kepler stars. Evidently, the sample of USP planets is not dominated by the evaporated cores of hot Jupiters. The metallicity distribution of stars with USP planets is indistinguishable from that of stars with short-period planets with sizes between 2 and 4 R ⊕. Thus, it remains possible that the USP planets are the solid cores of formerly gaseous planets that are smaller than Neptune. Based on observations obtained at the W. M. Keck Observatory, which is operated jointly by the University of California and the California Institute of Technology. Keck time was granted by NASA, the University of California, the California Institute of Technology, and the University of Hawaii.

Autocatalytic Activity of the Ubiquitin-Specific Protease Domain of Herpes Simplex Virus 1 VP1-2▿†

PubMed Central

Bolstad, M.; Abaitua, F.; Crump, C. M.; O'Hare, P.

2011-01-01

The herpes simplex virus (HSV) tegument protein VP1-2 is essential for virus entry and assembly. VP1-2 also contains a highly conserved ubiquitin-specific protease (USP) domain within its N-terminal region. Despite conservation of the USP and the demonstration that it can act on artificial substrates such as polyubiquitin chains, identification of the relevance of the USP in vivo to levels or function of any substrate remains limited. Here we show that HSV VP1-2 USP can act on itself and is important for stability. VP1-2 N-terminal variants encompassing the core USP domain itself were not affected by mutation of the catalytic cysteine residue (C65). However, extending the N-terminal region resulted in protein species requiring USP activity for accumulation. In this context, C65A mutation resulted in a drastic reduction in protein levels which could be stabilized by proteosomal inhibition or by the presence of normal C65. The functional USP domain could increase abundance of unstable variants, indicating action at least in part, in trans. Interestingly, full-length variants containing the inactive USP, although unstable when expressed in isolation, were stabilized by virus infection. The catalytically inactive VP1-2 retained complementation activity of a VP1-2-negative virus. Furthermore, a recombinant virus expressing a C65A mutant VP1-2 exhibited little difference in single-step growth curves and the kinetics and abundance of VP1-2 or a number of test proteins. Despite the absence of a phenotype for these replication parameters, the USP activity of VP1-2 may be required for function, including its own stability, under certain circumstances. PMID:21715485

USP37 deubiquitinates Cdt1 and contributes to regulate DNA replication.

PubMed

Hernández-Pérez, Santiago; Cabrera, Elisa; Amoedo, Hugo; Rodríguez-Acebes, Sara; Koundrioukoff, Stephane; Debatisse, Michelle; Méndez, Juan; Freire, Raimundo

2016-10-01

DNA replication control is a key process in maintaining genomic integrity. Monitoring DNA replication initiation is particularly important as it needs to be coordinated with other cellular events and should occur only once per cell cycle. Crucial players in the initiation of DNA replication are the ORC protein complex, marking the origin of replication, and the Cdt1 and Cdc6 proteins, that license these origins to replicate by recruiting the MCM2-7 helicase. To accurately achieve its functions, Cdt1 is tightly regulated. Cdt1 levels are high from metaphase and during G1 and low in S/G2 phases of the cell cycle. This control is achieved, among other processes, by ubiquitination and proteasomal degradation. In an overexpression screen for Cdt1 deubiquitinating enzymes, we isolated USP37, to date the first ubiquitin hydrolase controlling Cdt1. USP37 overexpression stabilizes Cdt1, most likely a phosphorylated form of the protein. In contrast, USP37 knock down destabilizes Cdt1, predominantly during G1 and G1/S phases of the cell cycle. USP37 interacts with Cdt1 and is able to de-ubiquitinate Cdt1 in vivo and, USP37 is able to regulate the loading of MCM complexes onto the chromatin. In addition, downregulation of USP37 reduces DNA replication fork speed. Taken together, here we show that the deubiquitinase USP37 plays an important role in the regulation of DNA replication. Whether this is achieved via Cdt1, a central protein in this process, which we have shown to be stabilized by USP37, or via additional factors, remains to be tested. Copyright © 2016 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Skin corrosion test: a comparison between reconstructed human epidermis and full thickness skin models.

PubMed

Catarino, Carolina Motter; do Nascimento Pedrosa, Tatiana; Pennacchi, Paula Comune; de Assis, Silvia Romano; Gimenes, Fabrícia; Consolaro, Márcia Edilaine Lopes; de Moraes Barros, Silvia Berlanga; Maria-Engler, Silvya Stuchi

2018-04-01

Currently, there is a strong global trend towards the development of in vitro models to replace the use of animals in safety evaluation tests. Reconstructed Human Epidermis (RHE) models have been employed as an alternative method to animal testing of skin corrosion and irritation potential of chemical compounds. However, the consequences of an absence of the dermal compartment in these models should be considered since the cross-talk between fibroblasts and keratinocytes is fundamental for promoting proper epidermal stratification, homeostasis, inflammatory response and wound healing. In this study, we compare in-house developed models of Reconstructed Human Epidermis (i.e. USP-RHE) and full thickness skin (i.e. USP-FTS) regarding their response when submitted to skin corrosion assays, based on Guideline 431 (OECD). The results show that both models correctly classified the four substances tested (2-phenylethyl bromide, benzylacetone, lactic acid, octanoic acid) as corrosive or non-corrosive. Furthermore, we have demonstrated higher cell viability of the USP-FTS model compared to the USP-RHE model, a sign of its improved barrier function, following the exposure to the substances test on the corrosion assay. This emphasizes the importance of employing in vitro models that are more physiologically relevant and that better mimic the in vivo situation for the toxicological screening of substances. Copyright © 2018 Elsevier B.V. All rights reserved.

Development of a simple analytical methodology for determination of glucosamine release from modified release matrix tablets.

PubMed

Wu, Yunqi; Hussain, Munir; Fassihi, Reza

2005-06-15

A simple spectrophotometric method for determination of glucosamine release from sustained release (SR) hydrophilic matrix tablet based on reaction with ninhydrin is developed, optimized and validated. The purple color (Ruhemann purple) resulted from the reaction was stabilized and measured at 570 nm. The method optimization was essential as many procedural parameters influenced the accuracy of determination including the ninhydrin concentration, reaction time, pH, reaction temperature, purple color stability period, and glucosamine/ninhydrin ratio. Glucosamine tablets (600 mg) with different hydrophilic polymers were formulated and manufactured on a rotary press. Dissolution studies were conducted (USP 26) using deionized water at 37+/-0.2 degrees C with paddle rotation of 50 rpm, and samples were removed manually at appropriate time intervals. Under given optimized reaction conditions that appeared to be critical, glucosamine was quantitatively analyzed and the calibration curve in the range of 0.202-2.020 mg (r=0.9999) was constructed. The recovery rate of the developed method was 97.8-101.7% (n=6). Reproducible dissolution profiles were achieved from the dissolution studies performed on different glucosamine tablets. The developed method is easy to use, accurate and highly cost-effective for routine studies relative to HPLC and other techniques.

Legibility of USP pictograms by clients of community pharmacies in Portugal.

PubMed

Soares, Maria Augusta

2013-02-01

Effective and safe use of medicines depends on patients' good understanding of the pharmacotherapy. Pictograms are a communication tool, as complement of verbal/written information, to facilitate drug use and, avoiding errors, being useful for drug effectiveness and safety. To assess the ability of pharmacy's clients, in understanding USP pictograms, establishing the relationship with their socio demographic profiles. The study was developed in community pharmacies, in Lisbon region. Cross sectional study, carried out in pharmacies in Lisbon. A structured questionnaire was used in pharmacies clients of 18 years old and above. Legibility of fifteen USP pictograms was studied using ISO and ANSI criteria. Correlation between the legibility of pictograms and pharmacies clients' demographic profile (age, gender, scholarship, frequency of medicines use) was evaluated. SPSS data base version 18 was used for descriptive analysis. Legibility of fifteen United States Pharmacopeia (USP) pictograms and, its relationship with clients' demographic data (scholarship degree, age, frequency of medicines use and, gender) was studied. From 751 responders, ten pictograms were legible by ISO and seven by ANSI. More than 30 % of the responders weren't able to understand five of the pictograms. It was found statistically significant relationships between some the understanding of some pictograms and clients' scholarships degree, age and frequency of medicines use. It was found that not all the fifteen tested USP pictograms were correctly comprehended by Portuguese pharmacies' clients, having found correlations with scholarship degree, daily use of medicines and age group, for some pictograms. To ensure the effectiveness of USP pictograms it is advisable to test patients' comprehension, before their use in general practice.

Floating gastroretentive drug delivery systems: Comparison of experimental and simulated dissolution profiles and floatation behavior.

PubMed

Eberle, Veronika A; Schoelkopf, Joachim; Gane, Patrick A C; Alles, Rainer; Huwyler, Jörg; Puchkov, Maxim

2014-07-16

Gastroretentive drug delivery systems (GRDDS) play an important role in the delivery of drug substances to the upper part of the gastrointestinal tract; they offer a possibility to overcome the limited gastric residence time of conventional dosage forms. The aim of the study was to understand drug-release and floatation mechanisms of a floating GRDDS based on functionalized calcium carbonate (FCC). The inherently low apparent density of the excipient (approx. 0.6 g/cm(3)) enabled a mechanism of floatation. The higher specific surface of FCC (approx. 70 m(2)) allowed sufficient hardness of resulting compacts. The floating mechanism of GRDDS was simulated in silico under simulated acidic and neutral conditions, and the results were compared to those obtained in vitro. United States Pharmacopeia (USP) dissolution methods are of limited usefulness for evaluating floating behavior and drug release of floating dosage forms. Therefore, we developed a custom-built stomach model to simultaneously analyze floating characteristics and drug release. In silico dissolution and floatation profiles of the FCC-based tablet were simulated using a three-dimensional cellular automata-based model. In simulated gastric fluid, the FCC-based tablets showed instant floatation. The compacts stayed afloat during the measurement in 0.1 N HCl and eroded completely while releasing the model drug substance. When water was used as dissolution medium, the tablets had no floating lag time and sank down during the measurement, resulting in a change of release kinetics. Floating dosage forms based on FCC appear promising. It was possible to manufacture floating tablets featuring a density of less than unity and sufficient hardness for further processing. In silico dissolution simulation offered a possibility to understand floating behavior and drug-release mechanism. Copyright © 2014 Elsevier B.V. All rights reserved.

A Nationwide Survey of the Quality of Antimalarials in Retail Outlets in Tanzania

PubMed Central

Kaur, Harparkash; Goodman, Catherine; Thompson, Eloise; Thompson, Katy-Anne; Masanja, Irene; Kachur, S. Patrick; Abdulla, Salim

2008-01-01

Introduction Retail pharmaceutical products are commonly used to treat fever and malaria in sub-Saharan African countries. Small scale studies have suggested that poor quality antimalarials are widespread throughout the region, but nationwide data are not available that could lead to generalizable conclusions about the extent to which poor quality drugs are available in African communities. This study aimed to assess the quality of antimalarials available from retail outlets across mainland Tanzania. Methods and Findings We systematically purchased samples of oral antimalarial tablets from retail outlets across 21 districts in mainland Tanzania in 2005. A total of 1080 antimalarial formulations were collected including 679 antifol antimalarial samples (394 sulfadoxine/pyrimethamine and 285 sulfamethoxypyrazine/pyrimethamine), 260 amodiaquine samples, 63 quinine samples, and 51 artemisinin derivative samples. A systematic subsample of 304 products was assessed for quality by laboratory based analysis to determine the amount of the active ingredient and dissolution profile by following the published United States Pharmacopoeia (USP) monogram for the particular tablet being tested. Products for which a published analytical monogram did not exist were assessed on amount of active ingredient alone. Overall 38 or 12.2% of the samples were found to be of poor quality. Of the antifolate antimalarial drugs tested 13.4% were found to be of poor quality by dissolution and content analysis using high-performance liquid chromatography (HPLC). Nearly one quarter (23.8%) of quinine tablets did not comply within the tolerance limits of the dissolution and quantification analysis. Quality of amodiaquine drugs was relatively better but still unacceptable as 7.5% did not comply within the tolerance limits of the dissolution analysis. Formulations of the artemisinin derivatives all contained the stated amount of active ingredient when analysed using HPLC alone. Conclusions Substandard antimalarial formulations were widely available in Tanzania at the time of this study. No products were detected that did not contain any amount of the stated active ingredient. Quinine and sulfadoxine/pyrimethamine products were the most widely available and also the most likely to be of poor quality. Substandard products were identified in all parts of the country and were labeled as made by both domestic and international manufacturers. With the expansion of the retail pharmaceutical sector as a delivery channel for antimalarial formulations the need for regular nationwide monitoring of their quality will become increasingly important. PMID:18923672

A nationwide survey of the quality of antimalarials in retail outlets in Tanzania.

PubMed

Kaur, Harparkash; Goodman, Catherine; Thompson, Eloise; Thompson, Katy-Anne; Masanja, Irene; Kachur, S Patrick; Abdulla, Salim

2008-01-01

Retail pharmaceutical products are commonly used to treat fever and malaria in sub-Saharan African countries. Small scale studies have suggested that poor quality antimalarials are widespread throughout the region, but nationwide data are not available that could lead to generalizable conclusions about the extent to which poor quality drugs are available in African communities. This study aimed to assess the quality of antimalarials available from retail outlets across mainland Tanzania. We systematically purchased samples of oral antimalarial tablets from retail outlets across 21 districts in mainland Tanzania in 2005. A total of 1080 antimalarial formulations were collected including 679 antifol antimalarial samples (394 sulfadoxine/pyrimethamine and 285 sulfamethoxypyrazine/pyrimethamine), 260 amodiaquine samples, 63 quinine samples, and 51 artemisinin derivative samples. A systematic subsample of 304 products was assessed for quality by laboratory based analysis to determine the amount of the active ingredient and dissolution profile by following the published United States Pharmacopoeia (USP) monogram for the particular tablet being tested. Products for which a published analytical monogram did not exist were assessed on amount of active ingredient alone. Overall 38 or 12.2% of the samples were found to be of poor quality. Of the antifolate antimalarial drugs tested 13.4% were found to be of poor quality by dissolution and content analysis using high-performance liquid chromatography (HPLC). Nearly one quarter (23.8%) of quinine tablets did not comply within the tolerance limits of the dissolution and quantification analysis. Quality of amodiaquine drugs was relatively better but still unacceptable as 7.5% did not comply within the tolerance limits of the dissolution analysis. Formulations of the artemisinin derivatives all contained the stated amount of active ingredient when analysed using HPLC alone. Substandard antimalarial formulations were widely available in Tanzania at the time of this study. No products were detected that did not contain any amount of the stated active ingredient. Quinine and sulfadoxine/pyrimethamine products were the most widely available and also the most likely to be of poor quality. Substandard products were identified in all parts of the country and were labeled as made by both domestic and international manufacturers. With the expansion of the retail pharmaceutical sector as a delivery channel for antimalarial formulations the need for regular nationwide monitoring of their quality will become increasingly important.

Chemical Potency and Degradation Products of Medications Stored Over 550 Earth Days at the International Space Station.

PubMed

Wotring, Virginia E

2016-01-01

Medications degrade over time, and degradation is hastened by extreme storage conditions. Current procedures ensure that medications aboard the International Space Station (ISS) are restocked before their expiration dates, but resupply may not be possible on future long-duration exploration missions. For this reason, medications stored on the ISS were returned to Earth for analysis. This was an opportunistic, observational pilot-scale investigation to test the hypothesis that ISS-aging does not cause unusual degradation. Nine medications were analyzed for active pharmaceutical ingredient (API) content and degradant amounts; results were compared to 2012 United States Pharmacopeia (USP) requirements. The medications were two sleep aids, two antihistamines/decongestants, three pain relievers, an antidiarrheal, and an alertness medication. Because the samples were obtained opportunistically from unused medical supplies, each medication was available at only 1 time point and no control samples (samples aged for a similar period on Earth) were available. One medication met USP requirements 5 months after its expiration date. Four of the nine (44% of those tested) medications tested met USP requirements 8 months post expiration. Another three medications (33%) met USP guidelines 2-3 months before expiration. One compound, a dietary supplement used as a sleep aid, failed to meet USP requirements at 11 months post expiration. No unusual degradation products were identified. Limited, evidence-based extension of medication shelf-lives may be possible and would be useful in preparation for lengthy exploration missions. Only analysis of flight-aged samples compared to appropriately matched ground controls will permit determination of the spaceflight environment on medication stability.

A dose-response study in animals to evaluate the anticoagulant effect of the stage 2 unfractionated heparin USP monograph change.

PubMed

Honchel, R; Carraway, J; Gopee, N; Callicott, R; Chen, J; Patton, R; Xu, Q; Zalkkar, J; Laniyonu, A; Krefting, I; Cato, M; Robie-Suh, K; Rieves, R

2011-08-01

The United States Pharmacopeia (USP) monograph for unfractionated heparin (UFH) was revised in October 2009. This revision was anticipated, based upon in vitro tests, to reduce UFH potency by approximately 10%. To study the potential in vivo consequences of the monograph change, we evaluated activated partial thromboplastin time (aPTT) and activated clotting time (ACT) responses in animals. Female mini-pigs and monkeys (n=8/species) were administered intravenously 60, 54, 48, or 42 U/kg and 50, 45, 40, or 35 U/kg "old" (pre-USP revision) UFH, respectively, in a Williams 4×4 crossover design. Blood samples for aPTT and ACT were collected at 15 min after dosing. The same study design was then repeated using "new" (post-USP revision) UFH. Mean "new" UFH aPTT and ACT values were generally lower than those for "old" UFH although individual animal responses varied considerably. The aPTT and ACT response was generally dose-proportional for both "old" and "new" UFH. These studies indicate that the USP monograph alteration for UFH may result in a modest reduction in the anticoagulant response across a population, but the variability in animal responses underscores the importance of individualization of clinical UFH dosing and the importance of anticoagulant test monitoring. Published by Elsevier Inc.

Effect on moisture permeability of typewriting on unit dose package surfaces.

PubMed

Rackson, J T; Zellhofer, M J; Birmingham, P H

1984-10-01

The effects of typewriting on labels of two unit dose packages with respect to moisture permeability were examined. Using an electric typewriter, a standard label format was imprinted on two different types of class A unit dose packages: (1) a heat-sealed paper-backed foil and cellofilm strip pouch, and (2) a copolyester and polyethylene multiple-cup blister with a heat-sealed paper-backed foil and cellofilm cover. The labels were typed at various typing-element impact settings. The official USP test for water permeation was then performed on typed packages and untyped control packages. The original untyped packages were confirmed to be USP class A quality. The packages for which successively harder impact settings were used showed a corresponding increase in moisture permeability. This resulted in a lowering of USP package ratings from class A to class B and D, some of which would be unsuitable for use in any unit dose system under current FDA repackaging standards. Typing directly onto the label of a unit dose package before it is sealed will most likely damage the package and possibly make it unfit for use. Pharmacists who must type labels for the unit dose packages studied should use the lowest possible typewriter impact setting and test for damage using the USP moisture-permeation test.

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.

A study of the shortest-period planets found with Kepler

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

Sanchis-Ojeda, Roberto; Rappaport, Saul; Winn, Joshua N.

2014-05-20

We present the results of a survey aimed at discovering and studying transiting planets with orbital periods shorter than one day (ultra-short-period, or USP, planets), using data from the Kepler spacecraft. We computed Fourier transforms of the photometric time series for all 200,000 target stars, and detected transit signals based on the presence of regularly spaced sharp peaks in the Fourier spectrum. We present a list of 106 USP candidates, of which 18 have not previously been described in the literature. This list of candidates increases the number of planet candidates with orbital periods shorter than about six hours frommore » two to seven. In addition, among the objects we studied, there are 26 USP candidates that had been previously reported in the literature which do not pass our various tests. All 106 of our candidates have passed several standard tests to rule out false positives due to eclipsing stellar systems. A low false positive rate is also implied by the relatively high fraction of candidates for which more than one transiting planet signal was detected. By assuming these multi-transit candidates represent coplanar multi-planet systems, we are able to infer that the USP planets are typically accompanied by other planets with periods in the range 1-50 days, in contrast with hot Jupiters which very rarely have companions in that same period range. Another clear pattern is that almost all USP planets are smaller than 2 R {sub ⊕}, possibly because gas giants in very tight orbits would lose their atmospheres by photoevaporation when subject to extremely strong stellar irradiation. Based on our survey statistics, USP planets exist around approximately (0.51 ± 0.07)% of G-dwarf stars, and (0.83 ± 0.18)% of K-dwarf stars.« less

Development of a level A in vitro-in vivo correlation for extended release dosage forms of quetiapine fumarate.

PubMed

Gonçalves de Lima, L; Rossi de Campos, D

2016-05-01

Quetiapine is an atypical antipsychotic recommended as first-line treatment for acute bipolar depression. The extended-release quetiapine formulation is intended to be administered as an once-daily dosing. The development of an in vitro-in vivo correlation (IVIVC) and the use of in vitro data to predict in vivo bioavailability parameters has been of great interest for the rational development and evaluation process for extended release dosage forms. The aim of this study was to develop an IVIVC for quetiapine extended release formulation. In vitro dissolution rate data were obtained using USP apparatus 2 at 50 rpm, in 3 bio-relevant dissolution media with different pH values (1.2, 4.5 and 6.8). The drug release profiles of the 2 extended release dosage forms were compared using the similarity factor (f 2). The relative bioavailability of quetiapine was evaluated by a single-dose, randomized-sequence, open-label, 2 period cross over study with 16 healthy volunteers. A linear level A IVIVC model was established using percentage of absorbed and dissolved data obtained at pH 1.2. The developed IVIVC model was employed to predict quetiapine concentration-time profiles, as well as the bioequivalence parameters for test formulation. Percent prediction errors were estimated for Cmax and AUC to evaluate the validity of the correlation. The values did not exceed 15%, proving the predictability of the correlation model. In conclusion, the established level A IVIVC model proved to be an excellent tool for predicting the rate and extent of quetiapine absorption as characterized by Cmax and AUC for test formulation. © Georg Thieme Verlag KG Stuttgart · New York.

Development of USPS Laboratory and pilot-scale testing protocols

Treesearch

Carl Houtman; Nancy Ross Sutherland; David Bormett; Donald Donermeyer

2000-01-01

The ultimate goal of the US Postal Service (USPS) Environmentally Benign Stamp Program is to develop stamp adhesives that can be removed by unit operations found in recycling mills. The maintenance of final product quality specifications for a recycling mill while loading the feedstock with a significant quantity of adhesive is the criterion for success of this program...

Compatibility of pressure sensitive adhesives with recycling unit operations

Treesearch

David Bormett; Carl Houtman; Said Abubakr; Joseph Peng

1999-01-01

Removal of pressure sensitive adhesives (PSAs) from recovered paper is a major problem facing the paper recycling industry. As a result of a United States Postal Service (USPS) initiative, which currently purchases about 12% of domestic PSA production, a team was formed consisting of representatives from the USPS, the Forest Products Laboratory, Springborn Testing and...

Innovative approach to solving "stickies" problem and developing environmentally benign pressure sensitive adhesives through partnerships

Treesearch

Said M. Abubakr; Joe Peng

1999-01-01

As a result of a United States Postal Service (USPS) initiative, a work team consisting of the USPS, the Forest Products Laboratory (FPL),Springborn Testing and Research (STR), and industry representatives wasformed. The industry representatives include papermakers, paper recyclers,paper collectors, equipment manufacturers, paper users, and adhesive and chemical...

Comparison of central corneal thickness measurements using ultrasound pachymetry, ultrasound biomicroscopy, and the Artemis-2 VHF scanner in normal eyes

PubMed Central

Al-Farhan, Haya M; Al-Otaibi, Wafa’a Majed

2012-01-01

Purpose To compare the precision of central corneal thickness (CCT) measurements taken with the handheld ultrasound pachymeter (USP), ultrasound biomicroscopy (UBM), and the Artemis-2 very high frequency ultrasound scanner (VHFUS) on normal subjects. Design Prospective study. Methods One eye from each of 61 normal subjects was randomly selected for this study. The measurements of the CCT were taken with the USP, VHFUS, and UBM. Results were compared statistically using repeated-measures analysis of variance (ANOVA), Pearson’s correlation coefficient, and limits of agreement. Results The average CCT (± standard deviation) was 530.1 ± 30.5 μm, 554.9 ± 31.7 μm, and 559.5 ± 30.7 μm for UBM, VHFUS, and USP respectively. The intraobserver repeatability analyses of variance are not significant for USP, UBM, and VHFUS. P-values were 0.17, 0.19, and 0.37 respectively. Repeated-measures ANOVA showed a significant difference between the three different methods of measuring CCT (P = 0.0001). The ANOVA test revealed no statistically significant difference between USP and VHFUS (P > 0.05), yet statistical significant differences with UBM versus USP and UBM versus VHFUS (P < 0.001). There were high correlations between the three instruments (P < 0.0001). The mean differences (and upper/lower limits of agreement) for CCT measurements were 29.4 ± 14.3 (2.7/56), 4.6 ± 8.6 (−14.7/23.8), and −24.8 ± 13.1 (−50.4/0.8) for USP versus UBM, USP versus VHFUS, and UBM versus VHFUS, respectively. Conclusion The UBM produces CCT measurements that vary significantly from those returned by the USP and the VHFUS, suggesting that the UBM may not be used interchangeably with either equipment for monitoring the CCT in the clinical setting. PMID:22848145

76 FR 65756 - Privacy Act of 1974; System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2011-10-24

... 600.400, Administrative Litigation Records; USPS 810.100, http://www.usps.com Registration; USPS 810... Records; USPS 870.200, Postage Meter and PC Postage Customer Data and Transaction Records; USPS 880.000....400 SYSTEM NAME: Administrative Litigation Records USPS 810.100 SYSTEM NAME: http://www.usps.com...

Poly (amidoamine) dendrimer-mediated hybrid formulation for combination therapy of ramipril and hydrochlorothiazide.

PubMed

Singh, Mayank Kumar; Pooja, Deep; Kulhari, Hitesh; Jain, Sanjay Kumar; Sistla, Ramakrishna; Chauhan, Abhay Singh

2017-01-01

We present a dendrimer-based hybrid formulation strategy to explore the potential of poly (amidoamine) PAMAM dendrimers to be used as drug carriers for combination therapy of an anti-hypertensive drug ramipril (RAPL) and a diuretic hydrochlorothiazide (HCTZ). The drug-dendrimer complexes were prepared by phase-equilibration method. The results showed that the solubility of RAPL and HCTZ was dependent on dendrimer concentration and pH of dendrimer solution. The solubility profile of both RAPL and HCTZ dendrimer complexes illustrated a non-linear relationship with dendrimer concentration. At 0.8% (w/v) dendrimer concentration, solubility of RAPL was increased 4.91 folds with amine-terminated while for HCTZ, solubility enhancement was highest (3.72 folds) with carboxy-terminated. The complexes were characterized by Fourier transform infrared spectroscopy, nuclear magnetic resonance analysis and high performance liquid chromatography. In-vitro drug dissolution performance of pure drugs, individual drug loaded dendrimer formulations and hybrid formulations was studied in USP dissolution medium (pH7.0) and in simulated gastric fluid (pH1.2). Dendrimer mediated formulations showed faster and complete dissolution compared to pure RAPL or HCTZ. Surprisingly, similar pattern of dissolution profile was established with hybrid formulations as compared to individual drug loaded dendrimers. The dendrimer-based hybrid formulations were found to be stable at dark and refrigerated conditions up to 5weeks. Conclusively, the proposed formulation strategy establishes a novel multitasking platform using dendrimer for simultaneous loading and delivery of multiple drugs for pharmaceutical applications. Copyright © 2016 Elsevier B.V. All rights reserved.

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.

Globule-size distribution in injectable 20% lipid emulsions: Compliance with USP requirements.

PubMed

Driscoll, David F

2007-10-01

The compliance of injectable 20% lipid emulsions with the globule-size limits in chapter 729 of the U.S. Pharmacopeia (USP) was examined. As established in chapter 729, dynamic light scattering was applied to determine mean droplet diameter (MDD), with an upper limit of 500 nm. Light obscuration was used to determine the size of fat globules found in the large-diameter tail, expressed as the volume-weighted percent fat exceeding 5 microm (PFAT(5)), with an upper limit of 0.05%. Compliance of seven different emulsions, six of which were stored in plastic bags, with USP limits was assessed. To avoid reaching coincidence limits during the application of method II from overly concentrated emulsion samples, a variable dilution scheme was used to optimize the globule-size measurements for each emulsion. One-way analysis of variance of globule-size distribution (GSD) data was conducted if any results of method I or II exceeded the respective upper limits. Most injectable lipid emulsions complied with limits established by USP chapter 729, with the exception of those of one manufacturer, which failed limits as proposed for to meet the PFAT(5) three of the emulsions tested. In contrast, all others studied (one packaged in glass and three packaged in plastic) met both criteria. Among seven injectable lipid emulsions tested for GSD, all met USP chapter 729 MDD requirements and three, all from the same manufacturer and packaged in plastic, did not meet PFAT(5) requirements.

Magnetic resonance imaging and image analysis for assessment of HPMC matrix tablets structural evolution in USP Apparatus 4.

PubMed

Kulinowski, Piotr; Dorożyński, Przemysław; Młynarczyk, Anna; Węglarz, Władysław P

2011-05-01

The purpose of the study was to present a methodology for the processing of Magnetic Resonance Imaging (MRI) data for the quantification of the dosage form matrix evolution during drug dissolution. The results of the study were verified by comparison with other approaches presented in literature. A commercially available, HPMC-based quetiapine fumarate tablet was studied with a 4.7T MR system. Imaging was performed inside an MRI probe-head coupled with a flow-through cell for 12 h in circulating water. The images were segmented into three regions using threshold-based segmentation algorithms due to trimodal structure of the image intensity histograms. Temporal evolution of dry glassy, swollen glassy and gel regions was monitored. The characteristic features were observed: initial high expansion rate of the swollen glassy and gel layers due to initial water uptake, dry glassy core disappearance and maximum area of swollen glassy region at 4 h, and subsequent gel layer thickness increase at the expense of swollen glassy layer. The temporal evolution of an HPMC-based tablet by means of noninvasive MRI integrated with USP Apparatus 4 was found to be consistent with both the theoretical model based on polymer disentanglement concentration and experimental VIS/FTIR studies.

Evaluation of hot-melt extrusion and injection molding for continuous manufacturing of immediate-release tablets.

PubMed

Melocchi, Alice; Loreti, Giulia; Del Curto, Maria Dorly; Maroni, Alessandra; Gazzaniga, Andrea; Zema, Lucia

2015-06-01

The exploitation of hot-melt extrusion and injection molding for the manufacturing of immediate-release (IR) tablets was preliminarily investigated in view of their special suitability for continuous manufacturing, which represents a current goal of pharmaceutical production because of its possible advantages in terms of improved sustainability. Tablet-forming agents were initially screened based on processability by single-screw extruder and micromolding machine as well as disintegration/dissolution behavior of extruded/molded prototypes. Various polymers, such as low-viscosity hydroxypropylcellulose, polyvinyl alcohol, polyvinyl alcohol-polyethylene glycol graft copolymer, various sodium starch glycolate grades (e.g., Explotab(®) CLV) that could be processed with no need for technological aids, except for a plasticizer, were identified. Furthermore, the feasibility of both extruded and molded IR tablets from low-viscosity hydroxypropylcellulose or Explotab(®) CLV was assessed. Explotab(®) CLV, in particular, showed thermoplastic properties and a very good aptitude as a tablet-forming agent, starting from which disintegrating tablets were successfully obtained by either techniques. Prototypes containing a poorly soluble model drug (furosemide), based on both a simple formulation (Explotab(®) CLV and water/glycerol as plasticizers) and formulations including dissolution/disintegration adjuvants (soluble and effervescent excipients) were shown to fulfill the USP 37 dissolution requirements for furosemide tablets. © 2015 Wiley Periodicals, Inc. and the American Pharmacists Association.

Zero-order delivery of a highly soluble, low dose drug alfuzosin hydrochloride via gastro-retentive system.

PubMed

Liu, Quan; Fassihi, Reza

2008-02-04

A composite gastro-retentive matrix for zero-order delivery of highly soluble drug alfuzosin hydrochloride (10mg) has been designed and characterized. Two systems containing polyethylene oxide (PEO), hydroxypropylmethylcellulose (HPMC), sodium bicarbonate, citric acid and polyvinyl pyrrolidone were dry blended and compressed into triple layer and bi-layer composite matrices. Dissolution studies using the USP 27 paddle method at 100 and 50rpm in pH 2.0 and 6.8 were performed using UV spectroscopy at 244nm, with automatic sampling over a 24h period using a marketed product as a reference to calculate the "f(2)" factor. Textural characteristics of each layer, the composite matrix as a whole, and floatation potential were determined under conditions similar to dissolution. Percent matrix swelling and erosion along with digital images were also obtained. Both systems proved to be effective in providing prolonged floatation, zero-order release, and complete disentanglement and erosion based on the analysis of data with "f(2)" of 68 and 71 for PEO and HPMC based systems, respectively. The kinetics of drug release, swelling and erosion, and dynamics of textural changes during dissolution for the designed composite systems offer a novel approach for developing gastro-retentive drug delivery system that has potential to enhance bioavailability and site-specific delivery to the proximal small intestine.

The impact of supersaturation level for oral absorption of BCS class IIb drugs, dipyridamole and ketoconazole, using in vivo predictive dissolution system: Gastrointestinal Simulator (GIS).

PubMed

Tsume, Yasuhiro; Matsui, Kazuki; Searls, Amanda L; Takeuchi, Susumu; Amidon, Gregory E; Sun, Duxin; Amidon, Gordon L

2017-05-01

The development of formulations and the assessment of oral drug absorption for Biopharmaceutical Classification System (BCS) class IIb drugs is often a difficult issue due to the potential for supersaturation and precipitation in the gastrointestinal (GI) tract. The physiological environment in the GI tract largely influences in vivo drug dissolution rates of those drugs. Thus, those physiological factors should be incorporated into the in vitro system to better assess in vivo performance of BCS class IIb drugs. In order to predict oral bioperformance, an in vitro dissolution system with multiple compartments incorporating physiologically relevant factors would be expected to more accurately predict in vivo phenomena than a one-compartment dissolution system like USP Apparatus 2 because, for example, the pH change occurring in the human GI tract can be better replicated in a multi-compartmental platform. The Gastrointestinal Simulator (GIS) consists of three compartments, the gastric, duodenal and jejunal chambers, and is a practical in vitro dissolution apparatus to predict in vivo dissolution for oral dosage forms. This system can demonstrate supersaturation and precipitation and, therefore, has the potential to predict in vivo bioperformance of oral dosage forms where this phenomenon may occur. In this report, in vitro studies were performed with dipyridamole and ketoconazole to evaluate the precipitation rates and the relationship between the supersaturation levels and oral absorption of BCS class II weak base drugs. To evaluate the impact of observed supersaturation levels on oral absorption, a study utilizing the GIS in combination with mouse intestinal infusion was conducted. Supersaturation levels observed in the GIS enhanced dipyridamole and ketoconazole absorption in mouse, and a good correlation between their supersaturation levels and their concentration in plasma was observed. The GIS, therefore, appears to represent in vivo dissolution phenomena and demonstrate supersaturation and precipitation of dipyridamole and ketoconazole. We therefore conclude that the GIS has been shown to be a good biopredictive tool to predict in vivo bioperformance of BCS class IIb drugs that can be used to optimize oral formulations. Copyright © 2017. Published by Elsevier B.V.

Designing an extended release waxy matrix tablet containing nicardipine–hydroxy propyl β cyclodextrin complex

PubMed Central

Al-Zein, Hind; Sakeer, Khalil; Alanazi, Fars K.

2011-01-01

Aim The current study aimed to prepare a sustained release tablet for a drug which has poor solubility in alkaline medium using complexation with cyclodextrin. Nicardipine hydrochloride (NC) a weak basic drug was chosen as a model drug for this study. Method Firstly the most suitable binary system NC-HPβCD was selected in order to improve drug solubility in the intestinal media and then embedding the complexed drug into a plastic matrix, by fusion method, consists of glycerol monostearate (GMS) as an inert waxy substance and polyethylene glycol 4000 (PEG4000) as a channeling agent, after that the final solid dispersion [(NC:HPβCD):GMS:PEG4000] which was prepared at different ratios was mixed with other excipients, avicel PH101, lactose, and talc, to get a tablet owning dissolution profile complying with the FDA and USP requirements for the extended release solid dosage forms. Results Infrared spectroscopy (IR), differential scanning colorimetry (DSC), polarized microscopy and X-ray diffractometry proved that the coevaporation technique was effective in preparing amorphous cyclodextrin complexes with NC and trapping of NC within the HPβCD cavity by dissolving both in ethanol and evaporate the solvent using a rotavapor at 65 °C. Dissolution profile of NC enhanced significantly in pH 6.8 from NC:HPβCD inclusion complex prepared by the rotavapor (t-test Student p < 0.05). The release of NC from tablet containing [(NC:HPβCD):GMS:PEG4000] [(1):0.75:0.5] (w/w/w) solid dispersion (F8) was complying with the FDA dissolution requirements for extended release dosage forms, and studying the kinetics of the release showed that the diffusional contribution is the major factor controlling the drug release from that formula. Conclusion The prepared waxy matrix tablet containing NC complexes with CD shows promising results as extended release tablets. PMID:23960765

Usp7 promotes medulloblastoma cell survival and metastasis by activating Shh pathway

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

Zhan, Meixiao; Zhuhai Precision Medicine Center, Zhuhai People's Hospital, Jinan University, Zhuhai; Sun, Xiaohan

The ubiquitin-specific protease Usp7 plays roles in multiple cellular processes through deubiquitinating and stabilizing numerous substrates, including P53, Pten and Gli. Aberrant Usp7 activity has been implicated in many disorders and tumorigenesis, making it as a potential target for therapeutic intervention. Although it is clear that Usp7 is involved in many types of cancer, its role in regulating medulloblastoma (MB) is still unknown. In this study, we show that knockdown of Usp7 inhibits the proliferation and migration of MB cells, while Usp7 overexpression exerts an opposite effect. Furthermore, we establish Usp7 knockout MB cell line using the CRISPR/Cas9 system andmore » further confirm that Usp7 knockout also blocks MB cell proliferation and metastasis. In addition, we reveal that knockdown of Usp7 compromises Shh pathway activity and decrease Gli protein levels, while P53 level and P53 target gene expression have no obvious changes. Finally, we find that Usp7 inhibitors apparently inhibit MB cell viability and migration. Taken together, our findings suggest that Usp7 is important for MB cell proliferation and metastasis by activating Shh pathway, and is a putative therapeutic target for MBs. - Highlights: • Loss of usp7 blocks the proliferation and metastasis of MB cells. • Usp7 regulates MB cell growth and migration through stimulating Shh pathway. • Usp7 inhibitors hamper MB cell proliferation and migration. • Usp7 inhibitors could attenuate Shh pathway activity.« less

Nuclear receptors HR96 and ultraspiracle from the fall armyworm (Spodoptera frugiperda), developmental expression and induction by xenobiotics.

PubMed

Giraudo, Maeva; Audant, Pascaline; Feyereisen, René; Le Goff, Gaëlle

2013-05-01

The fall armyworm Spodoptera frugiperda is a major polyphagous pest in agriculture and little is known on how this insect can adapt to the diverse and potentially toxic plant allelochemicals that they ingest or to insecticides. To investigate the involvement of nuclear receptors in the response of S. frugiperda to its chemical environment, we cloned SfHR96, a nuclear receptor orthologous to the mammalian xenobiotic receptors, pregnane X receptor (PXR) and constitutive androstane receptor (CAR). We also cloned ultraspiracle (USP), the ortholog of retinoid X receptor (RXR) that serves as partner of dimerization of PXR and CAR. Cloning of SfUSP revealed the presence of two isoforms, SfUSP-1 and SfUSP-2 in this species, that differ in their N-terminal region. The expression of these receptors as well as the ecdysone receptor was studied during specific steps of development in different tissues. SfHR96 was constitutively expressed in larval midgut, fat body and Malpighian tubules throughout the last two instars and pupal stage, as well as in Sf9 cells. EcR and SfUSP-2 showed peaks of expression before larval moults and during metamorphosis, whereas SfUSP-1 was mainly expressed in the pre-pupal stage. Receptor induction was followed after exposure of larvae or cells to 11 chemical compounds. SfHR96 was not inducible by the tested compounds. EcR was significantly induced by the 20-hydroxyecdysone agonist, methoxyfenozide, and SfUSP showed an increase expression when exposed to the juvenile hormone analog, methoprene. The cloning of these nuclear receptors is a first step in understanding the important capacities of adaptation of this insect pest. Copyright © 2013 Elsevier Ltd. All rights reserved.

USP17 is upregulated in osteosarcoma and promotes cell proliferation, metastasis, and epithelial-mesenchymal transition through stabilizing SMAD4.

PubMed

Song, Chenyang; Liu, Wenge; Li, Jiandong

2017-07-01

USP17 is upregulated in several cancers, indicating that USP17 might play essential functions in tumor development. However, the function of USP17 in osteosarcoma is still unknown. Our work aimed to investigate the function of USP17 in osteosarcoma. We found that the expression of USP17 was upregulated in osteosarcoma tissues and cell lines, including MG-63 and U2OS. Several functional experiments, such as colony formation analysis, Cell Counting Kit-8 assay, wound healing analysis, and transwell assay, showed that USP17 promoted cell proliferation, migration, and invasion. Moreover, we found that USP17 facilitated migration and invasion through promoting epithelial-mesenchymal transition. SMAD4 has been found to regulate epithelial-mesenchymal transition, co-immunopurification, and glutathione S-transferase pull-down analysis demonstrated that USP17 interacted with SMAD4. Furthermore, USP17 stabilized SMAD4 through its deubiquitinase activity. In conclusion, this study shows that USP17 enhances osteosarcoma cell proliferation and invasion through stabilizing SMAD4.

Replication of a low-pathogenic avian influenza virus is enhanced by chicken ubiquitin-specific protease 18.

PubMed

Tanikawa, Taichiro; Uchida, Yuko; Saito, Takehiko

2017-09-01

Previous research revealed the induction of chicken USP18 (chUSP18) in the lungs of chickens infected with highly pathogenic avian influenza viruses (HPAIVs). This activity was correlated with the degree of pathogenicity of the viruses to chickens. As mammalian ubiquitin-specific protease (USP18) is known to remove type I interferon (IFN I)-inducible ubiquitin-like molecules from conjugated proteins and block IFN I signalling, we explored the function of the chicken homologue of USP18 during avian influenza virus infection. With this aim, we cloned chUSP18 from cultured chicken cells and revealed that the putative chUSP18 ORF comprises 1137 bp. Comparative analysis of the predicted aa sequence of chUSP18 with those of human and mouse USP18 revealed relatively high sequence similarity among the sequences, including domains specific for the ubiquitin-specific processing protease family. Furthermore, we found that chUSP18 expression was induced by chicken IFN I, as observed for mammalian USP18. Experiments based on chUSP18 over-expression and depletion demonstrated that chUSP18 significantly enhanced the replication of a low-pathogenic avian influenza virus (LPAIV), but not an HPAIV. Our findings suggest that chUSP18, being similar to mammalian USP18, acts as a pro-viral factor during LPAIV replication in vitro.

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.

Termite and fungal resistance of in situ polymerized tributyltin acrylate and acetylated Indonesian and USA wood

Treesearch

Rebecca E. Ibach; Yusuf Sudo Hadi; Dodi Nandika; Sulaeman Yusuf; Yuliati Indrayani

2000-01-01

Wood [Indonesian pine (IP), Indonesian Jabon (IJ) and USA southern yellow pine (USP)] was either in situ polymerized with tributyltin acrylate (TBTA) or acetylated and then exposed to termite and fungal degradation both in laboratory tests and field exposure. The TBTA woods had an average weight percent gain (WPG) of 11% for IP, 12% for IJ, and 10% for USP. The...

USP7 Is a Suppressor of PCNA Ubiquitination and Oxidative-Stress-Induced Mutagenesis in Human Cells.

PubMed

Kashiwaba, Shu-ichiro; Kanao, Rie; Masuda, Yuji; Kusumoto-Matsuo, Rika; Hanaoka, Fumio; Masutani, Chikahide

2015-12-15

Mono-ubiquitinated PCNA activates error-prone DNA polymerases; therefore, strict regulation of PCNA mono-ubiquitination is crucial in avoiding undesired mutagenesis. In this study, we used an in vitro assay system to identify USP7 as a deubiquitinating enzyme of mono-ubiquitinated PCNA. Suppression of USP1, a previously identified PCNA deubiquitinase, or USP7 increased UV- and H2O2-induced PCNA mono-ubiquitination in a distinct and additive manner, suggesting that USP1 and USP7 make different contributions to PCNA deubiquitination in human cells. Cell-cycle-synchronization analyses revealed that USP7 suppression increased H2O2-induced PCNA ubiquitination throughout interphase, whereas USP1 suppression specifically increased ubiquitination in S-phase cells. UV-induced mutagenesis was elevated in USP1-suppressed cells, whereas H2O2-induced mutagenesis was elevated in USP7-suppressed cells. These results suggest that USP1 suppresses UV-induced mutations produced in a manner involving DNA replication, whereas USP7 suppresses H2O2-induced mutagenesis involving cell-cycle-independent processes such as DNA repair. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.

Function of ubiquitin (Ub) specific protease 15 (USP15) in HIV-1 replication and viral protein degradation.

PubMed

Pyeon, Dohun; Timani, Khalid Amine; Gulraiz, Fahad; He, Johnny J; Park, In-Woo

2016-09-02

HIV-1 Nef is necessary and may be sufficient for HIV-1-associated AIDS pathogenicity, in that knockout of Nef alone can protect HIV-infected patients from AIDS. We therefore investigated the feasibility of physical knockout of Nef, using the host ubiquitin proteasome system in HIV-1-infected cells. Our co-immunoprecipitation analysis demonstrated that Nef interacted with ubiquitin specific protease 15 (USP15), and that USP15, which is known to stabilize cellular proteins, degraded Nef. Nef could also cause decay of USP15, although Nef-mediated degradation of USP15 was weaker than USP15-mediated Nef degradation. Direct interaction between Nef and USP15 was essential for the observed reciprocal decay of the proteins. Further, USP15 degraded not only Nef but also HIV-1 structural protein, Gag, thereby substantially inhibiting HIV-1 replication. However, Gag did not degrade USP15, indicating that the Nef and USP15 complex, in distinction to other viral proteins, play an integral role in coordinating viral protein degradation and hence HIV-1 replication. Moreover, Nef and USP15 globally suppressed ubiquitylation of cellular proteins, indicating that these proteins are major determinants for the stability of cellular as well as viral proteins. Taken together, these data indicate that Nef and USP15 are vital in regulating degradation of viral and cellular proteins and thus HIV-1 replication, and specific degradation of viral, not cellular proteins, by USP15 points to USP15 as a candidate therapeutic agent to combat AIDS by eliminating viral proteins from the infected cells via USP15-mediated proteosomal degradation. Copyright © 2016 The Authors. Published by Elsevier B.V. All rights reserved.

USP39 promotes the growth of human hepatocellular carcinoma in vitro and in vivo.

PubMed

Yuan, Xianwen; Sun, Xitai; Shi, Xiaolei; Jiang, Chunping; Yu, Decai; Zhang, Weiwei; Guan, Wenxian; Zhou, Jianxin; Wu, Yafu; Qiu, Yudong; Ding, Yitao

2015-08-01

Ubiquitin specific protease 39 (USP39) plays an important role in mRNA splicing. In the present study, we investigated the role of USP39 in regulating the growth of hepatocellular carcinoma (HCC). We detected USP39 expression in more than 100 HCC clinical samples. The USP39 expression was significantly higher in the tumor tissues compared to the adjacent normal tissues, and was strongly associated with the pathological grade of HCC. USP39 knockdown inhibited cell proliferation and colony formation in vitro in the HepG2 cells, while upregulation of USP39 promoted tumor cell growth. FCM assay showed that USP39 knockdown led to G2/M arrest and induced apoptosis in the HepG2 cells. USP39 knockdown by shRNA inhibited xenograft tumor growth in nude mice. Moreover, USP39 knockdown led to the upregulation of p-Cdc2 and downregulation of p-Cdc25c and p-myt1, while the expression of total Cdc2, Cdc25c and myt1 was not changed in the USP39-knockdown cells. We also found that p-Cdc2 was decreased in the USP39-overexpressing cells and was upregulated in the xenografted tumors derived from the HepG2/KD cells from nude mice. Meanwhile, the expression levels of FoxM1 and its target genes PLK1 and cyclin B1 were decreased in the USP39-knockdown cells. These results suggest that USP39 may contribute to FoxM1 splicing in HCC tumor cells. Our data indicate that USP39 knockdown inhibited the growth of HCC both in vitro and in vivo through G2/M arrest, which was partly achieved via the inhibition of FoxM1 splicing.

USP22 acts as an oncoprotein to maintain glioma malignancy through deubiquitinating BMI1 for stabilization.

PubMed

Qiu, Guan-Zhong; Mao, Xiao-Yuan; Ma, Yue; Gao, Xing-Chun; Wang, Zhen; Jin, Ming-Zhu; Sun, Wei; Zou, Yong-Xiang; Lin, Jing; Fu, Hua-Lin; Jin, Wei-Lin

2018-05-22

USP22 is a member of "death-from-cancer" signature, which plays a key role in cancer progression. Although previous evidence has shown that USP22 is overexpressed and correlated with poor prognosis in glioma. The effect and mechanism of USP22 in glioma malignancy especially cancer stemness remain elusive. Here, we find USP22 is more enriched in stem-like tumorspheres than differentiated glioma cells. USP22 knockdown inhibits cancer stemness in glioma cell lines. With a cell-penetrating TAT-tag protein, BMI1, a robust glioma stem-cell marker, is found to mediate the effect of USP22 on glioma stemness. By immunofluorescence, USP22 and BMI1 are found to share similar intranuclear expression in glioma cells. By analysis with immunohistochemistry and bioinformatics, USP22 is found to positively correlated with BMI1 only in the post-translational level rather than transcriptional level. By immunoprecipitation and in vivo deubiquitination assay, USP22 is found to interact with and deubiquitinate BMI1 for protein stabilization. Microarray analysis reveals that USP22 and BMI1 mutually regulate a series of genes involved in glioma stemness such as POSTN, HEY2, PDGFRA and ATF3. In vivo study with nude mice confirms the role of USP22 in promoting glioma tumorigenesis by regulating BMI1. All these findings indicate USP22 as a novel deubiquitinase of BMI1 in glioma. We propose a working model of USP22-BMI1 axis, which promotes glioma stemness and tumorigenesis through oncogenic activation. Thus, targeting USP22 might be an effective strategy to treat glioma especially those with elevated BMI1 expression. This article is protected by copyright. All rights reserved. This article is protected by copyright. All rights reserved.

Mice lacking the USP2 deubiquitinating enzyme have severe male subfertility associated with defects in fertilization and sperm motility.

PubMed

Bedard, Nathalie; Yang, Yaoming; Gregory, Mary; Cyr, Daniel G; Suzuki, João; Yu, Xiaomin; Chian, Ri-Cheng; Hermo, Louis; O'Flaherty, Cristian; Smith, Charles E; Clarke, Hugh J; Wing, Simon S

2011-09-01

The ubiquitin-proteasome system plays an important role in spermatogenesis. However, the functions of deubiquitinating enzymes in this process remain poorly characterized. We previously showed that the deubiquitinating enzyme USP2 is induced in late elongating spermatids. To identify its function, we generated mice lacking USP2. Usp2 -/- mice appeared normal, and the weights of major organs, including the testis, did not differ from wild type (Usp2 +/+). However, although the numbers of testicular spermatids and epididymal spermatozoa were normal in Usp2 -/- males, these animals had a severe defect in fertility, yielding only 12% as many offspring as Usp2 +/+ littermates. Spermatogenesis in Usp2 -/- mice was morphologically normal except for the presence of abnormal aggregations of elongating spermatids and formation of multinucleated cells in some tubules. The epididymal epithelium was morphologically normal in Usp2 -/- mice, but some abnormal cells other than sperm were present in the lumen. Usp2 -/- epididymal spermatozoa manifested normal motility when incubated in culture media, but rapidly became immotile when incubated in PBS in contrast to Usp2 +/+ spermatozoa, which largely maintained motility under this condition. Usp2 -/- and +/+ spermatozoa underwent acrosome reactions in vitro with similar frequency. In vitro fertilization assays demonstrated a severe defect in the ability of Usp2 -/- spermatozoa to fertilize eggs. This could be bypassed by intracytoplasmic sperm injection or removal of the zona pellucida, which resulted in fertilization rates similar to that of Usp2 +/+ mice. We demonstrate for the first time, using mouse transgenic approaches, a role for the ubiquitin system in fertilization.

Rapidly-disintegrating sublingual tablets of epinephrine: role of non-medicinal ingredients in formulation development.

PubMed

Rachid, Ousama; Rawas-Qalaji, Mutasem; Simons, F Estelle R; Simons, Keith J

2012-11-01

Epinephrine is the drug of choice in the management of anaphylaxis. For first-aid treatment in the community, epinephrine autoinjectors (E-autos) are commonly prescribed, but are underutilized. In our laboratory, we developed a series of first-generation rapidly-disintegrating sublingual tablets (RDSTs) containing 40mg of epinephrine. One RDST had similar bioavailability to epinephrine 0.3mg from an auto-injector, as confirmed in a validated rabbit model, while other formulations containing different non-medicinal ingredients (NMIs) and with similar in vitro characteristics demonstrated much lower bioavailability. Subsequently, we evaluated the effect of changing the grade and proportion of NMIs, specifically mannitol and microcrystalline cellulose (MCC), on the in vitro characteristics of second- and third-generation RDSTs. Weight variation, content uniformity, breaking force, and friability were tested using official USP methods. Novel validated methods that simulate ambient conditions of the sublingual cavity were developed to test disintegration time, wetting time, and dissolution. Using these methods, it was possible to measure the effects of making small changes in NMIs on the in vitro characteristics of the formulations. The RDST formulation that resulted in the best in vitro characteristics contained the optimum proportion of mannitol and a specific ratio of coarse and fine particle grades of MCC. Appropriate comparative testing resulted in the selection of the RDST with the optimum in vitro characteristics. Copyright © 2012 Elsevier B.V. All rights reserved.

Human Cytomegalovirus Protein pUL38 Prevents Premature Cell Death by Binding to Ubiquitin-Specific Protease 24 and Regulating Iron Metabolism.

PubMed

Sun, Yamei; Bao, Qunchao; Xuan, Baoqin; Xu, Wenjia; Pan, Deng; Li, Qi; Qian, Zhikang

2018-07-01

Human cytomegalovirus (HCMV) protein pUL38 has been shown to prevent premature cell death by antagonizing cellular stress responses; however, the underlying mechanism remains unknown. In this study, we identified the host protein ubiquitin-specific protease 24 (USP24) as an interaction partner of pUL38. Mutagenesis analysis of pUL38 revealed that amino acids TFV at positions 227 to 230 were critical for its interaction with USP24. Mutant pUL38 TFV/AAA protein did not bind to USP24 and failed to prevent cell death induced by pUL38-deficient HCMV infection. Knockdown of USP24 suppressed the cell death during pUL38-deficient HCMV infection, suggesting that pUL38 achieved its function by antagonizing the function of USP24. We investigated the cellular pathways regulated by USP24 that might be involved in the cell death phenotype by testing several small-molecule compounds known to have a protective effect during stress-induced cell death. The iron chelators ciclopirox olamine and Tiron specifically protected cells from pUL38-deficient HCMV infection-induced cell death, thus identifying deregulated iron homeostasis as a potential mechanism. Protein levels of nuclear receptor coactivator 4 (NCOA4) and lysosomal ferritin degradation, a process called ferritinophagy, were also regulated by pUL38 and USP24 during HCMV infection. Knockdown of USP24 decreased NCOA4 protein stability and ferritin heavy chain degradation in lysosomes. Blockage of ferritinophagy by genetic inhibition of NCOA4 or Atg5/Atg7 prevented pUL38-deficient HCMV infection-induced cell death. Overall, these results support the hypothesis that pUL38 binds to USP24 to reduce ferritinophagy, which may then protect cells from lysosome dysfunction-induced cell death. IMPORTANCE Premature cell death is considered a first line of defense against various pathogens. Human cytomegalovirus (HCMV) is a slow-replicating virus that encodes several cell death inhibitors, such as pUL36 and pUL37x1, which allow it to overcome both extrinsic and intrinsic mitochondrion-mediated apoptosis. We previously identified HCMV protein pUL38 as another virus-encoded cell death inhibitor. In this study, we demonstrated that pUL38 achieved its activity by interacting with and antagonizing the function of the host protein ubiquitin-specific protease 24 (USP24). pUL38 blocked USP24-mediated ferritin degradation in lysosomes, which could otherwise be detrimental to the lysosome and initiate cell death. These novel findings suggest that iron metabolism is finely tuned during HCMV infection to avoid cellular toxicity. The results also provide a solid basis for further investigations of the role of USP24 in regulating iron metabolism during infection and other diseases. Copyright © 2018 American Society for Microbiology.

Automatic twin vessel recrystallizer. Effective purification of acetaminophen by successive automatic recrystallization and absolute determination of purity by DSC.

PubMed

Nara, Osamu

2011-01-24

I describe an interchangeable twin vessel (J, N) automatic glass recrystallizer that eliminates the time-consuming recovery and recycling of crystals for repeated recrystallization. The sample goes in the dissolution vessel J containing a magnetic stir-bar K; J is clamped to the upper joint H of recrystallizer body D. Empty crystallization vessel N is clamped to the lower joint M. Pure solvent is delivered to the dissolution vessel and the crystallization vessel via the head of the condenser A. Crystallization vessel is heated (P). The dissolution reservoir is stirred and heated by the solvent vapor (F). Continuous outflow of filtrate E out of J keeps N at a stable boiling temperature. This results in efficient dissolution, evaporation and separation of pure crystals Q. Pure solvent in the dissolution reservoir is recovered by suction. Empty dissolution and crystallization vessels are detached. Stirrer magnet is transferred to the crystallization vessel and the role of the vessels are then reversed. Evacuating mother liquor out of the upper twin vessel, the apparatus unit is ready for the next automatic recrystallization by refilling twin vessels with pure solvent. We show successive automatic recrystallization of acetaminophen from diethyl ether obtaining acetaminophen of higher melting temperatures than USP and JP reference standards by 8× automatic recrystallization, 96% yield at each stage. Also, I demonstrate a novel approach to the determination of absolute purity by combining the successive automatic recrystallization with differential scanning calorimetry (DSC) measurement requiring no reference standards. This involves the measurement of the criterial melting temperature T(0) corresponding to the 100% pure material and quantitative ΔT in DSC based on the van't Hoff law of melting point depression. The purity of six commercial acetaminophen samples and reference standards and an eight times recrystallized product evaluated were 98.8 mol%, 97.9 mol%, 99.1 mol%, 98.3 mol%, 98.4 mol%, 98.5 mol% and 99.3 mol% respectively. Copyright © 2010 Elsevier B.V. All rights reserved.

Postmarketing in vitro/in vivo assessment of fixed dose combination products of first line antiretrovirals.

PubMed

Joshi, A; Esseku, F; Silva, L; Igwilo, C; Oqua, D; Kunle, B; Obodozie, O; Inyang, U; Adeyeye, Moji C

2010-06-01

The purpose of this study was to evaluate the postmarket pharmaceutical equivalence, stability and bioequivalence of generic and innovator fixed dose combination products of lamivudine (3TC) and zidovudine (AZT) 150/300 mg tablets available in Nigeria. An isocratic HPLC-UV method was developed and validated for the quantitative determination of 3TC and AZT in human plasma and pharmaceutical samples. The model independent f(2) similarity factor was used to compare the dissolution profiles of the two products stored at accelerated and long-term stability conditions for 6 months. The f(2) values for 3TC and AZT in both products were found to be greater than 51. Also, the tablets were stable according to the USP potency and drug dissolution criteria with more than 80% of drug dissolution in 30 min indicating the pharmaceutical equivalence of the two products. The 90% confidence interval for the ratios of generic/innovator pharmacokinetic parameters for 3TC/AZT were 73.5-112.6/63.4-95.8 (C(max)); 68.5-105.6/68.0-114.8 (AUC(0-t)); and 64.2-106.2/80.1-120.3 (AUC(0-infinity)) respectively. The pharmacokinetic parameters failed to fully demonstrate bioequivalence between the products. The results underscored the importance of assessing the quality of the combination drug products that would ensure the safety and efficacy of the generic drug products available in the market. (c) 2010 Wiley-Liss, Inc. and the American Pharmacists Association

Characterization of currently marketed heparin products: key tests for quality assurance.

PubMed

Keire, David A; Ye, Hongping; Trehy, Michael L; Ye, Wei; Kolinski, Richard E; Westenberger, Benjamin J; Buhse, Lucinda F; Nasr, Moheb; Al-Hakim, Ali

2011-01-01

During the 2007-2008 heparin crisis, it was found that the United States Pharmacopeia (USP) testing monograph for unfractionated heparin sodium (UFH) did not detect the presence of the contaminant, oversulfated chondroitin sulfate (OSCS) in heparin. In response to this concern, new tests and specifications were developed by the Food and Drug Administration (FDA) and USP and put in place to not only detect the contaminant OSCS but also to improve assurance of quality and purity of the drug product. Additional tests were also developed to monitor the heparin supply chain for other possible economically motivated additives or impurities. In 2009, a new USP monograph was put in place that includes 500 MHz (1)H NMR, SAX-HPLC, %galactosamine in total hexosamine, and anticoagulation time assays with purified factor IIa or factor Xa. These tests represent orthogonal approaches for UFH identification, measurement of bioactivity, and for detection of process impurities or contaminants in UFH. The FDA has applied these analytical approaches to the study of UFH active pharmaceutical ingredients in the marketplace. Here, we describe results from a comprehensive survey of UFH collected from seven different sources after the 2009 monograph revision and compare these data with results obtained on other heparin samples collected during the 2007-2008 crisis.

Final Report for Intravenous Fluid Generation (IVGEN) Spaceflight Experiment

NASA Technical Reports Server (NTRS)

McQuillen, John B.; McKay, Terri L.; Griffin, DeVon W.; Brown, Dan F.; Zoldak, John T.

2011-01-01

NASA designed and operated the Intravenous Fluid Generation (IVGEN) experiment onboard the International Space Station (ISS), Increment 23/24, during May 2010. This hardware was a demonstration experiment to generate intravenous (IV) fluid from ISS Water Processing Assembly (WPA) potable water using a water purification technique and pharmaceutical mixing system. The IVGEN experiment utilizes a deionizing resin bed to remove contaminants from feedstock water to a purity level that meets the standards of the United States Pharmacopeia (USP), the governing body for pharmaceuticals in the United States. The water was then introduced into an IV bag where the fluid was mixed with USP-grade crystalline salt to produce USP normal saline (NS). Inline conductivity sensors quantified the feedstock water quality, output water purity, and NS mixing uniformity. Six 1.5-L bags of purified water were produced. Two of these bags were mixed with sodium chloride to make 0.9 percent NS solution. These two bags were returned to Earth to test for compliance with USP requirements. On-orbit results indicated that all of the experimental success criteria were met with the exception of the salt concentration. Problems with a large air bubble in the first bag of purified water resulted in a slightly concentrated saline solution of 117 percent of the target value of 0.9 g/L. The second bag had an inadequate amount of salt premeasured into the mixing bag resulting in a slightly deficient salt concentration of 93.8 percent of the target value. The USP permits a range from 95 to 105 percent of the target value. The testing plans for improvements for an operational system are also presented.

Automated Dissolution for Enteric-Coated Aspirin Tablets: A Case Study for Method Transfer to a RoboDis II.

PubMed

Ibrahim, Sarah A; Martini, Luigi

2014-08-01

Dissolution method transfer is a complicated yet common process in the pharmaceutical industry. With increased pharmaceutical product manufacturing and dissolution acceptance requirements, dissolution testing has become one of the most labor-intensive quality control testing methods. There is an increased trend for automation in dissolution testing, particularly for large pharmaceutical companies to reduce variability and increase personnel efficiency. There is no official guideline for dissolution testing method transfer from a manual, semi-automated, to automated dissolution tester. In this study, a manual multipoint dissolution testing procedure for an enteric-coated aspirin tablet was transferred effectively and reproducibly to a fully automated dissolution testing device, RoboDis II. Enteric-coated aspirin samples were used as a model formulation to assess the feasibility and accuracy of media pH change during continuous automated dissolution testing. Several RoboDis II parameters were evaluated to ensure the integrity and equivalency of dissolution method transfer from a manual dissolution tester. This current study provides a systematic outline for the transfer of the manual dissolution testing protocol to an automated dissolution tester. This study further supports that automated dissolution testers compliant with regulatory requirements and similar to manual dissolution testers facilitate method transfer. © 2014 Society for Laboratory Automation and Screening.

Water hyacinth: a possible alternative rate retarding natural polymer used in sustained release tablet design

PubMed Central

Khatun, Sabera; Sutradhar, Kumar B.

2014-01-01

In recent years natural polymers have been widely used because of their effectiveness and availability over synthetic polymers. In this present investigation matrix tablets of Metformin hydrochloride were formulated using Water hyacinth powder and its rate retardant activity was studied. Tablets were prepared using wet granulation method with 8% starch as granulating agent and 5, 10, 15, 20, 25 and 30% of Water hyacinth powder to the drug. In preformulation study, angle of repose, Carr's Index and Hausner ratio were calculated. Fourier Transform Infrared Spectroscopy (FTIR), Differential Scanning Calorimetry (DSC), and Scanning Electron Microscopy (SEM) studies were performed and no interactions were found between drug and excipients. Weight variation, friability, hardness, thickness, diameter, and in vitro release study were performed with the prepared matrix tablets. Dissolution studies were conducted using USP type II apparatus at a speed of 100 rpm at 37°C ± 0.5 temperature for 8 h. Though all the formulations comply with both BP and USP requirements, formulation F-1 (5% of Water hyacinth) was the best fitted formula. The drug release patterns were explained in different kinetic models such as Zero order, First order, Higuchi, Hixson Crowell, and Korsmeyer-Peppas equations. The current investigation implies that Water hyacinth has the potential to be used as a rate-retarding agent in sustained release drug formulations. PMID:24966835

USP22 acts as an oncogene by regulating the stability of cyclooxygenase-2 in non-small cell lung cancer

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

Xiao, Haibo; Tian, Yue; Yang, Yang

2015-05-08

The histone ubiquitin hydrolase ubiquitin-specific protease 22 (USP22) is an epigenetic modifier and an oncogene that is upregulated in many types of cancer. In non-small cell lung cancer (NSCLC), aberrant expression of USP22 is a predictor of poor survival, as is high expression of cyclooxygenase-2 (COX-2). Despite its oncogenic role, few substrates of USP22 have been identified and its mechanism of action in cancer remains unclear. Here, we identified COX-2 as a direct substrate of USP22 and showed that its levels are modulated by USP22 mediated deubiquitination. Silencing of USP22 downregulated COX-2, decreased its half-life, and inhibited lung carcinoma cellmore » proliferation by directly interacting with and modulating the stability and activity of COX-2 through the regulation of its ubiquitination status. The findings of the present study suggest a potential mechanism underlying the oncogenic role of USP22 mediated by the modulation of the stability and activity of COX-2. - Highlights: • USP22 interacts with COX-2. • USP22 deubiquitinates and stabilizes COX-2. • USP22 is required for COX-2-mediated upregulation of prostaglandin E2.« less

Characterization of currently marketed heparin products: key tests for LMWH quality assurance.

PubMed

Ye, Hongping; Toby, Timothy K; Sommers, Cynthia D; Ghasriani, Houman; Trehy, Michael L; Ye, Wei; Kolinski, Richard E; Buhse, Lucinda F; Al-Hakim, Ali; Keire, David A

2013-11-01

During the 2007-2008 heparin crisis it was found that the United States Pharmacopeia (USP) testing monograph for heparin sodium or low molecular weight heparins did not detect the presence of the contaminant, oversulfated chondroitin sulfate (OSCS). In response to this concern, new tests and specifications were developed by the Food and Drug Administration (FDA) and USP and put in place to detect not only the contaminant OSCS, but also to improve assurance of quality and purity of these drug products. The USP monographs for the low molecular weight heparins (LMWHs) approved for use in the United States (dalteparin, tinzaparin and enoxaparin) are also undergoing revision to include many of the same tests used for heparin sodium, including; one-dimensional (1D) 500 MHz (1)H NMR, SAX-HPLC, percent galactosamine in total hexosamine and anticoagulation time assays with purified Factor IIa or Factor Xa. These tests represent orthogonal approaches for heparin identification, measurement of bioactivity and for detection of process impurities or contaminants in these drug products. Here we describe results from a survey of multiple lots from three types of LMWHs in the US market which were collected after the 2009 heparin sodium monograph revision. In addition, innovator and generic versions of formulated enoxaparin products purchased in 2011 are compared using these tests and found to be highly similar within the discriminating power of the assays applied. Published by Elsevier B.V.

Molecular adaptation and resilience of the insect’s nuclear receptor USP

PubMed Central

2012-01-01

Background The maintenance of biological systems requires plasticity and robustness. The function of the ecdysone receptor, a heterodimer composed of the nuclear receptors ECR (NR1H1) and USP (NR2B4), was maintained in insects despite a dramatic divergence that occurred during the emergence of Mecopterida. This receptor is therefore a good model to study the evolution of plasticity. We tested the hypothesis that selection has shaped the Ligand-Binding Domain (LBD) of USP during evolution of Mecopterida. Results We isolated usp and cox1 in several species of Drosophilidae, Tenebrionidae and Blattaria and estimated non-synonymous/synonymous rate ratios using maximum-likelihood methods and codon-based substitution models. Although the usp sequences were mainly under negative selection, we detected relaxation at residues located on the surface of the LBD within Mecopterida families. Using branch-site models, we also detected changes in selective constraints along three successive branches of the Mecopterida evolution. Residues located at the bottom of the ligand-binding pocket (LBP) underwent strong positive selection during the emergence of Mecopterida. This change is correlated with the acquisition of a large LBP filled by phospholipids that probably allowed the stabilisation of the new Mecopterida structure. Later, when the two subgroups of Mecopterida (Amphiesmenoptera: Lepidoptera, Trichoptera; Antliophora: Diptera, Mecoptera, Siphonaptera) diverged, the same positions became under purifying selection. Similarly, several positions of the heterodimerisation interface experienced positive selection during the emergence of Mecopterida, rapidly followed by a phase of constrained evolution. An enlargement of the heterodimerisation surface is specific for Mecopterida and was associated with a reinforcement of the obligatory partnership between ECR and USP, at the expense of homodimerisation. Conclusions In order to explain the episodic mode of evolution of USP, we propose a model in which the molecular adaptation of this protein is seen as a process of resilience for the maintenance of the ecdysone receptor functionality. PMID:23039844

Stability Analysis of ISS Medications

NASA Technical Reports Server (NTRS)

Wotring, V. E.

2014-01-01

It is known that medications degrade over time, and that extreme storage conditions will hasten their degradation. The temperature and humidity conditions of the ISS have been shown to be within the ideal ranges for medication storage, but the effects of other environmental factors, like elevated exposure to radiation, have not yet been evaluated. Current operational procedures ensure that ISS medications are re-stocked before expiration, but this may not be possible on long duration exploration missions. For this reason, medications that have experienced long duration storage on the ISS were returned to JSC for analysis to determine any unusual effects of aging in the low- Earth orbit environment. METHODS Medications were obtained by the JSC Pharmacy from commercial distributors and were re-packaged by JSC pharmacists to conserve up mass and volume. All medication doses were part of the ISS crew medical kit and were transported to the International Space Station (ISS) via NASA's Shuttle Transportation System (Space Shuttle). After 568 days of storage, the medications were removed from the supply chain and returned to Earth on a Dragon (SpaceX) capsule. Upon return to Earth, medications were transferred to temperature and humidity controlled environmental chambers until analysis. Nine medications were chosen on the basis of their availability for study. The medications included several of the most heavily used by US crewmembers: 2 sleep aids, 2 antihistamines/decongestants, 3 pain relievers, an antidiarrheal and an alertness medication. Each medication was available at a single time point; analysis of the same medication at multiple time points was not possible. Because the samples examined in this study were obtained opportunistically from medical supplies, there were no control samples available (i.e. samples aged for a similar period of time on the ground); a significant limitation of this study. Medications were analyzed using the HPLC/MS methods described in the United States Pharmacopeia (USP) to measure the amount of intact active ingredient, identify degradation products and measure their amounts. Some analyses were conducted by an independent analytical laboratory, but certain (Schedule) medications could not be shipped to their facility and were analyzed at JSC. RESULTS Nine medications were analyzed with respect to active pharmaceutical ingredient (API) and degradant amounts. Results were compared to the USP requirements for API and degradants/impurities content for every FDA-approved medication. One medication met USP requirements at 5 months after its expiration date. Four of the nine (44% of those tested) medications tested met USP requirements up to 8 months post-expiration. Another 3 medications (33% of those tested) met USP guidelines 2-3 months before expiration. One medication, a compound classed by the FDA as a dietary supplement and sometimes used as a sleep aid, failed to meet USP requirements at 11 months post-expiration. CONCLUSION Analysis of each medication at a single time point provides limited information on the stability of a medication stored in particular conditions; it is not possible to predict how long a medication may be safe and effective from these data. Notwithstanding, five of the nine medications tested (56%) met USP requirements for API and degradants/impurities at least 5 months past expiration dates. The single compound that failed to meet USP requirements is not regulated as strictly as prescription medications are during manufacture; it is unknown if this medication would have met the requirements prior to flight. Notably, it was the furthest beyond its expiration date. Only more comprehensive analysis of flight-aged samples compared to appropriate ground controls will permit determination of spaceflight effects on medication stability.

CDDO-Me reveals USP7 as a novel target in ovarian cancer cells.

PubMed

Qin, Dongjun; Wang, Weiwei; Lei, Hu; Luo, Hao; Cai, Haiyan; Tang, Caixia; Wu, Yunzhao; Wang, Yingying; Jin, Jin; Xiao, Weilie; Wang, Tongdan; Ma, Chunmin; Xu, Hanzhang; Zhang, Jinfu; Gao, Fenghou; Wu, Ying-Li

2016-11-22

Deubiquitinating enzyme USP7 has been involved in the pathogenesis and progression of several cancers. Targeting USP7 is becoming an attractive strategy for cancer therapy. In this study, we identified synthetic triterpenoid C-28 methyl ester of 2-cyano-3, 12-dioxoolen-1, 9-dien-28-oic acid (CDDO-Me) as a novel inhibitor of USP7 but not of other cysteine proteases such as cathepsin B and cathepsin D. CDDO-Me inhibits USP7 activity via a mechanism that is independent of the presence of α, β-unsaturated ketones. Molecular docking studies showed that CDDO-Me fits well in the ubiquitin carboxyl terminus-binding pocket on USP7. Given that CDDO-Me is known to be effective against ovarian cancer cells, we speculated that CDDO-Me may target USP7 in ovarian cancer cells. We demonstrated that ovarian cancer cells have higher USP7 expression than their normal counterparts. Knockdown of USP7 inhibits the proliferation of ovarian cancer cells both in vitro and in vivo. Using the cellular thermal shift assay and the drug affinity responsive target stability assay, we further demonstrated that CDDO-Me directly binds to USP7 in cells, which leads to the decrease of its substrates such as MDM2, MDMX and UHRF1. CDDO-Me suppresses ovarian cancer tumor growth in an xenograft model. In conclusion, we demonstrate that USP7 is a novel target of ovarian cancer cells; targeting USP7 may contribute to the anti-cancer effect of CDDO-Me. The development of novel USP7 selective compounds based on the CDDO-Me-scaffold warrants further investigation.

CDDO-Me reveals USP7 as a novel target in ovarian cancer cells

PubMed Central

Cai, Haiyan; Tang, Caixia; Wu, Yunzhao; Wang, Yingying; Jin, Jin; Xiao, Weilie; Wang, Tongdan; Ma, Chunmin; Xu, Hanzhang; Zhang, Jinfu; Gao, Fenghou; Wu, Ying-Li

2016-01-01

Deubiquitinating enzyme USP7 has been involved in the pathogenesis and progression of several cancers. Targeting USP7 is becoming an attractive strategy for cancer therapy. In this study, we identified synthetic triterpenoid C-28 methyl ester of 2-cyano-3, 12-dioxoolen-1, 9-dien-28-oic acid (CDDO-Me) as a novel inhibitor of USP7 but not of other cysteine proteases such as cathepsin B and cathepsin D. CDDO-Me inhibits USP7 activity via a mechanism that is independent of the presence of α, β-unsaturated ketones. Molecular docking studies showed that CDDO-Me fits well in the ubiquitin carboxyl terminus-binding pocket on USP7. Given that CDDO-Me is known to be effective against ovarian cancer cells, we speculated that CDDO-Me may target USP7 in ovarian cancer cells. We demonstrated that ovarian cancer cells have higher USP7 expression than their normal counterparts. Knockdown of USP7 inhibits the proliferation of ovarian cancer cells both in vitro and in vivo. Using the cellular thermal shift assay and the drug affinity responsive target stability assay, we further demonstrated that CDDO-Me directly binds to USP7 in cells, which leads to the decrease of its substrates such as MDM2, MDMX and UHRF1. CDDO-Me suppresses ovarian cancer tumor growth in an xenograft model. In conclusion, we demonstrate that USP7 is a novel target of ovarian cancer cells; targeting USP7 may contribute to the anti-cancer effect of CDDO-Me. The development of novel USP7 selective compounds based on the CDDO-Me-scaffold warrants further investigation. PMID:27780924

Recurrent gain-of-function USP8 mutations in Cushing's disease

PubMed Central

Ma, Zeng-Yi; Song, Zhi-Jian; Chen, Jian-Hua; Wang, Yong-Fei; Li, Shi-Qi; Zhou, Liang-Fu; Mao, Ying; Li, Yi-Ming; Hu, Rong-Gui; Zhang, Zhao-Yun; Ye, Hong-Ying; Shen, Ming; Shou, Xue-Fei; Li, Zhi-Qiang; Peng, Hong; Wang, Qing-Zhong; Zhou, Dai-Zhan; Qin, Xiao-Lan; Ji, Jue; Zheng, Jie; Chen, Hong; Wang, Yin; Geng, Dao-Ying; Tang, Wei-Jun; Fu, Chao-Wei; Shi, Zhi-Feng; Zhang, Yi-Chao; Ye, Zhao; He, Wen-Qiang; Zhang, Qi-Lin; Tang, Qi-Sheng; Xie, Rong; Shen, Jia-Wei; Wen, Zu-Jia; Zhou, Juan; Wang, Tao; Huang, Shan; Qiu, Hui-Jia; Qiao, Ni-Dan; Zhang, Yi; Pan, Li; Bao, Wei-Min; Liu, Ying-Chao; Huang, Chuan-Xin; Shi, Yong-Yong; Zhao, Yao

2015-01-01

Cushing's disease, also known as adrenocorticotropic hormone (ACTH)-secreting pituitary adenomas (PAs) that cause excess cortisol production, accounts for up to 85% of corticotrophin-dependent Cushing's syndrome cases. However, the genetic alterations in this disease are unclear. Here, we performed whole-exome sequencing of DNA derived from 12 ACTH-secreting PAs and matched blood samples, which revealed three types of somatic mutations in a candidate gene, USP8 (encoding ubiquitin-specific protease 8), exclusively in exon 14 in 8 of 12 ACTH-secreting PAs. We further evaluated somatic USP8 mutations in additional 258 PAs by Sanger sequencing. Targeted sequencing further identified a total of 17 types of USP8 variants in 67 of 108 ACTH-secreting PAs (62.04%). However, none of these mutations was detected in other types of PAs (n = 150). These mutations aggregate within the 14-3-3 binding motif of USP8 and disrupt the interaction between USP8 and 14-3-3 protein, resulting in an elevated capacity to protect EGFR from lysosomal degradation. Accordingly, PAs with mutated USP8 display a higher incidence of EGFR expression, elevated EGFR protein abundance and mRNA expression levels of POMC, which encodes the precursor of ACTH. PAs with mutated USP8 are significantly smaller in size and have higher ACTH production than wild-type PAs. In surgically resected primary USP8-mutated tumor cells, USP8 knockdown or blocking EGFR effectively attenuates ACTH secretion. Taken together, somatic gain-of-function USP8 mutations are common and contribute to ACTH overproduction in Cushing's disease. Inhibition of USP8 or EGFR is promising for treating USP8-mutated corticotrophin adenoma. Our study highlights the potentially functional mutated gene in Cushing's disease and provides insights into the therapeutics of this disease. PMID:25675982

Electrochemical behavior and pH stability of artificial salivas for corrosion tests.

PubMed

Queiroz, Gláucia Maria Oliveira de; Silva, Leandro Freitas; Ferreira, José Tarcísio Lima; Gomes, José Antônio da Cunha P; Sathler, Lúcio

2007-01-01

It is assumed that the compositions of artificial salivas are similar to that of human saliva. However, the use of solutions with different compositions in in vitro corrosion studies can lead dissimilar electrolytes to exhibit dissimilar corrosivity and electrochemical stability. This study evaluated four artificial salivas as regards pH stability with time, redox potentials and the polarization response of an inert platinum electrode. The tested solutions were: SAGF medium, Mondelli artificial saliva, UFRJ artificial saliva (prepared at the School of Pharmacy, Federal University of Rio de Janeiro, RJ, Brazil) and USP-RP artificial saliva (prepared at the School of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, SP, Brazil). It was observed that pH variations were less than 1 unit during a 50-hour test. The SAGF medium, and the UFRJ and USP-RP solutions exhibited more oxidizing characteristics, whereas the Mondelli solution presented reducing properties. Anodic polarization revealed oxidation of the evaluated electrolytes at potentials below +600 mV SCE. It was observed that the UFRJ and USP-RP solutions presented more intense oxidation and reduction processes as compared to the Mondelli and SAGF solutions.

Substituted amylose matrices for oral drug delivery

NASA Astrophysics Data System (ADS)

Moghadam, S. H.; Wang, H. W.; Saddar El-Leithy, E.; Chebli, C.; Cartilier, L.

2007-03-01

High amylose corn starch was used to obtain substituted amylose (SA) polymers by chemically modifying hydroxyl groups by an etherification process using 1,2-epoxypropanol. Tablets for drug-controlled release were prepared by direct compression and their release properties assessed by an in vitro dissolution test (USP XXIII no 2). The polymer swelling was characterized by measuring gravimetrically the water uptake ability of polymer tablets. SA hydrophilic matrix tablets present sequentially a burst effect, typical of hydrophilic matrices, and a near constant release, typical of reservoir systems. After the burst effect, surface pores disappear progressively by molecular association of amylose chains; this allows the creation of a polymer layer acting as a diffusion barrier and explains the peculiar behaviour of SA polymers. Several formulation parameters such as compression force, drug loading, tablet weight and insoluble diluent concentration were investigated. On the other hand, tablet thickness, scanning electron microscope analysis and mercury intrusion porosimetry showed that the high crushing strength values observed for SA tablets were due to an unusual melting process occurring during tabletting although the tablet external layer went only through densification, deformation and partial melting. In contrast, HPMC tablets did not show any traces of a melting process.

Identification of candidate substrates of ubiquitin-specific protease 13 using 2D-DIGE

PubMed Central

Wang, Jianmin; Liu, Yingli; Tang, Lijuan; Qi, Sufen; Mi, Yingjun; Liu, Dianwu; Tian, Qingbao

2017-01-01

The present study aimed to identify candidate substrates of ubiquitin-specific protease (USP)13 using two-dimensional fluorescence difference gel electrophoresis (2D-DIGE). USP13 is a well-characterized member of the USP family, which regulates diverse cellular functions by cleaving ubiquitin from ubiquitinated protein substrates. However, existing studies indicate that USP13 has no detectable hydrolytic activity in vitro. This finding implies that USP13 likely has different substrate specificity. In this study, a USP cleavage assay was performed using two different types of model substrates (glutathione S-transferase-Ub52 and ubiquitin-β-galactosidase) to detect the deubiquitinating enzyme (DUB) activity of USP13. In addition, a proteomic approach was taken by using 2D-DIGE to detect cellular proteins whose expressoin is significantly altered in 293T cell lines following the overexpression of USP13 or its C345S mutant (the catalytically inactive form). The data indicated that USP13 still has no detectable DUB activity in vitro nor does C345S. The results of 2D-DIGE demonstrated that the expression of several proteins increased or decreased significantly in 293T cells following the overexpression of USP13. Mass spec troscopy analysis of gel spots identified 7 proteins, including 4 proteins with an increased expression, namely vinculin, thimet oligopeptidase, cleavage and polyadenylation specific factor 3, and methylosome protein 50, and 3 proteins with a decreased expression, namely adenylosuccinate synthetase, annexin and phosphoglycerate mutase. In addition, in the samples of 293T cell lines after the overexpression of USP13 and USP13 C345S, vinculin exhibited an increased expression, suggesting that it may be a candidate substrate of USP13. However, sufficient follow-up validation studies are required in order to determine whether vinculin protein directly interacts with USP13. PMID:28498477

Inactivation of USP14 Perturbs Ubiquitin Homeostasis and Delays the Cell Cycle in Mouse Embryonic Fibroblasts and in Fruit Fly Drosophila.

PubMed

Lee, Jung Hoon; Park, Seoyoung; Yun, Yejin; Choi, Won Hoon; Kang, Min-Ji; Lee, Min Jae

2018-01-01

The 26S proteasome is the key proteolytic complex for recognition and degradation of polyubiquitinated target substrates in eukaryotes. Among numerous proteasome-associated proteins, a deubiquitinating enzyme (DUB) USP14 has been identified as an endogenous inhibitor of the proteasome. Here, we explored the complex regulatory functions of USP14 that involve ubiquitin (Ub) homeostasis and substrate degradation in flies and mammals. USP14-null primary and immortalized mouse embryonic fibroblasts (MEFs) and USP14 knocked-down Drosophila were analyzed in this study. We measured proteasome and DUB activities using fluorogenic reporter substrates and adduct-forming probes. To examine the levels of ubiquitin, we performed immunoblotting and immunohistochemistry. Mass spectrometry (MS) was used to examine polyUb chain linkages and USP14-interacing proteins. Cell cycle was analyzed by flow cytometry, BrdU labeling, and phospho-histone H3 staining. The homeostasis of Ub in USP14-/-MEFs was markedly perturbed because of facilitated clearance of Ub. This phenomenon was recapitulated in muscles of USP14-deficient Drosophila with old ages. Absolute quantitation using MS also revealed that USP14-/- MEFs contained significantly increased amounts of Ub, compared with wild-type. The key phenotype of USP14-/- MEFs was their delayed proliferation originated from prolonged interphase possibly through aberrant degradation of cyclins A and B1. We found that knocking down USP14 in Drosophila resulted in delayed eye development associated with reduced mitotic activity. Our study identifies novel cellular functions of USP14 not only in cellular Ub hometostasis but also in cell cycle progression. USP14 was also essential for proper Drosophila eye development. These results strongly suggest that the USP14-mediated proteasome activity regulation may be directly related to various human diseases including cancer. © 2018 The Author(s). Published by S. Karger AG, Basel.

USP1 targeting impedes GBM growth by inhibiting stem cell maintenance and radioresistance

PubMed Central

Lee, Jin-Ku; Chang, Nakho; Yoon, Yeup; Yang, Heekyoung; Cho, Heejin; Kim, Eunhee; Shin, Yongjae; Kang, Wonyoung; Oh, Young Taek; Mun, Gyeong In; Joo, Kyeung Min; Nam, Do-Hyun; Lee, Jeongwu

2016-01-01

Background Clinical benefits from standard therapies against glioblastoma (GBM) are limited in part due to intrinsic radio- and chemoresistance of GBM and inefficient targeting of GBM stem-like cells (GSCs). Novel therapeutic approaches that overcome treatment resistance and diminish stem-like properties of GBM are needed. Methods We determined the expression levels of ubiquitination-specific proteases (USPs) by transcriptome analysis and found that USP1 is highly expressed in GBM. Using the patient GBM-derived primary tumor cells, we inhibited USP1 by shRNA-mediated knockdown or its specific inhibitor pimozide and evaluated the effects on stem cell marker expression, proliferation, and clonogenic growth of tumor cells. Results USP1 was highly expressed in gliomas relative to normal brain tissues and more preferentially in GSC enrichment marker (CD133 or CD15) positive cells. USP1 positively regulated the protein stability of the ID1 and CHEK1, critical regulators of DNA damage response and stem cell maintenance. Targeting USP1 by RNA interference or treatment with a chemical USP1 inhibitor attenuated clonogenic growth and survival of GSCs and enhanced radiosensitivity of GBM cells. Finally, USP1 inhibition alone or in combination with radiation significantly prolonged the survival of tumor-bearing mice. Conclusion USP1-mediated protein stabilization promotes GSC maintenance and treatment resistance, thereby providing a rationale for USP1 inhibition as a potential therapeutic approach against GBM. PMID:26032834

Deubiquitylases USP5 and USP13 are recruited to and regulate heat-induced stress granules through their deubiquitylating activities.

PubMed

Xie, Xuan; Matsumoto, Shunsuke; Endo, Akinori; Fukushima, Toshiaki; Kawahara, Hiroyuki; Saeki, Yasushi; Komada, Masayuki

2018-04-12

Stress granules are transient cytoplasmic foci induced by various stresses that contain translation-stalled mRNAs and RNA-binding proteins. They are proposed to modulate mRNA translation and stress responses. Here, we show that the deubiquitylases USP5 and USP13 are recruited to heat-induced stress granules. Heat-induced stress granules also contained K48- and K63-linked ubiquitin chains. Depletion of USP5 or USP13 resulted in elevated ubiquitin chain levels and accelerated assembly of heat-induced stress granules, suggesting that these enzymes regulate the stability of the stress granules through their ubiquitin isopeptidase activity. Moreover, disassembly of heat-induced stress granules after returning the cells to normal temperatures was markedly repressed by individual depletion of USP5 or USP13. Finally, overexpression of a ubiquitin mutant lacking the C-terminal diglycine motif caused the accumulation of unanchored ubiquitin chains and the repression of the disassembly of heat-induced stress granules. As unanchored ubiquitin chains are preferred substrates for USP5, we suggest that USP5 regulates the assembly and disassembly of heat-induced stress granules by mediating the hydrolysis of unanchored ubiquitin chains while USP13 regulates stress granules through deubiquitylating protein-conjugated ubiquitin chains.This article has an associated First Person interview with the first author of the paper. © 2018. Published by The Company of Biologists Ltd.

Isolation and Characterization of Two Proteins from Moraxella catarrhalis That Bear a Common Epitope

PubMed Central

McMichael, John C.; Fiske, Michael J.; Fredenburg, Ross A.; Chakravarti, Deb N.; VanDerMeid, Karl R.; Barniak, Vicki; Caplan, Jeffrey; Bortell, Eric; Baker, Steven; Arumugham, Rasappa; Chen, Dexiang

1998-01-01

The UspA1 and UspA2 proteins of Moraxella catarrhalis are potential vaccine candidates for preventing disease caused by this organism. We have characterized both proteins and evaluated their vaccine potential using both in vitro and in vivo assays. Both proteins were purified from the O35E isolate by Triton X-100 extraction, followed by ion-exchange and hydroxyapatite chromatography. Analysis of the sequences of internal peptides, prepared by enzymatic and chemical cleavage of the proteins, revealed that UspA1 and UspA2 exhibited distinct structural differences but shared a common sequence including an epitope recognized by the monoclonal antibody 17C7. By sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), purified UspA1 exhibited a molecular weight of approximately 350,000 when unheated and a molecular weight of 100,000 after being heated for 10 min at 100°C. In contrast, purified UspA2 exhibited an apparent molecular weight of 240,000 by SDS-PAGE that did not change with the length of time of heating. Their sizes as determined by gel filtration were 1,150,000 and 830,000 for UspA1 and UspA2, respectively. Preliminary results indicate the proteins have separate functions in bacterial pathogenesis. Purified UspA1 was found to bind HEp-2 cells, and sera against UspA1, but not against UspA2, blocked binding of the O35E isolate to the HEp-2 cells. UspA1 also bound fibronectin and appears to have a role in bacterial attachment. Purified UspA2, however, did not bind fibronectin but had an affinity for vitronectin. Both proteins elicited bactericidal antibodies in mice to homologous and heterologous disease isolates. Finally, mice immunized with each of the proteins, followed by pulmonary challenge with either the homologous or a heterologous isolate, cleared the bacteria more rapidly than mock-immunized mice. These results suggest that UspA1 and UspA2 serve different virulence functions and that both are promising vaccine candidates. PMID:9712790

USP <800>: Key Considerations and Changes for Health Systems

PubMed Central

Sahadeo, Priya; Weber, Robert J.

2015-01-01

On March 28, 2014, The United States Pharmacopeia and The National Formulary (USP-NF) published USP General Chapter <800> Hazardous Drugs–Handling in Healthcare Settings, as open for public comment in the USP Pharmacopeial Forum (PF) 40(3). Pharmacy directors must be proactive in understanding the impact that USP <800> will have on their processes for preparing sterile products. USP General Chapter <797> pertains to the compounding of both hazardous and nonhazardous drugs. USP <800> serves as a new standard to guide the handling of hazardous drugs in order to protect patients, health care personnel, and the environment. USP <800> describes hazardous drug handling related to the receipt, storage, compounding, dispensing, administration, and disposal of both sterile and nonsterile products and preparations. Regardless of all of the requirements listed in USP <800>, there is no substitute for disciplined, consistent work practices regarding proper sterile technique. This point should be emphasized with all compounding personnel. Even if one is compounding in the most compliant USP <800> cleanroom, improper technique can negate all the benefits of the physical structures. Pharmacy leaders at every level will play a key role in assisting an organization to achieve timely compliance with USP <800> standards. Until the standard becomes official, it is important for pharmacists to become familiarized with the latest draft to identify potential barriers to compliance and to strategize a plan to overcome barriers. Although complying with USP <800> may seem to be a daunting task, it can be manageable if approached in a systematic organized way. PMID:27729683

Internalization property of intestinal bacteria in colon cancer and HIV/AIDS patients.

PubMed

Wachsmannova, Lenka; Ciernikova, Sona; Majek, Juraj; Mego, Michal; Stevurkova, Viola; Zajac, Vladimir

2016-07-01

Bacteria from the intestinal tract of Slovak and American HIV/AIDS patients and Slovak colon cancer patients were tested for the capacity to be internalized by cells of the HL-60 cell line as well as by normal human lymphocytes. They were anticipated to possess a specific characteristic, i.e. a vigorous ability to be internalized by HL-60 cells and human lymphocytes. This assumption was confirmed by gentamicin protection assay. Internalization of bacteria from HIV/AIDS patients frequently resulted in partial (patients SKM1, SKM22) or complete lysis (patients SKK1-1, SKM12) of HL-60 cells. In comparison with intramucosal bacteria isolated from patients with colorectal cancer (TSG, 883, 660, 838, 536, MZRa), their capacity to internalize HL-60 cells was found to be 15-20 times higher (USP15/7, USP1/4, USP3/3, SK725/5). Partial lysis (patients USP15/7, USP3/3 and SKM22) and complete lysis (patients USP1/4, SKK1-1/1, SKM1/6, SKM12/5) were detected also after internalization of bacteria by normal human lymphocytes. Compared to the amount of intracellular bacteria isolated from patients with HIV/AIDS, the ability of bacteria from patients with colorectal cancer to internalize normal human lymphocytes was significantly lower (10-15 times), yet still higher than that of bacteria isolated from healthy people. Our results present the ability of bacteria of colon cancer patients and HIV/AIDS patients to internalize HL-60 cells and normal human lymphocytes. The findings underline the potentially important function of bacteria in the induction of colorectal cancer and immunodeficiency. The particularly high detection ability of bacteria from HIV/AIDS patients to internalize normal human cells emphasizes their potentially important role in the process of AIDS.

27 CFR 21.50 - Formula No. 25.

Code of Federal Regulations, 2011 CFR

2011-04-01

... pounds of iodine, U.S.P., and 15 pounds of either potassium iodide, U.S.P., or sodium iodide, U.S.P. (b) Authorized uses. (1) As a solvent: 230.Tinctures of iodine. 249.Miscellaneous external pharmaceuticals, U.S.P...

27 CFR 21.50 - Formula No. 25.

Code of Federal Regulations, 2010 CFR

2010-04-01

... pounds of iodine, U.S.P., and 15 pounds of either potassium iodide, U.S.P., or sodium iodide, U.S.P. (b) Authorized uses. (1) As a solvent: 230.Tinctures of iodine. 249.Miscellaneous external pharmaceuticals, U.S.P...

Release and diffusional modeling of metronidazole lipid matrices.

PubMed

Ozyazici, Mine; Gökçe, Evren H; Ertan, Gökhan

2006-07-01

In this study, the first aim was to investigate the swelling and relaxation properties of lipid matrix on diffusional exponent (n). The second aim was to determine the desired release profile of metronidazole lipid matrix tablets. We prepared metronidazole lipid matrix granules using Carnauba wax, Beeswax, Stearic acid, Cutina HR, Precirol ATO 5, and Compritol ATO 888 by hot fusion method and pressed the tablets of these granules. In vitro release test was performed using a standard USP dissolution apparatus I (basket method) with a stirring rate of 100 rpm at 37 degrees C in 900 ml of 0.1 N hydrochloric acid, adjusted to pH 1.2, as medium for the formulations' screening. Hardness, diameter-height ratio, friability, and swelling ratio were determined. Target release profile of metronidazole was also drawn. Stearic acid showed the highest and Carnauba wax showed the lowest release rates in all formulations used. Swelling ratios were calculated after the dissolution of tablets as 9.24%, 6.03%, 1.74%, and 1.07% for Cutina HR, Beeswax, Precirol ATO 5, and Compritol ATO 888, respectively. There was erosion in Stearic acid, but neither erosion nor swelling in Carnauba wax, was detected. According to the power law analysis, the diffusion mechanism was expressed as pure Fickian for Stearic acid and Carnauba wax and the coupling of Fickian and relaxation contributions for other Cutina HR, Beeswax, Compritol ATO 888, and Precirol ATO 5 tablets. It was found that Beeswax (kd=2.13) has a very close drug release rate with the target profile (kt=1.95). Our results suggested that swelling and relaxation properties of lipid matrices should be examined together for a correct evaluation on drug diffusion mechanism of insoluble matrices.

USP22 regulates oncogenic signaling pathways to drive lethal cancer progression.

PubMed

Schrecengost, Randy S; Dean, Jeffry L; Goodwin, Jonathan F; Schiewer, Matthew J; Urban, Mark W; Stanek, Timothy J; Sussman, Robyn T; Hicks, Jessica L; Birbe, Ruth C; Draganova-Tacheva, Rossitza A; Visakorpi, Tapio; DeMarzo, Angelo M; McMahon, Steven B; Knudsen, Karen E

2014-01-01

Increasing evidence links deregulation of the ubiquitin-specific proteases 22 (USP22) deubitiquitylase to cancer development and progression in a select group of tumor types, but its specificity and underlying mechanisms of action are not well defined. Here we show that USP22 is a critical promoter of lethal tumor phenotypes that acts by modulating nuclear receptor and oncogenic signaling. In multiple xenograft models of human cancer, modeling of tumor-associated USP22 deregulation demonstrated that USP22 controls androgen receptor accumulation and signaling, and that it enhances expression of critical target genes coregulated by androgen receptor and MYC. USP22 not only reprogrammed androgen receptor function, but was sufficient to induce the transition to therapeutic resistance. Notably, in vivo depletion experiments revealed that USP22 is critical to maintain phenotypes associated with end-stage disease. This was a significant finding given clinical evidence that USP22 is highly deregulated in tumors, which have achieved therapeutic resistance. Taken together, our findings define USP22 as a critical effector of tumor progression, which drives lethal phenotypes, rationalizing this enzyme as an appealing therapeutic target to treat advanced disease.

Divergence in Ubiquitin Interaction and Catalysis among the Ubiquitin-Specific Protease Family Deubiquitinating Enzymes.

PubMed

Tencer, Adam H; Liang, Qin; Zhuang, Zhihao

2016-08-23

Deubiquitinating enzymes (DUBs) are responsible for reversing mono- and polyubiquitination of proteins and play essential roles in numerous cellular processes. Close to 100 human DUBs have been identified and are classified into five families, with the ubiquitin-specific protease (USP) family being the largest (>50 members). The binding of ubiquitin (Ub) to USP is strikingly different from that observed for the DUBs in the ubiquitin C-terminal hydrolase (UCH) and ovarian tumor domain protease (OTU) families. We generated a panel of mutant ubiquitins and used them to probe the ubiquitin's interaction with a number of USPs. Our results revealed a remarkable divergence of USP-Ub interactions among the USP catalytic domains. Our double-mutant cycle analysis targeting the ubiquitin residues located in the tip, the central body, and the tail of ubiquitin also demonstrated different crosstalk among the USP-Ub interactions. This work uncovered intriguing divergence in the ubiquitin-binding mode in the USP family DUBs and raised the possibility of targeting the ubiquitin-binding hot spots on USPs for selective inhibition of USPs by small molecule antagonists.

Structure and catalytic regulatory function of ubiquitin specific protease 11 N-terminal and ubiquitin-like domains.

PubMed

Harper, Stephen; Gratton, Hayley E; Cornaciu, Irina; Oberer, Monika; Scott, David J; Emsley, Jonas; Dreveny, Ingrid

2014-05-13

The ubiquitin specific protease 11 (USP11) is implicated in DNA repair, viral RNA replication, and TGFβ signaling. We report the first characterization of the USP11 domain architecture and its role in regulating the enzymatic activity. USP11 consists of an N-terminal "domain present in USPs" (DUSP) and "ubiquitin-like" (UBL) domain, together referred to as DU domains, and the catalytic domain harboring a second UBL domain. Crystal structures of the DU domains show a tandem arrangement with a shortened β-hairpin at the two-domain interface and altered surface characteristics compared to the homologues USP4 and USP15. A conserved VEVY motif is a signature feature at the two-domain interface that shapes a potential protein interaction site. Small angle X-ray scattering and gel filtration experiments are consistent with the USP11DU domains and full-length USP11 being monomeric. Unexpectedly, we reveal, through kinetic assays of a series of deletion mutants, that the catalytic activity of USP11 is not regulated through intramolecular autoinhibition or activation by the N-terminal DU or UBL domains. Moreover, ubiquitin chain cleavage assays with all eight linkages reveal a preference for Lys(63)-, Lys(6)-, Lys(33)-, and Lys(11)-linked chains over Lys(27)-, Lys(29)-, and Lys(48)-linked and linear chains consistent with USP11's function in DNA repair pathways that is mediated by the protease domain. Our data support a model whereby USP11 domains outside the catalytic core domain serve as protein interaction or trafficking modules rather than a direct regulatory function of the proteolytic activity. This highlights the diversity of USPs in substrate recognition and regulation of ubiquitin deconjugation.

Ubiquitin-specific protease 8 links the PTEN-Akt-AIP4 pathway to the control of FLIPS stability and TRAIL sensitivity in glioblastoma multiforme.

PubMed

Panner, Amith; Crane, Courtney A; Weng, Changjiang; Feletti, Alberto; Fang, Shanna; Parsa, Andrew T; Pieper, Russell O

2010-06-15

The antiapoptotic protein FLIP(S) is a key suppressor of tumor necrosis factor-related apoptosis-inducing ligand (TRAIL)-induced apoptosis in human glioblastoma multiforme (GBM) cells. We previously reported that a novel phosphatase and tensin homologue (PTEN)-Akt-atrophin-interacting protein 4 (AIP4) pathway regulates FLIP(S) ubiquitination and stability, although the means by which PTEN and Akt were linked to AIP4 activity were unclear. Here, we report that a second regulator of ubiquitin metabolism, the ubiquitin-specific protease 8 (USP8), is a downstream target of Akt, and that USP8 links Akt to AIP4 and the regulation of FLIP(S) stability and TRAIL resistance. In human GBM xenografts, levels of USP8 correlated inversely with pAkt levels, and genetic or pharmacologic manipulation of Akt regulated USP8 levels in an inverse manner. Overexpression of wild-type USP8, but not catalytically inactive USP8, increased FLIP(S) ubiquitination, decreased FLIP(S) half-life, decreased FLIP(S) steady-state levels, and decreased TRAIL resistance, whereas short interfering RNA (siRNA)-mediated suppression of USP8 levels had the opposite effect. Because high levels of the USP8 deubiquitinase correlated with high levels of FLIP(S) ubiquitination, USP8 seemed to control FLIP(S) ubiquitination through an intermediate target. Consistent with this idea, overexpression of wild-type USP8 decreased the ubiquitination of the FLIP(S) E3 ubiquitin ligase AIP4, an event previously shown to increase AIP4-FLIP(S) interaction, whereas siRNA-mediated suppression of USP8 increased AIP4 ubiquitination. Furthermore, the suppression of FLIP(S) levels by USP8 overexpression was reversed by the introduction of siRNA targeting AIP4. These results show that USP8, a downstream target of Akt, regulates the ability of AIP4 to control FLIP(S) stability and TRAIL sensitivity.

Evaluation of a biphasic in vitro dissolution test for estimating the bioavailability of carbamazepine polymorphic forms.

PubMed

Deng, Jia; Staufenbiel, Sven; Bodmeier, Roland

2017-07-15

The purpose of this study was to discriminate three crystal forms of carbamazepine (a BCS II drug) by in vitro dissolution testing and to correlate in vitro data with published in vivo data. A biphasic dissolution system (phosphate buffer pH6.8 and octanol) was used to evaluate the dissolution of the three polymorphic forms and to compare it with conventional single phase dissolution tests performed under sink and non-sink conditions. Similar dissolution profiles of three polymorphic forms were observed in the conventional dissolution test under sink conditions. Although a difference in dissolution was seen in the single phase dissolution test under non-sink conditions as well as in the aqueous phase of the biphasic test, little relevance for in vivo data was observed. In contrast, the biphasic dissolution system could discriminate between the different polymorphic forms in the octanol phase with a ranking of form III>form I>dihydrate form. This was in agreement with the in vivo performance. The dissolved drug available for oral absorption, which was dominated by dissolution and solution-mediated phase transformation, could be reflected in the biphasic dissolution test. Moreover, a good correlation was established between in vitro dissolution in the octanol phase of the biphasic test and in vivo pharmacokinetic data (R 2 =0.99). The biphasic dissolution method is a valuable tool to discriminate between different crystal forms in the formulations of poorly soluble drugs. Copyright © 2017. Published by Elsevier B.V.

Identification of a novel higher molecular weight isoform of USP7/HAUSP that interacts with the Herpes simplex virus type-1 immediate early protein ICP0.

PubMed

Antrobus, Robin; Boutell, Chris

2008-10-01

The Herpes simplex virus type-1 (HSV-1) regulatory protein ICP0, a RING-finger E3 ubiquitin ligase, stimulates the onset of viral lytic replication and the reactivation of quiescent viral genomes from latency. Like many ubiquitin ligases ICP0 induces its own ubiquitination, a process that can lead to its proteasome-dependent degradation. ICP0 counteracts this activity by recruiting the cellular ubiquitin-specific protease USP7/HAUSP. Here we show that ICP0 can also interact with a previously unidentified isoform of USP7 (termed here USP7(beta)). This isoform is not a predominantly ubiquitinated, SUMO-modified, or phosphorylated species of USP7 but is constitutively expressed in a number of different cell types. Like USP7, USP7(beta) binds specifically to an electrophilic ubiquitin probe, indicating that it contains an accessible catalytic core with potential ubiquitin-protease activity. The interaction formed between ICP0 and USP7(beta) requires ICP0 to have an intact USP7-binding domain and results in its susceptibility to ICP0-mediated degradation during HSV-1 infection.

Usp16 contributes to somatic stem cell defects in Down syndrome

PubMed Central

Adorno, Maddalena; Sikandar, Shaheen; Mitra, Siddhartha S.; Kuo, Angera; Di Robilant, Benedetta Nicolis; Haro-Acosta, Veronica; Ouadah, Youcef; Quarta, Marco; Rodriguez, Jacqueline; Qian, Dalong; Reddy, Vadiyala M.; Cheshier, Samuel; Garner, Craig C.; Clarke, Michael F.

2013-01-01

SUMMARY Down syndrome (DS) results from full or partial trisomy of chromosome 21. However, the consequences of the underlying gene-dosage imbalance on adult tissues remain poorly understood. Here we show that in Ts65Dn mice, trisomic for 132 genes homologous to HSA21, triplication of Usp16 reduces self-renewal of hematopoietic stem cells and expansion of mammary epithelial cells, neural progenitors, and fibroblasts. Moreover, Usp16 is associated with decreased ubiquitination of Cdkn2a and accelerated senescence in Ts65Dn fibroblasts. Usp16 can remove ubiquitin from H2AK119, a critical mark for the maintenance of multiple somatic tissues. Downregulation of Usp16, either by mutation of a single normal USP16 allele or by shRNAs, largely rescues all these defects. Furthermore, in human tissues overexpression of USP16 reduces the expansion of normal fibroblasts and post-natal neural progenitors while downregulation of USP16 partially rescues the proliferation defects of DS fibroblasts. Taken together, these results suggest that USP16 plays an important role in antagonizing the self-renewal and/or senescence pathways in Down syndrome and could serve as an attractive target to ameliorate some of the associated pathologies. PMID:24025767

The diagnosis of nonclassic congenital adrenal hyperplasia due to 21-hydroxylase deficiency, based on serum basal or post-ACTH stimulation 17-hydroxyprogesterone, can lead to false-positive diagnosis.

PubMed

Ambroziak, Urszula; Kępczyńska-Nyk, Anna; Kuryłowicz, Alina; Małunowicz, Ewa Maria; Wójcicka, Anna; Miśkiewicz, Piotr; Macech, Magdalena

2016-01-01

As nonclassic congenital adrenal hyperplasia (NCCAH) needs to be taken into account in women with hyperandrogenism, we aimed to assess whether the recommended level of poststimulated 17OHP ≥30 nmol/l confirms NCCAH. Forty, consecutive women with biochemical and/or clinical hyperandrogenism (aged 25·4, 18-38) suspected of having NCCAH were recruited to the study. In patients with 17OHP level between 5·1 and 29·9 nmol/l an ACTH stimulation test was performed. In patients with basal or poststimulated 17OHP ≥30 nmol/l, twenty-four-hour urinary steroid profile (USP) analysis was performed and CYP21A2 mutation was assessed. In selected patients with poststimulated 17OHP <30 nmol/l USP was also performed. The group was divided into two subgroups with basal or poststimulated 17OHP ≥30 nmol/l (group A) and with poststimulated 17OHP <30 nmol/l (group B). Among 40 patients, basal or poststimulated 17OHP ≥30 nmol/l was found in 21, but NCCAH was confirmed by USP followed by genetic testing only in 5 (24%). Four patients were diagnosed as heterozygotes, and in twelve, no CYP21A2 mutation was detected. The diagnosis of NCCAH based only on serum 17OHP measurements (basal or poststimulated) may lead to false-positive diagnosis when performed by immunoassay with a cut-off value of ≥30 nmol/l. The definitive diagnosis can be established based on USP and/or genetic testing. © 2015 John Wiley & Sons Ltd.

Usp5 links suppression of p53 and FAS levels in melanoma to the BRAF pathway

PubMed Central

Potu, Harish; Peterson, Luke F.; Pal, Anupama; Verhaegen, Monique; Cao, Juxiang; Talpaz, Moshe; Donato, Nicholas J.

2014-01-01

Usp5 is a deubiquitinase (DUB) previously shown to regulate unanchored polyubiquitin (Ub) chains, p53 transcriptional activity and double-strand DNA repair. In BRAF mutant melanoma cells, Usp5 activity was suppressed by BRAF inhibitor (vemurafenib) in sensitive but not in acquired or intrinsically resistant cells. Usp5 knockdown overcame acquired vemurafenib resistance and sensitized BRAF and NRAS mutant melanoma cells to apoptosis initiated by MEK inhibitor, cytokines or DNA-damaging agents. Knockdown and overexpression studies demonstrated that Usp5 regulates p53 (and p73) levels and alters cell growth and cell cycle distribution associated with p21 induction. Usp5 also regulates the intrinsic apoptotic pathway by modulating p53-dependent FAS expression. A small molecule DUB inhibitor (EOAI3402143) phenocopied the FAS induction and apoptotic sensitization of Usp5 knockdown and fully blocked melanoma tumor growth in mice. Overall, our results demonstrate that BRAF activates Usp5 to suppress cell cycle checkpoint control and apoptosis by blocking p53 and FAS induction; all of which can be restored by small molecule-mediated Usp5 inhibition. These results suggest that Usp5 inhibition can provide an alternate approach in recovery of diminished p53 (or p73) function in melanoma and can add to the targeted therapies already used in the treatment of melanoma. PMID:24980819

USP22 knockdown enhanced chemosensitivity of hepatocellular carcinoma cells to 5-Fu by up-regulation of Smad4 and suppression of Akt

PubMed Central

Li, Jiazhi; Yang, Xiaozhou; Yin, Huimin; Xiao, Congshu; Sheng, Jie; Li, Yang; Tang, Bo; Li, Rongkuan

2017-01-01

USP22, a member of the deubiquitinases (DUBs) family, is known to be a key subunit of the human Spt-Ada-Gcn5 acetyltransferase (hSAGA) transcriptional cofactor complex. Within hSAGA, USP22 removes ubiquitin from histone proteins, thus regulating the transcription and expression of downstream genes. USP22 plays important roles in many cancers; however, its effect and the mechanism underlying HCC chemoresistance remain unclear. In the present study, we found that USP22 was highly expressed in chemoresistant HCC tissues and cells and was correlated with the prognosis of HCC patients who received chemotherapy. Silencing USP22 in chemoresistant HCC Bel/Fu cells dramatically inhibited proliferation, migration, invasion and epithelial-mesenchymal transition in vitro; suppressed tumorigenic and metastatic capacities in vivo; and inhibited drug resistance-related proteins (MDR1, LRP, MRP1). Mechanistically, we found that USP22 knockdown exerts its function through down-regulating PI3K and activating Smad4, which inhibited phosphorylation of Akt. Silencing Smad4 blocked USP22 knockdown-induced Akt inhibition in Bel/Fu cells. Our results, for the first time, provide evidence that USP22 plays a critical role in the development of chemoresistant HCC cells and that high USP22 expression serves as a molecular marker for the prognosis of HCC patients who undergo chemotherapy. PMID:28445968

USP22 knockdown enhanced chemosensitivity of hepatocellular carcinoma cells to 5-Fu by up-regulation of Smad4 and suppression of Akt.

PubMed

Zhang, Jing; Luo, Nan; Tian, Yu; Li, Jiazhi; Yang, Xiaozhou; Yin, Huimin; Xiao, Congshu; Sheng, Jie; Li, Yang; Tang, Bo; Li, Rongkuan

2017-04-11

USP22, a member of the deubiquitinases (DUBs) family, is known to be a key subunit of the human Spt-Ada-Gcn5 acetyltransferase (hSAGA) transcriptional cofactor complex. Within hSAGA, USP22 removes ubiquitin from histone proteins, thus regulating the transcription and expression of downstream genes. USP22 plays important roles in many cancers; however, its effect and the mechanism underlying HCC chemoresistance remain unclear. In the present study, we found that USP22 was highly expressed in chemoresistant HCC tissues and cells and was correlated with the prognosis of HCC patients who received chemotherapy. Silencing USP22 in chemoresistant HCC Bel/Fu cells dramatically inhibited proliferation, migration, invasion and epithelial-mesenchymal transition in vitro; suppressed tumorigenic and metastatic capacities in vivo; and inhibited drug resistance-related proteins (MDR1, LRP, MRP1). Mechanistically, we found that USP22 knockdown exerts its function through down-regulating PI3K and activating Smad4, which inhibited phosphorylation of Akt. Silencing Smad4 blocked USP22 knockdown-induced Akt inhibition in Bel/Fu cells. Our results, for the first time, provide evidence that USP22 plays a critical role in the development of chemoresistant HCC cells and that high USP22 expression serves as a molecular marker for the prognosis of HCC patients who undergo chemotherapy.

A Role for USP7 in DNA Replication

PubMed Central

Jagannathan, Madhav; Nguyen, Tin; Gallo, David; Luthra, Niharika; Brown, Grant W.; Saridakis, Vivian

2014-01-01

The minichromosome maintenance (MCM) complex, which plays multiple important roles in DNA replication, is loaded onto chromatin following mitosis, remains on chromatin until the completion of DNA synthesis, and then is unloaded by a poorly defined mechanism that involves the MCM binding protein (MCM-BP). Here we show that MCM-BP directly interacts with the ubiquitin-specific protease USP7, that this interaction occurs predominantly on chromatin, and that MCM-BP can tether USP7 to MCM proteins. Detailed biochemical and structure analyses of the USP7–MCM-BP interaction showed that the 155PSTS158 MCM-BP sequence mediates critical interactions with the TRAF domain binding pocket of USP7. Analysis of the effects of USP7 knockout on DNA replication revealed that lack of USP7 results in slowed progression through late S phase without globally affecting the fork rate or origin usage. Lack of USP7 also resulted in increased levels of MCM proteins on chromatin, and investigation of the cause of this increase revealed a defect in the dissociation of MCM proteins from chromatin in mid- to late S phase. This role of USP7 mirrors the previously described role for MCM-BP in MCM complex unloading and suggests that USP7 works with MCM-BP to unload MCM complexes from chromatin at the end of S phase. PMID:24190967

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

USP1 targeting impedes GBM growth by inhibiting stem cell maintenance and radioresistance.

PubMed

Lee, Jin-Ku; Chang, Nakho; Yoon, Yeup; Yang, Heekyoung; Cho, Heejin; Kim, Eunhee; Shin, Yongjae; Kang, Wonyoung; Oh, Young Taek; Mun, Gyeong In; Joo, Kyeung Min; Nam, Do-Hyun; Lee, Jeongwu

2016-01-01

Clinical benefits from standard therapies against glioblastoma (GBM) are limited in part due to intrinsic radio- and chemoresistance of GBM and inefficient targeting of GBM stem-like cells (GSCs). Novel therapeutic approaches that overcome treatment resistance and diminish stem-like properties of GBM are needed. We determined the expression levels of ubiquitination-specific proteases (USPs) by transcriptome analysis and found that USP1 is highly expressed in GBM. Using the patient GBM-derived primary tumor cells, we inhibited USP1 by shRNA-mediated knockdown or its specific inhibitor pimozide and evaluated the effects on stem cell marker expression, proliferation, and clonogenic growth of tumor cells. USP1 was highly expressed in gliomas relative to normal brain tissues and more preferentially in GSC enrichment marker (CD133 or CD15) positive cells. USP1 positively regulated the protein stability of the ID1 and CHEK1, critical regulators of DNA damage response and stem cell maintenance. Targeting USP1 by RNA interference or treatment with a chemical USP1 inhibitor attenuated clonogenic growth and survival of GSCs and enhanced radiosensitivity of GBM cells. Finally, USP1 inhibition alone or in combination with radiation significantly prolonged the survival of tumor-bearing mice. USP1-mediated protein stabilization promotes GSC maintenance and treatment resistance, thereby providing a rationale for USP1 inhibition as a potential therapeutic approach against GBM. © The Author(s) 2015. Published by Oxford University Press on behalf of the Society for Neuro-Oncology. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

The nucleolar ubiquitin-specific protease USP36 deubiquitinates and stabilizes c-Myc

PubMed Central

Sun, Xiao-Xin; He, Xia; Yin, Li; Komada, Masayuki; Sears, Rosalie C.; Dai, Mu-Shui

2015-01-01

c-Myc protein stability and activity are tightly regulated by the ubiquitin-proteasome system. Aberrant stabilization of c-Myc contributes to many human cancers. c-Myc is ubiquitinated by SCFFbw7 (a SKP1-cullin-1-F-box complex that contains the F-box and WD repeat domain-containing 7, Fbw7, as the F-box protein) and several other ubiquitin ligases, whereas it is deubiquitinated and stabilized by ubiquitin-specific protease (USP) 28. The bulk of c-Myc degradation appears to occur in the nucleolus. However, whether c-Myc is regulated by deubiquitination in the nucleolus is not known. Here, we report that the nucleolar deubiquitinating enzyme USP36 is a novel c-Myc deubiquitinase. USP36 interacts with and deubiquitinates c-Myc in cells and in vitro, leading to the stabilization of c-Myc. This USP36 regulation of c-Myc occurs in the nucleolus. Interestingly, USP36 interacts with the nucleolar Fbw7γ but not the nucleoplasmic Fbw7α. However, it abolished c-Myc degradation mediated both by Fbw7γ and by Fbw7α. Consistently, knockdown of USP36 reduces the levels of c-Myc and suppresses cell proliferation. We further show that USP36 itself is a c-Myc target gene, suggesting that USP36 and c-Myc form a positive feedback regulatory loop. High expression levels of USP36 are found in a subset of human breast and lung cancers. Altogether, these results identified USP36 as a crucial and bono fide deubiquitinating enzyme controlling c-Myc’s nucleolar degradation pathway. PMID:25775507

Stratifin regulates stabilization of receptor tyrosine kinases via interaction with ubiquitin-specific protease 8 in lung adenocarcinoma.

PubMed

Kim, Yunjung; Shiba-Ishii, Aya; Nakagawa, Tomoki; Iemura, Shun-Ichiro; Natsume, Tohru; Nakano, Noriyuki; Matsuoka, Ryota; Sakashita, Shingo; Lee, SangJoon; Kawaguchi, Atsushi; Sato, Yukio; Noguchi, Masayuki

2018-06-07

Previously we have reported that stratifin (SFN, 14-3-3 sigma) acts as a novel oncogene, accelerating the tumor initiation and progression of lung adenocarcinoma. Here, pull-down assay and LC-MS/MS analysis revealed that ubiquitin-specific protease 8 (USP8) specifically bound to SFN in lung adenocarcinoma cells. Both USP8 and SFN showed higher expression in human lung adenocarcinoma than in normal lung tissue, and USP8 expression was significantly correlated with SFN expression. Expression of SFN, but not of USP8, was associated with histological subtype, pathological stage, and poor prognosis. USP8 stabilizes receptor tyrosine kinases (RTKs) such as EGFR and MET by deubiquitination, contributing to the proliferative activity of many human cancers including non-small cell lung cancer. In vitro, USP8 binds to SFN and they co-localize at the early endosomes in lung adenocarcinoma cells. Moreover, USP8 or SFN knockdown leads to downregulation of tumor cellular proliferation and upregulation of apoptosis, p-EGFR or p-MET, which are related to the degradation pathway, and accumulation of ubiquitinated RTKs, leading to lysosomal degradation. Additionally, mutant USP8, which is unable to bind to SFN, reduces the expression of RTKs and p-STAT3. We also found that interaction with SFN is critical for USP8 to exert its autodeubiquitination function and avoid dephosphorylation by PP1. Our findings demonstrate that SFN enhances RTK stabilization through abnormal USP8 regulation in lung adenocarcinoma, suggesting that SFN could be a more suitable therapeutic target for lung adenocarcinoma than USP8.

USP1 deubiquitinase: cellular functions, regulatory mechanisms and emerging potential as target in cancer therapy

PubMed Central

2013-01-01

Reversible protein ubiquitination is emerging as a key process for maintaining cell homeostasis, and the enzymes that participate in this process, in particular E3 ubiquitin ligases and deubiquitinases (DUBs), are increasingly being regarded as candidates for drug discovery. Human DUBs are a group of approximately 100 proteins, whose cellular functions and regulatory mechanisms remain, with some exceptions, poorly characterized. One of the best-characterized human DUBs is ubiquitin-specific protease 1 (USP1), which plays an important role in the cellular response to DNA damage. USP1 levels, localization and activity are modulated through several mechanisms, including protein-protein interactions, autocleavage/degradation and phosphorylation, ensuring that USP1 function is carried out in a properly regulated spatio-temporal manner. Importantly, USP1 expression is deregulated in certain types of human cancer, suggesting that USP1 could represent a valid target in cancer therapy. This view has gained recent support with the finding that USP1 inhibition may contribute to revert cisplatin resistance in an in vitro model of non-small cell lung cancer (NSCLC). Here, we describe the current knowledge on the cellular functions and regulatory mechanisms of USP1. We also summarize USP1 alterations found in cancer, combining data from the literature and public databases with our own data. Finally, we discuss the emerging potential of USP1 as a target, integrating published data with our novel findings on the effects of the USP1 inhibitor pimozide in combination with cisplatin in NSCLC cells. PMID:23937906

In vitro-in vivo correlation for nevirapine extended release tablets.

PubMed

Macha, Sreeraj; Yong, Chan-Loi; Darrington, Todd; Davis, Mark S; MacGregor, Thomas R; Castles, Mark; Krill, Steven L

2009-12-01

An in vitro-in vivo correlation (IVIVC) for four nevirapine extended release tablets with varying polymer contents was developed. The pharmacokinetics of extended release formulations were assessed in a parallel group study with healthy volunteers and compared with corresponding in vitro dissolution data obtained using a USP apparatus type 1. In vitro samples were analysed using HPLC with UV detection and in vivo samples were analysed using a HPLC-MS/MS assay; the IVIVC analyses comparing the two results were performed using WinNonlin. A Double Weibull model optimally fits the in vitro data. A unit impulse response (UIR) was assessed using the fastest ER formulation as a reference. The deconvolution of the in vivo concentration time data was performed using the UIR to estimate an in vivo drug release profile. A linear model with a time-scaling factor clarified the relationship between in vitro and in vivo data. The predictability of the final model was consistent based on internal validation. Average percent prediction errors for pharmacokinetic parameters were <10% and individual values for all formulations were <15%. Therefore, a Level A IVIVC was developed and validated for nevirapine extended release formulations providing robust predictions of in vivo profiles based on in vitro dissolution profiles. Copyright 2009 John Wiley & Sons, Ltd.

Sustained delivery of salbutamol and beclometasone from spray-dried double emulsions.

PubMed

Learoyd, Tristan P; Burrows, Jane L; French, Eddie; Seville, Peter C

2010-01-01

The sustained delivery of multiple agents to the lung offers potential benefits to patients. This study explores the preparation of highly respirable dual-loaded spray-dried double emulsions. Spray-dried powders were produced from water-in-oil-in-water (w/o/w) double emulsions, containing salbutamol sulphate and/or beclometasone dipropionate in varying phases. The double emulsions contained the drug release modifier polylactide co-glycolide (PLGA 50 : 50) in the intermediate organic phase of the original micro-emulsion and low molecular weight chitosan (Mw<190 kDa: emulsion stabilizer) and leucine (aerosolization enhancer) in the tertiary aqueous phase. Following spray-drying resultant powders were physically characterized: with in vitro aerosolization performance and drug release investigated using a Multi-Stage Liquid Impinger and modified USP II dissolution apparatus, respectively. Powders generated were of a respirable size exhibiting emitted doses of over 95% and fine particle fractions of up to 60% of the total loaded dose. Sustained drug release profiles were observed during dissolution for powders containing agents in the primary aqueous and secondary organic phases of the original micro-emulsion; the burst release of agents was witnessed from the tertiary aqueous phase. The novel spray-dried emulsions from this study would be expected to deposit and display sustained release character in the lung.

Temozolomide-based dry powder formulations for lung tumor-related inhalation treatment.

PubMed

Wauthoz, Nathalie; Deleuze, Philippe; Saumet, Amandine; Duret, Christophe; Kiss, Robert; Amighi, Karim

2011-04-01

Temozolomide dry powder formulations for inhalation, performed with no excipient or with a lipid or lactose coating, have been evaluated. The particle size of raw temozolomide in suspension was reduced by a high-pressure homogenizing technique, and the solvent was evaporated by spray-drying to obtain a dry powder. The physicochemical properties of this powder were evaluated and included its crystalline state, thermal properties, morphology, particle size and moisture and drug content, and these properties were determined by X-ray powder diffraction, differential scanning calorimetry, scanning electron microscopy, laser light scattering, thermogravimetric analysis and high-performance liquid chromatography, respectively. The aerodynamic properties and release profiles were also evaluated using a multistage liquid impinger and a modified USP type 2 dissolution apparatus adapted for inhaler products, respectively. The dry powder inhalation formulations had a high temozolomide content that ranged from 70% to 100% in the crystalline state and low moisture content. Aerodynamic evaluations showed high fine-particle fractions of up to 51% related to the metered dose. The dissolution profile revealed a similarly fast temozolomide release from the formulations. Dry temozolomide powder formulations, based on the use of acceptable excipients for inhalation and showing good dispersion properties, represent an attractive alternative for use in local lung cancer therapy.

Mutations in the deubiquitinase gene USP8 cause Cushing's disease.

PubMed

Reincke, Martin; Sbiera, Silviu; Hayakawa, Akira; Theodoropoulou, Marily; Osswald, Andrea; Beuschlein, Felix; Meitinger, Thomas; Mizuno-Yamasaki, Emi; Kawaguchi, Kohei; Saeki, Yasushi; Tanaka, Keiji; Wieland, Thomas; Graf, Elisabeth; Saeger, Wolfgang; Ronchi, Cristina L; Allolio, Bruno; Buchfelder, Michael; Strom, Tim M; Fassnacht, Martin; Komada, Masayuki

2015-01-01

Cushing's disease is caused by corticotroph adenomas of the pituitary. To explore the molecular mechanisms of endocrine autonomy in these tumors, we performed exome sequencing of 10 corticotroph adenomas. We found somatic mutations in the USP8 deubiquitinase gene in 4 of 10 adenomas. The mutations clustered in the 14-3-3 protein binding motif and enhanced the proteolytic cleavage and catalytic activity of USP8. Cleavage of USP8 led to increased deubiqutination of the EGF receptor, impairing its downregulation and sustaining EGF signaling. USP8 mutants enhanced promoter activity of the gene encoding proopiomelanocortin. In summary, our data show that dominant mutations in USP8 cause Cushing's disease via activation of EGF receptor signaling.

Ubiquitin-specific protease 11 (USP11) functions as a tumor suppressor through deubiquitinating and stabilizing VGLL4 protein

PubMed Central

Zhang, Encheng; Shen, Bing; Mu, Xingyu; Qin, Yan; Zhang, Fang; Liu, Yong; Xiao, Jiantao; Zhang, Pingzhao; Wang, Chenji; Tan, Mingyue; Fan, Yu

2016-01-01

VGLL4 is a transcriptional repressor that interacts with transcription factors TEADs and inhibits YAP-induced overgrowth and tumorigenesis. VGLL4 protein was dramatically reduced in various types of human cancers. But how VGLL4 protein is post-transcriptional regulated is poorly understood. In this study, we identify deubiquitinating enzyme USP11 as a novel VGLL4 interactor. We reveal that the USP domain of USP11 and the N-terminal region of VGLL4 are required for mutual binding. USP11 controls VGLL4 protein stability by promoting its deubiquitination. Furthermore, our results show that knockdown of USP11 promotes cell growth, migration, and invasion in a YAP-dependent manner. Together, our results suggest that USP11 may exert its tumor suppressor role by modulating VGLL4/YAP-TEADs regulatory loop. PMID:28042509

Nucleophosmin/B23 regulates ubiquitin dynamics in nucleoli by recruiting deubiquitylating enzyme USP36.

PubMed

Endo, Akinori; Kitamura, Naomi; Komada, Masayuki

2009-10-09

The nucleolus is a subnuclear compartment with multiple cellular functions, including ribosome biogenesis. USP36 is a deubiquitylating enzyme that localizes to nucleoli and plays an essential role in regulating the structure and function of the organelle. However, how the localization of USP36 is regulated remains unknown. Here, we identified a short stretch of basic amino acids (RGKEKKIKKFKREKRR) that resides in the C-terminal region of USP36 and serves as a nucleolar localization signal for the protein. We found that this motif interacts with a central acidic region of nucleophosmin/B23, a major nucleolar protein involved in various nucleolar functions. Knockdown of nucleophosmin/B23 resulted in a significant reduction in the amount of USP36 in nucleoli, without affecting the cellular USP36 level. This was associated with elevated ubiquitylation levels of fibrillarin, a USP36 substrate protein in nucleoli. We conclude that nucleophosmin/B23 recruits USP36 to nucleoli, thereby serving as a platform for the regulation of nucleolar protein functions through ubiquitylation/deubiquitylation.

USP10 Is an Essential Deubiquitinase for Hematopoiesis and Inhibits Apoptosis of Long-Term Hematopoietic Stem Cells.

PubMed

Higuchi, Masaya; Kawamura, Hiroki; Matsuki, Hideaki; Hara, Toshifumi; Takahashi, Masahiko; Saito, Suguru; Saito, Kousuke; Jiang, Shuying; Naito, Makoto; Kiyonari, Hiroshi; Fujii, Masahiro

2016-12-13

Self-renewal, replication, and differentiation of hematopoietic stem cells (HSCs) are regulated by cytokines produced by niche cells in fetal liver and bone marrow. HSCs must overcome stresses induced by cytokine deprivation during normal development. In this study, we found that ubiquitin-specific peptidase 10 (USP10) is a crucial deubiquitinase for mouse hematopoiesis. All USP10 knockout (KO) mice died within 1 year because of bone marrow failure with pancytopenia. Bone marrow failure in these USP10-KO mice was associated with remarkable reductions of long-term HSCs (LT-HSCs) in bone marrow and fetal liver. Such USP10-KO fetal liver exhibited enhanced apoptosis of hematopoietic stem/progenitor cells (HSPCs) including LT-HSCs but not of lineage-committed progenitor cells. Transplantation of USP10-competent bone marrow cells into USP10-KO mice reconstituted multilineage hematopoiesis. These results suggest that USP10 is an essential deubiquitinase in hematopoiesis and functions by inhibiting apoptosis of HSPCs including LT-HSCs. Copyright © 2016 The Author(s). Published by Elsevier Inc. All rights reserved.

Selective and cell-active inhibitors of the USP1/UAF1 deubiquitinase complex reverse cisplatin resistance in non-small cell lung cancer cells

PubMed Central

Chen, Junjun; Dexheimer, Thomas S.; Ai, Yongxing; Liang, Qin; Villamil, Mark A.; Inglese, James; Maloney, David J; Jadhav, Ajit; Simeonov, Anton; Zhuang, Zhihao

2012-01-01

Ubiquitin-specific proteases (USPs) have in recent years emerged as a promising therapeutic target class. We identified selective small-molecule inhibitors against a deubiquitinase complex, the human USP1/UAF1, through quantitative high throughput screening (qHTS) of a collection of bioactive molecules. The top inhibitors, pimozide and GW7647, inhibited USP1/UAF1 noncompetitively with a Ki of 0.5 and 0.7 μM respectively, and displayed selectivity against a number of deubiquitinases, deSUMOylase and cysteine proteases. The USP1/UAF1 inhibitors act synergistically with cisplatin in inhibiting cisplatin-resistant non-small cell lung cancer (NSCLC) cell proliferation. USP1/UAF1 represents a promising target for drug intervention because of its involvement in translesion synthesis and Fanconi anemia pathway important for normal DNA damage response. Our results support USP1/UAF1 as a potential therapeutic target and provide the first example of targeting the USP/WD40 repeat protein complex for inhibitor discovery. PMID:22118673

The histone H2A deubiquitinase Usp16 regulates hematopoiesis and hematopoietic stem cell function.

PubMed

Gu, Yue; Jones, Amanda E; Yang, Wei; Liu, Shanrun; Dai, Qian; Liu, Yudong; Swindle, C Scott; Zhou, Dewang; Zhang, Zhuo; Ryan, Thomas M; Townes, Tim M; Klug, Christopher A; Chen, Dongquan; Wang, Hengbin

2016-01-05

Epigenetic mechanisms play important regulatory roles in hematopoiesis and hematopoietic stem cell (HSC) function. Subunits of polycomb repressive complex 1 (PRC1), the major histone H2A ubiquitin ligase, are critical for both normal and pathological hematopoiesis; however, it is unclear which of the several counteracting H2A deubiquitinases functions along with PRC1 to control H2A ubiquitination (ubH2A) level and regulates hematopoiesis in vivo. Here we investigated the function of Usp16 in mouse hematopoiesis. Conditional deletion of Usp16 in bone marrow resulted in a significant increase of global ubH2A level and lethality. Usp16 deletion did not change HSC number but was associated with a dramatic reduction of mature and progenitor cell populations, revealing a role in governing HSC lineage commitment. ChIP- and RNA-sequencing studies in HSC and progenitor cells revealed that Usp16 bound to many important hematopoietic regulators and that Usp16 deletion altered the expression of genes in transcription/chromosome organization, immune response, hematopoietic/lymphoid organ development, and myeloid/leukocyte differentiation. The altered gene expression was partly rescued by knockdown of PRC1 subunits, suggesting that Usp16 and PRC1 counterbalance each other to regulate cellular ubH2A level and gene expression in the hematopoietic system. We further discovered that knocking down Cdkn1a (p21cip1), a Usp16 target and regulated gene, rescued the altered cell cycle profile and differentiation defect of Usp16-deleted HSCs. Collectively, these studies identified Usp16 as one of the histone H2A deubiquitinases, which coordinates with the H2A ubiquitin ligase PRC1 to regulate hematopoiesis, and revealed cell cycle regulation by Usp16 as key for HSC differentiation.

Investigation of the performance of the disintegration test for dietary supplements.

PubMed

Almukainzi, May; Salehi, Mahnor; Araci Bou-Chacra, Nadia; Löbenberg, Raimar

2010-12-01

The aim of this study was to investigate how beaker size, basket assembly, use of disk, and immersion medium impact the disintegration time of dietary supplements. The disintegration times were determined for five tablet and two capsule products. A two-station disintegration tester was used with Apparatus A or Apparatus B as described in the United States Pharmacopeia (USP) chapters, <701> and <2040>. Two beakers complying with the harmonized specifications were used, one with a volume of 1,000 mL and one with a 1,500-mL volume. The disintegration data were analyzed using ANOVA for the following factors: beaker size, equipment (App A and B) and condition (with/without disk). Two tablet products were not sensitive to any changes in the test conditions or equipment configurations. One product was only partially sensitive to the test conditions. The other products showed impact on the disintegration time for all test conditions. The results revealed that these tablet products might pass or fail current USP disintegration requirements depending on the equipment configuration. Similar results were obtained for the two investigated capsule formulations. One product might fail current USP disintegration requirements if the large beaker was used, but might pass the disintegration requirements when the small beaker was used. Hydroxy propyl methyl cellulose capsules were mostly influenced if sodium instead of a potassium buffer was used as the immersion medium. The results demonstrate that the current harmonized ICH specifications for the disintegration test are insufficient to make the disintegration test into reliable test for dietary supplements.

Modification of crystal habit of ibuprofen using the phase partition technique: effect of aerosil and tween 80 in binding solvent.

PubMed

Umprayn, K; Luengtummuen, A; Kitiyadisai, C; Pornpiputsakul, T

2001-11-01

A ternary diagram, representing the solubility of binding solvent (chloroform) in a mixture of ethanol and water, was constructed. For this study, the solvent mixture that gave the best ibuprofen pellets (IPs) was composed of chloroform.ethanol:water at a ratio of 1.5%:8%:90.5%. The suitable agitator speed, temperature, and mixing time were found to be 1,500 rpm, 25 degrees C +/- 2 degrees C, and 20 min, respectively. In addition, suitable stirring time when the phase partition process of IPs began was 15 min. IPs obtained from these conditions were small and round, approximately 1 mm; surface determination by scanning electron microscopy (SEM) indicated that the IPs were composed of drug microcrystals rearranged on the surface. For the dissolution, IPs showed lower drug release when compared with pure ibuprofen crystal (IC) (f2 analysis). An attempt to modify the dissolution property of IP by incorporating various concentrations of Aerosil and Tween 80 in the binding solvent was made. Microscopic appearance showed that both Aerosil and Tween 80 gave less spherical pellets when compared with the use of binding solvent alone. For both the Aerosil and Tween 80 employed, the results indicated a change in rearrangement of drug microcrystals and a change in crystal habit. However, Tween 80 gave more change of the crystallographic direction of drug microcrystals than Aerosil. In term of dissolution, the results showed that employing Tween 80 at 1.2% gave the highest drug release compared to the use of Aerosil and IC alone (f2 analysis). These pellets had a good flow property, as indicated by Carr's compressibility, flow rate, and angle of repose, and they can be compressed into a tablet, encapsulated by suitable polymer, or pulverized to obtain micronized crystals. In the case of compression into tablets, the dissolution profiles of these tablets compared with those of commercial product meet the USP 24 requirement (Q > or = 80% at 60 min).

78 FR 18352 - Determination That QUESTRAN (Cholestyramine for Oral Suspension, USP), Equivalent to 4 Grams, and...

Federal Register 2010, 2011, 2012, 2013, 2014

2013-03-26

...] Determination That QUESTRAN (Cholestyramine for Oral Suspension, USP), Equivalent to 4 Grams, and QUESTRAN LIGHT (Cholestyramine for Oral Suspension, USP), Equivalent to 4 Grams, Were Not Withdrawn From Sale for Reasons of...), equivalent to (EQ) 4 grams (g), and QUESTRAN LIGHT (cholestyramine for oral suspension, USP), EQ 4 g, were...

77 FR 50702 - Ranbaxy Laboratories Limited; Withdrawal of Approval of 27 Abbreviated New Drug Applications

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-22

... Tablets USP, 1 gram. 065043 Cefuroxime Axetil Tablets USP, 125 mg, 250 mg, and 500 mg. 065080 Dispermox (amoxicillin tablets for oral suspension USP), 200 mg and 400 mg. 065092 Raniclor (cefaclor chewable tablets USP), 125 mg, 187 mg, 250 mg, and 375 mg. 065100 Panixine Disperdose (cephalexin tablets for oral...

CAPNS1 Regulates USP1 Stability and Maintenance of Genome Integrity

PubMed Central

Cataldo, Francesca; Peche, Leticia Y.; Klaric, Enio; Brancolini, Claudio; Myers, Michael P.

2013-01-01

Calpains regulate a wide spectrum of biological functions, including migration, adhesion, apoptosis, secretion, and autophagy, through the modulating cleavage of specific substrates. Ubiquitous microcalpain (μ-calpain) and millicalpain (m-calpain) are heterodimers composed of catalytic subunits encoded, respectively, by CAPN1 and CAPN2 and a regulatory subunit encoded by CAPNS1. Here we show that calpain is required for the stability of the deubiquitinating enzyme USP1 in several cell lines. USP1 modulates DNA replication polymerase choice and repair by deubiquitinating PCNA. The ubiquitinated form of the USP1 substrate PCNA is stabilized in CAPNS1-depleted U2OS cells and mouse embryonic fibroblasts (MEFs), favoring polymerase-η loading on chromatin and increased mutagenesis. USP1 degradation directed by the cell cycle regulator APC/Ccdh1, which marks USP1 for destruction in the G1 phase, is upregulated in CAPNS1-depleted cells. USP1 stability can be rescued upon forced expression of calpain-activated Cdk5/p25, previously reported as a cdh1 repressor. These data suggest that calpain stabilizes USP1 by activating Cdk5, which in turn inhibits cdh1 and, consequently, USP1 degradation. Altogether these findings point to a connection between the calpain system and the ubiquitin pathway in the regulation of DNA damage response and place calpain at the interface between cell cycle modulation and DNA repair. PMID:23589330

Tandem UIMs confer Lys48 ubiquitin chain substrate preference to deubiquitinase USP25

PubMed Central

Kawaguchi, Kohei; Uo, Kazune; Tanaka, Toshiaki; Komada, Masayuki

2017-01-01

Ubiquitin-specific protease (USP) 25, belonging to the USP family of deubiquitinases, harbors two tandem ubiquitin-interacting motifs (UIMs), a ~20-amino-acid α-helical stretch that binds to ubiquitin. However, the role of the UIMs in USP25 remains unclear. Here we show that the tandem UIM region binds to Lys48-, but not Lys63-, linked ubiquitin chains, where the two UIMs played a critical and cooperative role. Purified USP25 exhibited higher ubiquitin isopeptidase activity to Lys48-, than to Lys63-, linked ubiquitin chains. Mutations that disrupted the ubiquitin-binding ability of the tandem UIMs resulted in a reduced ubiquitin isopeptidase activity of USP25, suggesting a role for the UIMs in exerting the full catalytic activity of USP25. Moreover, when mutations that convert the binding preference from Lys48- to Lys63-linked ubiquitin chains were introduced into the tandem UIM region, the USP25 mutants acquired elevated and reduced isopeptidase activity toward Lys63- and Lys48-linked ubiquitin chains, respectively. These results suggested that the binding preference of the tandem UIMs toward Lys48-linked ubiquitin chains contributes not only to the full catalytic activity but also to the ubiquitin chain substrate preference of USP25, possibly by selectively holding the Lys48-linked ubiquitin chain substrates in the proximity of the catalytic core. PMID:28327663

The Advantages and Challenges of Unannounced Standardized Patients Methodology to Assess Healthcare Communication

PubMed Central

Siminoff, Laura A.; Rogers, Heather L.; Waller, Allison C.; Harris-Haywood, Sonja; Esptein, Ronald M.; Borrell Carrio, Francesc; Gliva-McConvey, Gayle; Longo, Daniel R.

2011-01-01

Objective This paper provides an overview of the implementation of using Unannounced Standardized Patients (USPs) to conduct health communication research in clinical settings. Methods Certain types of health communication situations are difficult to capture because of their rarity or unpredictable nature. In primary care the real reasons for a visit are frequently unknown until the consultation is well under way. Therefore, it is logistically difficult for communication studies to capture many real-time communications between patients and their physicians. Although the USP methodology is ideal for capturing these communication behaviors, challenges to using this method include developing collaborative relationships with clinical practices, logistical issues such as safeguarding the identity of the USP, training USPs and creating their identities, maintaining fidelity to the role, and analyzing the resultant data. Results This paper discusses the challenges and solutions to USP implementation. We provide an example of how to implement a USP study using an on-going study being conducted in primary care practices. Conclusion This paper explores the advantages and challenges as well as strategies to overcome obstacles to implementing a USP study. Practice Implications Despite the challenges, USP methodology can contribute much to our understanding of health communication and practice. PMID:21316182

The deubiquitination enzyme USP46 functions as a tumor suppressor by controlling PHLPP-dependent attenuation of Akt signaling in colon cancer

PubMed Central

Li, Xin; Stevens, Payton D.; Yang, Haihua; Gulhati, Pat; Wang, Wei; Evers, B. Mark; Gao, Tianyan

2012-01-01

PHLPP is a family of Ser/Thr protein phosphatases that serve as tumor suppressors by negatively regulating Akt. Our recent studies have demonstrated that the ubiquitin proteasome pathway plays an important role in the downregulation of PHLPP in colorectal cancer. In this study, we show that the deubiquitinase USP46 stabilizes the expression of both PHLPP isoforms by reducing the rate of PHLPP degradation. USP46 binds to PHLPP and directly removes the polyubiquitin chains from PHLPP in vitro and in cells. Increased USP46 expression correlates with decreased ubiquitination and upregulation of PHLPP proteins in colon cancer cells, whereas knockdown of USP46 has the opposite effect. Functionally, USP46-mediated stabilization of PHLPP and the subsequent inhibition of Akt result in a decrease in cell proliferation and tumorigenesis of colon cancer cells in vivo. Moreover, reduced USP46 protein level is found associated with poor PHLPP expression in colorectal cancer patient specimens. Taken together, these results indentify a tumor suppressor role of USP46 in promoting PHLPP expression and inhibiting Akt signaling in colon cancer. PMID:22391563

Molecular mechanism for USP7-mediated DNMT1 stabilization by acetylation

NASA Astrophysics Data System (ADS)

Cheng, Jingdong; Yang, Huirong; Fang, Jian; Ma, Lixiang; Gong, Rui; Wang, Ping; Li, Ze; Xu, Yanhui

2015-05-01

DNMT1 is an important epigenetic regulator that plays a key role in the maintenance of DNA methylation. Here we determined the crystal structure of DNMT1 in complex with USP7 at 2.9 Å resolution. The interaction between the two proteins is primarily mediated by an acidic pocket in USP7 and Lysine residues within DNMT1's KG linker. This intermolecular interaction is required for USP7-mediated stabilization of DNMT1. Acetylation of the KG linker Lysine residues impair DNMT1-USP7 interaction and promote the degradation of DNMT1. Treatment with HDAC inhibitors results in an increase in acetylated DNMT1 and decreased total DNMT1 protein. This negative correlation is observed in differentiated neuronal cells and pancreatic cancer cells. Our studies reveal that USP7-mediated stabilization of DNMT1 is regulated by acetylation and provide a structural basis for the design of inhibitors, targeting the DNMT1-USP7 interaction surface for therapeutic applications.

Developing a quality by design approach to model tablet dissolution testing: an industrial case study.

PubMed

Yekpe, Ketsia; Abatzoglou, Nicolas; Bataille, Bernard; Gosselin, Ryan; Sharkawi, Tahmer; Simard, Jean-Sébastien; Cournoyer, Antoine

2018-07-01

This study applied the concept of Quality by Design (QbD) to tablet dissolution. Its goal was to propose a quality control strategy to model dissolution testing of solid oral dose products according to International Conference on Harmonization guidelines. The methodology involved the following three steps: (1) a risk analysis to identify the material- and process-related parameters impacting the critical quality attributes of dissolution testing, (2) an experimental design to evaluate the influence of design factors (attributes and parameters selected by risk analysis) on dissolution testing, and (3) an investigation of the relationship between design factors and dissolution profiles. Results show that (a) in the case studied, the two parameters impacting dissolution kinetics are active pharmaceutical ingredient particle size distributions and tablet hardness and (b) these two parameters could be monitored with PAT tools to predict dissolution profiles. Moreover, based on the results obtained, modeling dissolution is possible. The practicality and effectiveness of the QbD approach were demonstrated through this industrial case study. Implementing such an approach systematically in industrial pharmaceutical production would reduce the need for tablet dissolution testing.

Ti:sapphire/KrF hybrid laser system generating trains of subterawatt subpicosecond UV pulses

NASA Astrophysics Data System (ADS)

Zvorykin, V. D.; Ionin, A. A.; Levchenko, A. O.; Mesyats, G. A.; Seleznev, L. V.; Sinitsyn, D. V.; Ustinovskii, N. N.; Shutov, A. V.

2014-05-01

The GARPUN-MTW Ti:sapphire/KrF hybrid laser system is used to investigate different multipass schemes for amplifying trains of ultrashort pulses (USPs) of subpicosecond duration. It is shown that, for an USP repetition period of 3 - 5 ns, which exceeds the gain-medium recovery time (~2 ns), trains are amplified in the same way as single USPs. Due to this, a train can efficiently extract pump energy from the amplifier and sum energies of individual USPs. The energy of a four-USP train, extracted during four passes through the preamplifier and two passes through the final KrF amplifier (4 + 2 scheme), is saturated at a level of 1.6 J and corresponds to maximum USP peak powers of about 0.6 TW. The energy of amplified spontaneous emission (ASE), on the contrary, rapidly increases at a large total gain length Leff ≈ 6 m and is approximately equal to the USP energy. In the (4 + 1) and (2 + 2) schemes the USP energy decreases only slightly, to Eout = 1.3 and 1.2 J, and the ASE fraction is reduced to about 10% and 3%, respectively. USP self-focusing leads to multiple laser beam filamentation and a 200-fold local increase in the radiation intensity in filaments, to ~2 × 1011 W cm-2, a level at which the nonlinear loss in the output CaF2 windows of the KrF amplifier, caused by three-photon absorption, nonlinear scattering, and broadening of the radiation spectrum to a value exceeding the gain band of the KrF laser transition, becomes the main factor determining the saturation of the USP output energy.

Ubiquitin-specific Protease 7 Regulates Nucleotide Excision Repair through Deubiquitinating XPC Protein and Preventing XPC Protein from Undergoing Ultraviolet Light-induced and VCP/p97 Protein-regulated Proteolysis*

PubMed Central

He, Jinshan; Zhu, Qianzheng; Wani, Gulzar; Sharma, Nidhi; Han, Chunhua; Qian, Jiang; Pentz, Kyle; Wang, Qi-en; Wani, Altaf A.

2014-01-01

Ubiquitin specific protease 7 (USP7) is a known deubiquitinating enzyme for tumor suppressor p53 and its downstream regulator, E3 ubiquitin ligase Mdm2. Here we report that USP7 regulates nucleotide excision repair (NER) via deubiquitinating xeroderma pigmentosum complementation group C (XPC) protein, a critical damage recognition factor that binds to helix-distorting DNA lesions and initiates NER. XPC is ubiquitinated during the early stage of NER of UV light-induced DNA lesions. We demonstrate that transiently compromising cellular USP7 by siRNA and chemical inhibition leads to accumulation of ubiquitinated forms of XPC, whereas complete USP7 deficiency leads to rapid ubiquitin-mediated XPC degradation upon UV irradiation. We show that USP7 physically interacts with XPC in vitro and in vivo. Overexpression of wild-type USP7, but not its catalytically inactive or interaction-defective mutants, reduces the ubiquitinated forms of XPC. Importantly, USP7 efficiently deubiquitinates XPC-ubiquitin conjugates in deubiquitination assays in vitro. We further show that valosin-containing protein (VCP)/p97 is involved in UV light-induced XPC degradation in USP7-deficient cells. VCP/p97 is readily recruited to DNA damage sites and colocalizes with XPC. Chemical inhibition of the activity of VCP/p97 ATPase causes an increase in ubiquitinated XPC on DNA-damaged chromatin. Moreover, USP7 deficiency severely impairs the repair of cyclobutane pyrimidine dimers and, to a lesser extent, affects the repair of 6-4 photoproducts. Taken together, our findings uncovered an important role of USP7 in regulating NER via deubiquitinating XPC and by preventing its VCP/p97-regulated proteolysis. PMID:25118285

Ecdysone receptor (EcR) and ultraspiracle (USP) genes from the cyclopoid copepod Paracyclopina nana: Identification and expression in response to water accommodated fractions (WAFs).

PubMed

Puthumana, Jayesh; Lee, Min-Chul; Han, Jeonghoon; Kim, Hui-Su; Hwang, Dae-Sik; Lee, Jae-Seong

2017-02-01

Ecdysteroid hormones are pivotal in the development, growth, and molting of arthropods, and the hormone pathway is triggered by binding ecdysteroid to a heterodimer of the two nuclear receptors; ecdysone receptors (EcR) and ultraspiracle (USP). We have characterized EcR and USP genes, and their 5'-untranslated region (5'-UTR) from the copepod Paracyclopina nana, and studied mRNA transcription levels in post-embryonic stages and in response to water accommodated fractions (WAFs) of crude oil. The open reading frames (ORF) of EcR and USP were 1470 and 1287bp that encoded 490 and 429 amino acids with molecular weight of 121.18 and 105.03kDa, respectively. Also, a well conserved DNA-binding domain (DBD) and ligand-binding domain (LBD) were identified which confirmed by phylogenetic analysis. Messenger RNA transcriptional levels of EcR and USP were developmental stage-specific in early post-embryonic stages (N3-4). However, an evoked expression of USP was observed throughout copepodid stage and in adult females. WAFs (40 and 80%) were acted as an ecdysone agonist in P. nana, and elicited the mRNA transcription levels in adults. Developmental stage-specific transcriptional activation of EcR and USP in response to WAFs was observed. USP gene was down-regulated in the nauplius in response to WAF, whereas up-regulation of USP was observed in the adults. This study represents the first data of molecular elucidation of EcR and USP genes and their regulatory elements from P. nana and the developmental stage specific expression in response to WAFs, which can be used as potential biomarkers for environmental stressors with ecotoxicological evaluations in copepods. Copyright © 2016 Elsevier Inc. All rights reserved.

The Gene of the Ubiquitin-Specific Protease 8 Is Frequently Mutated in Adenomas Causing Cushing's Disease.

PubMed

Perez-Rivas, Luis G; Theodoropoulou, Marily; Ferraù, Francesco; Nusser, Clara; Kawaguchi, Kohei; Stratakis, Constantine A; Faucz, Fabio Rueda; Wildemberg, Luiz E; Assié, Guillaume; Beschorner, Rudi; Dimopoulou, Christina; Buchfelder, Michael; Popovic, Vera; Berr, Christina M; Tóth, Miklós; Ardisasmita, Arif Ibrahim; Honegger, Jürgen; Bertherat, Jerôme; Gadelha, Monica R; Beuschlein, Felix; Stalla, Günter; Komada, Masayuki; Korbonits, Márta; Reincke, Martin

2015-07-01

We have recently reported somatic mutations in the ubiquitin-specific protease USP8 gene in a small series of adenomas of patients with Cushing's disease. To determine the prevalence of USP8 mutations and the genotype-phenotype correlation in a large series of patients diagnosed with Cushing's disease. We performed a retrospective, multicentric, genetic analysis of 134 functioning and 11 silent corticotroph adenomas using Sanger sequencing. Biochemical and clinical features were collected and examined within the context of the mutational status of USP8, and new mutations were characterized by functional studies. A total of 145 patients who underwent surgery for an ACTH-producing pituitary adenoma. Mutational status of USP8. Biochemical and clinical features included sex, age at diagnosis, tumor size, preoperative and postoperative hormonal levels, and comorbidities. We found somatic mutations in USP8 in 48 (36%) pituitary adenomas from patients with Cushing's disease but in none of 11 silent corticotropinomas. The prevalence was higher in adults than in pediatric cases (41 vs 17%) and in females than in males (43 vs 17%). Adults having USP8-mutated adenomas were diagnosed at an earlier age than those with wild-type lesions (36 vs 44 y). Mutations were primarily found in adenomas of 10 ± 7 mm and were inversely associated with the development of postoperative adrenal insufficiency. All the mutations affected the residues Ser718 or Pro720, including five new identified alterations. Mutations reduced the interaction between USP8 and 14-3-3 and enhanced USP8 activity. USP8 mutants diminished epidermal growth factor receptor ubiquitination and induced Pomc promoter activity in immortalized AtT-20 corticotropinoma cells. USP8 is frequently mutated in adenomas causing Cushing's disease, especially in those from female adult patients diagnosed at a younger age.

Acinetobacter baumannii universal stress protein A plays a pivotal role in stress response and is essential for pneumonia and sepsis pathogenesis.

PubMed

Elhosseiny, Noha M; Amin, Magdy A; Yassin, Aymen S; Attia, Ahmed S

2015-01-01

Acinetobacter baumannii is one of the most significant threats to global public health. This threat is compounded by the fact that A. baumannii is rapidly becoming resistant to all relevant antimicrobials. Identifying key microbial factors through which A. baumannii resists hostile host environment is paramount to the development of novel antimicrobials targeting infections caused by this emerging pathogen. An attractive target could be a molecule that plays a role in the pathogenesis and stress response of A. baumannii. Accordingly, the universal stress protein A (UspA) was chosen to be fully investigated in this study. A platform of A. baumannii constructs, expressing various levels of the uspA gene ranging from zero to thirteen folds of wild-type level, and a recombinant E. coli strain, were employed to investigate the role of UspA in vitro stress and in vivo pathogenesis. The UspA protein plays a significant role in protecting A. baumannii from H(2)O(2), low pH, and the respiratory toxin 2,4-DNP. A. baumannii UspA protein plays an essential role in two of the deadliest types of infection caused by A. baumannii; pneumonia and sepsis. This distinguishes A. baumannii UspA from its closely related homolog, the Staphylococcus aureus Usp2, as well as from the less similar Burkholderia glumae Usps. Heterologous and overexpression experiments suggest that UspA mediates its role via an indirect mechanism. Our study highlights the role of UspA as an important contributor to the A. baumannii stress and virulence machineries, and polishes it as a plausible target for new therapeutics. Copyright © 2014 Elsevier GmbH. All rights reserved.

A High-Throughput Screening Method for Identification of Inhibitors of the Deubiquitinating Enzyme USP14

PubMed Central

Lee, Byung-Hoon; Finley, Daniel; King, Randall W.

2013-01-01

Deubiquitinating enzymes (DUBs) reverse the process of ubiquitination, and number nearly 100 in humans. In principle, DUBs represent promising drug targets, as several of the enzymes have been implicated in human diseases. The isopeptidase activity of DUBs can be selectively inhibited by targeting the catalytic site with drug-like compounds. Notably, the mammalian 26S proteasome is associated with three major DUBs: RPN11, UCH37 and USP14. Because the ubiquitin ‘chain-trimming’ activity of USP14 can inhibit proteasome function, inhibitors of USP14 can stimulate proteasomal degradation. We recently established a high-throughput screening (HTS) method to discover small-molecule inhibitors specific for USP14. The protocols in this article cover the necessary procedures for preparing assay reagents, performing HTS for USP14 inhibitors, and carrying out post-HTS analysis. PMID:23788557

DUB3 and USP7 de-ubiquitinating enzymes control replication inhibitor Geminin: molecular characterization and associations with breast cancer.

PubMed

Hernández-Pérez, S; Cabrera, E; Salido, E; Lim, M; Reid, L; Lakhani, S R; Khanna, K K; Saunus, J M; Freire, R

2017-08-17

Correct control of DNA replication is crucial to maintain genomic stability in dividing cells. Inappropriate re-licensing of replicated origins is associated with chromosomal instability (CIN), a hallmark of cancer progression that at the same time provides potential opportunities for therapeutic intervention. Geminin is a critical inhibitor of the DNA replication licensing factor Cdt1. To properly achieve its functions, Geminin levels are tightly regulated through the cell cycle by ubiquitin-dependent proteasomal degradation, but the de-ubiquitinating enzymes (DUBs) involved had not been identified. Here we report that DUB3 and USP7 control human Geminin. Overexpression of either DUB3 or USP7 increases Geminin levels through reduced ubiquitination. Conversely, depletion of DUB3 or USP7 reduces Geminin levels, and DUB3 knockdown increases re-replication events, analogous to the effect of Geminin depletion. In exploring potential clinical implications, we found that USP7 and Geminin are strongly correlated in a cohort of invasive breast cancers (P<1.01E-08). As expected, Geminin expression is highly prognostic. Interestingly, we found a non-monotonic relationship between USP7 and breast cancer-specific survival, with both very low or high levels of USP7 associated with poor outcome, independent of estrogen receptor status. Altogether, our data identify DUB3 and USP7 as factors that regulate DNA replication by controlling Geminin protein stability, and suggest that USP7 may be involved in Geminin dysregulation during breast cancer progression.

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

3D printing of tablets containing multiple drugs with defined release profiles.

PubMed

Khaled, Shaban A; Burley, Jonathan C; Alexander, Morgan R; Yang, Jing; Roberts, Clive J

2015-10-30

We have employed three-dimensional (3D) extrusion-based printing as a medicine manufacturing technique for the production of multi-active tablets with well-defined and separate controlled release profiles for three different drugs. This 'polypill' made by a 3D additive manufacture technique demonstrates that complex medication regimes can be combined in a single tablet and that it is viable to formulate and 'dial up' this single tablet for the particular needs of an individual. The tablets used to illustrate this concept incorporate an osmotic pump with the drug captopril and sustained release compartments with the drugs nifedipine and glipizide. This combination of medicines could potentially be used to treat diabetics suffering from hypertension. The room temperature extrusion process used to print the formulations used excipients commonly employed in the pharmaceutical industry. Attenuated Total Reflectance Fourier Transform Infrared Spectroscopy (ATR-FTIR) and X-ray powder diffraction (XRPD) were used to assess drug-excipient interaction. The printed formulations were evaluated for drug release using USP dissolution testing. We found that the captopril portion showed the intended zero order drug release of an osmotic pump and noted that the nifedipine and glipizide portions showed either first order release or Korsmeyer-Peppas release kinetics dependent upon the active/excipient ratio used. Copyright © 2015. Published by Elsevier B.V.

Assessment of the pharmaceutical quality of marketed enteric coated pantoprazole sodium sesquihydrate products.

PubMed

Mostafa, Haitham F; Ibrahim, Mohamed A; Mahrous, Gamal M; Sakr, Adel

2011-04-01

Pantoprazole sodium sesquihydrate (PSS) is a proton pump inhibitor, used in acid-related disorders, like peptic ulcer and gastroesophageal reflux. Increasing the number of pantoprazole containing products in the market, raises questions of its efficacy and generic substitution. The pharmaceutical quality of 6 generic PSS enteric coated tablets in 2 local markets was assessed relative to the innovator product (pantozol®). Uniformity of dosage unit, disintegration and in vitro drug release were determined using United States pharmacopeia for delayed release tablets. The similarity factor (f2) was assessed using the FDA recommended approach (f2 similarity factor). The content uniformity of the innovator product was 98.39% of the labeled claim with RSD value of 1.08%, while the content of generic products ranged from 96.98% to 98.80% with RSD values of 1.24-2.19%. All the products showed no disintegration, cracks or swelling in 0.1 N HCl, except product 1, which showed complete disintegration after 20 min. However, the disintegration of all the products in phosphate buffer met USP requirements. Dissolution of tablets in 0.1 N HCl showed no drug release after 2 h except product 1 in which one tablet showed a drug release more than 10% at acid stage level A1. In addition, three tablets of this product showed dissolution of 45%, 48% and 69% at acid stage level A2. The similarity factor f2 of the products was between 71 and 74 indicating the similarity in dissolution profiles of all the products in accordance to FDA requirements, except product 1 in which f2 value was 18.67.

The deubiquitinating enzyme USP36 controls selective autophagy activation by ubiquitinated proteins.

PubMed

Taillebourg, Emmanuel; Gregoire, Isabel; Viargues, Perrine; Jacomin, Anne-Claire; Thevenon, Dominique; Faure, Mathias; Fauvarque, Marie-Odile

2012-05-01

Initially described as a nonspecific degradation process induced upon starvation, autophagy is now known also to be involved in the degradation of specific ubiquitinated substrates such as mitochondria, bacteria and aggregated proteins, ensuring crucial functions in cell physiology and immunity. We report here that the deubiquitinating enzyme USP36 controls selective autophagy activation in Drosophila and in human cells. We show that dUsp36 loss of function autonomously inhibits cell growth while activating autophagy. Despite the phenotypic similarity, dUSP36 is not part of the TOR signaling pathway. Autophagy induced by dUsp36 loss of function depends on p62/SQSTM1, an adaptor for delivering cargo marked by polyubiquitin to autophagosomes. Consistent with p62 requirement, dUsp36 mutant cells display nuclear aggregates of ubiquitinated proteins, including Histone H2B, and cytoplasmic ubiquitinated proteins; the latter are eliminated by autophagy. Importantly, USP36 function in p62-dependent selective autophagy is conserved in human cells. Our work identifies a novel, crucial role for a deubiquitinating enzyme in selective autophagy.

Ubiquitin specific protease 2 acts as a key modulator for the regulation of cell cycle by adiponectin and leptin in cancer cells.

PubMed

Nepal, Saroj; Shrestha, Anup; Park, Pil-Hoon

2015-09-05

Adiponectin and leptin, both produced from adipose tissue, cause cell cycle arrest and progression, respectively in cancer cells. Ubiquitin specific protease-2 (USP-2), a deubiquitinating enzyme, is known to impair proteasome-induced degradation of cyclin D1, a critical cell cycle regulator. Herein, we investigated the effects of these adipokines on USP-2 expression and its potential role in the modulation of cell cycle. Treatment with globular adiponectin (gAcrp) decreased, whereas leptin increased USP-2 expression both in human hepatoma and breast cancer cells. In addition, overexpression or gene silencing of USP-2 affected cyclin D1 expression and cell cycle progression/arrest by adipokines. Adiponectin and leptin also modulated in vitro proteasomal activity, which was partially dependent on USP-2 expression. Taken together, our results reveal that modulation of USP-2 expression plays a crucial role in cell cycle regulation by adipokines. Thus, USP-2 would be a promising therapeutic target for the modulation of cancer cell growth by adipokines. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

USP48 restrains resection by site-specific cleavage of the BRCA1 ubiquitin mark from H2A.

PubMed

Uckelmann, Michael; Densham, Ruth M; Baas, Roy; Winterwerp, Herrie H K; Fish, Alexander; Sixma, Titia K; Morris, Joanna R

2018-01-15

BRCA1-BARD1-catalyzed ubiquitination of histone H2A is an important regulator of the DNA damage response, priming chromatin for repair by homologous recombination. However, no specific deubiquitinating enzymes (DUBs) are known to antagonize this function. Here we identify ubiquitin specific protease-48 (USP48) as a H2A DUB, specific for the C-terminal BRCA1 ubiquitination site. Detailed biochemical analysis shows that an auxiliary ubiquitin, an additional ubiquitin that itself does not get cleaved, modulates USP48 activity, which has possible implications for its regulation in vivo. In cells we reveal that USP48 antagonizes BRCA1 E3 ligase function and in BRCA1-proficient cells loss of USP48 results in positioning 53BP1 further from the break site and in extended resection lengths. USP48 repression confers a survival benefit to cells treated with camptothecin and its activity acts to restrain gene conversion and mutagenic single-strand annealing. We propose that USP48 promotes genome stability by antagonizing BRCA1 E3 ligase function.

USP7 is a SUMO deubiquitinase essential for DNA replication.

PubMed

Lecona, Emilio; Rodriguez-Acebes, Sara; Specks, Julia; Lopez-Contreras, Andres J; Ruppen, Isabel; Murga, Matilde; Muñoz, Javier; Mendez, Juan; Fernandez-Capetillo, Oscar

2016-04-01

Post-translational modification of proteins by ubiquitin (Ub) and Ub-like modifiers regulates DNA replication. We have previously shown that chromatin around replisomes is rich in SUMO and poor in Ub, whereas mature chromatin exhibits an opposite pattern. How this SUMO-rich, Ub-poor environment is maintained at sites of DNA replication in mammalian cells remains unexplored. Here we identify USP7 as a replisome-enriched SUMO deubiquitinase that is essential for DNA replication. By acting on SUMO and SUMOylated proteins, USP7 counteracts their ubiquitination. Inhibition or genetic deletion of USP7 leads to the accumulation of Ub on SUMOylated proteins, which are displaced away from replisomes. Our findings provide a model explaining the differential accumulation of SUMO and Ub at replication forks and identify an essential role of USP7 in DNA replication that should be considered in the development of USP7 inhibitors as anticancer agents.

Dry powder inhalers: An overview of the in vitro dissolution methodologies and their correlation with the biopharmaceutical aspects of the drug products.

PubMed

Velaga, Sitaram P; Djuris, Jelena; Cvijic, Sandra; Rozou, Stavroula; Russo, Paola; Colombo, Gaia; Rossi, Alessandra

2018-02-15

In vitro dissolution testing is routinely used in the development of pharmaceutical products. Whilst the dissolution testing methods are well established and standardized for oral dosage forms, i.e. tablets and capsules, there are no pharmacopoeia methods or regulatory requirements for testing the dissolution of orally inhaled powders. Despite this, a wide variety of dissolution testing methods for orally inhaled powders has been developed and their bio-relevance has been evaluated. This review provides an overview of the in vitro dissolution methodologies for dry inhalation products, with particular emphasis on dry powder inhalers, where the dissolution behavior of the respirable particles can have a role on duration and absorption of the drug. Dissolution mechanisms of respirable particles as well as kinetic models have been presented. A more recent biorelevant dissolution set-ups and media for studying inhalation biopharmaceutics were also reviewed. In addition, factors affecting interplay between dissolution and absorption of deposited particles in the context of biopharmaceutical considerations of inhalation products were examined. Copyright © 2017 Elsevier B.V. All rights reserved.

Multicenter validation of the value of BASFI and BASDAI in Chinese ankylosing spondylitis and undifferentiated spondyloarthropathy patients

PubMed Central

Lin, Zhiming; He, Peigen; Gao, Jiesheng; Zuo, Xiaoxia; Ye, Zhizhong; Shao, Fengmin; Zhan, Feng; Lin, Jinying; Li, Li; Wei, Yanlin; Xu, Manlong; Liao, Zetao; Lin, Qu

2009-01-01

The objectives of this study were to evaluate the reliability of Bath ankylosing spondylitis functional index (BASFI) and Bath ankylosing spondylitis disease activity index (BASDAI) in Chinese ankylosing spondylitis (AS) and undifferentiated spondyloarthropathy (USpA) patients. 664 AS patients by the revised New York criteria for AS and 252 USpA patients by the European Spondyloarthropathy Study Group criteria were enrolled. BASDAI and BASFI questionnaires were translated into Chinese. Participants were required to fill in BASFI and BASDAI questionnaires again after 24 h. Moreover, BASDAI and BASFI were compared in AS patients receiving Enbrel or infliximab before and after treatment. For AS group, BASDAI ICC: 0.9502 (95% CI: 0.9330–0.9502, α = 0.9702), BASFI ICC: 0.9587 (95% CI: 0.9521–0.9645, α = 0.9789). For USpA group, BASDAI ICC: 0.9530 (95% CI: 0.9402–0.9632, α = 0.9760), BASFI ICC: 0.9900 (95% CI: 0.9871–0.9922, α = 0.9950). In the AS group, disease duration, occipital wall distance, modified Schober test, chest expansion, ESR, and CRP showed significant correlation with BASDAI and BASFI (all P < 0.01). In the USpA group, onset age, ESR, and CRP were significantly correlated with BASDAI (all P < 0.05), while modified Schober test, ESR, and CRP were significantly associated with BASFI (all P < 0.05). The change in BASDAI and BASFI via Enbrel or infliximab treatment showed a significant positive correlation (P < 0.01). The two instruments have good reliability and reference value regarding the evaluation of patient’s condition and anti-TNF-α treatment response. PMID:20012866

De-agglomeration Effect of the US Pharmacopeia and Alberta Throats on Carrier-Based Powders in Commercial Inhalation Products.

PubMed

Leung, Sharon Shui Yee; Tang, Patricia; Zhou, Qi Tony; Tong, Zhenbo; Leung, Cassandra; Decharaksa, Janwit; Yang, Runyu; Chan, Hak-Kim

2015-11-01

The US pharmacopeia (USP) and Alberta throats were recently reported to cause further de-agglomeration of carrier-free powders emitted from some dry powder inhalers (DPIs). This study assessed if they have similar influences on commercially available carrier-based DPIs. A straight tube, a USP throat, and an Alberta throat (non-coated and coated) were used for cascade impaction testing. Aerosol fine particle fraction (FPF ≤ 5 μm) was computed to evaluate throat-induced de-agglomeration. Computational fluid dynamics are employed to simulate airflow patterns and particle trajectories inside the USP and Alberta throats. For all tested products, no significant differences in the in vitro aerosol performance were observed between the USP throat and the straight tube. Using fine lactose carriers (<10 μm), Symbicort(®) and Oxis(™) showed minimal impaction inside the Alberta throat and resulted in similar FPF among all induction ports. For products using coarse lactose carriers (>10 μm), impaction frequency and energy inside the Alberta throat were significant. Further de-agglomeration was noted inside the non-coated Alberta throat for Seretide(®) and Spiriva(®), but agglomerates emitted from Relenza(®), Ventolin(®), and Foradil(®) did not further break up into smaller fractions. The coated Alberta throat considerably reduced the FPF values of these products due to the high throat retention, but they generally agreed better with the in vivo data. In conclusion, depending on the powder formulation (including carrier particle size), the inhaler, and the induction port, further de-agglomeration could happen ex-inhaler and create differences in the in vitro measurements.

TDEM survey in urban environmental for hydrogeological study at USP campus in São Paulo city, Brazil

NASA Astrophysics Data System (ADS)

Porsani, Jorge Luís; Bortolozo, Cassiano Antonio; Almeida, Emerson Rodrigo; Sobrinho, Esther Novais Santos; Santos, Thiago Gomes dos

2012-01-01

In this work, some TDEM (Time Domain Electromagnetic) results at USP ( University of São Paulo) campus in São Paulo city, Brazil, are presented. The data were acquired focusing on two mains objectives: (i) to map geoelectrical stratigraphy of São Paulo sedimentary basin, emphasizing on hydrogeological studies about sedimentary and crystalline aquifers, and (ii) to analyze the viability of TDEM data acquisition use in urban environment. The study area is located in São Paulo basin border, characterized by Resende and São Paulo formations, which are constituted by sand-clays sediments over a granite-gneissic basement. Two equipments were used in order to acquire database: Protem47 (low power), and Protem57-MK2 (high power). Capacitive noise affect obtained data with Protem47 due to the presence of metal pipes buried at IAG/USP (Institute of Astronomy, Geophysics, and Atmospheric Science) test site at USP. On the other hand, capacitive noise did not affect acquired data with Protem57-MK2, and the data present high signal to noise ratio. Surveys helped in determining sedimentary and crystalline aquifers, characterized by a fracture zone with water inside basin basement (conductive zone). Results show good agreement with local geology obtained from lithological boreholes located in the study areas. Moreover, it shows that TDEM method can be used in urban environments with a countless potential in hydrogeological studies, offering great reliability. Studies showed that main TDEM-method limitation at USP was the lack of space for opening the transmitter loop. Results are very promising and open new perspectives for TDEM-method use in urban environments as this area remains unexplored.

Measurements of donor endothelial keratoplasty lenticules prepared from fresh donated whole eyes by using ultrasound and optical coherence tomography.

PubMed

Kanavi, Mozhgan Rezaei; Nemati, Farzan; Chamani, Tahereh; Kheiri, Bahar; Javadi, Mohammad Ali

2017-03-01

This study was conducted to analyze the profile and thickness of endothelial keratoplasty lenticules prepared from fresh donated whole eyes with Visante optical coherence tomography (V-OCT) compared to measurements obtained from ultrasound pachymetry (USP) at the Central Eye Bank of Iran. Microkeratome-assisted precut corneas were prepared for Descemet stripping automated endothelial keratoplasty by using standard eye bank protocol. Central posterior lenticule thickness (CPLT) on fresh whole eye, before excising corneoscleral disc and transferring to Optisol-GS, was measured by USP. V-OCT was used to measure central, paracentral, and midperipheral thicknesses of lenticules after transferring the tissue to Optisol-GS. Chi Square and Bonferroni tests were respectively used to uncover the differences between the USP and V-OCT measurements and also the thickness profile of lenticules. Postoperative reports for the entire transplanted lenticules were recorded. Accordingly, on evaluation of 312 enrolled precut corneas, CPLT measurements by V-OCT versus USP were statistically different (mean: 136 µm vs 165 µm, respectively; P = 0.008). Thickness profile of the posterior lenticules revealed increased thickness from the central to the peripheral parts of the cornea (mean increase of 16 µm at the pericentral and 64.2 µm at the peripheral locations, respectively); however, the increase in the thickness was relatively symmetrical. Postoperative reports of transplanted lenticules were unremarkable, since there were no posterior flap detachments. In essence, V-OCT measurements of microkeratome-assisted precut lenticules prepared from fresh donated whole eyes averaged 29 μm thinner than USP measurements and revealed a significant but symmetric increase of thickness towards the peripheral parts of the corneas. However, the variation in the thickness profile did not affect the attachment or the clarity of transplanted precut lenticlues.

Evaluation of physical and chemical changes in pharmaceuticals flown on space missions.

PubMed

Du, Brian; Daniels, Vernie R; Vaksman, Zalman; Boyd, Jason L; Crady, Camille; Putcha, Lakshmi

2011-06-01

Efficacy and safety of medications used for the treatment of astronauts in space may be compromised by altered stability in space. We compared physical and chemical changes with time in 35 formulations contained in identical pharmaceutical kits stowed on the International Space Station (ISS) and on Earth. Active pharmaceutical content (API) was determined by ultra- and high-performance liquid chromatography after returning to Earth. After stowage for 28 months in space, six medications aboard the ISS and two of matching ground controls exhibited changes in physical variables; nine medications from the ISS and 17 from the ground met the United States Pharmacopeia (USP) acceptance criteria for API content after 28 months of storage. A higher percentage of medications from each flight kit had lower API content than the respective ground controls. The number of medications failing API requirement increased as a function of time in space, independent of expiration date. The rate of degradation was faster in space than on the ground for many of the medications, and most solid dosage forms met USP standard for dissolution after storage in space. Cumulative radiation dose was higher and increased with time in space, whereas temperature and humidity remained similar to those on the ground. Exposure to the chronic low dose of ionizing radiation aboard the spacecraft as well as repackaging of solid dosage forms in flight-specific dispensers may adversely affect stability of pharmaceuticals. Characterization of degradation profiles of unstable formulations and identification of chemical attributes of stability in space analog environments on Earth will facilitate development of space-hardy medications.

Validation of laboratory-scale recycling test method of paper PSA label products

Treesearch

Carl Houtman; Karen Scallon; Richard Oldack

2008-01-01

Starting with test methods and a specification developed by the U.S. Postal Service (USPS) Environmentally Benign Pressure Sensitive Adhesive Postage Stamp Program, a laboratory-scale test method and a specification were developed and validated for pressure-sensitive adhesive labels, By comparing results from this new test method and pilot-scale tests, which have been...

Disintegration of highly soluble immediate release tablets: a surrogate for dissolution.

PubMed

Gupta, Abhay; Hunt, Robert L; Shah, Rakhi B; Sayeed, Vilayat A; Khan, Mansoor A

2009-01-01

The purpose of the work was to investigate correlation between disintegration and dissolution for immediate release tablets containing a high solubility drug and to identify formulations where disintegration test, instead of the dissolution test, may be used as the acceptance criteria based on International Conference on Harmonization Q6A guidelines. A statistical design of experiments was used to study the effect of filler, binder, disintegrating agent, and tablet hardness on the disintegration and dissolution of verapamil hydrochloride tablets. All formulation variables, i.e., filler, binder, and disintegrating agent, were found to influence tablet dissolution and disintegration, with the filler and disintegrating agent exerting the most significant influence. Slower dissolution was observed with increasing disintegration time when either the filler or the disintegrating agent was kept constant. However, no direct corelationship was observed between the disintegration and dissolution across all formulations due to the interactions between different formulation components. Although all tablets containing sodium carboxymethyl cellulose as the disintegrating agent, disintegrated in less than 3 min, half of them failed to meet the US Pharmacopeia 30 dissolution criteria for the verapamil hydrochloride tablets highlighting the dependence of dissolution process on the formulation components other than the disintegrating agent. The results identified only one formulation as suitable for using the disintegration test, instead of the dissolution test, as drug product acceptance criteria and highlight the need for systematic studies before using the disintegration test, instead of the dissolution test as the drug acceptance criteria.

Proteasome-associated deubiquitinase ubiquitin-specific protease 14 regulates prostate cancer proliferation by deubiquitinating and stabilizing androgen receptor.

PubMed

Liao, Yuning; Liu, Ningning; Hua, Xianliang; Cai, Jianyu; Xia, Xiaohong; Wang, Xuejun; Huang, Hongbiao; Liu, Jinbao

2017-02-02

Androgen receptor (AR) is frequently over-expressed and plays a critical role in the growth and progression of human prostate cancer. The therapy attempting to target AR signalling was established in decades ago but the treatment of prostate cancer is far from being satisfactory. The assignable cause is that our understanding of the mechanism of AR regulation and re-activation remains incomplete. Increasing evidence suggests that deubiquitinases are involved in the regulation of cancer development and progression but the specific underlying mechanism often is not elucidated. In the current study, we have identified ubiquitin-specific protease 14 (USP14) as a novel regulator of AR, inhibiting the degradation of AR via deubiquitinating this oncoprotein in the androgen-responsive prostate cancer cells. We found that (i) USP14 could bind to AR, and additionally, both genetic and pharmacological inhibition of USP14 accelerated the ubiquitination and degradation of AR; (ii) downregulation or inhibition of USP14 suppressed cell proliferation and colony formation of LNcap cells and, conversely, overexpression of USP14 promoted the proliferation; and (iii) reduction or inhibition of USP14 induced G0/G1 phase arrest in LNcap prostate cancer cells. Hence, we conclude that USP14 promotes prostate cancer progression likely through stabilization of AR, suggesting that USP14 could be a promising therapeutic target for prostate cancer.

Physical stability of 20% lipid injectable emulsions via simulated syringe infusion: effects of glass vs plastic product packaging.

PubMed

Driscoll, David F; Ling, Pei-Ra; Bistrian, Bruce R

2007-01-01

The United States Pharmacopeia (USP) has proposed large-globule-size limits to ensure the physical stability of lipid injectable emulsions, expressed as the percent fat >5 microm, or PFAT(5), not exceeding 0.05%. Visibly obvious phase separation as free oil has been shown to occur in some samples if PFAT(5) is >0.4%. We recently found that lipids, newly packaged in plastic (P), exceed the proposed USP limits and seem to produce less stable total nutrient admixtures compared with those made from conventional glass (G), which do meet proposed USP standards. We tested the possible stability differences between 20% lipid injectable emulsions in either P or G in a simulated neonatal syringe infusion study. Eighteen individual syringes were prepared from each 20% lipid injectable emulsion product (n = 36) and attached to a syringe pump set at an infusion rate of 0.5 mL/hour. The starting PFAT(5) levels were measured at time 0 and after 24 hours of infusion, using a laser-based light obscuration technique as described by the USP Chapter <729>. The data were assessed by a 2-way analysis of variance (ANOVA) with Container (G vs P) and Time as the independent variables and PFAT as the dependent variable. At time 0, the starting PFAT(5) level for lipids packaged in G was 0.006% +/- 0.001% vs 0.162% +/- 0.026% for P, whereas at the end of the infusion they were 0.013% +/- 0.003% and 0.328% +/- 0.046%, respectively. Significant differences were noted overall between groups for Container, Time, and Container-Time interaction (all p < .001). Bonferroni tests showed significant differences in PFAT(5) levels between Containers at time 0 (T-0; p < .001) and T-0 vs T-24 for P-based lipids (p < .001), whereas no such differences were noted for Time for the G-based lipids. Similar results were noted for PFAT(10) levels. We confirm that presently available lipid injectable emulsions packaged in newly introduced plastic containers exceed the proposed USP <729> PFAT(5) limits and subsequently become significantly less stable during a simulated syringe-based infusion. Although modest growth (p = NS) in large-diameter fat globules was observed for the glass-based lipids, they remained within proposed USP globule size limits throughout the study. Glass-based lipids seem to be a more stable dosage form and potentially a safer way to deliver lipids via syringe infusion to critically ill neonates.

27 CFR 21.51 - Formula No. 25-A.

Code of Federal Regulations, 2010 CFR

2010-04-01

... solution composed of 20 pounds of iodine, U.S.P.; 15 pounds of either potassium iodide, U.S.P., or sodium iodide, U.S.P.; and 15 pounds of water. (b) Authorized uses. (1) As a solvent: 230.Tinctures of iodine...

The Gene of the Ubiquitin-Specific Protease 8 Is Frequently Mutated in Adenomas Causing Cushing's Disease

PubMed Central

Perez-Rivas, Luis G.; Theodoropoulou, Marily; Ferraù, Francesco; Nusser, Clara; Kawaguchi, Kohei; Stratakis, Constantine A.; Faucz, Fabio Rueda; Wildemberg, Luiz E.; Assié, Guillaume; Beschorner, Rudi; Dimopoulou, Christina; Buchfelder, Michael; Popovic, Vera; Berr, Christina M.; Tóth, Miklós; Ardisasmita, Arif Ibrahim; Honegger, Jürgen; Bertherat, Jerôme; Gadelha, Monica R.; Beuschlein, Felix; Stalla, Günter; Komada, Masayuki; Korbonits, Márta

2015-01-01

Context: We have recently reported somatic mutations in the ubiquitin-specific protease USP8 gene in a small series of adenomas of patients with Cushing's disease. Objective: To determine the prevalence of USP8 mutations and the genotype-phenotype correlation in a large series of patients diagnosed with Cushing's disease. Design: We performed a retrospective, multicentric, genetic analysis of 134 functioning and 11 silent corticotroph adenomas using Sanger sequencing. Biochemical and clinical features were collected and examined within the context of the mutational status of USP8, and new mutations were characterized by functional studies. Patients: A total of 145 patients who underwent surgery for an ACTH-producing pituitary adenoma. Main Outcomes Measures: Mutational status of USP8. Biochemical and clinical features included sex, age at diagnosis, tumor size, preoperative and postoperative hormonal levels, and comorbidities. Results: We found somatic mutations in USP8 in 48 (36%) pituitary adenomas from patients with Cushing's disease but in none of 11 silent corticotropinomas. The prevalence was higher in adults than in pediatric cases (41 vs 17%) and in females than in males (43 vs 17%). Adults having USP8-mutated adenomas were diagnosed at an earlier age than those with wild-type lesions (36 vs 44 y). Mutations were primarily found in adenomas of 10 ± 7 mm and were inversely associated with the development of postoperative adrenal insufficiency. All the mutations affected the residues Ser718 or Pro720, including five new identified alterations. Mutations reduced the interaction between USP8 and 14-3-3 and enhanced USP8 activity. USP8 mutants diminished epidermal growth factor receptor ubiquitination and induced Pomc promoter activity in immortalized AtT-20 corticotropinoma cells. Conclusions: USP8 is frequently mutated in adenomas causing Cushing's disease, especially in those from female adult patients diagnosed at a younger age. PMID:25942478

miR-132 suppresses the migration and invasion of lung cancer cells by blocking USP9X-induced epithelial-mesenchymal transition

PubMed Central

Guo, Huihui; Zhang, Xilin; Chen, Qiuqiang; Bao, Ying; Dong, Chaohui; Wang, Xiang

2018-01-01

miR-132, a microRNA, has been reported to be down-regulated in several human cancers and is related with tumor progression; however, its function in non-small cell lung cancer (NSCLC) progression remains unclear. This study aimed to investigate the putative role of miR-132 in the metastasis of NSCLC. We determined the function of miR-132 in the migration and invasion of a NSCLC cell line in vitro using a miR-132 inhibitor and mimic. Our results showed overexpression of miR-132 significantly inhibited the migration and invasion of NSCLC cells in vitro. We then identified USP9X as a potential target of miR-132, and demonstrated miR-132 could regulate the expression of USP9X at both the mRNA and protein level. miR-132 could directly bind to the 3’ untranslated region (3’-UTR) of USP9X. Inhibition of USP9X by its inhibitor WP1130 reduced the migration and invasion of NSCLC cells. Furthermore, USP9X inhibition also reversed the increased migration and invasion mediated by miR-132 inhibition. We found USP9X inhibition up-regulated expression of the epithelial-mesenchymal transition (EMT) marker E-cadherin, but down-regulated vimentin expression. A similar effect was seen with miR-132 overexpression, while the opposite effect occurred with miR-132 knockdown. USP9X inhibition reversed the miR-132 inhibitor-induced vimentin up-regulation and E-cadherin down-regulation. Taken together, these results indicate miR-132 prohibits the migration and invasion of NSCLC cells via targeting USP9X-induced EMT. Our data provides further evidence for the critical role of miR-132 and USP9X in regulating cell invasion and migration of NSCLC. PMID:29423007

miR-132 suppresses the migration and invasion of lung cancer cells by blocking USP9X-induced epithelial-mesenchymal transition.

PubMed

Guo, Huihui; Zhang, Xilin; Chen, Qiuqiang; Bao, Ying; Dong, Chaohui; Wang, Xiang

2018-01-01

miR-132, a microRNA, has been reported to be down-regulated in several human cancers and is related with tumor progression; however, its function in non-small cell lung cancer (NSCLC) progression remains unclear. This study aimed to investigate the putative role of miR-132 in the metastasis of NSCLC. We determined the function of miR-132 in the migration and invasion of a NSCLC cell line in vitro using a miR-132 inhibitor and mimic. Our results showed overexpression of miR-132 significantly inhibited the migration and invasion of NSCLC cells in vitro . We then identified USP9X as a potential target of miR-132, and demonstrated miR-132 could regulate the expression of USP9X at both the mRNA and protein level. miR-132 could directly bind to the 3' untranslated region (3'-UTR) of USP9X. Inhibition of USP9X by its inhibitor WP1130 reduced the migration and invasion of NSCLC cells. Furthermore, USP9X inhibition also reversed the increased migration and invasion mediated by miR-132 inhibition. We found USP9X inhibition up-regulated expression of the epithelial-mesenchymal transition (EMT) marker E-cadherin, but down-regulated vimentin expression. A similar effect was seen with miR-132 overexpression, while the opposite effect occurred with miR-132 knockdown. USP9X inhibition reversed the miR-132 inhibitor-induced vimentin up-regulation and E-cadherin down-regulation. Taken together, these results indicate miR-132 prohibits the migration and invasion of NSCLC cells via targeting USP9X-induced EMT. Our data provides further evidence for the critical role of miR-132 and USP9X in regulating cell invasion and migration of NSCLC.

Biosynthesis of nucleotide sugars by a promiscuous UDP-sugar pyrophosphorylase from Arabidopsis thaliana (AtUSP).

PubMed

Liu, Jun; Zou, Yang; Guan, Wanyi; Zhai, Yafei; Xue, Mengyang; Jin, Lan; Zhao, Xueer; Dong, Junkai; Wang, Wenjun; Shen, Jie; Wang, Peng George; Chen, Min

2013-07-01

Nucleotide sugars are activated forms of monosaccharides and key intermediates of carbohydrate metabolism in all organisms. The availability of structurally diverse nucleotide sugars is particularly important for the characterization of glycosyltransferases. Given that limited methods are available for preparation of nucleotide sugars, especially their useful non-natural derivatives, we introduced herein an efficient one-step three-enzyme catalytic system for the synthesis of nucleotide sugars from monosaccharides. In this study, a promiscuous UDP-sugar pyrophosphorylase (USP) from Arabidopsis thaliana (AtUSP) was used with a galactokinase from Streptococcus pneumoniae TIGR4 (SpGalK) and an inorganic pyrophosphatase (PPase) to effectively synthesize four UDP-sugars. AtUSP has better tolerance for C4-derivatives of Gal-1-P compared to UDP-glucose pyrophosphorylase from S. pneumoniae TIGR4 (SpGalU). Besides, the nucleotide substrate specificity and kinetic parameters of AtUSP were systematically studied. AtUSP exhibited considerable activity toward UTP, dUTP and dTTP, the yield of which was 87%, 85% and 84%, respectively. These results provide abundant information for better understanding of the relationship between substrate specificity and structural features of AtUSP. Copyright © 2013 Elsevier Ltd. All rights reserved.

USP1 regulates AKT phosphorylation by modulating the stability of PHLPP1 in lung cancer cells.

PubMed

Zhiqiang, Zhang; Qinghui, Yang; Yongqiang, Zhang; Jian, Zhang; Xin, Zhao; Haiying, Ma; Yuepeng, Guo

2012-07-01

Hyperactivation of phosphatidylinositol 3-kinase/Akt signaling is commonly associated with human tumors including lung cancers. PH domain leucine-rich repeat protein phosphatase 1 (PHLPP1), which terminates Akt signaling by directly dephosphorylating and inactivating Akt, has been identified as a tumor suppressor. The protein level of PHLPP1 is regulated by E3 ligase beta-TRCP, however, the deubiquitinase for PHLPP1 is still not known. The mRNA levels of USP1 and PHLPP1 in lung cancer cells and tissues were determined by real-time PCR. The half-life of PHLPP1 was detected by CHX assay. The interaction between USP1 and PHLPP1 was examined by immunoprecipitation and GST pull-down assay. Both USP1 and PHLPP1 are low expressed in lung cancer cells and tissues and silencing of USP1 by RNA interference significantly decreased the half-life of PHLPP1, which in turn amplified Akt1 phosphorylation. Our data identified a novel USP1-PHLPP1-Akt signaling axis, and decreased USP1 level in lung cancer cells may play an important role in lung cancer progress.

The USP1-UAF1 complex interacts with RAD51AP1 to promote homologous recombination repair.

PubMed

Cukras, Scott; Lee, Euiho; Palumbo, Emily; Benavidez, Pamela; Moldovan, George-Lucian; Kee, Younghoon

2016-10-01

USP1 deubiquitinating enzyme and its stoichiometric binding partner UAF1 play an essential role in promoting DNA homologous recombination (HR) repair in response to various types of DNA damaging agents. Deubiquitination of FANCD2 may be attributed to the key role of USP1-UAF1 complex in regulating HR repair, however whether USP1-UAF1 promotes HR repair independently of FANCD2 deubiquitination is not known. Here we show evidence that the USP1-UAF1 complex has a FANCD2-independent function in promoting HR repair. Proteomic search of UAF1-interacting proteins revealed that UAF1 associates with RAD51AP1, a RAD51-interacting protein implicated in HR repair. We show that UAF1 mediates the interaction between USP1 and RAD51AP1, and that depletion of USP1 or UAF1 led to a decreased stability of RAD51AP1. Protein interaction mapping analysis identified some key residues within RAD51AP1 required for interacting with the USP1-UAF1 complex. Cells expressing the UAF1 interaction-deficient mutant of RAD51AP1 show increased chromosomal aberrations in response to Mitomycin C treatment. Moreover, similar to the RAD51AP1 depleted cells, the cells expressing UAF1-interaction deficient RAD51AP1 display persistent RAD51 foci following DNA damage exposure, indicating that these factors regulate a later step during the HR repair. These data altogether suggest that the USP1-UAF1 complex promotes HR repair via multiple mechanisms: through FANCD2 deubiquitination, as well as by interacting with RAD51AP1.

The USP1-UAF1 complex interacts with RAD51AP1 to promote homologous recombination repair

PubMed Central

Cukras, Scott; Lee, Euiho; Palumbo, Emily; Benavidez, Pamela; Moldovan, George-Lucian; Kee, Younghoon

2016-01-01

ABSTRACT USP1 deubiquitinating enzyme and its stoichiometric binding partner UAF1 play an essential role in promoting DNA homologous recombination (HR) repair in response to various types of DNA damaging agents. Deubiquitination of FANCD2 may be attributed to the key role of USP1-UAF1 complex in regulating HR repair, however whether USP1-UAF1 promotes HR repair independently of FANCD2 deubiquitination is not known. Here we show evidence that the USP1-UAF1 complex has a FANCD2-independent function in promoting HR repair. Proteomic search of UAF1-interacting proteins revealed that UAF1 associates with RAD51AP1, a RAD51-interacting protein implicated in HR repair. We show that UAF1 mediates the interaction between USP1 and RAD51AP1, and that depletion of USP1 or UAF1 led to a decreased stability of RAD51AP1. Protein interaction mapping analysis identified some key residues within RAD51AP1 required for interacting with the USP1-UAF1 complex. Cells expressing the UAF1 interaction-deficient mutant of RAD51AP1 show increased chromosomal aberrations in response to Mitomycin C treatment. Moreover, similar to the RAD51AP1 depleted cells, the cells expressing UAF1-interaction deficient RAD51AP1 display persistent RAD51 foci following DNA damage exposure, indicating that these factors regulate a later step during the HR repair. These data altogether suggest that the USP1-UAF1 complex promotes HR repair via multiple mechanisms: through FANCD2 deubiquitination, as well as by interacting with RAD51AP1. PMID:27463890

USP15 regulates type I interferon response and is required for pathogenesis of neuroinflammation.

PubMed

Torre, Sabrina; Polyak, Maria J; Langlais, David; Fodil, Nassima; Kennedy, James M; Radovanovic, Irena; Berghout, Joanne; Leiva-Torres, Gabriel A; Krawczyk, Connie M; Ilangumaran, Subburaj; Mossman, Karen; Liang, Chen; Knobeloch, Klaus-Peter; Healy, Luke M; Antel, Jack; Arbour, Nathalie; Prat, Alexandre; Majewski, Jacek; Lathrop, Mark; Vidal, Silvia M; Gros, Philippe

2017-01-01

Genes and pathways in which inactivation dampens tissue inflammation present new opportunities for understanding the pathogenesis of common human inflammatory diseases, including inflammatory bowel disease, rheumatoid arthritis and multiple sclerosis. We identified a mutation in the gene encoding the deubiquitination enzyme USP15 (Usp15 L749R ) that protected mice against both experimental cerebral malaria (ECM) induced by Plasmodium berghei and experimental autoimmune encephalomyelitis (EAE). Combining immunophenotyping and RNA sequencing in brain (ECM) and spinal cord (EAE) revealed that Usp15 L749R -associated resistance to neuroinflammation was linked to dampened type I interferon responses in situ. In hematopoietic cells and in resident brain cells, USP15 was coexpressed with, and functionally acted together with the E3 ubiquitin ligase TRIM25 to positively regulate type I interferon responses and to promote pathogenesis during neuroinflammation. The USP15-TRIM25 dyad might be a potential target for intervention in acute or chronic states of neuroinflammation.

USP15 regulates dynamic protein–protein interactions of the spliceosome through deubiquitination of PRP31

PubMed Central

Das, Tanuza; Park, Joon Kyu; Park, Jinyoung; Kim, Eunji; Rape, Michael

2017-01-01

Abstract Post-translational modifications contribute to the spliceosome dynamics by facilitating the physical rearrangements of the spliceosome. Here, we report USP15, a deubiquitinating enzyme, as a regulator of protein–protein interactions for the spliceosome dynamics. We show that PRP31, a component of U4 snRNP, is modified with K63-linked ubiquitin chains by the PRP19 complex and deubiquitinated by USP15 and its substrate targeting factor SART3. USP15SART3 makes a complex with USP4 and this ternary complex serves as a platform to deubiquitinate PRP31 and PRP3. The ubiquitination and deubiquitination status of PRP31 regulates its interaction with the U5 snRNP component PRP8, which is required for the efficient splicing of chromosome segregation related genes, probably by stabilizing the U4/U6.U5 tri-snRNP complex. Collectively, our data suggest that USP15 plays a key role in the regulation of dynamic protein–protein interactions of the spliceosome. PMID:28088760

USP7 is a SUMO deubiquitinase essential for DNA replication

PubMed Central

Lecona, Emilio; Rodriguez-Acebes, Sara; Specks, Julia; Lopez-Contreras, Andres J; Ruppen, Isabel; Murga, Matilde; Muñoz, Javier; Mendez, Juan; Fernandez-Capetillo, Oscar

2016-01-01

Post-translational modification of proteins by ubiquitin (Ub) and Ub-like modifiers regulates various aspects of DNA replication. We previously showed that the chromatin around replisomes is rich in SUMO and depleted in Ub, whereas an opposite pattern is observed in mature chromatin. How this SUMO-rich/Ub-low environment is maintained at sites of DNA replication is not known. Here we identify USP7 as a replisome-enriched SUMO deubiquitinase that is essential for DNA replication. By acting on SUMO and SUMOylated proteins, USP7 counteracts their ubiquitination. Chemical inhibition or genetic deletion of USP7 leads to the accumulation of Ub on SUMOylated proteins, which are displaced to chromatin away from replisomes. Our findings provide a model to explain the differential accumulation of SUMO and Ub at replication forks, and identify an essential role of USP7 in DNA replication that should be taken into account for the use of USP7 inhibitors as anticancer agents. PMID:26950370

USP19-Mediated Deubiquitination Facilitates the Stabilization of HRD1 Ubiquitin Ligase.

PubMed

Harada, Kumi; Kato, Masako; Nakamura, Nobuhiro

2016-11-02

In the endoplasmic reticulum (ER), misfolded and unfolded proteins are eliminated by a process called ER-associated protein degradation (ERAD) in order to maintain cell homeostasis. In the ERAD pathway, several ER-localized E3 ubiquitin ligases target ERAD substrate proteins for ubiquitination and subsequent proteasomal degradation. However, little is known about how the functions of the ERAD ubiquitin ligases are regulated. Recently, USP19, an ER-anchored deubiquitinating enzyme (DUB), has been suggested to be involved in the regulation of ERAD. In this study, HRD1, an ERAD ubiquitin ligase, is shown to be a novel substrate for USP19. We demonstrate that USP19 rescues HRD1 from proteasomal degradation by deubiquitination of K48-linked ubiquitin chains. In addition, the altered expression of USP19 affects the steady-state levels of HRD1. These results suggest that USP19 regulates the stability of HRD1 and provide insight into the regulatory mechanism of the ERAD ubiquitin ligases.

In Vitro Evaluation of the Size, Knot Holding Capacity, and Knot Security of the Forwarder Knot Compared to Square and Surgeon's Knots Using Large Gauge Suture.

PubMed

Gillen, Alex M; Munsterman, Amelia S; Hanson, R Reid

2016-11-01

To investigate the strength, size, and holding capacity of the self-locking forwarder knot compared to surgeon's and square knots using large gauge suture. In vitro mechanical study. Knotted suture. Forwarder, surgeon's, and square knots were tested on a universal testing machine under linear tension using 2 and 3 USP polyglactin 910 and 2 USP polydioxanone. Knot holding capacity (KHC) and mode of failure were recorded and relative knot security (RKS) was calculated as a percentage of KHC. Knot volume and weight were assessed by digital micrometer and balance, respectively. ANOVA and post hoc testing were used tocompare strength between number of throws, suture, suture size, and knot type. P<.05 was considered significant. Forwarder knots had a higher KHC and RKS than surgeon's or square knots for all suture types and number of throws. No forwarder knots unraveled, but a proportion of square and surgeon's knots with <6 throws did unravel. Forwarder knots had a smaller volume and weight than surgeon's and square knots with equal number of throws. The forwarder knot of 4 throws using 3 USP polyglactin 910 had the highest KHC, RKS, and the smallest size and weight. Forwarder knots may be an alternative for commencing continuous patterns in large gauge suture, without sacrificing knot integrity, but further in vivo and ex vivo testing is required to assess the effects of this sliding knot on tissue perfusion before clinical application. © Copyright 2016 by The American College of Veterinary Surgeons.

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

Zhang, Wei; Sartori, Maria A.; Makhnevych, Taras

Post-translational modification of the p53 signaling pathway plays an important role in cell cycle progression and stress-induced apoptosis. Indeed, a large body of work has shown that dysregulation of p53 and its E3 ligase MDM2 by the ubiquitin-proteasome system (UPS) promotes carcinogenesis and malignant transformation. Thus, drug discovery efforts have focused on the restoration of wild-type p53 activity or inactivation of oncogenic mutant p53 by targeted inhibition of UPS components, particularly key deubiquitinases (DUBs) of the ubiquitin-specific protease (USP) class. However, development of selective small-molecule USP inhibitors has been challenging, partly due to the highly conserved structural features of themore » catalytic sites across the class. To tackle this problem, we devised a protein engineering strategy for rational design of inhibitors for DUBs and other UPS proteins. We employed a phage-displayed ubiquitin variant (UbV) library to develop inhibitors targeting the DUBs USP7 and USP10, which are involved in regulating levels of p53 and MDM2. We were able to identify UbVs that bound USP7 or USP10 with high affinity and inhibited deubiquitination activity. We solved the crystal structure of UbV.7.2 and rationalized the molecular basis for enhanced affinity and specificity for USP7. Finally, cell death was increased significantly by UbV.7.2 expression in a colon cancer cell line that was treated with the chemotherapy drug cisplatin, demonstrating the therapeutic potential of inhibiting USP7 by this approach« less

Influence of pH on in vitro disintegration of phosphate binders.

PubMed

Stamatakis, M K; Alderman, J M; Meyer-Stout, P J

1998-11-01

Hyperphosphatemia, a common complication in patients with end-stage renal disease, is treated with oral phosphate-binding medications that restrict phosphorus absorption from the gastrointestinal (GI) tract. Impaired product performance, such as failure to disintegrate and/or dissolve in the GI tract, could limit the efficacy of the phosphate binder. Disintegration may be as important as dissolution for predicting in vitro product performance for medications that act locally on the GI tract, such as phosphate binders. Furthermore, patients with end-stage renal disease have a wide range in GI pH, and pH can influence a product's performance. The purpose of this study was to determine the effect of pH on in vitro disintegration of phosphate binders. Fifteen different commercially available phosphate binders (seven calcium carbonate tablet formulations, two calcium acetate tablet formulations, three aluminum hydroxide capsule formulations, and three aluminum hydroxide tablet formulations) were studied using the United States Pharmacopeia (USP) standard disintegration apparatus. Phosphate binders were tested in simulated gastric fluid (pH 1.5), distilled water (pH 5.1), and simulated intestinal fluid (pH 7.5). Product failure was defined as two or more individual tablets or capsules failing to disintegrate completely within 30 minutes. Results indicate that 9 of the 15 phosphate binders tested showed statistically significant differences in disintegration time (DT) based on pH. The percentage of binders that passed the disintegration study test in distilled water, gastric fluid, and intestinal fluid were 80%, 80%, and 73%, respectively. The findings of this study show that the disintegration of commercially available phosphate binders is highly variable. The pH significantly affected in vitro disintegration in the majority of phosphate binders tested; how significantly this affects in vivo performance has yet to be studied.

Preparation and Physicochemical Evaluation of Controlled-release Carbon Source Tablet for Groundwater in situ Denitrification

NASA Astrophysics Data System (ADS)

Kim, Y.; Kang, J. H.; Yeum, Y.; Han, K. J.; Kim, D. W.; Park, C. W.

2015-12-01

Nitric nitrogen could be the one of typical pollution source such asNO3-through domestic sewage, livestock and agricultural wastewater. Resident microflorain aquifer has known to remove the nitric nitrogen spontaneously following the denitration process with the carbon source (CS) as reactant. However, it could be reacted very slowly with the rack of CS and there have been some studies for controlled addition of CS (Ref #1-3). The aim of this study was to prepare the controlled-release carbon source (CR-CS) tablet and to evaluate in vitro release profile for groundwater in situ denitrification. CR-CS tablet could be manufactured by direct compression method using hydraulic laboratory press (Caver® 3850) with 8 mm rounded concave punch/ die.Seven kinds of CR-CS tablet were prepared to determine the nature of the additives and their ratio such as sodium silicate, dicalcium phosphate, bentonite and sand#8.For each formulation, the LOD% and flowability of pre-mixed powders and the hardness of compressed tablets were analyzed. In vitro release study was performed to confirm the dissolution profiles following the USP Apparatus 2 method with Distilled water of 900mL, 20 °C. As a result, for each lubricated powders, they were compared in terms of ability to give an acceptable dry pre-mixed powder for tableting process. The hardness of the compressed tablets is acceptable whatever the formulations tested. After in vitro release study, it could confirm that the different formulations of CR-CS tablet have a various release rate patterns, which could release 100% at 3 hrs, 6 hrs and 12 hrs. The in vitro dissolution profiles were in good correlation of Higuchi release kinetic model. In conclusion, this study could be used as a background for development and evaluation of the controlled-release carbon source (CR-CS) tablet for the purification of groundwater following the in situ denitrification.

PLS and first derivative of ratio spectra methods for determination of hydrochlorothiazide and propranolol hydrochloride in tablets.

PubMed

Vignaduzzo, Silvana E; Maggio, Rubén M; Castellano, Patricia M; Kaufman, Teodoro S

2006-12-01

Two new analytical methods have been developed as convenient and useful alternatives for simultaneous determination of hydrochlorothiazide (HCT) and propranolol hydrochloride (PRO) in pharmaceutical formulations. The methods are based on the first derivative of ratio spectra (DRS) and on partial least squares (PLS) analysis of the ultraviolet absorption spectra of the samples in the 250-350-nm region. The methods were calibrated between 8.7 and 16.0 mg L(-1) for HCT and between 14.0 and 51.5 mg L(-1) for PRO. An asymmetric full-factorial design and wavelength selection (277-294 nm for HCT and 297-319 for PRO) were used for the PLS method and signal intensities at 276 and 322 nm were used in the DRS method for HCT and PRO, respectively. Performance characteristics of the analytical methods were evaluated by use of validation samples and both methods showed to be accurate and precise, furnishing near quantitative analyte recoveries (100.4 and 99.3% for HCT and PRO by use of PLS) and relative standard deviations below 2%. For PLS the lower limits of quantification were 0.37 and 0.66 mg L(-1) for HCT and PRO, respectively, whereas for DRS they were 1.15 and 3.05 mg L(-1) for HCT and PRO, respectively. The methods were used for quantification of HCT and PRO in synthetic mixtures and in two commercial tablet preparations containing different proportions of the analytes. The results of the drug content assay and the tablet dissolution test were in statistical agreement (p < 0.05) with those furnished by the official procedures of the USP 29. Preparation of dissolution profiles of the combined tablet formulations was also performed with the aid of the proposed methods. The methods are easy to apply, use relatively simple equipment, require minimum sample pre-treatment, enable high sample throughput, and generate less solvent waste than other procedures.

78 FR 62712 - Rate Adjustment

Federal Register 2010, 2011, 2012, 2013, 2014

2013-10-22

....e., in an across-the-board fashion. Id. at 2, 12, 35. The Postal Service states that the Governors... Services Worksheets USPS-R2010-4R/7 Product Cost & Contribution Estimation Model (Public Version) USPS... Product Cost & Contribution Estimation Model (Non- Public Version) USPS-R2010-4R/NP2 Cost Factor...

39 CFR 241.3 - Discontinuance of USPS-operated retail facilities.

Code of Federal Regulations, 2013 CFR

2013-07-01

... 39 Postal Service 1 2013-07-01 2013-07-01 false Discontinuance of USPS-operated retail facilities... ESTABLISHMENT CLASSIFICATION, AND DISCONTINUANCE § 241.3 Discontinuance of USPS-operated retail facilities. (a... of whether an existing retail Post Office, station, or branch should be discontinued. The rules cover...

39 CFR 241.3 - Discontinuance of USPS-operated retail facilities.

Code of Federal Regulations, 2014 CFR

2014-07-01

... 39 Postal Service 1 2014-07-01 2014-07-01 false Discontinuance of USPS-operated retail facilities... ESTABLISHMENT CLASSIFICATION, AND DISCONTINUANCE § 241.3 Discontinuance of USPS-operated retail facilities. (a... of whether an existing retail Post Office, station, or branch should be discontinued. The rules cover...

39 CFR 241.3 - Discontinuance of USPS-operated retail facilities.

Code of Federal Regulations, 2012 CFR

2012-07-01

... 39 Postal Service 1 2012-07-01 2012-07-01 false Discontinuance of USPS-operated retail facilities... ESTABLISHMENT CLASSIFICATION, AND DISCONTINUANCE § 241.3 Discontinuance of USPS-operated retail facilities. (a... of whether an existing retail Post Office, station, or branch should be discontinued. The rules cover...

The deubiquitinase Usp27x stabilizes the BH3-only protein Bim and enhances apoptosis.

PubMed

Weber, Arnim; Heinlein, Melanie; Dengjel, Jörn; Alber, Claudia; Singh, Prafull Kumar; Häcker, Georg

2016-05-01

Bim is a pro-apoptotic Bcl-2 family member of the BH3-only protein subgroup. Expression levels of Bim determine apoptosis susceptibility in non-malignant and in tumour cells. Bim protein expression is downregulated by proteasomal degradation following ERK-dependent phosphorylation and ubiquitination. Here, we report the identification of a deubiquitinase, Usp27x, that binds Bim upon its ERK-dependent phosphorylation and can upregulate its expression levels. Overexpression of Usp27x reduces ERK-dependent Bim ubiquitination, stabilizes phosphorylated Bim, and induces apoptosis in PMA-stimulated cells, as well as in tumour cells with a constitutively active Raf/ERK pathway. Loss of endogenous Usp27x enhances the Bim-degrading activity of oncogenic Raf. Overexpression of Usp27x induces low levels of apoptosis in melanoma and non-small cell lung cancer (NSCLC) cells and substantially enhances apoptosis induced in these cells by the inhibition of ERK signalling. Finally, deletion of Usp27x reduces apoptosis in NSCLC cells treated with an EGFR inhibitor. Thus, Usp27x can trigger via its proteolytic activity the deubiquitination of Bim and enhance its levels, counteracting the anti-apoptotic effects of ERK activity, and therefore acts as a tumour suppressor. © 2016 The Authors.

Quantitative analysis by next generation sequencing of hematopoietic stem and progenitor cells (LSK) and of splenic B cells transcriptomes from wild-type and Usp3-knockout mice.

PubMed

Lancini, Cesare; Gargiulo, Gaetano; van den Berk, Paul C M; Citterio, Elisabetta

2016-03-01

The data described here provide genome-wide expression profiles of murine primitive hematopoietic stem and progenitor cells (LSK) and of B cell populations, obtained by high throughput sequencing. Cells are derived from wild-type mice and from mice deficient for the ubiquitin-specific protease 3 (USP3; Usp3Δ/Δ). Modification of histone proteins by ubiquitin plays a crucial role in the cellular response to DNA damage (DDR) (Jackson and Durocher, 2013) [1]. USP3 is a histone H2A deubiquitinating enzyme (DUB) that regulates ubiquitin-dependent DDR in response to DNA double-strand breaks (Nicassio et al., 2007; Doil et al., 2008) [2], [3]. Deletion of USP3 in mice increases the incidence of spontaneous tumors and affects hematopoiesis [4]. In particular, Usp3-knockout mice show progressive loss of B and T cells and decreased functional potential of hematopoietic stem cells (HSCs) during aging. USP3-deficient cells, including HSCs, display enhanced histone ubiquitination, accumulate spontaneous DNA damage and are hypersensitive to ionizing radiation (Lancini et al., 2014) [4]. To address whether USP3 loss leads to deregulation of specific molecular pathways relevant to HSC homeostasis and/or B cell development, we have employed the RNA-sequencing technology and investigated transcriptional differences between wild-type and Usp3Δ/Δ LSK, naïve B cells or in vitro activated B cells. The data relate to the research article "Tight regulation of ubiquitin-mediated DNA damage response by USP3 preserves the functional integrity of hematopoietic stem cells" (Lancini et al., 2014) [4]. The RNA-sequencing and analysis data sets have been deposited in NCBI׳s Gene Expression Omnibus (Edgar et al., 2002) [5] and are accessible through GEO Series accession number GSE58495 (http://www.ncbi.nlm.nih.gov/geo/query/acc.cgi?acc=GSE58495). With this article, we present validation of the RNA-seq data set through quantitative real-time PCR and comparative analysis.

The ubiquitin-specific protease USP15 promotes RIG-I-mediated antiviral signaling by deubiquitylating TRIM25.

PubMed

Pauli, Eva-Katharina; Chan, Ying Kai; Davis, Meredith E; Gableske, Sebastian; Wang, May K; Feister, Katharina F; Gack, Michaela U

2014-01-07

Ubiquitylation is an important mechanism for regulating innate immune responses to viral infections. Attachment of lysine 63 (Lys(63))-linked ubiquitin chains to the RNA sensor retinoic acid-inducible gene-I (RIG-I) by the ubiquitin E3 ligase tripartite motif protein 25 (TRIM25) leads to the activation of RIG-I and stimulates production of the antiviral cytokines interferon-α (IFN-α) and IFN-β. Conversely, Lys(48)-linked ubiquitylation of TRIM25 by the linear ubiquitin assembly complex (LUBAC) stimulates the proteasomal degradation of TRIM25, thereby inhibiting the RIG-I signaling pathway. Here, we report that ubiquitin-specific protease 15 (USP15) deubiquitylates TRIM25, preventing the LUBAC-dependent degradation of TRIM25. Through protein purification and mass spectrometry analysis, we identified USP15 as an interaction partner of TRIM25 in human cells. Knockdown of endogenous USP15 by specific small interfering RNA markedly enhanced the ubiquitylation of TRIM25. In contrast, expression of wild-type USP15, but not its catalytically inactive mutant, reduced the Lys(48)-linked ubiquitylation of TRIM25, leading to its stabilization. Furthermore, ectopic expression of USP15 enhanced the TRIM25- and RIG-I-dependent production of type I IFN and suppressed RNA virus replication. In contrast, depletion of USP15 resulted in decreased IFN production and markedly enhanced viral replication. Together, these data identify USP15 as a critical regulator of the TRIM25- and RIG-I-mediated antiviral immune response, thereby highlighting the intricate regulation of innate immune signaling.

Structure of the USP15 N-terminal domains: a β-hairpin mediates close association between the DUSP and UBL domains.

PubMed

Harper, Stephen; Besong, Tabot M D; Emsley, Jonas; Scott, David J; Dreveny, Ingrid

2011-09-20

Ubiquitin specific protease 15 (USP15) functions in COP9 signalosome mediated regulation of protein degradation and cellular signaling through catalyzing the ubiquitin deconjugation reaction of a discrete number of substrates. It influences the stability of adenomatous polyposis coli, IκBα, caspase-3, and the human papillomavirus type 16 E6. USP15 forms a subfamily with USP4 and USP11 related through a shared presence of N-terminal "domain present in ubiquitin specific proteases" (DUSP) and "ubiquitin-like" (UBL) domains (DU subfamily). Here we report the 1.5 Å resolution crystal structure of the human USP15 N-terminal domains revealing a 80 Å elongated arrangement with the DU domains aligned in tandem. This architecture is generated through formation of a defined interface that is dominated by an intervening β-hairpin structure (DU finger) that engages in an intricate hydrogen-bonding network between the domains. The UBL domain is closely related to ubiquitin among β-grasp folds but is characterized by the presence of longer loop regions and different surface characteristics, indicating that this domain is unlikely to act as ubiquitin mimic. Comparison with the related murine USP4 DUSP-UBL crystal structure reveals that the main DU interdomain contacts are conserved. Analytical ultracentrifugation, small-angle X-ray scattering, and gel filtration experiments revealed that USP15 DU is monomeric in solution. Our data provide a framework to advance study of the structure and function of the DU subfamily. © 2011 American Chemical Society

The Ubiquitin-Specific Protease USP15 Promotes RIG-I–Mediated Antiviral Signaling by Deubiquitylating TRIM25

PubMed Central

Pauli, Eva-Katharina; Chan, Ying Kai; Davis, Meredith E.; Gableske, Sebastian; Wang, May K.; Feister, Katharina F.; Gack, Michaela U.

2014-01-01

Ubiquitylation is an important mechanism for regulating innate immune responses to viral infections. Attachment of lysine 63 (Lys63)–linked ubiquitin chains to the RNA sensor retinoic acid–inducible gene-I (RIG-I) by the ubiquitin E3 ligase tripartite motif protein 25 (TRIM25) leads to the activation of RIG-I and stimulates production of the antiviral cytokines interferon-α (IFN-α) and IFN-β. Conversely, Lys48-linked ubiquitylation of TRIM25 by the linear ubiquitin assembly complex (LUBAC) stimulates the proteasomal degradation of TRIM25, thereby inhibiting the RIG-I signaling pathway. Here, we report that ubiquitin-specific protease 15 (USP15) deubiquitylates TRIM25, preventing the LUBAC-dependent degradation of TRIM25. Through protein purification and mass spectrometry analysis, we identified USP15 as an interaction partner of TRIM25 in human cells. Knockdown of endogenous USP15 by specific small interfering RNA markedly enhanced the ubiquitylation of TRIM25. In contrast, expression of wild-type USP15, but not its catalytically inactive mutant, reduced the Lys48-linked ubiquitylation of TRIM25, leading to its stabilization. Furthermore, ectopic expression of USP15 enhanced the TRIM25- and RIG-I–dependent production of type I IFN and suppressed RNA virus replication. In contrast, depletion of USP15 resulted in decreased IFN production and markedly enhanced viral replication. Together, these data identify USP15 as a critical regulator of the TRIM25- and RIG-I–mediated antiviral immune response, thereby highlighting the intricate regulation of innate immune signaling. PMID:24399297

The differences between the branded and generic medicines using solid dosage forms: In-vitro dissolution testing

PubMed Central

Al Ameri, Mubarak Nasser; Nayuni, Nanda; Anil Kumar, K.G.; Perrett, David; Tucker, Arthur; Johnston, Atholl

2011-01-01

Introduction Dissolution is the amount of substance that goes into solution per unit time under standardised conditions of liquid/solid interface, solvent composition and temperature. Dissolution is one of the most important tools to predict the in-vivo bioavailability and in some cases to determine bioequivalence and assure interchangeability. Aim To compare the differences in dissolution behaviour of solid dosage forms between innovators (reference products) and their generic counterparts (tested products). Methods Four replicates for each batch of 37 tested medicines was carried out using A PT-DT70 dissolution tester from Pharma Test. A total of 13 branded medicines and 24 generic counterparts were obtained locally and internationally to detect any differences in their dissolution behaviour. They were tested according to the British Pharmacopeia, European Pharmacopeia and the US Pharmacopeia with the rate of dissolution determined by ultra-violet Spectrophotometery. Results Most tested medicines complied with the pharmacopoeial specifications and achieved 85% dissolution in 60 min. However, some generic medicines showed significant differences in dissolution rate at 60 and 120 min. Many generic medicines showed a slower dissolution rate than their branded counterparts such as the generic forms of omeprazole 20 mg. Some showed an incomplete dissolution such as the generic form of nifedipine 10 mg. Other generics showed faster dissolution rate than their branded counterpart such as the generic forms of meloxicam 15 mg. Moreover, some generics from different batches of the same manufacturer showed significant differences in their dissolution rate such as the generic forms of meloxicam 7.5 mg. Nevertheless, some generic medicines violated the EMA and the FDA guidelines for industry when they failed to achieve 85% dissolution at 60 min, such as the generic form of diclofenac sodium 50 mg. Conclusion Most medicines in this study complied with the pharmacopeial limits. However, some generics dissolved differently than their branded counterparts. This can clearly question the interchangeability between the branded and its generic counterpart or even among generics. PMID:25755988

Excitation of atoms and ions in plasmas by ultra-short electromagnetic pulses

NASA Astrophysics Data System (ADS)

Astapenko, V. A.; Sakhno, S. V.; Svita, S. Yu; Lisitsa, V. S.

2017-02-01

The problem of atoms and ions diagnostics in rarefied and dense plasmas by ultrashort laser pulses (USP) is under consideration. The application of USP provides: 1) excitation from ground states due to their carrier frequency high enough, 2) penetration into optically dense media due to short pulses duration. The excitation from ground atomic states increases sharply populations of excited atomic states in contrast with standard laser induced fluorescence spectroscopy based on radiative transitions between excited atomic states. New broadening parameter in radiation absorption, namely inverse pulse duration time 1/τ appears in addition to standard line-shape width in the profile G(ω). The Lyman-beta absorption spectra for USP are calculated for Holtsmark static broadening mechanism. Excitation of highly charged H-like ions in hot plasmas is described by both Gaussian shapes for Doppler broadening and pulse spectrum resulting in analytical absorption line-shape. USP penetration into optically thick media and corresponding excitation probability are calculated. It is shown a great effect of USP duration on excitation probabilities in optically thick media. The typical situations for plasma diagnostics by USP are discussed in details.

High expression of ubiquitin-specific peptidase 39 is associated with the development of vascular remodeling

PubMed Central

He, Shuai; Zhong, Wei; Yin, Li; Wang, Yifei; Qiu, Zhibing; Song, Gang

2017-01-01

Vascular remodeling is the primary cause underlying the failure of angioplasty surgeries, including vascular stenting, transplant vasculopathy and vein grafts. Multiple restenosis-associated proteins and genes have been identified to account for this. In the present study, the functions of ubiquitin-specific peptidase 39 (USP39) were investigated in the context of two vascular remodeling models (a mouse common carotid artery ligation and a pig bilateral saphenous vein-carotid artery interposition graft). USP39 has previously been observed to be upregulated in ligated arteries, and this result was confirmed in the pig vein graft model. In addition, Transwell assay results demonstrated that vascular smooth muscle cell (VSMC) migration was suppressed by lentiviral vector-mediated downregulation of USP39 and enhanced by upregulation of USP39. Furthermore, knockdown of USP39 inhibited VSMC cell proliferation and the expression of cyclin D1 and cyclin-dependent kinase 4, as analyzed via cell counting, MTT assay and western blotting. These results suggest that USP39 may represent a novel therapeutic target for treating vascular injury and preventing vein-graft failure. PMID:28447728

A new modified wetting test and an alternative disintegration test for orally disintegrating tablets.

PubMed

Hooper, Patrick; Lasher, Jason; Alexander, Kenneth S; Baki, Gabriella

2016-02-20

Industrial manufacturing of solid oral dosage forms require quality tests, such as friability, hardness, and disintegration. The United States Pharmacopeia (USP) disintegration test uses 900mL of water. However, recent studies of orally disintegrating tablets (ODTs) have shown that this volume does not accurately portray the oral environment. In our study, various tests were conducted with a more moderate amount of water that accurately resembles the oral environment. A simulated wetting test was performed to calculate the water absorption ratio. Results showed that wetting was comparable to disintegration. Although the wetting test worked for most types of ODTs, it had limitations that produced inaccurate results. This led to the use of a modified shaking water bath test. This test was found to work for all types of ODT products and was not subject to the limitations of the wetting test. The shake test could provide disintegration times rather than water permeation times; however, it could not be used to calculate the water absorption ratio. A strong correlation was observed between the standardized shake test and the USP disintegration times for the tablets. This shake test could be used during the development stages and quality tests for ODTs with relative ease. Copyright © 2015 Elsevier B.V. All rights reserved.

IVGEN Post Flight Analysis

NASA Technical Reports Server (NTRS)

Mcquillen, John; Brown, Dan; Hussey, Sam; Zoldak, John

2014-01-01

The Intravenous Fluid Generation (IVGEN) Experiment was a technology demonstration experiment that purified ISS potable water, mixed it with salt, and transferred it through a sterilizing filter. On-orbit performance was verified as appropriate and two 1.5 l bags of normal saline solution were returned to earth for post-flight testing by a FDA certified laboratory for compliance with United States Pharmacopiea (USP) standards. Salt concentration deviated from required values and an analysis identified probable causes. Current efforts are focused on Total Organic Content (TOC) testing, and shelf life.The Intravenous Fluid Generation (IVGEN) Experiment demonstrated the purification of ISS potable water, the mixing of the purified water with sodium chloride, and sterilization of the solution via membrane filtration. On-orbit performance was monitored where feasible and two 1.5-liter bags of normal saline solution were returned to earth for post-flight testing by a FDA-registered laboratory for compliance with United States Pharmacopeia (USP)standards [1]. Current efforts have been focused on challenge testing with identified [2] impurities (total organic-carbon), and shelf life testing. The challenge testing flowed known concentrations of contaminants through the IVGEN deionizing cartridge and membrane filters to test their effectiveness. One finding was that the filters and DI-resin themselves contribute to the contaminant load during initial startup, suggesting that the first 100 ml of fluid be discarded. Shelf life testing is ongoing and involves periodic testing of stored DI cartridges and membrane filters that are capped and sealed in hermetic packages. The testing is conducted at six month intervals measuring conductivity and endotoxins in the effluent. Currently, the packaging technique has been successfully demonstrated for one year of storage testing. The USP standards specifies that the TOC be conducted at point of generation as opposed to point of consumption. Samples were generated and shipped to an FDA facility however, testing determined that the samples failed the TOC specification with most likely due to leaching from the sample container. Shelf life testing is examining packaging techniques and periodic testing of samples of DI cartridges that are capped and sealed in hermetic packages. Periodic testing of the purified water output will be conducted at six month intervals.

Results of Characterization and Retrieval Testing on Tank 241-C-109 Heel Solids

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

Callaway, William S.

Eight samples of heel solids from tank 241-C-109 were delivered to the 222-S Laboratory for characterization and dissolution testing. After being drained thoroughly, one-half to two-thirds of the solids were off-white to tan solids that, visually, were fairly evenly graded in size from coarse silt (30-60 μm) to medium pebbles (8-16 mm). The remaining solids were mostly strongly cemented aggregates ranging from coarse pebbles (16-32 mm) to fine cobbles (6-15 cm) in size. Solid phase characterization and chemical analysis indicated that the air-dry heel solids contained ≈58 wt% gibbsite [Al(OH){sub 3}] and ≈37 wt% natrophosphate [Na{sub 7}F(PO{sub 4}){sub 2}·19H{sub 2}O].more » The strongly cemented aggregates were mostly fine-grained gibbsite cemented with additional gibbsite. Dissolution testing was performed on two test samples. One set of tests was performed on large pieces of aggregate solids removed from the heel solids samples. The other set of dissolution tests was performed on a composite sample prepared from well-drained, air-dry heel solids that were crushed to pass a 1/4-in. sieve. The bulk density of the composite sample was 2.04 g/mL. The dissolution tests included water dissolution followed by caustic dissolution testing. In each step of the three-step water dissolution tests, a volume of water approximately equal to 3 times the initial volume of the test solids was added. In each step, the test samples were gently but thoroughly mixed for approximately 2 days at an average ambient temperature of 25 °C. The caustic dissolution tests began with the addition of sufficient 49.6 wt% NaOH to the water dissolution residues to provide ≈3.1 moles of OH for each mole of Al estimated to have been present in the starting composite sample and ≈2.6 moles of OH for each mole of Al potentially present in the starting aggregate sample. Metathesis of gibbsite to sodium aluminate was then allowed to proceed over 10 days of gentle mixing of the test samples at temperatures ranging from 26-30 °C. The metathesized sodium aluminate was then dissolved by addition of volumes of water approximately equal to 1.3 times the volumes of caustic added to the test slurries. Aluminate dissolution was allowed to proceed for 2 days at ambient temperatures of ≈29 °C. Overall, the sequential water and caustic dissolution tests dissolved and removed 80.0 wt% of the tank 241-C-109 crushed heel solids composite test sample. The 20 wt% of solids remaining after the dissolution tests were 85-88 wt% gibbsite. If the density of the residual solids was approximately equal to that of gibbsite, they represented ≈17 vol% of the initial crushed solids composite test sample. In the water dissolution tests, addition of a volume of water ≈6.9 times the initial volume of the crushed solids composite was sufficient to dissolve and recover essentially all of the natrophosphate present. The ratio of the weight of water required to dissolve the natrophosphate solids to the estimated weight of natrophosphate present was 8.51. The Environmental Simulation Program (OLI Systems, Inc., Morris Plains, New Jersey) predicts that an 8.36 w/w ratio would be required to dissolve the estimated weight of natrophosphate present in the absence of other components of the heel solids. Only minor amounts of Al-bearing solids were removed from the composite solids in the water dissolution tests. The caustic metathesis/aluminate dissolution test sequence, executed at temperatures ranging from 27-30 °C, dissolved and recovered ≈69 wt% of the gibbsite estimated to have been present in the initial crushed heel solids composite. This level of gibbsite recovery is consistent with that measured in previous scoping tests on the dissolution of gibbsite in strong caustic solutions. Overall, the sequential water and caustic dissolution tests dissolved and removed 80.3 wt% of the tank 241-C-109 aggregate solids test sample. The residual solids were 92-95 wt% gibbsite. Only a minor portion (≈4.5 wt%) of the aggregate solids was dissolved and recovered in the water dissolution test. Other than some smoothing caused by continuous mixing, the aggregates were essentially unaffected by the water dissolution tests. During the caustic metathesis/aluminate dissolution test sequence, ≈81 wt% of the gibbsite estimated to have been present in the aggregate solids was dissolved and recovered. The pieces of aggregate were significantly reduced in size but persisted as distinct pieces of solids. The increased level of gibbsite recovery, as compared to that for the crushed heel solids composite, suggests that the way the gibbsite solids and caustic solution are mixed is a key determinant of the overall efficiency of gibbsite dissolution and recovery. The liquids recovered after the caustic dissolution tests on the crushed solids composite and the aggregate solids were observed for 170 days. No precipitation of gibbsite was observed. The distribution of particle sizes in the residual solids recovered following the dissolution tests on the crushed heel solids composite was characterized. Wet sieving indicated that 21.4 wt% of the residual solids were >710 μm in size, and laser light scattering indicated that the median equivalent spherical diameter in the <710-μm solids was 35 μm. The settling behavior of the residual solids following the large-scale dissolution tests was also studied. When dispersed at a concentration of ≈1 vol% in water, ≈24 wt% of the residual solids settled at a rate >0.43 in./s; ≈68 wt% settled at rates between 0.02 and 0.43 in./s; and ≈7 wt% settled slower than 0.02 in./s.« less

The Promoter of AtUSP Is Co-regulated by Phytohormones and Abiotic Stresses in Arabidopsis thaliana.

PubMed

Bhuria, Monika; Goel, Parul; Kumar, Sanjay; Singh, Anil K

2016-01-01

Universal stress proteins (USPs) are known to be expressed in response to various abiotic stresses in a wide variety of organisms, such as bacteria, archaebacteria, protists, algae, fungi, plants, and animals. However, in plants, biological function of most of the USPs still remains obscure. In the present study, Arabidopsis USP gene ( AtUSP ) showed induction in response to abscisic acid (ABA) and various abiotic stresses viz . heat, dehydration, salt, osmotic, and cold stresses. Additionally, in silico analysis of AtUSP promoter identified several cis -elements responsive to phytohormones and abiotic stresses such as ABRE, ERE, DRE, and HSE, etc. To functionally validate the AtUSP promoter, the 1115 bp region of promoter was characterized under phytohormone and abiotic stress treatments. Deletion analysis of promoter was carried out by cloning the full length promoter (D0) and its three 5' deletion derivatives, D1 (964 bp), D2 (660 bp), and D3 (503 bp) upstream of the β-glucuronidase (GUS) reporter gene, which were then stably transformed in Arabidopsis plants. The AtUSP promoter (D0) showed minimal activity under non-stress conditions which was enhanced in response to phytohormone treatments (ABA and ACC) and abiotic stresses such as dehydration, heat, cold, salt, and osmotic stresses. The seedlings harboring D1 and D2 deletion fragments showed constitutive GUS expression even under control condition with increased activity almost under all the treatments. However, D3 seedlings exhibited complete loss of activity under control condition with induction under ACC treatment, dehydration, heat, oxidative, salt, and osmotic stresses. Thus, present study clearly showed that AtUSP promoter is highly inducible by phytohormones and multiple abiotic stresses and it can be exploited as stress inducible promoter to generate multi-stress tolerant crops with minimal effects on their other important traits.

Molecular Evolution of Ultraspiracle Protein (USP/RXR) in Insects

PubMed Central

Hult, Ekaterina F.; Tobe, Stephen S.; Chang, Belinda S. W.

2011-01-01

Ultraspiracle protein/retinoid X receptor (USP/RXR) is a nuclear receptor and transcription factor which is an essential component of a heterodimeric receptor complex with the ecdysone receptor (EcR). In insects this complex binds ecdysteroids and plays an important role in the regulation of growth, development, metamorphosis and reproduction. In some holometabolous insects, including Lepidoptera and Diptera, USP/RXR is thought to have experienced several important shifts in function. These include the acquisition of novel ligand-binding properties and an expanded dimerization interface with EcR. In light of these recent hypotheses, we implemented codon-based likelihood methods to investigate if the proposed shifts in function are reflected in changes in site-specific evolutionary rates across functional and structural motifs in insect USP/RXR sequences, and if there is any evidence for positive selection at functionally important sites. Our results reveal evidence of positive selection acting on sites within the loop connecting helices H1 and H3, the ligand-binding pocket, and the dimer interface in the holometabolous lineage leading to the Lepidoptera/Diptera/Trichoptera. Similar analyses conducted using EcR sequences did not indicate positive selection. However, analyses allowing for variation across sites demonstrated elevated non-synonymous/synonymous rate ratios (d N/d S), suggesting relaxed constraint, within the dimerization interface of both USP/RXR and EcR as well as within the coactivator binding groove and helix H12 of USP/RXR. Since the above methods are based on the assumption that d S is constant among sites, we also used more recent models which relax this assumption and obtained results consistent with traditional random-sites models. Overall our findings support the evolution of novel function in USP/RXR of more derived holometabolous insects, and are consistent with shifts in structure and function which may have increased USP/RXR reliance on EcR for cofactor recruitment. Moreover, these findings raise important questions regarding hypotheses which suggest the independent activation of USP/RXR by its own ligand. PMID:21901121

Effects of drug-carrier interactions on drug dissolution from binary and ternary matrices

NASA Astrophysics Data System (ADS)

Iqbal, Zafar

For nearly five decades, pharmaceutical researchers have studied solid solutions of drugs in polymers as a potential means to enhance the dissolution of drugs with poor aqueous solubility. This has become of greater importance in recent years because most new potential drug compounds (new chemical entities) exhibit poor water solubility and present great challenges to scientists who must design dosage forms from which the drugs are bioavailable. During the formulation of a solid solution, the drug undergoes physical but not chemical alterations that increase its chemical potential in the formulation relative to that of the pure drug in its stable form. This increased chemical potential is responsible for enhanced dissolution as well as physical instabilities, such as amorphous to crystalline conversions and precipitation within the solid state. The chemical potential is derived from the Gibbs free energy, so it is reasonable to explain the behavior of solid solution systems in terms of thermodynamics. Solid solutions and dispersions have been extensively studied by pharmaceutical scientists, both with regard to manufacturing aspects and the proposal of various models in attempts to explain the physical bases for how these systems work. Recently, Dave and Bellantone proposed a model based on the thermodynamic changes resulting from the formulation of binary solid solutions of a drug in the polymer PVP. Their model introduced a modification of the F-H theory, which was used to quantify the drug-polymer interaction energies and calculate the entropy of mixing of the drug and polymer. In this work, the model of Dave and Bellantone was extended to include three-component systems, consisting of one drug mixed in a carrier matrix consisting of mixture of two polymers or a polymer and a surfactant. For this research, solid solutions were formed using various drug weight fractions in the formulations. The study focused on the following points: (1) Prepare solid solution formulations and perform appropriate physical characterizations. (2) Characterize the increase in drug dissolution rates resulting from solid solution formulations. (3) Relate the initial dissolution rates to the drug solubility. (4) Explain the solubility enhancement from solid solution dosage in terms of the drug polymer interactions using the extended thermodynamic model. Two poorly water soluble drugs, levonorgestrel (LEVO) and ethinyl estradiol (EE) were formulated in seven solid solution preparations comprised of four carrier systems. Materials used as carriers included various combinations of the polymers PVP K-30, Copovidone (COP), Poloxamer 182, and the surfactant TweenRTM 20. Additionally, ibuprofen (IBU) was used in three formulations consisting of various combinations of PVP K-30, Copovidone and TweenRTM 20. Formulations with various drug weight fractions (0.5%--30%) were prepared using the solvent evaporation technique. Each formulation was tested for dissolution using intrinsic dissolution apparatus (USP). The solid solutions were compressed into tablets into the sample die that maintained a constant surface area during the dissolution process. DSC, XRD and NIRS scans identified that the crystalline peaks of the drug disappeared with the addition of the polymer for all ratios of EE, indicating the formation of solid solutions (to within the limits of detection of the equipment). This was also observed for the LEVO dispersions up to 10% drug loading. At higher drug loading, solutions were formed but some small degree crystallinity was also present. For each experiment, the initial dissolution rates were obtained from the slope of the mass dissolved vs. time plots taken at early times, and volume normalized initial dissolution rates RV were calculated by dividing the initial dissolution rate by the volume fraction of the drug in the formulation. Comparison of the RV values for the various formulations with a reference RV (typically that of the pure drug or of the formulation with the highest polymer content) allowed calculation of relative volume normalized dissolution rates (RNV). The various RNV were used in the thermodynamic model for data analyses and to determine the interactions between the drug and carrier molecules. It was generally seen that RNV increased with decreased drug fraction, and was adequately modeled by the equations derived from the extended thermodynamic model. It was concluded that the model proposed for the binary and ternary systems successfully represented the mechanism of drug-polymer interaction and the energy changes taken place within the dispersion systems. The dissolution data analysis and subsequent understanding of physical modifications in the dispersion systems characterized by XRD, NIRS and DSC further substantiated the findings. The understanding of the fundamental physical might help scientists to predict the effects of mixing various drugs and polymers, and the effects of varying ratios.

In-vitro Drug Dissolution Studies in Medicinal Compounds.

PubMed

Bozal-Palabiyik, Burcin; Uslu, Bengi; Ozkan, Yalcin; Ozkan, Sibel A

2018-03-22

After oral administration, drug absorption from solid dosage forms depend on the release of the drug active compounds from the dosage form, the dissolution or solubilization of the drug under physiological conditions, and the permeability across the gastrointestinal tract. Dissolution testing is an essential part of designing more effective solid dosage forms in pharmaceutical industry. Moreover dissolution testing contributes to the selection of appropriate formulation excipients for improving the dosage form efficiency. This study aims to analyze in-vitro drug dissolution testing in solid dosage forms since 2010 in order to present a comprehensive outlook of recent trends. In doing that the previous studies in the literature are summarized in the form of a table to demonstrate the apparatuses used for dissolution testing, the media in which the solid dosage form is dissolved, the method preferred for analysis from dissolution media, the conditions of analyses and the results obtained. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Optimization of Dissolution Compartments in a Biorelevant Dissolution Apparatus Golem v2, Supported by Multivariate Analysis.

PubMed

Stupák, Ivan; Pavloková, Sylvie; Vysloužil, Jakub; Dohnal, Jiří; Čulen, Martin

2017-11-23

Biorelevant dissolution instruments represent an important tool for pharmaceutical research and development. These instruments are designed to simulate the dissolution of drug formulations in conditions most closely mimicking the gastrointestinal tract. In this work, we focused on the optimization of dissolution compartments/vessels for an updated version of the biorelevant dissolution apparatus-Golem v2. We designed eight compartments of uniform size but different inner geometry. The dissolution performance of the compartments was tested using immediate release caffeine tablets and evaluated by standard statistical methods and principal component analysis. Based on two phases of dissolution testing (using 250 and 100 mL of dissolution medium), we selected two compartment types yielding the highest measurement reproducibility. We also confirmed a statistically ssignificant effect of agitation rate and dissolution volume on the extent of drug dissolved and measurement reproducibility.

Nodular fasciitis: a novel model of transient neoplasia induced by MYH9-USP6 gene fusion.

PubMed

Erickson-Johnson, Michele R; Chou, Margaret M; Evers, Barbara R; Roth, Christopher W; Seys, Amber R; Jin, Long; Ye, Ying; Lau, Alan W; Wang, Xiaoke; Oliveira, Andre M

2011-10-01

Nodular fasciitis (NF) is a relatively common mass-forming and self-limited subcutaneous pseudosarcomatous myofibroblastic proliferation of unknown pathogenesis. Due to its rapid growth and high mitotic activity, NF is often misdiagnosed as a sarcoma. While studying the USP6 biology in aneurysmal bone cyst and other mesenchymal tumors, we identified high expression levels of USP6 mRNA in two examples of NF. This finding led us to further examine the mechanisms underlying USP6 overexpression in these lesions. Upon subsequent investigation, genomic rearrangements of the USP6 locus were found in 92% (44 of 48) of NF. Rapid amplification of 5'-cDNA ends identified MYH9 as the translocation partner. RT-PCR and direct sequencing revealed the fusion of the MYH9 promoter region to the entire coding region of USP6. Control tumors and tissues were negative for this fusion. Xenografts of cells overexpressing USP6 in nude mice exhibited clinical and histological features similar to human NF. The identification of a sensitive and specific abnormality in NF holds the potential to be used diagnostically. Considering the self-limited nature of the lesion, NF may represent a model of 'transient neoplasia', as it is, to our knowledge, the first example of a self-limited human disease characterized by a recurrent somatic gene fusion event. © 2011 USCAP, Inc All rights reserved

Quality of anthelminthic medicines available in Jimma Ethiopia.

PubMed

Belew, Sileshi; Suleman, Sultan; Wynendaele, Evelien; D'Hondt, Matthias; Kosgei, Anne; Duchateau, Luc; De Spiegeleer, Bart

2018-01-01

Soil-transmitted helminthiasis and schistosomiasis are major public health problems in Ethiopia. Mass deworming of at-risk population using a single dose administration of 400mg albendazole (ABZ) or 500mg mebendazole (MBZ) for treatment of common intestinal worms and 40mg of praziquantel (PZQ) per kg body weight for treatment of schistosomiasis is one of the strategies recommended by World Health Organization (WHO) in order to control the morbidity of soil-transmitted helminthiasis and schistosomiasis. Since storage condition, climate, way of transportation and distribution route could all affect the quality of medicines, regular assessment by surveys is very critical to ensure the therapeutic outcome, to minimize risk of toxicity to the patient and resistance of parasites. Therefore, this study was conducted to assess the pharmaceutical quality of ABZ, MBZ and PZQ tablet brands commonly available in Jimma town (south west Ethiopia). Retail pharmacies (n=10) operating in Jimma town were selected using simple random sampling method. Samples of anthelminthic medicines available in the selected pharmacies were collected. Sample information was recorded and encompassed trade name, active ingredient name, manufacturer's name and full address, labeled medicine strength, dosage form, number of units per container, dosage statement, batch/lot number, manufacturing and expiry dates, storage information and presence of leaflets/package insert. Moreover, a first visual inspection was performed encompassing uniformity of color, uniformity of size, breaks, cracks, splits, embedded surface spots or visual contaminations. Finally, physico-chemical quality attributes investigated encompassed mass uniformity, quantity of active pharmaceutical ingredient (API), disintegration and dissolution, all following Pharmacopoeial test methods The physical characteristics of dosage form, packaging and labeling information of all samples complied with criteria given in the WHO checklists. The mass uniformity of tablets of each brand of ABZ, MBZ and PZQ complied with the pharmacopoeial specification limits, i.e no more than 2 individual masses >5% of average tablet weight, and none deviate by more than 10%. The quantity of APIs in all investigated tablet brands were within the 90-110% label claim (l.c.) limits, ranging between 95.05 and 110.09% l.c. Disintegration times were in line with the pharmacopoeial specification limit for immediate release (IR) tablets, ranging between 0.5 and 13min. However, the dissolution results (mean±SD, n=6) of one ABZ brand (i.e. Wormin ® , Q=59.21±0.99% at 30min) and two PZQ brands (i.e. Bermoxel ® , Q=63.43%±0.7 and Distocide ® , Q=62.43%±1.67, at 75min) showed poor dissolution, failing the United States Pharmacopoeia (USP) dissolution specification limit. Copyright © 2017 Elsevier B.V. All rights reserved.

Microwave-assisted digestion using nitric acid for heavy metals and sulfated ash testing in active pharmaceutical ingredients.

PubMed

Pluhácek, T; Hanzal, J; Hendrych, J; Milde, D

2016-04-01

The monitoring of inorganic impurities in active pharmaceutical ingredients plays a crucial role in the quality control of the pharmaceutical production. The heavy metals and residue on ignition/sulfated ash methods employing microwave-assisted digestion with concentrated nitric acid have been demonstrated as alternatives to inappropriate compendial methods recommended in United States Pharmacopoeia (USP) and European Pharmacopoeia (Ph. Eur.). The recoveries using the heavy metals method ranged between 89% and 122% for nearly all USP and Ph. Eur. restricted elements as well as the recoveries of sodium sulfate spikes were around 100% in all tested matrices. The proposed microwave-assisted digestion method allowed simultaneous decomposition of 15 different active pharmaceutical ingredients with sample weigh up to 1 g. The heavy metals and sulfated ash procedures were successfully applied to the determination of heavy metals and residue on ignition/sulfated ash content in mycophenolate mofetil, nicergoline and silymarin.

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2012 CFR

2012-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2010 CFR

2010-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2013 CFR

2013-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2011 CFR

2011-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

27 CFR 21.65 - Formula No. 38-B.

Code of Federal Regulations, 2014 CFR

2014-04-01

.... Cinnamic aldehyde, N.F. IX. Cinnamon oil, N.F. Citronella oil, natural. Clove oil, N.F. Coal tar, U.S.P..., terpeneless. Spike lavender oil, natural. Storax, U.S.P. Thyme oil, N.F. XII. Thymol, N.F. Tolu balsam, U.S.P... the denaturant for analysis. (b) Authorized uses. (1) As a solvent: 111.Hair and scalp preparations...

Investigating the Impact of Drug Crystallinity in Amorphous Tacrolimus Capsules on Pharmacokinetics and Bioequivalence Using Discriminatory In Vitro Dissolution Testing and Physiologically Based Pharmacokinetic Modeling and Simulation.

PubMed

Purohit, Hitesh S; Trasi, Niraj S; Sun, Dajun D; Chow, Edwin C Y; Wen, Hong; Zhang, Xinyuan; Gao, Yi; Taylor, Lynne S

2018-05-01

Delivering a drug in amorphous form in a formulated product is a strategy used to enhance the apparent solubility of a drug substance and its oral bioavailability. Drug crystallization in such products may occur during the manufacturing process or on storage, reducing the solubility advantage of the amorphous drug. However, the impact of partial drug crystallization in the drug product on the resulting bioavailability and pharmacokinetics is unknown. In this study, dissolution testing of commercial tacrolimus capsules (which are formulated to contain amorphous drug), both fresh and those containing different amounts of crystalline drug, was conducted using both United States Pharmacopeia and noncompendial dissolution tests with different dissolution media and volumes. A physiologically based pharmacokinetic (PBPK) absorption model was developed to predict the impact of crystallinity extent on the oral absorption of the products and to evaluate the discriminatory ability of the different dissolution methods. Virtual bioequivalence simulations between partially crystallized tacrolimus capsules versus fresh Prograf or generic tacrolimus capsules were performed using the PBPK model and in vitro dissolution data of the various fresh and partially crystallized capsules under United States Pharmacopeia and noncompendial dissolution conditions. The results suggest that compendial dissolution tests may not be sufficiently discriminatory with respect to the presence of crystallinity in an amorphous formulation. Nonsink dissolution tests using lower dissolution volumes generate more discriminatory profiles that predict different pharmacokinetics of tacrolimus capsules containing different extents of drug crystallinity. In conclusion, the PBPK modeling approach can be used to assess the impact of partial drug crystallinity in the formulated product and to guide the development of appropriate dissolution methods. Copyright © 2018 American Pharmacists Association®. All rights reserved.

Dissolution testing of orally disintegrating tablets.

PubMed

Kraemer, Johannes; Gajendran, Jayachandar; Guillot, Alexis; Schichtel, Julian; Tuereli, Akif

2012-07-01

For industrially manufactured pharmaceutical dosage forms, product quality tests and performance tests are required to ascertain the quality of the final product. Current compendial requirements specify a disintegration and/or a dissolution test to check the quality of oral solid dosage forms. These requirements led to a number of compendial monographs for individual products and, at times, the results obtained may not be reflective of the dosage form performance. Although a general product performance test is desirable for orally disintegrating tablets (ODTs), the complexity of the release controlling mechanisms and short time-frame of release make such tests difficult to establish. For conventional oral solid dosage forms (COSDFs), disintegration is often considered to be the prerequisite for subsequent dissolution. Hence, disintegration testing is usually insufficient to judge product performance of COSDFs. Given the very fast disintegration of ODTs, the relationship between disintegration and dissolution is worthy of closer scrutiny. This article reviews the current status of dissolution testing of ODTs to establish the product quality standards. Based on experimental results, it appears that it may be feasible to rely on the dissolution test without a need for disintegration studies for selected ODTs on the market. © 2012 The Authors. JPP © 2012 Royal Pharmaceutical Society.

Somatic USP8 Gene Mutations Are a Common Cause of Pediatric Cushing Disease.

PubMed

Faucz, Fabio R; Tirosh, Amit; Tatsi, Christina; Berthon, Annabel; Hernández-Ramírez, Laura C; Settas, Nikolaos; Angelousi, Anna; Correa, Ricardo; Papadakis, Georgios Z; Chittiboina, Prashant; Quezado, Martha; Pankratz, Nathan; Lane, John; Dimopoulos, Aggeliki; Mills, James L; Lodish, Maya; Stratakis, Constantine A

2017-08-01

Somatic mutations in the ubiquitin-specific protease 8 (USP8) gene have been recently identified as the most common genetic alteration in patients with Cushing disease (CD). However, the frequency of these mutations in the pediatric population has not been extensively assessed. We investigated the status of the USP8 gene at the somatic level in a cohort of pediatric patients with corticotroph adenomas. The USP8 gene was fully sequenced in both germline and tumor DNA samples from 42 pediatric patients with CD. Clinical, biochemical, and imaging data were compared between patients with and without somatic USP8 mutations. Five different USP8 mutations (three missense, one frameshift, and one in-frame deletion) were identified in 13 patients (31%), all of them located in exon 14 at the previously described mutational hotspot, affecting the 14-3-3 binding motif of the protein. Patients with somatic mutations were older at disease presentation [mean 5.1 ± 2.1 standard deviation (SD) vs 13.1 ± 3.6 years, P = 0.03]. Levels of urinary free cortisol, midnight serum cortisol, and adrenocorticotropic hormone, as well as tumor size and frequency of invasion of the cavernous sinus, were not significantly different between the two groups. However, patients harboring somatic USP8 mutations had a higher likelihood of recurrence compared with patients without mutations (46.2% vs 10.3%, P = 0.009). Somatic USP8 gene mutations are a common cause of pediatric CD. Patients harboring a somatic mutation had a higher likelihood of tumor recurrence, highlighting the potential importance of this molecular defect for the disease prognosis and the development of targeted therapeutic options. Copyright © 2017 Endocrine Society

USP7 small-molecule inhibitors interfere with ubiquitin binding.

PubMed

Kategaya, Lorna; Di Lello, Paola; Rougé, Lionel; Pastor, Richard; Clark, Kevin R; Drummond, Jason; Kleinheinz, Tracy; Lin, Eva; Upton, John-Paul; Prakash, Sumit; Heideker, Johanna; McCleland, Mark; Ritorto, Maria Stella; Alessi, Dario R; Trost, Matthias; Bainbridge, Travis W; Kwok, Michael C M; Ma, Taylur P; Stiffler, Zachary; Brasher, Bradley; Tang, Yinyan; Jaishankar, Priyadarshini; Hearn, Brian R; Renslo, Adam R; Arkin, Michelle R; Cohen, Frederick; Yu, Kebing; Peale, Frank; Gnad, Florian; Chang, Matthew T; Klijn, Christiaan; Blackwood, Elizabeth; Martin, Scott E; Forrest, William F; Ernst, James A; Ndubaku, Chudi; Wang, Xiaojing; Beresini, Maureen H; Tsui, Vickie; Schwerdtfeger, Carsten; Blake, Robert A; Murray, Jeremy; Maurer, Till; Wertz, Ingrid E

2017-10-26

The ubiquitin system regulates essential cellular processes in eukaryotes. Ubiquitin is ligated to substrate proteins as monomers or chains and the topology of ubiquitin modifications regulates substrate interactions with specific proteins. Thus ubiquitination directs a variety of substrate fates including proteasomal degradation. Deubiquitinase enzymes cleave ubiquitin from substrates and are implicated in disease; for example, ubiquitin-specific protease-7 (USP7) regulates stability of the p53 tumour suppressor and other proteins critical for tumour cell survival. However, developing selective deubiquitinase inhibitors has been challenging and no co-crystal structures have been solved with small-molecule inhibitors. Here, using nuclear magnetic resonance-based screening and structure-based design, we describe the development of selective USP7 inhibitors GNE-6640 and GNE-6776. These compounds induce tumour cell death and enhance cytotoxicity with chemotherapeutic agents and targeted compounds, including PIM kinase inhibitors. Structural studies reveal that GNE-6640 and GNE-6776 non-covalently target USP7 12 Å distant from the catalytic cysteine. The compounds attenuate ubiquitin binding and thus inhibit USP7 deubiquitinase activity. GNE-6640 and GNE-6776 interact with acidic residues that mediate hydrogen-bond interactions with the ubiquitin Lys48 side chain, suggesting that USP7 preferentially interacts with and cleaves ubiquitin moieties that have free Lys48 side chains. We investigated this idea by engineering di-ubiquitin chains containing differential proximal and distal isotopic labels and measuring USP7 binding by nuclear magnetic resonance. This preferential binding protracted the depolymerization kinetics of Lys48-linked ubiquitin chains relative to Lys63-linked chains. In summary, engineering compounds that inhibit USP7 activity by attenuating ubiquitin binding suggests opportunities for developing other deubiquitinase inhibitors and may be a strategy more broadly applicable to inhibiting proteins that require ubiquitin binding for full functional activity.

Dissolution Failure of Solid Oral Drug Products in Field Alert Reports.

PubMed

Sun, Dajun; Hu, Meng; Browning, Mark; Friedman, Rick L; Jiang, Wenlei; Zhao, Liang; Wen, Hong

2017-05-01

From 2005 to 2014, 370 data entries of dissolution failures of solid oral drug products were assessed with respect to the solubility of drug substances, dosage forms [immediate release (IR) vs. modified release (MR)], and manufacturers (brand name vs. generic). The study results show that the solubility of drug substances does not play a significant role in dissolution failures; however, MR drug products fail dissolution tests more frequently than IR drug products. When multiple variables were analyzed simultaneously, poorly water-soluble IR drug products failed the most dissolution tests, followed by poorly soluble MR drug products and very soluble MR drug products. Interestingly, the generic drug products fail dissolution tests at an earlier time point during a stability study than the brand name drug products. Whether the dissolution failure of these solid oral drug products has any in vivo implication will require further pharmacokinetic, pharmacodynamic, clinical, and drug safety evaluation. Food and Drug Administration is currently conducting risk-based assessment using in-house dissolution testing, physiologically based pharmacokinetic modeling and simulation, and post-market surveillance tools. At the meantime, this interim report will outline a general scheme of monitoring dissolution failures of solid oral dosage forms as a pharmaceutical quality indicator. Published by Elsevier Inc.

Dose uniformity of scored and unscored tablets: Application of the FDA Tablet Scoring Guidance for Industry.

PubMed

Ciavarella, Anthony; Khan, Mansoor; Gupta, Abhay; Faustino, Patrick

2016-06-20

This FDA laboratory study examines the impact of tablet splitting, the effect of tablet splitters, and the presence of a tablet score on the dose uniformity of two model drugs. Whole tablets were purchased from five manufacturers for amlodipine and six for gabapentin. Two splitters were used for each drug product and the gabapentin tablets were also split by hand. Whole and split amlodipine tablets were tested for content uniformity following the general chapter of the United States Pharmacopeia (USP) Uniformity of Dosage Units <905>, which is a requirement of the new FDA Guidance for Industry on tablet scoring. The USP weight variation method was used for gabapentin split tablets based on the recommendation of the guidance. All whole tablets met the USP acceptance criteria for the Uniformity of Dosage Units. Variation in whole tablet content ranged from 0.5-2.1 standard deviation (SD) of the % label claim. Splitting the unscored amlodipine tablets resulted in a significant increase in dose variability of 6.5-25.4 SD when compared to whole tablets. Split tablets from all amlodipine drug products did not meet the USP acceptance criteria for content uniformity. Variation in the weight for gabapentin split tablets was greater than the whole tablets, ranging from 1.3-9.3 SD. All fully scored gabapentin products met the USP acceptance criteria for weight variation. Size, shape, and the presence or absence of a tablet score can affect the content uniformity and weight variation of amlodipine and gabapentin tablets. Tablet splitting produced higher variability. Differences in dose variability and fragmentation were observed between tablet splitters and hand splitting. These results are consistent with the FDA's concerns that tablet splitting "can affect how much drug is present in the split tablet and available for absorption" as stated in the guidance (1). Copyright © 2016, Parenteral Drug Association.

The DUSP–Ubl domain of USP4 enhances its catalytic efficiency by promoting ubiquitin exchange

PubMed Central

Clerici, Marcello; Luna-Vargas, Mark P. A.; Faesen, Alex C.; Sixma, Titia K.

2014-01-01

Ubiquitin-specific protease USP4 is emerging as an important regulator of cellular pathways, including the TGF-β response, NF-κB signalling and splicing, with possible roles in cancer. Here we show that USP4 has its catalytic triad arranged in a productive conformation. Nevertheless, it requires its N-terminal DUSP–Ubl domain to achieve full catalytic turnover. Pre-steady-state kinetics measurements reveal that USP4 catalytic domain activity is strongly inhibited by slow dissociation of ubiquitin after substrate hydrolysis. The DUSP–Ubl domain is able to enhance ubiquitin dissociation, hence promoting efficient turnover. In a mechanism that requires all USP4 domains, binding of the DUSP–Ubl domain promotes a change of a switching loop near the active site. This ‘allosteric regulation of product discharge’ provides a novel way of regulating deubiquitinating enzymes that may have relevance for other enzyme classes. PMID:25404403

The deubiquitinases USP33 and USP20 coordinate beta2 adrenergic receptor recycling and resensitization.

PubMed

Berthouze, Magali; Venkataramanan, Vidya; Li, Yi; Shenoy, Sudha K

2009-06-17

Agonist-induced ubiquitination of the beta(2) adrenergic receptor (beta(2)AR) functions as an important post-translational modification to sort internalized receptors to the lysosomes for degradation. We now show that this ubiquitination is reversed by two deubiquitinating enzymes, ubiquitin-specific proteases (USPs) 20 and 33, thus, inhibiting lysosomal trafficking when concomitantly promoting receptor recycling from the late-endosomal compartments as well as resensitization of recycled receptors at the cell surface. Dissociation of constitutively bound endogenously expressed USPs 20 and 33 from the beta(2)AR immediately after agonist stimulation and reassociation on prolonged agonist treatment allows receptors to first become ubiquitinated and then deubiquitinated, thus, providing a 'trip switch' between degradative and recycling pathways at the late-endosomal compartments. Thus, USPs 20 and 33 serve as novel regulators that dictate both post-endocytic sorting as well as the intensity and extent of beta(2)AR signalling from the cell surface.

Industry's View on Using Quality Control, Biorelevant, and Clinically Relevant Dissolution Tests for Pharmaceutical Development, Registration, and Commercialization.

PubMed

Grady, Haiyan; Elder, David; Webster, Gregory K; Mao, Yun; Lin, Yiqing; Flanagan, Talia; Mann, James; Blanchard, Andy; Cohen, Michael J; Lin, Judy; Kesisoglou, Filippos; Hermans, Andre; Abend, Andreas; Zhang, Limin; Curran, David

2018-01-01

This article intends to summarize the current views of the IQ Consortium Dissolution Working Group, which comprises various industry companies, on the roles of dissolution testing throughout pharmaceutical product development, registration, commercialization, and beyond. Over the past 3 decades, dissolution testing has evolved from a routine and straightforward test as a component of end-product release into a comprehensive set of tools that the developer can deploy at various stages of the product life cycle. The definitions of commonly used dissolution approaches, how they relate to one another and how they may be applied in modern drug development, and life cycle management is described in this article. Specifically, this article discusses the purpose, advantages, and limitations of quality control, biorelevant, and clinically relevant dissolution methods. Copyright © 2018 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Ketoprofen suppository dosage forms: in vitro release and in vivo absorption studies in rabbits.

PubMed

Babar, A; Bellete, T; Plakogiannis, F M

1999-02-01

In vitro release of ketoprofen from suppository bases and in vivo absorption in rabbits were studied. Suppositories containing 50 mg of ketoprofen were prepared using theobroma oil, esterified (c10-c18) fatty acids, and polyethylene glycol 1000 bases. The displacement values of the drug were determined and found to be of the order of theobroma oil > esterified (c10-c18) fatty acids and polyethylene glycol 1000 bases. The suppository hardness data revealed that the theobroma oil base produced relatively brittle suppositories. Using the USP dissolution method, the release of ketoprofen was observed to be greatest from polyethylene glycol 1000 suppositories. With the dialysis technique, the maximum release of drug was obtained from theobroma oil suppository containing polysorbate 40 at a 6% level. Selected suppository formulations were evaluated for rectal absorption studies in rabbits. The in vivo data showed that the optimum drug absorption took place from the polyethylene glycol 1000 base and theobroma oil formulation containing 6% polysorbate 40.

A Content Analysis of Unique Selling Propositions of Tobacco Print Ads.

PubMed

Johnson Shen, Megan; Banerjee, Smita C; Greene, Kathryn; Carpenter, Amanda; Ostroff, Jamie S

2017-03-01

We describe the unique selling propositions (USPs) (propositions used to convince customers to use a particular brand/product by focusing on the unique benefit) of print tobacco ads. A qualitative content analysis was conducted of print tobacco ads (N = 171) selected from August 2012 to August 2013 for cigarettes, moist snuff, e-cigarettes, cigars, and snus to determine the content and themes of USPs for tobacco ads. Cigarette ad USP themes focused on portraying the product as attractive; moist snuff ads focused on portraying product as masculine; cigar ads focused on selling a "high end product;" and new and emerging tobacco products (e-cigarette, snus) focused on directly comparing these products to cigarettes. Whereas traditional tobacco product ads used USPs focused on themes of enjoyment and pleasure (eg, attractive for cigarettes, "high end product" for cigars), new and emerging tobacco product ads offered the unique benefit (USP) of their product being a better and "safer" alternative to traditional tobacco products. Snuff's USPs focused nearly exclusively on the masculinity of their products. Our results provide targets for potential tobacco regulatory actions that could be implemented to reduce demand for tobacco products by reducing their perceived unique benefits.

Saturation scanning of ubiquitin variants reveals a common hot spot for binding to USP2 and USP21.

PubMed

Leung, Isabel; Dekel, Ayelet; Shifman, Julia M; Sidhu, Sachdev S

2016-08-02

A detailed understanding of the molecular mechanisms whereby ubiquitin (Ub) recognizes enzymes in the Ub proteasome system is crucial for understanding the biological function of Ub. Many structures of Ub complexes have been solved and, in most cases, reveal a large structural epitope on a common face of the Ub molecule. However, owing to the generally weak nature of these interactions, it has been difficult to map in detail the functional contributions of individual Ub side chains to affinity and specificity. Here we took advantage of Ub variants (Ubvs) that bind tightly to particular Ub-specific proteases (USPs) and used phage display and saturation scanning mutagenesis to comprehensively map functional epitopes within the structural epitopes. We found that Ubvs that bind to USP2 or USP21 contain a remarkably similar core functional epitope, or "hot spot," consisting mainly of positions that are conserved as the wild type sequence, but also some positions that prefer mutant sequences. The Ubv core functional epitope contacts residues that are conserved in the human USP family, and thus it is likely important for the interactions of Ub across many family members.

Development of matrix-based theophylline sustained-release microtablets.

PubMed

Rey, H; Wagner, K G; Wehrlé, P; Schmidt, P C

2000-01-01

Microtablets containing high theophylline content (from 60% to 80%) based on a Eudragit RS PO matrix were produced on a rotary tablet press. The influence of the compaction pressure, the plasticizer content used for the granulation of theophylline particles, and the amount of theophylline on the drug release were investigated. The effects of surface area and the addition of magnesium stearate as a hydrophobic agent on the drug release were studied. The storage stabilities of the release rate at room temperature and at 50 degrees C were also determined. Dissolution profiles expressed as percentage of theophylline dissolved were obtained over 8 hr in 900 ml of purified water at 37 degrees C and 75 rpm. It was observed that the compaction pressure (from 200 MPa to 250 MPa) had no effect on the theophylline release. The use of triethyl citrate (TEC) as a plasticizer in the granulation of theophylline enhanced the physical properties of the microtablets. Theophylline content in the range 60% to 80% did not affect the drug release. The theophylline release obtained was a function of the quotient surface area/tablet weight and therefore was dependent on the tablet diameter. To reduce the dissolution rates, magnesium stearate was added in a concentration up to 50% of the matrix material. Tablets of this hydrophobic formulation fulfilled the requirements of USP 23 for theophylline sustained-release preparations. Storage at room temperature for 3 months and at 50 degrees C for 2 months showed no significant influence on the theophylline release.

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.

Dissolution comparisons using a Multivariate Statistical Distance (MSD) test and a comparison of various approaches for calculating the measurements of dissolution profile comparison.

PubMed

Cardot, J-M; Roudier, B; Schütz, H

2017-07-01

The f 2 test is generally used for comparing dissolution profiles. In cases of high variability, the f 2 test is not applicable, and the Multivariate Statistical Distance (MSD) test is frequently proposed as an alternative by the FDA and EMA. The guidelines provide only general recommendations. MSD tests can be performed either on raw data with or without time as a variable or on parameters of models. In addition, data can be limited-as in the case of the f 2 test-to dissolutions of up to 85% or to all available data. In the context of the present paper, the recommended calculation included all raw dissolution data up to the first point greater than 85% as a variable-without the various times as parameters. The proposed MSD overcomes several drawbacks found in other methods.

Studies of inactivation mechanism of non-enveloped icosahedral virus by a visible ultrashort pulsed laser

PubMed Central

2014-01-01

Background Low-power ultrashort pulsed (USP) lasers operating at wavelengths of 425 nm and near infrared region have been shown to effectively inactivate viruses such as human immunodeficiency virus (HIV), M13 bacteriophage, and murine cytomegalovirus (MCMV). It was shown previously that non-enveloped, helical viruses such as M13 bacteriophage, were inactivated by a USP laser through an impulsive stimulated Raman scattering (ISRS) process. Recently, enveloped virus like MCMV has been shown to be inactivated by a USP laser via protein aggregation induced by an ISRS process. However, the inactivation mechanism for a clinically important class of viruses – non-enveloped, icosahedral viruses remains unknown. Results and discussions We have ruled out the following four possible inactivation mechanisms for non-enveloped, icosahedral viruses, namely, (1) inactivation due to ultraviolet C (UVC) photons produced by non-linear optical process of the intense, fundamental laser beam at 425 nm; (2) inactivation caused by thermal heating generated by the direct laser absorption/heating of the virion; (3) inactivation resulting from a one-photon absorption process via chromophores such as porphyrin molecules, or indicator dyes, potentially producing reactive oxygen or other species; (4) inactivation by the USP lasers in which the extremely intense laser pulse produces shock wave-like vibrations upon impact with the viral particle. We present data which support that the inactivation mechanism for non-enveloped, icosahedral viruses is the impulsive stimulated Raman scattering process. Real-time PCR experiments show that, within the amplicon size of 273 bp tested, there is no damage on the genome of MNV-1 caused by the USP laser irradiation. Conclusion We conclude that our model non-enveloped virus, MNV-1, is inactivated by the ISRS process. These studies provide fundamental knowledge on photon-virus interactions on femtosecond time scales. From the analysis of the transmission electron microscope (TEM) images of viral particles before and after USP laser irradiation, the locations of weak structural links on the capsid of MNV-1 were revealed. This important information will greatly aid our understanding of the structure of non-enveloped, icosahedral viruses. We envision that this non-invasive, efficient viral eradication method will find applications in the disinfection of pharmaceuticals, biologicals and blood products in the near future. PMID:24495489

Data integration in physiology using Bayes’ rule and minimum Bayes’ factors: deubiquitylating enzymes in the renal collecting duct

PubMed Central

Xue, Zhe; Chen, Jia-Xu; Zhao, Yue; Medvar, Barbara

2017-01-01

A major challenge in physiology is to exploit the many large-scale data sets available from “-omic” studies to seek answers to key physiological questions. In previous studies, Bayes’ theorem has been used for this purpose. This approach requires a means to map continuously distributed experimental data to probabilities (likelihood values) to derive posterior probabilities from the combination of prior probabilities and new data. Here, we introduce the use of minimum Bayes’ factors for this purpose and illustrate the approach by addressing a physiological question, “Which deubiquitylating enzymes (DUBs) encoded by mammalian genomes are most likely to regulate plasma membrane transport processes in renal cortical collecting duct principal cells?” To do this, we have created a comprehensive online database of 110 DUBs present in the mammalian genome (https://hpcwebapps.cit.nih.gov/ESBL/Database/DUBs/). We used Bayes’ theorem to integrate available information from large-scale data sets derived from proteomic and transcriptomic studies of renal collecting duct cells to rank the 110 known DUBs with regard to likelihood of interacting with and regulating transport processes. The top-ranked DUBs were OTUB1, USP14, PSMD7, PSMD14, USP7, USP9X, OTUD4, USP10, and UCHL5. Among these USP7, USP9X, OTUD4, and USP10 are known to be involved in endosomal trafficking and have potential roles in endosomal recycling of plasma membrane proteins in the mammalian cortical collecting duct. PMID:28039431

Data integration in physiology using Bayes' rule and minimum Bayes' factors: deubiquitylating enzymes in the renal collecting duct.

PubMed

Xue, Zhe; Chen, Jia-Xu; Zhao, Yue; Medvar, Barbara; Knepper, Mark A

2017-03-01

A major challenge in physiology is to exploit the many large-scale data sets available from "-omic" studies to seek answers to key physiological questions. In previous studies, Bayes' theorem has been used for this purpose. This approach requires a means to map continuously distributed experimental data to probabilities (likelihood values) to derive posterior probabilities from the combination of prior probabilities and new data. Here, we introduce the use of minimum Bayes' factors for this purpose and illustrate the approach by addressing a physiological question, "Which deubiquitylating enzymes (DUBs) encoded by mammalian genomes are most likely to regulate plasma membrane transport processes in renal cortical collecting duct principal cells?" To do this, we have created a comprehensive online database of 110 DUBs present in the mammalian genome (https://hpcwebapps.cit.nih.gov/ESBL/Database/DUBs/). We used Bayes' theorem to integrate available information from large-scale data sets derived from proteomic and transcriptomic studies of renal collecting duct cells to rank the 110 known DUBs with regard to likelihood of interacting with and regulating transport processes. The top-ranked DUBs were OTUB1, USP14, PSMD7, PSMD14, USP7, USP9X, OTUD4, USP10, and UCHL5. Among these USP7, USP9X, OTUD4, and USP10 are known to be involved in endosomal trafficking and have potential roles in endosomal recycling of plasma membrane proteins in the mammalian cortical collecting duct. Copyright © 2017 the American Physiological Society.

Recent advances in testing of microsphere drug delivery systems.

PubMed

Andhariya, Janki V; Burgess, Diane J

2016-01-01

This review discusses advances in the field of microsphere testing. In vitro release-testing methods such as sample and separate, dialysis membrane sacs and USP apparatus IV have been used for microspheres. Based on comparisons of these methods, USP apparatus IV is currently the method of choice. Accelerated in vitro release tests have been developed to shorten the testing time for quality control purposes. In vitro-in vivo correlations using real-time and accelerated release data have been developed, to minimize the need to conduct in vivo performance evaluation. Storage stability studies have been conducted to investigate the influence of various environmental factors on microsphere quality throughout the product shelf life. New tests such as the floating test and the in vitro wash-off test have been developed along with advancement in characterization techniques for other physico-chemical parameters such as particle size, drug content, and thermal properties. Although significant developments have been made in microsphere release testing, there is still a lack of guidance in this area. Microsphere storage stability studies should be extended to include microspheres containing large molecules. An agreement needs to be reached on the use of particle sizing techniques to avoid inconsistent data. An approach needs to be developed to determine total moisture content of microspheres.

Artificial Recruitment of UAF1-USP Complexes by a PHLPP1-E1 Chimeric Helicase Enhances Human Papillomavirus DNA Replication

PubMed Central

Gagnon, David; Lehoux, Michaël

2015-01-01

ABSTRACT The E1 helicase from anogenital human papillomavirus (HPV) types interacts with the cellular WD repeat-containing protein UAF1 in complex with the deubiquitinating enzyme USP1, USP12, or USP46. This interaction stimulates viral DNA replication and is required for maintenance of the viral episome in keratinocytes. E1 associates with UAF1 through a short UAF1-binding site (UBS) located within the N-terminal 40 residues of the protein. Here, we investigated if the E1 UBS could be replaced by the analogous domain from an unrelated protein, the pleckstrin homology domain and leucine-rich repeat protein phosphatase 1 (PHLPP1). We found that PHLPP1 and E1 interact with UAF1 in a mutually exclusive manner and mapped the minimal PHLPP1 UBS (PUBS) to a 100-amino-acid region sufficient for assembly into UAF1-USP complexes. Similarly to the E1 UBS, overexpression of PUBS in trans inhibited HPV DNA replication, albeit less efficiently. Characterization of a PHLPP1-E1 chimeric helicase revealed that PUBS could partially substitute for the E1 UBS in enhancing viral DNA replication and that the stimulatory effect of PUBS likely involves recruitment of UAF1-USP complexes, as it was abolished by mutations that weaken UAF1-binding and by overexpression of catalytically inactive USPs. Although functionally similar to the E1 UBS, PUBS is larger in size and requires both the WD repeat region and C-terminal ubiquitin-like domain of UAF1 for interaction, in contrast to E1, which does not contact the latter. Overall, this comparison of two heterologous UBSs indicates that these domains function as transferable protein interaction modules and provide further evidence that the association of E1 with UAF1-containing deubiquitinating complexes stimulates HPV DNA replication. IMPORTANCE The E1 protein from anogenital HPV types interacts with the UAF1-associated deubiquitinating enzymes USP1, USP12, and USP46 to stimulate replication of the viral genome. Little is known about the molecular nature of the E1-UAF1 interaction and, more generally, how UAF1-USP complexes recognize their substrate proteins. To address this question, we characterized the UAF1-binding site (UBS) of PHLPP1, a protein unrelated to E1. Using a PHLPP1-E1 chimeric helicase, we show that the PHLPP1 UBS (PUBS) can partially substitute for the E1 UBS in stimulating HPV DNA replication. This stimulation required conserved sequences in PUBS that meditate its interaction with UAF1, including a motif common to the E1 UBS. These results indicate that UAF1-binding sequences function as transferable protein interaction modules and provide further evidence that UAF1-USP complexes stimulate HPV DNA replication. PMID:25833051

Artificial Recruitment of UAF1-USP Complexes by a PHLPP1-E1 Chimeric Helicase Enhances Human Papillomavirus DNA Replication.

PubMed

Gagnon, David; Lehoux, Michaël; Archambault, Jacques

2015-06-01

The E1 helicase from anogenital human papillomavirus (HPV) types interacts with the cellular WD repeat-containing protein UAF1 in complex with the deubiquitinating enzyme USP1, USP12, or USP46. This interaction stimulates viral DNA replication and is required for maintenance of the viral episome in keratinocytes. E1 associates with UAF1 through a short UAF1-binding site (UBS) located within the N-terminal 40 residues of the protein. Here, we investigated if the E1 UBS could be replaced by the analogous domain from an unrelated protein, the pleckstrin homology domain and leucine-rich repeat protein phosphatase 1 (PHLPP1). We found that PHLPP1 and E1 interact with UAF1 in a mutually exclusive manner and mapped the minimal PHLPP1 UBS (PUBS) to a 100-amino-acid region sufficient for assembly into UAF1-USP complexes. Similarly to the E1 UBS, overexpression of PUBS in trans inhibited HPV DNA replication, albeit less efficiently. Characterization of a PHLPP1-E1 chimeric helicase revealed that PUBS could partially substitute for the E1 UBS in enhancing viral DNA replication and that the stimulatory effect of PUBS likely involves recruitment of UAF1-USP complexes, as it was abolished by mutations that weaken UAF1-binding and by overexpression of catalytically inactive USPs. Although functionally similar to the E1 UBS, PUBS is larger in size and requires both the WD repeat region and C-terminal ubiquitin-like domain of UAF1 for interaction, in contrast to E1, which does not contact the latter. Overall, this comparison of two heterologous UBSs indicates that these domains function as transferable protein interaction modules and provide further evidence that the association of E1 with UAF1-containing deubiquitinating complexes stimulates HPV DNA replication. The E1 protein from anogenital HPV types interacts with the UAF1-associated deubiquitinating enzymes USP1, USP12, and USP46 to stimulate replication of the viral genome. Little is known about the molecular nature of the E1-UAF1 interaction and, more generally, how UAF1-USP complexes recognize their substrate proteins. To address this question, we characterized the UAF1-binding site (UBS) of PHLPP1, a protein unrelated to E1. Using a PHLPP1-E1 chimeric helicase, we show that the PHLPP1 UBS (PUBS) can partially substitute for the E1 UBS in stimulating HPV DNA replication. This stimulation required conserved sequences in PUBS that meditate its interaction with UAF1, including a motif common to the E1 UBS. These results indicate that UAF1-binding sequences function as transferable protein interaction modules and provide further evidence that UAF1-USP complexes stimulate HPV DNA replication. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Dissolution enhancement of tadalafil by liquisolid technique.

PubMed

Lu, Mei; Xing, Haonan; Yang, Tianzhi; Yu, Jiankun; Yang, Zhen; Sun, Yanping; Ding, Pingtian

2017-02-01

This study aimed to enhance the dissolution of tadalafil, a poorly water-soluble drug by applying liquisolid technique. The effects of two critical formulation variables, namely drug concentration (17.5% and 35%, w/w) and excipients ratio (10, 15 and 20) on dissolution rates were investigated. Pre-compression tests, including particle size distribution, flowability determination, Fourier transform infrared (FT-IR), differential scanning calorimetry (DSC), X-ray diffractometry (XRD) and scanning electron microscopy (SEM), were carried out to investigate the mechanism of dissolution enhancement. Tadalafil liquisolid tablets were prepared and their quality control tests, dissolution study, contact angle measurement, Raman mapping, and storage stability test were performed. The results suggested that all the liquisolid tablets exhibited significantly higher dissolution rates than the conventional tablets and pure tadalafil. FT-IR spectrum reflected no drug-excipient interactions. DSC and XRD studies indicated reduction in crystallinity of tadalafil, which was further confirmed by SEM and Raman mapping outcomes. The contact angle measurement demonstrated obvious increase in wetting property. Taken together, the reduction of particle size and crystallinity, and the improvement of wettability were the main mechanisms for the enhanced dissolution rate. No significant changes were observed in drug crystallinity and dissolution behavior after storage based on XRD, SEM and dissolution results.

Comprehensive validation scheme for in situ fiber optics dissolution method for pharmaceutical drug product testing.

PubMed

Mirza, Tahseen; Liu, Qian Julie; Vivilecchia, Richard; Joshi, Yatindra

2009-03-01

There has been a growing interest during the past decade in the use of fiber optics dissolution testing. Use of this novel technology is mainly confined to research and development laboratories. It has not yet emerged as a tool for end product release testing despite its ability to generate in situ results and efficiency improvement. One potential reason may be the lack of clear validation guidelines that can be applied for the assessment of suitability of fiber optics. This article describes a comprehensive validation scheme and development of a reliable, robust, reproducible and cost-effective dissolution test using fiber optics technology. The test was successfully applied for characterizing the dissolution behavior of a 40-mg immediate-release tablet dosage form that is under development at Novartis Pharmaceuticals, East Hanover, New Jersey. The method was validated for the following parameters: linearity, precision, accuracy, specificity, and robustness. In particular, robustness was evaluated in terms of probe sampling depth and probe orientation. The in situ fiber optic method was found to be comparable to the existing manual sampling dissolution method. Finally, the fiber optic dissolution test was successfully performed by different operators on different days, to further enhance the validity of the method. The results demonstrate that the fiber optics technology can be successfully validated for end product dissolution/release testing. (c) 2008 Wiley-Liss, Inc. and the American Pharmacists Association

Equivalence studies for complex active ingredients and dosage forms.

PubMed

Bhattycharyya, Lokesh; Dabbah, Roger; Hauck, Walter; Sheinin, Eric; Yeoman, Lynn; Williams, Roger

2005-11-17

This article examines the United States Pharmacopeia (USP) and its role in assessing the equivalence and inequivalence of biological and biotechnological drug substances and products-a role USP has played since its founding in 1820. A public monograph in the United States Pharmacopeia-National Formulary helps practitioners and other interested parties understand how an article's strength, quality, and purity should be controlled. Such a monograph is a standard to which all manufactured ingredients and products should conform, and it is a starting point for subsequent-entry manufacturers, recognizing that substantial additional one-time characterization studies may be needed to document equivalence. Review of these studies is the province of the regulatory agency, but compendial tests can provide clarity and guidance in the process.

Tannate complexes of antihistaminic drug: sustained release and taste masking approaches.

PubMed

Rahman, Ziyaur; Zidan, Ahmed S; Berendt, Robert T; Khan, Mansoor A

2012-01-17

The aim of this investigation was to evaluate the complexation potential of brompheniramine maleate (BPM) and tannic acid (TA) for sustained release and taste masking effects. The complexes (1:1-1:7 TA to BPM ratio) were prepared by the solvent evaporation method using methanol, phosphate buffer pH 6.8 or 0.1N HCl as common solvents. The complexes were characterized microscopically by scanning electron microscopy (SEM), chemically by Fourier transform infrared (FTIR) and solid-state NMR (SSNMR), thermally by differential scanning calorimetry (DSC), for crystallinity by powder X-ray powder diffraction (PXRD), for organoleptic evaluation by electronic tongue (e-tongue), and for solubility in 0.1N HCl and phosphate buffer pH 6.8. The dissolution studies were carried out using the USP II method at 50 rpm in 500 ml of dissolution media (0.1N HCl or phosphate buffer pH 6.8). SEM images revealed that the morphology of complexes were completely different from the individual components, and all complexes had the same morphological characteristics, irrespective of the solvent used for their preparation, pH or ratio of BPM and TA. The FTIR spectra showed the presence of chemical interactions between the TA and BPM. DSC, PXRD and SSNMR indicated that the drug lost its crystalline nature by formation of the complex. Complexation has significantly reduced the solubility of BPM and sustained the drug release up to 24h in phosphate buffer pH 6.8 media. The bitter taste of the BPM was completely masked which was indicated by Euclidean distance values which was far from the drug but near to its placebo in the complexes in all ratios studied. The taste masked complexes can be potentially developed as suitable dosage forms for pediatric use. In summary, complexation of BPM and TA effectively sustained the dissolution and masked the bitter taste of drug for the development of suitable dosage forms for pediatric use. Published by Elsevier B.V.

In-vitro characterization of 5-aminosalicylic acid release from MMX mesalamine tablets and determination of tablet coating thickness.

PubMed

Tenjarla, Srini; Abinusawa, Adeyinka

2011-01-01

Substantial variability in gastrointestinal pH is observed in patients with ulcerative colitis (UC). We characterized the effect of pH on 5-aminosalicylic acid (5-ASA) release from MMX mesalamine tablets (Shire Pharmaceuticals Inc., Wayne, PA, USA), examined thickness/uniformity of tablet film coatings, and explored the influence of simulating altered gastrointestinal motility. Nondestructive, three-dimensional, terahertz pulse imaging (TPI) was used to characterize the film coating of three lots of MMX mesalamine tablets (n=36). Thereafter, 5-ASA release from these tablets was evaluated using United States Pharmacopeia (USP) apparatus II at pH 6.8 and 7.2. Onset of tablet film-coat breach and mean dissolution time were determined for each lot. 5-ASA release was also assessed at three different paddle rotation speeds (50, 75, and 100 rpm) at pH 7.2. The mean ± SD film-coating thickness of the three lots of MMX mesalamine tablets were 109.2 ± 16.8, 113.1 ± 19.5, and 113.8 ± 19.8 μM, respectively. At pH 6.8 (100 rpm), the onset of film-coat breach was 10-30 minutes, whereas at pH 7.2 this was observed within 10 minutes. 5-ASA release was uniform at both pH conditions, with minimal lot-to-lot variability. Complete drug release was achieved within 6 hours under both pH conditions. 5-ASA release increased in proportion with paddle speed, but remained prolonged at all speeds. 5-ASA release from MMX mesalamine is unaffected by normal variations in simulated intracolonic pH. The dissolution profile of 5-ASA from MMX mesalamine tablets may be attributed to consistent outer film coatings and the hydrogel-forming matrix that controls the drug release after dissolution of the film coating.

Channelled tablets: An innovative approach to accelerating drug release from 3D printed tablets.

PubMed

Sadia, Muzna; Arafat, Basel; Ahmed, Waqar; Forbes, Robert T; Alhnan, Mohamed A

2018-01-10

Conventional immediate release dosage forms involve compressing the powder with a disintegrating agent that enables rapid disintegration and dissolution upon oral ingestion. Among 3D printing technologies, the fused deposition modelling (FDM) 3D printing technique has a considerable potential for patient-specific dosage forms. However, the use of FDM 3D printing in tablet manufacturing requires a large portion of polymer, which slows down drug release through erosion and diffusion mechanisms. In this study, we demonstrate for the first time the use of a novel design approach of caplets with perforated channels to accelerate drug release from 3D printed tablets. This strategy has been implemented using a caplet design with perforating channels of increasing width (0.2, 0.4, 0.6, 0.8 or 1.0mm) and variable length, and alignment (parallel or at right angle to tablet long axis). Hydrochlorothiazide (BCS class IV drug) was chosen as the model drug as enhanced dissolution rate is vital to guarantee oral bioavailability. The inclusion of channels exhibited an increase in the surface area/volume ratio, however, the release pattern was also influenced by the width and the length of the channel. A channel width was ≥0.6mm deemed critical to meet the USP criteria of immediate release products. Shorter multiple channels (8.6mm) were more efficient at accelerating drug release than longer channels (18.2mm) despite having comparable surface area/mass ratio. This behaviour may be linked to the reduced flow resistance within the channels and the faster fragmentation during dissolution of these tablets. In conclusion, the width and length of the channel should be carefully considered in addition to surface area/mass when optimizing drug release from 3D printed designs. The incorporation of short channels can be adopted in the designs of dosage forms, implants or stents to enhance the release rate of eluting drug from polymer-rich structures. Copyright © 2017 Elsevier B.V. All rights reserved.

Droplet-size distribution and stability of commercial injectable lipid emulsions containing fish oil.

PubMed

Gallegos, Críspulo; Valencia, Concepción; Partal, Pedro; Franco, José M; Maglio, Omay; Abrahamsson, Malin; Brito-de la Fuente, Edmundo

2012-08-01

The droplet size of commercial fish oil-containing injectable lipid emulsions, including conformance to United States Pharmacopeia (USP) standards on fat-globule size, was investigated. A total of 18 batches of three multichamber parenteral products containing the emulsion SMOFlipid as a component were analyzed. Samples from multiple lots of the products were evaluated to determine compliance with standards on the volume-weighted percentage of fat exceeding 0.05% (PFAT(5)) specified in USP chapter 729 to ensure the physical stability of i.v. lipid emulsions. The products were also analyzed to determine the effects of various storage times (3, 6, 9, and 12 months) and storage temperatures (25, 30, and 40 °C) on product stability. Larger-size lipid particles were quantified via single-particle optical sensing (SPOS). The emulsion's droplet-size distribution was determined via laser light scattering. SPOS and light-scattering analysis demonstrated mean PFAT(5) values well below USP-specified globule-size limits for all the tested products under all study conditions. In addition, emulsion aging at any storage temperature in the range studied did not result in a significant increase of PFAT(5) values, and mean droplet-size values did not change significantly during storage of up to 12 months at temperatures of 25-40 °C. PFAT(5) values were below the USP upper limits in SMOFlipid samples from multiple lots of three multichamber products after up to 12 months of storage at 25 or 30 °C or 6 months of storage at 40 °C.

Coherent anti-Stokes Raman Scattering (CARS) Microscopy Visualizes Pharmaceutical Tablets During Dissolution

PubMed Central

Fussell, Andrew L.; Kleinebudde, Peter; Herek, Jennifer; Strachan, Clare J.; Offerhaus, Herman L.

2014-01-01

Traditional pharmaceutical dissolution tests determine the amount of drug dissolved over time by measuring drug content in the dissolution medium. This method provides little direct information about what is happening on the surface of the dissolving tablet. As the tablet surface composition and structure can change during dissolution, it is essential to monitor it during dissolution testing. In this work coherent anti-Stokes Raman scattering microscopy is used to image the surface of tablets during dissolution while UV absorption spectroscopy is simultaneously providing inline analysis of dissolved drug concentration for tablets containing a 50% mixture of theophylline anhydrate and ethyl cellulose. The measurements showed that in situ CARS microscopy is capable of imaging selectively theophylline in the presence of ethyl cellulose. Additionally, the theophylline anhydrate converted to theophylline monohydrate during dissolution, with needle-shaped crystals growing on the tablet surface during dissolution. The conversion of theophylline anhydrate to monohydrate, combined with reduced exposure of the drug to the flowing dissolution medium resulted in decreased dissolution rates. Our results show that in situ CARS microscopy combined with inline UV absorption spectroscopy is capable of monitoring pharmaceutical tablet dissolution and correlating surface changes with changes in dissolution rate. PMID:25045833

USP21 regulates Hippo pathway activity by mediating MARK protein turnover.

PubMed

Nguyen, Hung Thanh; Kugler, Jan-Michael; Loya, Anand C; Cohen, Stephen M

2017-09-08

The Hippo pathway, which acts to repress the activity of YAP and TAZ trancriptional co-activators, serve as a barrier for oncogenic transformation. Unlike other oncoproteins, YAP and TAZ are rarely activated by mutations or amplified in cancer. However, elevated YAP/TAZ activity is frequently observed in cancer and often correlates with worse survival. The activity and stability of Hippo pathway components, including YAP/TAZ, AMOT and LATS1/2, are regulated by ubiquitin-mediated protein degradation. Aberrant expression of ubiquitin ligase complexes that regulate the turnover of Hippo components and deubiquitylating enzymes that counteract these ubiquitin ligases have been implicated in human cancer. Here we identify the USP21 deubiquitylating enzyme as a novel regulator of Hippo pathway activity. We provide evidence that USP21 regulates YAP/TAZ activity by controlling the stability of MARK kinases, which promote Hippo signaling. Low expression of USP21 in early stage renal clear cell carcinoma suggests that USP21 may be a useful biomarker.

Can laboratory and pilot recycling trials predict adhesive removal in commercial recycling systems? : results from the USPS environmentally benign stamp project

Treesearch

Carl Houtman; Daniel Seiter; Nancy Ross Sutherland; Donald Donermeyer

2002-01-01

The ultimate goal of the US Postal Service (USPS) Environmentally Benign Stamp Program is to develop stamp laminates, i.e., face paper, adhesive and siliconized liner, that do not cause difficulties in recycling mills. The criterion for success, and the USPS definition of benignity, is the avoidance of process and product quality hardships when such PSA laminates are...

A Content Analysis of Unique Selling Propositions of Tobacco Print Ads

PubMed Central

Shen, Megan Johnson; Banerjee, Smita C.; Greene, Kathryn; Carpenter, Amanda; Ostroff, Jamie S.

2017-01-01

Objectives The present study described the unique selling propositions (USPs) (propositions used to convince customers to use a particular brand/product by focusing on the unique benefit) of print tobacco ads. Methods A qualitative content analysis was conducted of print tobacco ads (N = 171) selected from August 2012-August 2013 for cigarettes, moist snuff, e-cigarettes, cigars, and snus to determine the content and themes of USPs for tobacco ads. Results Cigarette ad USP themes focused on portraying the product as attractive; moist snuff ads focused on portraying product as masculine; cigar ads focused on selling a “high end product;” and new and emerging tobacco products (e-cigarette, snus) focused on directly comparing these products to cigarettes. Conclusions Whereas traditional tobacco product ads used USPs focused on themes of enjoyment and pleasure (eg, attractive for cigarettes, “high end product” for cigars), new and emerging tobacco product ads offered the unique benefit (USP) of their product being a better and “safer” alternative to traditional tobacco products. Snuff’s USPs focused nearly exclusively on the masculinity of their products. Results of this study provide targets for potential tobacco regulatory actions that could be implemented to reduce demand for tobacco products by reducing their perceived unique benefits. PMID:28452697

USP4 inhibits SMAD4 monoubiquitination and promotes activin and BMP signaling.

PubMed

Zhou, Fangfang; Xie, Feng; Jin, Ke; Zhang, Zhengkui; Clerici, Marcello; Gao, Rui; van Dinther, Maarten; Sixma, Titia K; Huang, Huizhe; Zhang, Long; Ten Dijke, Peter

2017-06-01

SMAD4 is a common intracellular effector for TGF-β family cytokines, but the mechanism by which its activity is dynamically regulated is unclear. We demonstrated that ubiquitin-specific protease (USP) 4 strongly induces activin/BMP signaling by removing the inhibitory monoubiquitination from SMAD4. This modification was triggered by the recruitment of the E3 ligase, SMURF2, to SMAD4 following ligand-induced regulatory (R)-SMAD-SMAD4 complex formation. Whereas the interaction of the negative regulator c-SKI inhibits SMAD4 monoubiquitination, the ligand stimulates the recruitment of SMURF2 to the c-SKI-SMAD2 complex and triggers c-SKI ubiquitination and degradation. Thus, SMURF2 has a role in termination and initiation of TGF-β family signaling. An increase in monoubiquitinated SMAD4 in USP4-depleted mouse embryonic stem cells (mESCs) decreased both the BMP- and activin-induced changes in the embryonic stem cell fate. USP4 sustained SMAD4 activity during activin- and BMP-mediated morphogenic events in early zebrafish embryos. Moreover, zebrafish depleted of USP4 exhibited defective cell migration and slower coordinated cell movement known as epiboly, both of which could be rescued by SMAD4. Therefore, USP4 is a critical determinant of SMAD4 activity. © 2017 The Authors.

USP7 Attenuates Hepatic Gluconeogenesis Through Modulation of FoxO1 Gene Promoter Occupancy

PubMed Central

Hall, Jessica A.; Tabata, Mitsuhisa; Rodgers, Joseph T.

2014-01-01

Hepatic forkhead protein FoxO1 is a key component of systemic glucose homeostasis via its ability to regulate the transcription of rate-limiting enzymes in gluconeogenesis. Important in the regulation of FoxO1 transcriptional activity are the modifying/demodifying enzymes that lead to posttranslational modification. Here, we demonstrate the functional interaction and regulation of FoxO1 by herpesvirus-associated ubiquitin-specific protease 7 (USP7; also known as herpesvirus-associated ubiquitin-specific protease, HAUSP), a deubiquitinating enzyme. We show that USP7-mediated mono-deubiquitination of FoxO1 results in suppression of FoxO1 transcriptional activity through decreased FoxO1 occupancy on the promoters of gluconeogenic genes. Knockdown of USP7 in primary hepatocytes leads to increased expression of FoxO1-target gluconeogenic genes and elevated glucose production. Consistent with this, USP7 gain-of-function suppresses the fasting/cAMP-induced activation of gluconeogenic genes in hepatocyte cells and in mouse liver, resulting in decreased hepatic glucose production. Notably, we show that the effects of USP7 on hepatic glucose metabolism depend on FoxO1. Together, these results place FoxO1 under the intimate regulation of deubiquitination and glucose metabolic control with important implication in diseases such as diabetes. PMID:24694308

Insight into the Development of Dissolution Media for BCS Class II Drugs: A Review from Quality Control and Prediction of In Vivo Performance Perspectives.

PubMed

Wu, Chunnuan; Liu, Yan; He, Zhonggui; Sun, Jin

2016-01-01

To assess in vivo behavior through in vitro method, the dissolution test is mostly used, both for quality control (QC) and for development purpose. In view of the fact that a dissolution test can hardly achieve two goals at the same time, the design of dissolution testing generally varies along with the development stage of drug products and therefore the selection of dissolution media may change with the goals of the dissolution test. To serve the QC purpose, a dissolution medium is designed to provide a sink condition; for development purpose, the dissolution medium is required to simulate the physiological conditions in the gastrointestinal tract as far as possible. In this review, we intended to provide an initial introduction to the various dissolution media applied for QC and formulation development purposes for poorly water soluble drugs. We focused on these methods like addition of cosolvents, surfactants and utilization of biphasic media, applied to provide sink conditions which are difficult to be achieved by simple aqueous buffers for lipophilic drugs, and introduced the development of physiologically relevant media for human and animals like dog and rat with respect to the choice of buffers, bile salts, lipids and so on. In addition, we further discussed the influence of biorelevant dissolution media on the modification of drug Biopharmaceutical Classification System (BCS) classification, especially for BCS class II drugs with low solubility and high permeability, the solubility of which is relatively sensitive to the presence of bile salts and lipids.

Trauma team utilization of universal precautions: if you see something, say something.

PubMed

Peponis, T; Cropano, M C; Larentzakis, A; van der Wilden, M G; Mejaddam, Y A; Sideris, C A; Michailidou, M; Fikry, K; Bramos, A; Janjua, S; Chang, Y; King, D R

2017-02-01

The risks deriving from the lack of compliance with universal safety precautions (USPs) are unequivocal. However, the adoption of these prophylactic precautions by healthcare providers remains unacceptably low. We hypothesized that trauma teams are not routinely adhering to USPs and that a brief educational intervention, followed by real-time peer feedback, would substantially improve compliance rates. This before-and-after interventional study took place in the resuscitation bay of a Level I Trauma Center during trauma team activations. Six USPs were examined: hand washing (before and after patient contact), use of gloves, gowns, eye protection, and masks. Surgery and Emergency Medicine attending physicians, residents, and nurses, who had direct patient contact, were included. Following 162 baseline observations, an educational intervention in the form of brief lectures was conducted, emphasizing the danger to self from dereliction of USPs. Subsequently, 167 post-intervention observations were made after a one-month period of knowledge decay. Finally, real-time feedback was provided by trauma team leaders and study staff. Adherence to prophylactic measures was recorded again. Baseline compliance rates were dismal. Only hand washing prior to patient interaction, the use of eye protection, and the use of masks improved significantly (p < 0.05) after the educational initiative. However, compliance rates remained suboptimal. No difference was noted regarding the three other USPs. Impressively, following real-time behavioral corrections, compliance improved to nearly 90 % for all USPs (p < 0.05). Compliance with OSHA-required USPs during trauma team activations is unacceptably low, but can be dramatically improved through simple educational interventions, combined with real-time peer feedback.

The USP8 mutational status may predict drug susceptibility in corticotroph adenomas of Cushing's disease.

PubMed

Hayashi, Kyohei; Inoshita, Naoko; Kawaguchi, Kohei; Ibrahim Ardisasmita, Arif; Suzuki, Hisanori; Fukuhara, Noriaki; Okada, Mitsuo; Nishioka, Hiroshi; Takeuchi, Yasuhiro; Komada, Masayuki; Takeshita, Akira; Yamada, Shozo

2016-02-01

Somatic mutations in the ubiquitin-specific peptidase USP8 gene were recently detected in one- to two-third(s) of corticotroph adenomas of Cushing's disease (CD). These mutations may lead to the deubiquitination of EGFR, thereby increasing EGFR signaling, which has been implicated in ACTH hypersecretion. Our objective was to determine the impact of USP8 mutations on the clinicopathological features of CD. USP8 mutations as well as clinicopathological characteristics were examined in 60 corticotroph adenomas including 15 Crooke's cell adenomas (CCAs), a rare histological variant presenting with generally aggressive behavior, using qRT-PCR and/or immunohistochemistry. USP8 mutations were exclusively detected in women, except for one case, with a prevalence of 42.2% in non-CCA and 13.3% in CCA (overall 35%). Clinically well-behaved presentations including microadenoma and curative resection were more common in mutated cases. The expression of EGFR was not associated with the mutation status. In contrast, mutated tumors expressed significantly higher levels of POMC, SSTR5, and MGMT. Microadenomas that strongly express POMC were common among mutated tumors, which may lead to the mechanisms by which very small adenomas secrete excess ACTH to present overt CD. While USP8 mutations were less likely to enhance tumorous ACTH hypersecretion via EGFR-mediated activation, the presence of USP8 mutations may predict favorable responses to the somatostatin analog pasireotide, which exhibits high affinity for SSTR5. In contrast, non-mutated aggressive tumors such as CCA may respond better to the alkylating agent temozolomide because of their significantly weak expression of MGMT. © 2016 European Society of Endocrinology.

The downregulation of Mcl-1 via USP9X inhibition sensitizes solid tumors to Bcl-xl inhibition

PubMed Central

2012-01-01

Background It has been shown in many solid tumors that the overexpression of the pro-survival Bcl-2 family members Bcl-xL and Mcl-1 confers resistance to a variety of chemotherapeutic agents. Mcl-1 is a critical survival protein in a variety of cell lineages and is critically regulated via ubiquitination. Methods The Mcl-1, Bcl-xL and USP9X expression patterns in human lung and colon adenocarcinomas were evaluated via immunohistochemistry. Interaction between USP9X and Mcl-1 was demonstrated by immunoprecipitation-western blotting. The protein expression profiles of Mcl-1, Bcl-xL and USP9X in multiple cancer cell lines were determined by western blotting. Annexin-V staining and cleaved PARP western blotting were used to assay for apoptosis. The cellular toxicities after various treatments were measured via the XTT assay. Results In our current analysis of colon and lung cancer samples, we demonstrate that Mcl-1 and Bcl-xL are overexpressed and also co-exist in many tumors and that the expression levels of both genes correlate with the clinical staging. The downregulation of Mcl-1 or Bcl-xL via RNAi was found to increase the sensitivity of the tumor cells to chemotherapy. Furthermore, our analyses revealed that USP9X expression correlates with that of Mcl-1 in human cancer tissue samples. We additionally found that the USP9X inhibitor WP1130 promotes Mcl-1 degradation and increases tumor cell sensitivity to chemotherapies. Moreover, the combination of WP1130 and ABT-737, a well-documented Bcl-xL inhibitor, demonstrated a chemotherapeutic synergy and promoted apoptosis in different tumor cells. Conclusion Mcl-1, Bcl-xL and USP9X overexpression are tumor survival mechanisms protective against chemotherapy. USP9X inhibition increases tumor cell sensitivity to various chemotherapeutic agents including Bcl-2/Bcl-xL inhibitors. PMID:23171055

Investigation and simulation of dissolution with concurrent degradation under healthy and hypoalbuminaemic simulated parenteral conditions- case example Amphotericin B.

PubMed

Díaz de León-Ortega, Ricardo; D'Arcy, Deirdre M; Bolhuis, A; Fotaki, N

2018-06-01

Guidance on dissolution testing for parenteral formulations is limited and not often related in vivo performance. Critically ill patients represent a target cohort, frequently hypoalbuminaemic, to whom certain parenteral formulations are administered. Amphotericin B (AmB) is a poorly soluble, highly protein-bound drug, available as lipid-based formulations and used in critical illness. The aim of this study was to develop media representing hypoalbuminaemic and healthy plasma, and to understand and simulate the dissolution profile of AmB in biorelevant media. Dissolution media were prepared with bovine serum albumin (BSA) in Krebs-Ringer buffer, and tested in a flow through cell apparatus and a bottle/stirrer setup. Drug activity was tested against Candida albicans. BSA concentration was positively associated with solubility, degradation rate and maximum amount dissolved and negatively associated with dissolution rate constant and antifungal activity. In the bottle/stirrer setup, a biexponential model successfully described simultaneous dissolution and degradation and increased in agitation reduced the discriminatory ability of the test. The hydrodynamics provided by the flow-through cell apparatus was not adequate to dissolve the drug. Establishing discriminating test methods with albumin present in the dissolution media, representing the target population, supports future development of biorelevant and clinically relevant tests for parenteral formulations. Copyright © 2018 Elsevier B.V. All rights reserved.

In Vitro Comparison of a Novel Single Probe Dual-Energy Lithotripter to Current Devices.

PubMed

Carlos, Evan C; Wollin, Daniel A; Winship, Brenton B; Jiang, Ruiyang; Radvak, Daniela; Chew, Ben H; Gustafson, Michael R; Simmons, W Neal; Zhong, Pei; Preminger, Glenn M; Lipkin, Michael E

2018-06-01

The LithoClast Trilogy is a novel single probe, dual-energy lithotripter with ultrasonic (US) vibration and electromagnetic impact forces. ShockPulse and LithoClast Select are existing lithotripters that also use a combination of US and mechanical impact energies. We compared the efficacy and tip motion of these devices in an in vitro setting. Begostones, in the ratio 15:3, were used in all trials. Test groups were Trilogy, ShockPulse, Select ultrasound (US) only, and Select ultrasound with pneumatic (USP). For clearance testing, a single investigator facile with each lithotripter fragmented 10 stones per device. For drill testing, a hands-free apparatus with a submerged balance was used to apply 1 or 2 lbs of pressure on a stone in contact with the device tip. High-speed photography was used to assess Trilogy and ShockPulse's probe tip motion. Select-USP was slowest and Trilogy fastest on clearance testing (p < 0.01). On 1 lbs drill testing, Select-US was slowest (p = 0.001). At 2 lbs, ShockPulse was faster than Select US (p = 0.027), but did not significantly outpace Trilogy nor Select-USP. At either weight, there was no significant difference between Trilogy and ShockPulse. During its US function, Trilogy's maximum downward tip displacement was 0.041 mm relative to 0.0025 mm with ShockPulse. Trilogy had 0.25 mm of maximum downward displacement during its impactor function while ShockPulse had 0.01 mm. Single probe dual-energy devices, such as Trilogy and ShockPulse, represent the next generation of lithotripters. Trilogy more efficiently cleared stone than currently available devices, which could be explained by its larger probe diameter and greater downward tip displacement during both US and impactor functions.

In vitro dynamic solubility test: influence of various parameters.

PubMed Central

Thélohan, S; de Meringo, A

1994-01-01

This article discusses the dissolution of mineral fibers in simulated physiological fluids (SPF), and the parameters that affect the solubility measurement in a dynamic test where an SPF runs through a cell containing fibers (Scholze and Conradt test). Solutions simulate either the extracellular fluid (pH 7.6) or the intracellular fluid (pH 4.5). The fibers have various chemical compositions and are either continuously drawn or processed as wool. The fiber solubility is determined by the amount of SiO2 (and occasionally other ions) released in the solution. Results are stated as percentage of the initial silica content released or as dissolution rate v in nm/day. The reproducibility of the test is higher with the less soluble fibers (10% solubility), than with highly soluble fibers (20% solubility). The influence of test parameters, including SPF, test duration, and surface area/volume (SA/V), has been studied. The pH and the inorganic buffer salts have a major influence: industrial glasswool composition is soluble at pH 7.6 but not at pH 4.5. The opposite is true for rock- (basalt) wool composition. For slightly soluble fibers, the dissolution rate v remains constant with time, whereas for highly soluble fibers, the dissolution rate decreases rapidly. The dissolution rates believed to occur are v1, initial dissolution rate, and v2, dissolution rate of the residual fibers. The SA of fibers varies with the mass of the fibers tested, or with the fiber diameter at equal mass. Volume, V, is the chosen flow rate. An increase in the SA/V ratio leads to a decrease in the dissolution rate.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:7882964

In vitro dynamic solubility test: influence of various parameters.

PubMed

Thélohan, S; de Meringo, A

1994-10-01

This article discusses the dissolution of mineral fibers in simulated physiological fluids (SPF), and the parameters that affect the solubility measurement in a dynamic test where an SPF runs through a cell containing fibers (Scholze and Conradt test). Solutions simulate either the extracellular fluid (pH 7.6) or the intracellular fluid (pH 4.5). The fibers have various chemical compositions and are either continuously drawn or processed as wool. The fiber solubility is determined by the amount of SiO2 (and occasionally other ions) released in the solution. Results are stated as percentage of the initial silica content released or as dissolution rate v in nm/day. The reproducibility of the test is higher with the less soluble fibers (10% solubility), than with highly soluble fibers (20% solubility). The influence of test parameters, including SPF, test duration, and surface area/volume (SA/V), has been studied. The pH and the inorganic buffer salts have a major influence: industrial glasswool composition is soluble at pH 7.6 but not at pH 4.5. The opposite is true for rock- (basalt) wool composition. For slightly soluble fibers, the dissolution rate v remains constant with time, whereas for highly soluble fibers, the dissolution rate decreases rapidly. The dissolution rates believed to occur are v1, initial dissolution rate, and v2, dissolution rate of the residual fibers. The SA of fibers varies with the mass of the fibers tested, or with the fiber diameter at equal mass. Volume, V, is the chosen flow rate. An increase in the SA/V ratio leads to a decrease in the dissolution rate.(ABSTRACT TRUNCATED AT 250 WORDS)

Field-scale Prediction of Enhanced DNAPL Dissolution Using Partitioning Tracers and Flow Pattern Effects

NASA Astrophysics Data System (ADS)

Wang, F.; Annable, M. D.; Jawitz, J. W.

2012-12-01

The equilibrium streamtube model (EST) has demonstrated the ability to accurately predict dense nonaqueous phase liquid (DNAPL) dissolution in laboratory experiments and numerical simulations. Here the model is applied to predict DNAPL dissolution at a PCE-contaminated dry cleaner site, located in Jacksonville, Florida. The EST is an analytical solution with field-measurable input parameters. Here, measured data from a field-scale partitioning tracer test were used to parameterize the EST model and the predicted PCE dissolution was compared to measured data from an in-situ alcohol (ethanol) flood. In addition, a simulated partitioning tracer test from a calibrated spatially explicit multiphase flow model (UTCHEM) was also used to parameterize the EST analytical solution. The ethanol prediction based on both the field partitioning tracer test and the UTCHEM tracer test simulation closely matched the field data. The PCE EST prediction showed a peak shift to an earlier arrival time that was concluded to be caused by well screen interval differences between the field tracer test and alcohol flood. This observation was based on a modeling assessment of potential factors that may influence predictions by using UTCHEM simulations. The imposed injection and pumping flow pattern at this site for both the partitioning tracer test and alcohol flood was more complex than the natural gradient flow pattern (NGFP). Both the EST model and UTCHEM were also used to predict PCE dissolution under natural gradient conditions, with much simpler flow patterns than the forced-gradient double five spot of the alcohol flood. The NGFP predictions based on parameters determined from tracer tests conducted with complex flow patterns underestimated PCE concentrations and total mass removal. This suggests that the flow patterns influence aqueous dissolution and that the aqueous dissolution under the NGFP is more efficient than dissolution under complex flow patterns.

Ruggedness/robustness evaluation and system suitability test on United States Pharmacopoeia XXVI assay ginsenosides in Asian and American ginseng by high-performance liquid chromatography.

PubMed

Li, Yong-Guo; Chen, Ming; Chou, Gui-Xin; Wang, Zheng-Tao; Hu, Zhi-Bi

2004-09-03

The work of the ruggedness/robustness evaluation and system suitability tests was oriented to profound understand the practicability of using assay methods issued by United States Pharmacopoeia (USP XXVI and XXVII) for ginsenosides in Asian ginseng and American ginseng. The items chosen for the method validation included quantitative related items such as recovery of Rg(1) and Rb(1), respectively, and qualitative related items such as resolution, theoretical plate number, relative retention time of two critical-band-pairs, Rg(1)/Re and Rb(1) with its neighboring peak, respectively. Totally, 16 column types were used for comparison of different vendors, different packing materials, different size, etc. and five sets of LC systems and two laboratories were involved in comparing the data of both quantitative and qualitative items. The results showed that different packing materials of columns used might significantly alters separation. The column packing material Hypersil afforded the preferable separating for the ginsenosides. No significant difference was observed from the different instrumentations and inter-laboratories. Our results suggest a modification of the system suitability test as given in USP26-NF21 and the latest version of USP27-NF22, which was not suitable for most systems. Using resolutions of Rg(1)/Re and Rb(1) with its neighboring peak as critical parameters for the ginsenosides assay and omitting the relative retention time of both Rg(1)/Re and Rb(1) with its neighboring peak is our suggestion for a more reasonable, yet practicable system suitability. Six typical chromatograms gain from different columns were figured out as well.

Scattering of ultrashort electromagnetic pulses on metal clusters

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

Astapenko, V. A., E-mail: astval@mail.ru; Sakhno, S. V.

We have calculated and analyzed the probability of ultrashort electromagnetic pulse (USP) scattering on small metal clusters in the frequency range of plasmon resonances during the field action. The main attention is devoted to dependence of the probability of scattering on the pulse duration for various detunings of the USP carrier frequency from the plasmon resonance frequency. Peculiarities of the USP scattering from plasmon resonances with various figures of merit are revealed.

Scattering of ultrashort electromagnetic pulses on metal clusters

NASA Astrophysics Data System (ADS)

Astapenko, V. A.; Sakhno, S. V.

2016-12-01

We have calculated and analyzed the probability of ultrashort electromagnetic pulse (USP) scattering on small metal clusters in the frequency range of plasmon resonances during the field action. The main attention is devoted to dependence of the probability of scattering on the pulse duration for various detunings of the USP carrier frequency from the plasmon resonance frequency. Peculiarities of the USP scattering from plasmon resonances with various figures of merit are revealed.

Collaborative study for the establishment of the WHO 3(rd) International Standard for Endotoxin, the Ph. Eur. endotoxin biological reference preparation batch 5 and the USP Reference Standard for Endotoxin Lot H0K354.

PubMed

Findlay, L; Desai, T; Heath, A; Poole, S; Crivellone, M; Hauck, W; Ambrose, M; Morris, T; Daas, A; Rautmann, G; Buchheit, K H; Spieser, J M; Terao, E

2015-01-01

An international collaborative study was organised jointly by the World Health Organization (WHO)/National Institute for Biological Standards and Control (NIBSC), the United States Pharmacopeia (USP) and the European Directorate for the Quality of Medicines & HealthCare (EDQM/Council of Europe) for the establishment of harmonised replacement endotoxin standards for these 3 organisations. Thirty-five laboratories worldwide, including Official Medicines Control Laboratories (OMCLs) and manufacturers enrolled in the study. Three candidate preparations (10/178, 10/190 and 10/196) were produced with the same material and same formulation as the current reference standards with the objective of generating a new (3(rd)) International Standard (IS) with the same potency (10 000 IU/vial) as the current (2(nd)) IS, as well as new European Pharmacopoeia (Ph. Eur.). and USP standards. The suitability of the candidate preparations to act as the reference standard in assays for endotoxin performed according to compendial methods was evaluated. Their potency was calibrated against the WHO 2(nd) IS for Endotoxin (94/580). Gelation and photometric methods produced similar results for each of the candidate preparations. The overall potency estimates for the 3 batches were comparable. Given the intrinsic assay precision, the observed differences between the batches may be considered unimportant for the intended use of these materials. Overall, these results were in line with those generated for the establishment of the current preparations of reference standards. Accelerated degradation testing of vials stored at elevated temperatures supported the long-term stability of the 3 candidate preparations. It was agreed between the 3 organisations that batch 10/178 be shared between WHO and EDQM and that batches 10/190 and 10/196 be allocated to USP, with a common assigned value of 10 000 IU/vial. This value maintains the continuity of the global harmonisation of reference materials and unitage for the testing of endotoxins in parenteral pharmaceutical products. Based on the results of the collaborative study, batch 10/178 was established by the European Pharmacopoeia Commission as the Ph. Eur. Endotoxin Biological Reference Preparation (BRP) batch 5. The same batch was also established by the Expert Committee on Biological Standardisation (ECBS) of WHO as the WHO 3(rd) IS for Endotoxin. Batch 10/190 was adopted as the USP Endotoxin Reference Standard, lot H0K354 and vials from this same batch (10/190) will serve as the United States Food and Drug Administration (USFDA) Endotoxin Standard, EC-7.

Lyophilic matrix method for dissolution and release studies of nanoscale particles.

PubMed

Pessi, Jenni; Svanbäck, Sami; Lassila, Ilkka; Hæggström, Edward; Yliruusi, Jouko

2017-10-25

We introduce a system with a lyophilic matrix to aid dissolution studies of powders and particulate systems. This lyophilic matrix method (LM method) is based on the ability to discriminate between non-dissolved particles and the dissolved species. In the LM method the test substance is embedded in a thin lyophilic core-shell matrix. This permits rapid contact with the dissolution medium while minimizing dispersion of non-dissolved particles without presenting a substantial diffusion barrier. The method produces realistic dissolution and release results for particulate systems, especially those featuring nanoscale particles. By minimizing method-induced effects on the dissolution profile of nanopowders, the LM method overcomes shortcomings associated with current dissolution tests. Copyright © 2017 Elsevier B.V. All rights reserved.

Comparative Application of PLS and PCR Methods to Simultaneous Quantitative Estimation and Simultaneous Dissolution Test of Zidovudine - Lamivudine Tablets.

PubMed

Üstündağ, Özgür; Dinç, Erdal; Özdemir, Nurten; Tilkan, M Günseli

2015-01-01

In the development strategies of new drug products and generic drug products, the simultaneous in-vitro dissolution behavior of oral dosage formulations is the most important indication for the quantitative estimation of efficiency and biopharmaceutical characteristics of drug substances. This is to force the related field's scientists to improve very powerful analytical methods to get more reliable, precise and accurate results in the quantitative analysis and dissolution testing of drug formulations. In this context, two new chemometric tools, partial least squares (PLS) and principal component regression (PCR) were improved for the simultaneous quantitative estimation and dissolution testing of zidovudine (ZID) and lamivudine (LAM) in a tablet dosage form. The results obtained in this study strongly encourage us to use them for the quality control, the routine analysis and the dissolution test of the marketing tablets containing ZID and LAM drugs.

The impact of calcium carbonate as pore forming agent and drug entrapment method towards drug dissolution mechanism of amoxicillin trihydrate encapsulated by chitosan-methyl cellulose semi-IPN hydrogel for floating drug delivery system

NASA Astrophysics Data System (ADS)

Dewantara, Fauzi; Budianto, Emil

2018-04-01

Chitosan-methyl cellulose semi-IPN hydrogel is used as floating drug delivery system, and calcium carbonate also added as pore forming agent. The hydrogel network arranged by not only using biopolymer chitosan and methyl cellulose, but also the crosslink agent that is glutaraldehyde. Amoxicillin trihydrate entrapped into the polymer network with two different method, in situ loading and post loading. Furthermore both method has been tested for drug entrapment efficiency along with drug dissolution test, and the result for drug entrapment efficiency is in situ loading method has highest value of 100%, compared to post loading method which has value only 71%. Moreover, at the final time of drug dissolution test shows in situ loading method has value of 96% for total accumulative of drug dissolution, meanwhile post loading method has 72%. The value of drug dissolution test from both method is used for analyzing drug dissolution mechanism of amoxicillin trihydrate from hydrogel network with four mathematical drug mechanism models as parameter. The polymer network encounter destructive degradation causes by acid solution which used as dissolution medium, and the level of degradation is observed with optical microscope. However the result shows that degradation of the polymer network doesn't affect drug dissolution mechanism directly. Although the pore forming agent causes the pore inside the hydrogel network create interconnection and it was quite influential to drug dissolution mechanism. Interconnected pore is observed with Scanning Electron Microscope (SEM) and shows that the amount and area of interconnected pore inside the hydrogel network is increasing as drug dissolution goes on.

A generalized plate method for estimating total aerobic microbial count.

PubMed

Ho, Kai Fai

2004-01-01

The plate method outlined in Chapter 61: Microbial Limit Tests of the U.S. Pharmacopeia (USP 61) provides very specific guidance for assessing total aerobic bioburden in pharmaceutical articles. This methodology, while comprehensive, lacks the flexibility to be useful in all situations. By studying the plate method as a special case within a more general family of assays, the effects of each parameter in the guidance can be understood. Using a mathematical model to describe the plate counting procedure, a statistical framework for making more definitive statements about total aerobic bioburden is developed. Such a framework allows the laboratory scientist to adjust the USP 61 methods to satisfy specific practical constraints. In particular, it is shown that the plate method can be conducted, albeit with stricter acceptance criteria, using a test specimen quantity that is smaller than the 10 g or 10 mL prescribed in the guidance. Finally, the interpretation of results proffered by the guidance is re-examined within this statistical framework and shown to be overly aggressive.

Spectrum Management Guidelines for National and Service Test and Training Ranges

DTIC Science & Technology

2017-07-12

GPS Global Positioning System ISM Installation Spectrum Manager JTIDS Joint Tactical Information Distribution System KMR Kwajalein Missile Range... information UAV unmanned aerial vehicle US&P United States and Possessions Spectrum Management Guidelines for National and Service Test and Training...frequency deconfliction processes. The AFC will inform the range or center commander and the Installation Spectrum Manager (ISM) at the

Errors in reporting on dissolution research: methodological and statistical implications.

PubMed

Jasińska-Stroschein, Magdalena; Kurczewska, Urszula; Orszulak-Michalak, Daria

2017-02-01

In vitro dissolution testing provides useful information at clinical and preclinical stages of the drug development process. The study includes pharmaceutical papers on dissolution research published in Polish journals between 2010 and 2015. They were analyzed with regard to information provided by authors about chosen methods, performed validation, statistical reporting or assumptions used to properly compare release profiles considering the present guideline documents addressed to dissolution methodology and its validation. Of all the papers included in the study, 23.86% presented at least one set of validation parameters, 63.64% gave the results of the weight uniformity test, 55.68% content determination, 97.73% dissolution testing conditions, and 50% discussed a comparison of release profiles. The assumptions for methods used to compare dissolution profiles were discussed in 6.82% of papers. By means of example analyses, we demonstrate that the outcome can be influenced by the violation of several assumptions or selection of an improper method to compare dissolution profiles. A clearer description of the procedures would undoubtedly increase the quality of papers in this area.

Overexpression of a Cytosolic Abiotic Stress Responsive Universal Stress Protein (SbUSP) Mitigates Salt and Osmotic Stress in Transgenic Tobacco Plants

PubMed Central

Udawat, Pushpika; Jha, Rajesh K.; Sinha, Dinkar; Mishra, Avinash; Jha, Bhavanath

2016-01-01

The universal stress protein (USP) is a ubiquitous protein and plays an indispensable role in plant abiotic stress tolerance. The genome of Salicornia brachiata contains two homologs of intron less SbUSP gene which encodes for salt and osmotic responsive USP. In vivo localization reveals that SbUSP is a membrane bound cytosolic protein. The role of the gene was functionally validated by developing transgenic tobacco and compared with control [wild-type (WT) and vector control (VC)] plants under different abiotic stress condition. Transgenic lines (T1) exhibited higher chlorophyll, relative water, proline, total sugar, reducing sugar, free amino acids, polyphenol contents, osmotic potential, membrane stability, and lower electrolyte leakage and lipid peroxidation (malondialdehyde content) under stress treatments than control (WT and VC) plants. Lower accumulation of H2O2 and O2− radicals was also detected in transgenic lines compared to control plants under stress conditions. Present study confers that overexpression of the SbUSP gene enhances plant growth, alleviates ROS buildup, maintains ion homeostasis and improves the physiological status of the plant under salt and osmotic stresses. Principal component analysis exhibited a statistical distinction of plant response to salinity stress, and a significant response was observed for transgenic lines under stress, which provides stress endurance to the plant. A possible signaling role is proposed that some downstream genes may get activated by abiotic stress responsive cytosolic SbUSP, which leads to the protection of cell from oxidative damages. The study unveils that ectopic expression of the gene mitigates salt or osmotic stress by scavenging ROS and modulating the physiological process of the plant. PMID:27148338

CSN-associated USP48 confers stability to nuclear NF-κB/RelA by trimming K48-linked Ub-chains.

PubMed

Schweitzer, Katrin; Naumann, Michael

2015-02-01

Diligent balance of nuclear factor kappa B (NF-κB) activity is essential owing to NF-κB's decisive role in cellular processes including inflammation, immunity and cell survival. Ubiquitin/proteasome-system (UPS)-dependent degradation of activated NF-κB/RelA involves the cullin-RING-ubiquitin-ligase (CRL) ECS(SOCS1). The COP9 signalosome (CSN) controls ubiquitin (Ub) ligation by CRLs through the removal of the CRL-activating Ub-like modifier NEDD8 from their cullin subunits and through deubiquitinase (DUB) activity of associated DUBs. However, knowledge about DUBs involved in the regulation of NF-κB activity within the nucleus is scarce. In this study we observed that USP48, a DUB of hitherto ill-defined function identified through a siRNA screen, associates with the CSN and RelA in the nucleus. We show that USP48 trims rather than completely disassembles long K48-linked free and substrate-anchored Ub-chains, a catalytic property only shared with ataxin-3 (Atx3) and otubain-1 (OTU1), and that USP48 Ub-chain-trimming activity is regulated by casein-kinase-2 (CK2)-mediated phosphorylation in response to cytokine-stimulation. Functionally, we demonstrate for the first time the CSN and USP48 to cooperatively stabilize the nuclear pool of RelA, thereby facilitating timely induction and shutoff of NF-κB target genes. In summary, this study demonstrates that USP48, a nuclear DUB regulated by CK2, controls the UPS-dependent turnover of activated NF-κB/RelA in the nucleus together with the CSN. Thereby USP48 contributes to a timely control of immune responses. Copyright © 2014 Elsevier B.V. All rights reserved.

Development and Validation of New Discriminative Dissolution Method for Carvedilol Tablets

PubMed Central

Raju, V.; Murthy, K. V. R.

2011-01-01

The objective of the present study was to develop and validate a discriminative dissolution method for evaluation of carvedilol tablets. Different conditions such as type of dissolution medium, volume of dissolution medium and rotation speed of paddle were evaluated. The best in vitro dissolution profile was obtained using Apparatus II (paddle), 50 rpm, 900 ml of pH 6.8 phosphate buffer as dissolution medium. The drug release was evaluated by high-performance liquid chromatographic method. The dissolution method was validated according to current ICH and FDA guidelines using parameters such as the specificity, accuracy, precision and stability were evaluated and obtained results were within the acceptable range. The comparison of the obtained dissolution profiles of three different products were investigated using ANOVA-based, model-dependent and model-independent methods, results showed that there is significant difference between the products. The dissolution test developed and validated was adequate for its higher discriminative capacity in differentiating the release characteristics of the products tested and could be applied for development and quality control of carvedilol tablets. PMID:22923865

Initial load-to-failure and failure analysis in single- and double-row repair techniques for rotator cuff repair.

PubMed

Baums, M H; Buchhorn, G H; Gilbert, F; Spahn, G; Schultz, W; Klinger, H-M

2010-09-01

This experimental study aimed to compare the load-to-failure rate and stiffness of single- versus double-row suture techniques for repairing rotator cuff lesions using two different suture materials. Additionally, the mode of failure of each repair was evaluated. In 32 sheep shoulders, a standardized tear of the infraspinatus tendon was created. Then, n = 8 specimen were randomized to four repair methods: (1) Double-row Anchor Ethibond coupled with polyester sutures, USP No. 2; (2) Double-Row Anchor HiFi with polyblend polyethylene sutures, USP No. 2; (3) Single-Row Anchor Ethibond coupled with braided polyester sutures, USP No. 2; and (4) Single-Row Anchor HiFi with braided polyblend polyethylene sutures, USP No. 2. Arthroscopic Mason-Allen stitches were placed (single-row) and combined with medial horizontal mattress stitches (double-row). All specimens were loaded to failure at a constant displacement rate on a material testing machine. Group 4 showed lowest load-to-failure result with 155.7 +/- 31.1 N compared to group 1 (293.4 +/- 16.1 N) and group 2 (397.7 +/- 7.4 N) (P < 0.001). Stiffness was highest in group 2 (162 +/- 7.3 N/mm) and lowest in group 4 (84.4 +/- 19.9 mm) (P < 0.001). In group 4, the main cause of failure was due to the suture cutting through the tendon (n = 6), a failure case observed in only n = 1 specimen in group 2 (P < 0.001). A double-row technique combined with arthroscopic Mason-Allen/horizontal mattress stitches provides high initial failure strength and may minimize the risk of the polyethylene sutures cutting through the tendon in rotator cuff repair when a single load force is used.

Dissolution of Simulated and Radioactive Savannah River Site High-Level Waste Sludges with Oxalic Acid & Citric Acid Solutions

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

STALLINGS, MARY

This report presents findings from tests investigating the dissolution of simulated and radioactive Savannah River Site sludges with 4 per cent oxalic acid and mixtures of oxalic and citric acid previously recommended by a Russian team from the Khlopin Radium Institute and the Mining and Chemical Combine (MCC). Testing also included characterization of the simulated and radioactive waste sludges. Testing results showed the following: Dissolution of simulated HM and PUREX sludges with oxalic and citric acid mixtures at SRTC confirmed general trends reported previously by Russian testing. Unlike the previous Russian testing six sequential contacts of a mixture of oxalicmore » acid citric acids at a 2:1 ratio (v/w) of acid to sludge did not produce complete dissolution of simulated HM and PUREX sludges. We observed that increased sludge dissolution occurred at a higher acid to sludge ratio, 50:1 (v/w), compared to the recommended ratio of 2:1 (v/w). We observed much lower dissolution of aluminum in a simulated HM sludge by sodium hydroxide leaching. We attribute the low aluminum dissolution in caustic to the high fraction of boehmite present in the simulated sludge. Dissolution of HLW sludges with 4 per cent oxalic acid and oxalic/citric acid followed general trends observed with simulated sludges. The limited testing suggests that a mixture of oxalic and citric acids is more efficient for dissolving HM and PUREX sludges and provides a more homogeneous dissolution of HM sludge than oxalic acid alone. Dissolution of HLW sludges in oxalic and oxalic/citric acid mixtures produced residual sludge solids that measured at higher neutron poison to equivalent 235U weight ratios than that in the untreated sludge solids. This finding suggests that residual solids do not present an increased nuclear criticality safety risk. Generally the neutron poison to equivalent 235U weight ratios of the acid solutions containing dissolved sludge components are lower than those in the untreated sludge solids. We recommend that these results be evaluated further to determine if these solutions contain sufficient neutron poisons. We observed low general corrosion rates in tests in which carbon steel coupons were contacted with solutions of oxalic acid, citric acid and mixtures of oxalic and citric acids. Wall thinning can be minimized by maintaining short contact times with these acid solutions. We recommend additional testing with oxalic and oxalic/citric acid mixtures to measure dissolution performance of sludges that have not been previously dried. This testing should include tests to clearly ascertain the effects of total acid strength and metal complexation on dissolution performance. Further work should also evaluate the downstream impacts of citric acid on the SRS High-Level Waste System (e.g., radiochemical separations in the Salt Waste Processing Facility and addition of organic carbon in the Saltstone and Defense Waste Processing facilities).« less

39 CFR 266.9 - Exemptions.

Code of Federal Regulations, 2010 CFR

2010-07-01

... and evaluative purposes, it is impossible to determine in advance what information might be of... Records, USPS 100.300; Personnel Research Records, 100.600; and Emergency Management Records, USPS 500.300...

39 CFR 266.9 - Exemptions.

Code of Federal Regulations, 2013 CFR

2013-07-01

... and evaluative purposes, it is impossible to determine in advance what information might be of... Records, USPS 100.300; Personnel Research Records, 100.600; and Emergency Management Records, USPS 500.300...

39 CFR 266.9 - Exemptions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... and evaluative purposes, it is impossible to determine in advance what information might be of... Records, USPS 100.300; Personnel Research Records, 100.600; and Emergency Management Records, USPS 500.300...

39 CFR 266.9 - Exemptions.

Code of Federal Regulations, 2011 CFR

2011-07-01

... and evaluative purposes, it is impossible to determine in advance what information might be of... Records, USPS 100.300; Personnel Research Records, 100.600; and Emergency Management Records, USPS 500.300...

39 CFR 266.9 - Exemptions.

Code of Federal Regulations, 2012 CFR

2012-07-01

... and evaluative purposes, it is impossible to determine in advance what information might be of... Records, USPS 100.300; Personnel Research Records, 100.600; and Emergency Management Records, USPS 500.300...

[Morphological spectrum of USP6 rearranged lesions].

PubMed

Mechtersheimer, G; Werner, M

2018-03-01

USP6, also known as Tre-2 and TRE17, is an ubiquitase-specific proteinase that was identified more than two decades ago as a potential oncogene when it exhibited transforming properties upon overexpression in NIH 3T3 cells. Until recently, however, little was known about the function and the oncogenetic activation of USP6. The identification of rearrangements of the USP6 gene in aneurysmal bone cyst and in nodular fasciitis has not only led to a better understanding of the pathogenesis of these entities, but is also a useful tool in their diagnosis and differential diagnostic delineation from morphological mimics. In this review, the clinical, pathomorphological, and molecular genetic aspects of aneurysmal bone cyst and of nodular fasciitis, as well as from related lesions, are presented and discussed.

Crushed tablets: does the administration of food vehicles and thickened fluids to aid medication swallowing alter drug release?

PubMed

Manrique, Yady J; Lee, Danielle J; Islam, Faiza; Nissen, Lisa M; Cichero, Julie A Y; Stokes, Jason R; Steadman, Kathryn J

2014-01-01

To evaluate the influence of co-administered vehicles on in vitro dissolution in simulated gastric fluid of crushed immediate release tablets as an indicator for potential drug bioavailability compromise. Release and dissolution of crushed amlodipine, atenolol, carbamazepine and warfarin tablets were tested with six foods and drinks that are frequently used in the clinical setting as mixers for crushed medications (water, orange juice, honey, yoghurt, strawberry jam and water thickened with Easythick powder) in comparison to whole tablets. Five commercial thickening agents (Easythick Advanced, Janbak F, Karicare, Nutilis, Viscaid) at three thickness levels were tested for their effect on the dissolution of crushed atenolol tablets. Atenolol dissolution was unaffected by mixing crushed tablets with thin fluids or food mixers in comparison to whole tablets or crushed tablets in water, but amlodipine was delayed by mixing with jam. Mixing crushed warfarin and carbamazepine tablets with honey, jam or yoghurt caused them to resemble the slow dissolution of whole tablets rather than the faster dissolution of crushed tablets in water or orange juice. Crushing and mixing any of the four medications with thickened water caused a significant delay in dissolution. When tested with atenolol, all types of thickening agents at the greatest thickness significantly restricted dissolution, and products that are primarily based on xanthan gum also delayed dissolution at the intermediate thickness level. Dissolution testing, while simplistic, is a widely used and accepted method for comparing drug release from different formulations as an indicator for in vivo bioavailability. Thickened fluids have the potential to retard drug dissolution when used at the thickest levels. These findings highlight potential clinical implications of the addition of these agents to medications for the purpose of dose delivery and indicate that further investigation of thickened fluids and their potential to influence therapeutic outcomes is warranted.

Developing a Terrestrial Biogeochemical Cycle Modeling System to Support the Management of Fort Benning and its Surrounding Areas

DTIC Science & Technology

2010-12-01

Soil Survey Geographic database USDA U.S. Department of Agriculture USLE Universal Soil Loss Equation USPED Unit-Stream-Power Erosion and...2003). A suite of models has been developed to simulate soil erosion and deposition, ranging from empirical (e.g., USLE and MUSLE at http... Soil Erosion and Deposition 4.4.1 USPED The algorithm for the simulation of soil erosion in USPED is similar to that of the USLE or RUSLE model

Synthesis of thiolated arabinoxylan and its application as sustained release mucoadhesive film former.

PubMed

Zaman, Muhammad; Hanif, Muhammad; Sultana, Kishwar; Atta-Ur-Rehman

2018-02-08

The present work aimed to synthesize thiolated arabinoxylan (TAX), and to evaluate its mucoadhesive potential. Synthesis of TAX was accomplished by esterification of arabinoxylan (AX) with thioglycolic acid (TGA). The appearance of a characteristic peak at 2516 cm -1 in the FTIR spectrum of TAX, and presence of 6.01 ± 1.03 m moles of thiol per gram of the polymer confirmed successful thiolation of AX. The incorporation of the thiol group considerably promoted mucoadhesive strength of the polymer-viz. 3.99-fold. Moreover, in vivo safety analysis in albino rats revealed TAX to be safe in the concentration range of 750-1000 mg kg -1 body weight. Synthesized TAX was utilized to prepare Tizanidine HCl (TZN HCl) loaded sustained release (SR) mucoadhesive buccal films using a solvent casting technique. Results proved that the prepared films were of uniform thickness, good mechanical strength (with folding endurance >300), acceptable moisture contents (5%-7%) and surface pH (6.23 ± 0.81 to 6.43 ± 0.49) compatible to that of the buccal cavity. Presence of greater that 90% of drug contents indicated the excellent drug loading ability of the prepared films. Results of in vitro dissolution studies and ex vivo permeation studies conducted respectively by USP dissolution apparatus II and Franz diffusion cell indicated that sustained effect of TAX was achieved for 8 h. These results have conclusively proven that TAX has the potential to improve the bioavailability of TZN HCl due to enhanced mucoadhesion in buccal cavity, hence signifying its suitability as a mucoadhesive buccal film former.

The preparation and evaluation of sustained release suppositories containing ketoprofen and Eudragit RL 100 by using factorial design.

PubMed

Ozgüney, I; Ozcan, I; Ertan, G; Güneri, T

2007-01-01

The preparation of ketoprofen (KP) sustained release (SR) suppositories was designed according to the 3(2) x 2(1) factorial design as three different KP:Eudragit RL 100 ratios (1:0.5, 1:1, 1:2), three particle sizes of prepared granules (250-500, 500-710, and 710-1000 microm) and two different PEG 400:PEG 6000 ratios (40:60, 50:50). The conventional KP suppositories were also prepared by using Witepsol H 15, Massa Estarinum B, Cremao and the mixture of PEG 400:PEG 6000. The dissolution studies of suppositories prepared were carried out according to the USP XXIII basket method in the phosphate buffer (pH = 7.2) at 50 rpm, and it was shown that the dissolution time was sustained up to 8 hours. According to the results of the factorial design, the most important independent variable on t50 and t80 was drug:polymer ratios. The log of partition coefficient of KP was determined as 1.46, showing the high affinity to the oily phase. n exponent and kinetic studies were conducted to explain diffusion mechanism, and it is understood that if the inert KP:Eudragit RL 100 ratio is increased in the particles, the Fickian difusion dominates and the best kinetic turns to Higuchi from the Hixson-Crowell. There is neither crystalline form of KP nor degradation product in the suppositories detected with the differential scanning calorimetry (DSC) studies. In addition to these studies, antiinflammatory activity of SR suppositories also determined that it was significantly extended according to the conventional suppositories.

Rapid analysis of drug dissolution by paper spray ionization mass spectrometry.

PubMed

Liu, Yang; Liu, Ning; Zhou, Ya-Nan; Lin, Lan; He, Lan

2017-03-20

With a great quantity of solid dosage tested by dissolution technology, developing a rapid and sensitive method to access the content of drug within dissolution media is highly desired by analysts and scientists. Traditionally, dissolution media is not compatible with mass spectrometry since the inorganic salts in the media might damage the mass spectrometer. Here, paper spray ionization mass spectrometry (PSI-MS), one of the ambient mass spectrometry technologies, is developed to characterize the content of drugs in dissolution media. The porous structure of paper can effectively retain salts from entering mass spectrometer. This makes the measurement of drug content within dissolution media by mass spectrometer possible. After the experimental parameters were optimized, calibration curves of model drugs - enalapril, quinapril and benazepril were established by using corresponding deuterated internal standards. PSI-MS was then deployed to characterize the content of enalapril from the dissolution testing of enalapril tablets. The results from PSI-MS are comparable to those from HPLC characterization. More importantly, the analysis time of 6 samples is shortened from 90min to 6min. Detection limit of enalapril maleate tablets by PSI-MS is 1/300 of LC. PSI-MS is rapid, sensitive and accurate in analyzing drug content from dissolution tests. Copyright © 2016 Elsevier B.V. All rights reserved.

Progressive Hearing Loss in Mice Carrying a Mutation in Usp53

PubMed Central

Kazmierczak, Marcin; Harris, Suzan L.; Kazmierczak, Piotr; Shah, Prahar; Starovoytov, Valentin; Ohlemiller, Kevin K.

2015-01-01

Disordered protein ubiquitination has been linked to neurodegenerative disease, yet its role in inner ear homeostasis and hearing loss is essentially unknown. Here we show that progressive hearing loss in the ethylnitrosourea-generated mambo mouse line is caused by a mutation in Usp53, a member of the deubiquitinating enzyme family. USP53 contains a catalytically inactive ubiquitin-specific protease domain and is expressed in cochlear hair cells and a subset of supporting cells. Although hair cell differentiation is unaffected in mambo mice, outer hair cells degenerate rapidly after the first postnatal week. USP53 colocalizes and interacts with the tight junction scaffolding proteins TJP1 and TJP2 in polarized epithelial cells, suggesting that USP53 is part of the tight junction complex. The barrier properties of tight junctions of the stria vascularis appeared intact in a biotin tracer assay, but the endocochlear potential is reduced in adult mambo mice. Hair cell degeneration in mambo mice precedes endocochlear potential decline and is rescued in cochlear organotypic cultures in low potassium milieu, indicating that hair cell loss is triggered by extracellular factors. Remarkably, heterozygous mambo mice show increased susceptibility to noise injury at high frequencies. We conclude that USP53 is a novel tight junction-associated protein that is essential for the survival of auditory hair cells and normal hearing in mice, possibly by modulating the barrier properties and mechanical stability of tight junctions. SIGNIFICANCE STATEMENT Hereditary hearing loss is extremely prevalent in the human population, but many genes linked to hearing loss remain to be discovered. Forward genetics screens in mice have facilitated the identification of genes involved in sensory perception and provided valuable animal models for hearing loss in humans. This involves introducing random mutations in mice, screening the mice for hearing defects, and mapping the causative mutation. Here, we have identified a mutation in the Usp53 gene that causes progressive hearing loss in the mambo mouse line. We demonstrate that USP53 is a catalytically inactive deubiquitinating enzyme and a novel component of tight junctions that is necessary for sensory hair cell survival and inner ear homeostasis. PMID:26609154

[Translation and linguistic validation in classical Arabic of the urinary symptom profile (USP) questionnaire].

PubMed

Arabi, H; Bendeddouche, I; Khalfaoui, S; Louardi, N; Ameur, A; Lebreton, F; Amarenco, G

2013-04-01

The objective was to translate and linguistically validate in classical Arabic; the French version of the Urinary Symptom Profile (USP), the scale adapted to vesico-sphincter disorders. Prospective study of 30 patients suffering the vesico-sphincter disorders. The translation was obtained by the method: translation back-translation. Patients completed the final questionnaire on day 0 and day 15. The feasibility, acceptability, internal consistency using Cronbach's alpha and test-retest repeatability by the interclass correlation coefficient (ICC) with the confidence interval (CI) were studied. The sample consisted of 30 subjects including 20 men (66.6%) and 10 women (33.3%). The mean age was 48±18, 14 years ranging from 25 to 70 years. The questionnaire was feasible and acceptable. The Cronbach's alpha of the three dimensions, urinary stress incontinence, overactive bladder and voiding difficulties was respectively 0.9880, 0.9774 and 0.9683, respectively; the ICC was 0.9762 (95% CI: 0.9307-0.9919), 0.9558 (CI 95%: 0.8738-0.9849) and 0.9385 (95% CI: 0.8274-0.9789). The Arabic version of the classic USP had excellent internal consistency and excellent repeatability enable a full assessment of all urinary disorders and their severity. Copyright © 2013 Elsevier Masson SAS. All rights reserved.

Performance Equivalence and Validation of the Soleris Automated System for Quantitative Microbial Content Testing Using Pure Suspension Cultures.

PubMed

Limberg, Brian J; Johnstone, Kevin; Filloon, Thomas; Catrenich, Carl

2016-09-01

Using United States Pharmacopeia-National Formulary (USP-NF) general method <1223> guidance, the Soleris(®) automated system and reagents (Nonfermenting Total Viable Count for bacteria and Direct Yeast and Mold for yeast and mold) were validated, using a performance equivalence approach, as an alternative to plate counting for total microbial content analysis using five representative microbes: Staphylococcus aureus, Bacillus subtilis, Pseudomonas aeruginosa, Candida albicans, and Aspergillus brasiliensis. Detection times (DTs) in the alternative automated system were linearly correlated to CFU/sample (R(2) = 0.94-0.97) with ≥70% accuracy per USP General Chapter <1223> guidance. The LOD and LOQ of the automated system were statistically similar to the traditional plate count method. This system was significantly more precise than plate counting (RSD 1.2-2.9% for DT, 7.8-40.6% for plate counts), was statistically comparable to plate counting with respect to variations in analyst, vial lots, and instruments, and was robust when variations in the operating detection thresholds (dTs; ±2 units) were used. The automated system produced accurate results, was more precise and less labor-intensive, and met or exceeded criteria for a valid alternative quantitative method, consistent with USP-NF general method <1223> guidance.

Effects of suppression and acceptance of sadness on the urge for non-suicidal self-injury and self-punishment.

PubMed

Svaldi, Jennifer; Dorn, Christina; Matthies, Swantje; Philipsen, Alexandra

2012-12-30

The present study wanted to test the course of the urge for non-suicidal self-injury (UNSSI) and the urge for self-punishment (USP) when suppressing or accepting upcoming emotions in response to a sadness-inducing film clip in female participants with borderline personality disorder (BPD). Thirty-six women with BPD were allocated either to a condition in which they were asked to engage in expressive suppression or acceptance while watching a sadness-inducing film clip. Ratings of UNSSI, USP, and positive and negative emotions were assessed prior to the clip (baseline), immediately after it (t1) and after a 5min waiting period (t2), during which participants viewed landscape pictures. Additionally, physiological measures were obtained. Main results revealed a significant increase in UNSSI from baseline to t2 in the acceptance, but not in the suppression group. Furthermore, USP scores significantly increased from baseline to t2 in the acceptance, but not in the suppression condition. However, there was no differential impact on the sympathetic and parasympathetic branch depending on strategy. The results are in line with recent literature showing that expressive suppression in BPD may also have an adaptive function. Copyright © 2012 Elsevier Ireland Ltd. All rights reserved.

Multimodal Assessment of Corneal Thinning Using Optical Coherence Tomography, Scheimpflug Imaging, Pachymetry, and Slit-Lamp Examination.

PubMed

Oatts, Julius T; Keenan, Jeremy D; Mannis, Tova; Lietman, Tom M; Rose-Nussbaumer, Jennifer

2017-04-01

To assess the relationship between corneal thinning measured by clinician-graded slit-lamp examination compared with ultrasound pachymetry (USP), anterior segment optical coherence tomography (AS-OCT), and the Pentacam. Patients with corneal thinning underwent USP, AS-OCT, Pentacam measurements and standardized clinical grading by 2 cornea specialists estimating thinning on slit-lamp examination. Reproducibility of each testing modality was assessed using the intraclass correlation coefficient. Bland-Altman plots were used to determine precision and limits of agreement (LOA) between imaging modalities and clinical grading. We included 22 patients with corneal thinning secondary to infectious or inflammatory keratitis. Mean percent stromal thinning estimated by grader 1 was 51% (SD 31) and grader 2 was 49% (SD 33). The intraclass correlation coefficient between the masked examiners was 0.95 (95% confidence interval, 0.88-0.98). Graders were more similar to each other than to any other modality with 2% difference and 4.6% of measurements outside the LOA. When measuring the area of maximum thinning, AS-OCT measured approximately 10% thicker than human graders while the Pentacam measured approximately 10% thinner than human graders with 16.7% outside the LOA. USP measured approximately 20% thinner than human graders with 5.6% outside the LOA. Trained corneal specialists have a high degree of agreement in location and degree of corneal thinning when measured in a standardized fashion on the same day. Other testing modalities had acceptable reproducibility and agreement with clinical examination and each other, although Scheimpflug imaging fared worse for corneal thinning, particularly in the periphery, than the other modalities.

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.

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.

Modeling of inertial deposition in scaled models of rat and human nasal airways: Towards in vitro regional dosimetry in small animals

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

Xi, Jinxiang; Kim, JongWon; Si, Xiuhua A.

Rodents are routinely used in inhalation toxicology tests as human surrogates. However, in vitro dosimetry tests in rodent casts are still scarce due to small rodent airways and in vitro tests to quantify sub-regional dosimetry are still impractical. We hypothesized that for inertial particles whose deposition is dominated by airflow convection (Reynolds number) and particle inertia (Stokes number), the deposition should be similar among airway replicas of different scales if their Reynolds and Stokes numbers are kept the same. In this study, we aimed to (1) numerically test the hypothesis in three airway geometries: a USP induction port, a humanmore » nose model, and a Sprague-Dawley rat nose model, and (2) find the range of applicability of this hypothesis. Five variants of the USP and human nose models and three variants of the rat nose model were tested. Inhalation rates and particle sizes were scaled to match the Reynolds number and Stokes numbers. A low-Reynolds-number k–ω model was used to resolve the airflow and a Lagrangian tracking algorithm was used to simulate the particle transport and deposition. Statistical analysis of predicted doses was conducted using ANOVA. For normal inhalation rates and particle dia- meters ranging from 0.5 to 24 mm, the deposition differences between the life-size and scaled models are insignificant for all airway geometries considered (i.e., human nose, USP, and rat nose). Furthermore, the deposition patterns and exit particle profiles also look similar among scaled models. However, deposition rates and patterns start to deviate if inhalation rates are too low, or particle sizes are too large. For the rat nose, the threshold velocity was found to be 0.71 m/s and the threshold Froude number to be 50. Results of this study provide a theoretical foundation for sub-regional in vitro dosimetry tests in small animals and for interpretation of data from inter-species or intra-species with varying body sizes.« less

Isolation and characterization of a novel pollen-specific promoter in maize (Zea mays L.).

PubMed

Wang, He; Fan, Mingxia; Wang, Guohong; Zhang, Chunyu; Shi, Lei; Wei, Zhengyi; Ma, Wenjuan; Chang, Jing; Huang, Senxin; Lin, Feng

2017-06-01

ZmSTK2_USP, located on the long arm of chromosome 4, belongs to the serine/threonine kinase gene in maize. The sequence analysis of 2100 bp upstream from the start codon ATG has shown that it contains cis-element motifs and two types of anther/pollen-specific promoter elements (GTGA and AGAAA), suggesting that it is the pollen-specific promoter. To investigate the function of ZmSTK2_USP promoter, the GUS gene fusion system was employed. In proZmSTK2_USP-GUS genetically modified plants, GUS activity was detected in mature pollen grains and pollen tubes but not found in other floral and vegetative tissues. These results show that proZmSTK2_USP is the pollen-specific promoter and drives pollen-specific activity during the middle stage of pollen development until pollen maturation.

Particulate-matter content of 11 cephalosporin injections: conformance with USP limits.

PubMed

Parkins, D A; Taylor, A J

1987-05-01

The particulate-matter content of 11 dry-powder cephalosporin injections was determined using a modified version of the official United States Pharmacopeial Convention (USP) method for particulate matter in small-volume injections (SVIs). Ten vials of each cephalosporin product were each constituted with 10 mL of Water for Injections BP that had been filtered through a 0.22-micron membrane. The pooled contents of the 10 vials for each product were allowed to stand under reduced pressure to ensure removal of gas bubbles. Particulate-matter content was determined using a HIAC/Royco particle counter on six 10-mL samples obtained from the pooled solutions for each product. All solution preparation and particle counting was performed in a horizontal-laminar-airflow hood. Modifications of the USP method used in this study included the use of six rather than two samples from each pooled solution, the addition of diluent to the injections through the rubber closure with a needle instead of into the open container, and changes in the degassing method. Particle counts for all products examined were lower than USP limits for SVIs. All but two products contained less than 15% of USP limits for particles greater than or equal to 10 microns in effective diameter and particles greater than or equal to 25 microns in effective diameter. The standard USP method for degassing (standing for two minutes) was inadequate. Application of reduced pressure for up to 10 minutes was necessary for thorough degassing of products.(ABSTRACT TRUNCATED AT 250 WORDS)

CRISPR/Cas9 knockout of USP18 enhances type I IFN responsiveness and restricts HIV-1 infection in macrophages.

PubMed

Taylor, Jared P; Cash, Melanie N; Santostefano, Katherine E; Nakanishi, Mahito; Terada, Naohiro; Wallet, Mark A

2018-02-13

The IFN-stimulated gene ubiquitin-specific proteinase 18 (USP18) encodes a protein that negatively regulates T1 IFN signaling via stearic inhibition of JAK1 recruitment to the IFN-α receptor 2 subunit (IFNAR2). Here, we demonstrate that USP18 expression is induced by HIV-1 in a T1 IFN-dependent manner. Experimental depletion of USP18 by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing results in a significant restriction of HIV-1 replication in an induced pluripotent stem cell (iPSC)-derived macrophage model. In the absence of USP18, macrophages have increased responsiveness to stimulation with T1 IFNs with prolonged phosphorylation of STAT1 and STAT2 and increased expression of IFN-stimulated genes that are key for antiviral responses. Interestingly, HIV-1 requires some signaling through the T1 IFN receptor to replicate efficiently because a neutralizing antibody that inhibits T1 IFN activity reduces HIV-1 replication rate in monocyte-derived macrophages. USP18 induction by HIV-1 tunes the IFN response to optimal levels allowing for efficient transcription from the HIV-1 LTR promoter while minimizing the T1 IFN-induced antiviral response that would otherwise restrict viral replication and spread. Finally, iPSC and CRISPR/Cas9 gene targeting offer a powerful tool to study host factors that regulate innate immune responses. ©2018 Society for Leukocyte Biology.

Born dry in the photoevaporation desert: Kepler's ultra-short-period planets formed water-poor

NASA Astrophysics Data System (ADS)

Lopez, Eric D.

2017-11-01

Recent surveys have uncovered an exciting new population of ultra-short-period (USP) planets with orbital periods less than a day. These planets typically have radii ≲1.5 R⊕, indicating that they likely have rocky compositions. This stands in contrast to the overall distribution of planets out to ∼100 d, which is dominated by low-density sub-Neptunes above 2 R⊕, which must have gaseous envelopes to explain their size. However, on the USP orbits, planets are bombarded by intense levels of photoionizing radiation and consequently gaseous sub-Neptunes are extremely vulnerable to losing their envelopes to atmospheric photoevaporation. Using models of planet evolution, I show that the rocky USP planets can easily be produced as the evaporated remnants of sub-Neptunes with H/He envelopes and that we can therefore understand the observed dearth of USP sub-Neptunes as a natural consequence of photoevaporation. Critically however, planets on USP orbits could often retain their envelopes if they are formed with very high-metallicity water-dominated envelopes. Such water-rich planets would commonly be ≳2 R⊕ today, which is inconsistent with the observed evaporation desert, indicating that most USP planets likely formed from water-poor material within the snow-line. Finally, I examine the special case of 55 Cancri e and its possible composition in the light of recent observations, and discuss the prospects for further characterizing this population with future observations.

Comparison of contamination rates between preserved and preservative-free fluoroquinolone eyedrops.

PubMed

Kim, Mo Sae; Kim, Hong Kyun; Kim, Joon Mo; Choi, Chul Young

2013-03-01

To evaluate the antimicrobial effectiveness of preservative-free fluoroquinolone products compared with benzalkonium chloride containing fluoroquinolones using the challenge test provided by the United States Pharmacopeia (USP) and the in-use test. 1. Challenge test: to compare the growth of microorganisms between different fluoroquinolone preparations, four test organisms, including Staphylococcus aureus, Pseudomonas aeruginosa, Candida albicans, and Aspergillus niger were chosen among five microorganisms listed by USP 2004. The inoculated products were sampled for microbial survivors at days 7, 14, and 28 following initial inoculation at room temperature. The number of surviving organisms were calculated as a Log10 reduction from the original inocula. 2. In-use test: a total of 100 bottles were collected after instillation of preservative-free fluoroquinolone eyedrops in volunteer patients after 1 week of use. The remaining fluid and tips of the bottles were cultured. Colonies on the plates were counted at the end of the incubation period. All microorganisms were identified by Gram staining and biochemical assays. 1. Challenge test: preservative-free gatifloxacin and levofloxacin demonstrated a lower log reduction against A. niger than preserved fluoroquinolones and preservative-free moxifloxacin at all time points. 2. In-use test: There was no contamination identified on plates inoculated by preservative-free quinolone bottles after 1 week of use in this study. Physicians should be aware of the lower antifungal preservative effectiveness of some preservative-free fluoroquinolone preparations than preserved ones.

Flow-injection system for automated dissolution testing of isoniazid tablets with chemiluminescence detection.

PubMed

Li, B; Zhang, Z; Liu, W

2001-05-30

A simple and sensitive flow-injection chemiluminescence (CL) system for automated dissolution testing is described and evaluated for monitoring of dissolution profiles of isoniazid tablets. The undissolved suspended particles in the dissolved solution were eliminated via on-line filter. The novel CL system of KIO(4)-isoniazid was also investigated. The sampling frequency of the system was 120 h(-1). The dissolution profiles of isoniazid fast-release tablets from three sources were determined, which demonstrates the stability, great sensitivity, large dynamic measuring range and robustness of the system.

Regulatory Perspectives on Strength-Dependent Dissolution Profiles and Biowaiver Approaches for Immediate Release (IR) Oral Tablets in New Drug Applications.

PubMed

Suarez-Sharp, Sandra; Delvadia, Poonam R; Dorantes, Angelica; Duan, John; Externbrink, Anna; Gao, Zongming; Ghosh, Tapash; Miksinski, Sarah Pope; Seo, Paul

2016-05-01

Dissolution profile comparisons are used by the pharmaceutical industry to assess the similarity in the dissolution characteristics of two formulations to decide whether the implemented changes, usually minor/moderate in nature, will have an impact on the in vitro/in vivo performance of the drug product. When similarity testing is applied to support the approval of lower strengths of the same formulation, the traditional approach for dissolution profile comparison is not always applicable for drug products exhibiting strength-dependent dissolution and may lead to incorrect conclusions about product performance. The objective of this article is to describe reasonable biopharmaceutic approaches for developing a biowaiver strategy for low solubility, proportionally similar/non-proportionally similar in composition immediate release drug products that exhibit strength-dependent dissolution profiles. The paths highlighted in the article include (1) approaches to address biowaiver requests, such as the use of multi-unit dissolution testing to account for sink condition differences between the higher and lower strengths; (2) the use of a single- vs. strength-dependent dissolution method; and (3) the use of single- vs. strength-dependent dissolution acceptance criteria. These approaches are cost- and time-effective and can avoid unnecessary bioequivalence studies.

COMMITTEES: SQM2009 - 14th International Conference on Strangeness in Quark Matter SQM2009 - 14th International Conference on Strangeness in Quark Matter

NASA Astrophysics Data System (ADS)

2008-04-01

Local Organizing Committee Takeshi Kodama Chair, UFRJ Jun Takahashi Co-chair, UNICAMP Ignácio Bediaga e Hickman CBPF Eduardo Fraga UFRJ Frederique Grassi USP Yogiro Hama USP Gastão Krein IFT Erasmo Madureira Ferreira UFRJ Marcelo G. Munhoz USP Fernando Navarra USP Sandra Padula IFT Alejandro Szanto de Toledo USP César Augusto Zen Vasconcellos UFRGS International Advisory Committee Jörg Aichelin Nantes Federico Antinori Padova Tamás Biró Budapest Peter Braun-Munzinger GSI Jean Cleymans Cape Town Láaszló Csernai Bergen Timothy Hallman BNL Huan Zhong Huang UCLA Takeshi Kodama Rio de Janeiro Yu-Gang Ma Shanghai Jes Madsen Aarhus Ágnes Mócsy Pratt University Berndt Müller Duke University Grazyna Odyniec LBNL Helmut Oeschler Darmstadt Johann Rafelski Arizona Hans Georg Ritter LBNL Gunther Rolland MIT Karel Šafařík CERN Ladislav Sandor Kosice University Jack Sandweiss Yale University George S F Stephans MIT Horst Stöcker Frankfurt Larry McLerranBNL Helmut Satz Universitä Bielefeld Nu Xu LBNL Fuqiang Wang Purdue University William A. Zajc Columbia University Pengfei Zhuang Tsinghua University

Aberrant phosphorylation of SMAD4 Thr277-mediated USP9x-SMAD4 interaction by free fatty acids promotes breast cancer metastasis

PubMed Central

Wu, Yong; Yu, Xiaoting; Yi, Xianghua; Wu, Ke; Dwabe, Sami; Atefi, Mohammad; Elshimali, Yahya; Kemp, Kevin T.; Bhat, Kruttika; Haro, Jesse; Sarkissyan, Marianna; Vadgama, Jaydutt V

2017-01-01

Obesity increases the risk of distant metastatic recurrence and reduces breast cancer (BC) survival. However, the mechanisms behind this pathology and identification of relevant therapeutic targets are poorly defined. Plasma free fatty acids (FFA) levels are elevated in obese individuals. Here we report that TGF-β transiently activates ERK and subsequently phosphorylates SMAD4 at Thr277, which facilitates a SMAD4-USP9x interaction, SMAD4 nuclear retention, and stimulates TGF-β /SMAD3-mediated transcription of Twist and Snail. USP9x inhibited the E3 ubiquitin-protein ligase TIF1γ from binding and monoubiquitinating SMAD4, hence maintaining SMAD4 nuclear retention. FFA further facilitated TGF-β-induced ERK activation, SMAD4 phosphorylation and nuclear retention, promoting TGF-β-dependent cancer progression. Inhibition of ERK and USP9x suppressed obesity-induced metastasis. Additionally, clinical data indicated that phospho-ERK and -SMAD4 levels correlate with activated TGF-β signaling and metastasis in overweight/obese patient BC specimens. Altogether, we demonstrate the vital interaction of USP9x and SMAD4 for governing TGF-β signaling and dyslipidemia-induced, aberrant TGF-β activation during BC metastasis. PMID:28115363

A high-confidence interaction map identifies SIRT1 as a mediator of acetylation of USP22 and the SAGA coactivator complex.

PubMed

Armour, Sean M; Bennett, Eric J; Braun, Craig R; Zhang, Xiao-Yong; McMahon, Steven B; Gygi, Steven P; Harper, J Wade; Sinclair, David A

2013-04-01

Although many functions and targets have been attributed to the histone and protein deacetylase SIRT1, a comprehensive analysis of SIRT1 binding proteins yielding a high-confidence interaction map has not been established. Using a comparative statistical analysis of binding partners, we have assembled a high-confidence SIRT1 interactome. Employing this method, we identified the deubiquitinating enzyme ubiquitin-specific protease 22 (USP22), a component of the deubiquitinating module (DUBm) of the SAGA transcriptional coactivating complex, as a SIRT1-interacting partner. We found that this interaction is highly specific, requires the ZnF-UBP domain of USP22, and is disrupted by the inactivating H363Y mutation within SIRT1. Moreover, we show that USP22 is acetylated on multiple lysine residues and that alteration of a single lysine (K129) within the ZnF-UBP domain is sufficient to alter interaction of the DUBm with the core SAGA complex. Furthermore, USP22-mediated recruitment of SIRT1 activity promotes the deacetylation of individual SAGA complex components. Our results indicate an important role of SIRT1-mediated deacetylation in regulating the formation of DUBm subcomplexes within the larger SAGA complex.

United States Pharmacopeial Convention

MedlinePlus

... Online USP Compounding USP Donor Portal Chromatographic Columns Social Media Linked In Twitter Facebook You Tube QualityMatters Blog ... Events & Training Get Involved Partner Volunteer Provide Input Social Media Linked In Twitter Facebook You Tube QualityMatters Blog ...

27 CFR 21.51 - Formula No. 25-A.

Code of Federal Regulations, 2013 CFR

2013-04-01

... iodide, U.S.P.; and 15 pounds of water. (b) Authorized uses. (1) As a solvent: 230.Tinctures of iodine. 249.Miscellaneous external pharmaceuticals, U.S.P. or N.F. (2) Miscellaneous uses: 812.Product...

27 CFR 21.51 - Formula No. 25-A.

Code of Federal Regulations, 2012 CFR

2012-04-01

... iodide, U.S.P.; and 15 pounds of water. (b) Authorized uses. (1) As a solvent: 230.Tinctures of iodine. 249.Miscellaneous external pharmaceuticals, U.S.P. or N.F. (2) Miscellaneous uses: 812.Product...

27 CFR 21.51 - Formula No. 25-A.

Code of Federal Regulations, 2014 CFR

2014-04-01

... iodide, U.S.P.; and 15 pounds of water. (b) Authorized uses. (1) As a solvent: 230.Tinctures of iodine. 249.Miscellaneous external pharmaceuticals, U.S.P. or N.F. (2) Miscellaneous uses: 812.Product...

27 CFR 21.51 - Formula No. 25-A.

Code of Federal Regulations, 2011 CFR

2011-04-01

... iodide, U.S.P.; and 15 pounds of water. (b) Authorized uses. (1) As a solvent: 230.Tinctures of iodine. 249.Miscellaneous external pharmaceuticals, U.S.P. or N.F. (2) Miscellaneous uses: 812.Product...

Modeling solid-state transformations occurring in dissolution testing.

PubMed

Laaksonen, Timo; Aaltonen, Jaakko

2013-04-15

Changes in the solid-state form can occur during dissolution testing of drugs. This can often complicate interpretation of results. Additionally, there can be several mechanisms through which such a change proceeds, e.g. solvent-mediated transformation or crystal growth within the drug material itself. Here, a mathematical model was constructed to study the dissolution testing of a material, which undergoes such changes. The model consisted of two processes: the recrystallization of the drug from a supersaturated liquid state caused by the dissolution of the more soluble solid form and the crystal growth of the stable solid form at the surface of the drug formulation. Comparison to experimental data on theophylline dissolution showed that the results obtained with the model matched real solid-state changes and that it was able to distinguish between cases where the transformation was controlled either by solvent-mediated crystallization or solid-state crystal growth. Copyright © 2013 Elsevier B.V. All rights reserved.

Developing a Spatially Distributed Terrestrial Biogeochemical Cycle Modeling System to Support the Management of Fort Benning and its Surrounding Areas

DTIC Science & Technology

2010-12-01

nitrogen SSURGO Soil Survey Geographic database USDA U.S. Department of Agriculture USLE Universal Soil Loss Equation USPED Unit-Stream-Power...Zaluski et al., 2003). A suite of models has been developed to simulate soil erosion and deposition, ranging from empirical (e.g., USLE and MUSLE at http...Estimating Soil Erosion and Deposition 4.4.1 USPED The algorithm for the simulation of soil erosion in USPED is similar to that of the USLE or RUSLE

Department of the Army Supply Bulletin, Army Medical Department Supply Information, SB8-75-11

DTIC Science & Technology

2001-11-20

SULFATE INJECTION USP 10MG 1ML CARTRIDGE-NEEDLE UNIT10S MFR: SANOFI LOT/SER NO: C790PD NSN: 6505-00-812-2596 NOM: MORPHINE SULFATE INJECTION...100 TABLETS PER BOTTLE MFR: SANOFI LOT/SER NO: SP344 NSN: 6505-01-178-7903 NOM: PYRIDOSTIGMINE BROMIDE TABLETS USP 30MG I.S. 210 TABS...ML 2ML SYRINGE WITH NEEDLE 10/PACKAGE MFR: SANOFI LOT/SER NO: C740RL NSN: 6505-01-274-0951 NOM: DIAZEPAM INJECTION USP 5MG/ML 2ML SYRINGE

27 CFR 21.151 - List of denaturants authorized for denatured spirits.

Code of Federal Regulations, 2010 CFR

2010-04-01

... Denatured Rum (S.D.R.) Acetaldehyde S.D.A. 29. Acetone, U.S.P S.D.A. 23-A, 23-H. Acetaldol C.D.A. 18. Almond... alcohol S.D.A. 39, 39-A, 39-B, 40, 40-A, 40-B, 40-C. Camphor, U.S.P S.D.A. 27, 27-A, 38-B. Caustic soda.... Formaldehyde solution, U.S.P S.D.A. 22, 38-C, 38-D. Gasoline C.D.A. 18, 19; S.D.A. 28-A. Gasoline, unleaded C.D...

27 CFR 21.151 - List of denaturants authorized for denatured spirits.

Code of Federal Regulations, 2011 CFR

2011-04-01

... Denatured Rum (S.D.R.) Acetaldehyde S.D.A. 29. Acetone, U.S.P S.D.A. 23-A, 23-H. Acetaldol C.D.A. 18. Almond... alcohol S.D.A. 39, 39-A, 39-B, 40, 40-A, 40-B, 40-C. Camphor, U.S.P S.D.A. 27, 27-A, 38-B. Caustic soda.... Formaldehyde solution, U.S.P S.D.A. 22, 38-C, 38-D. Gasoline C.D.A. 18, 19; S.D.A. 28-A. Gasoline, unleaded C.D...

Statistical Considerations Concerning Dissimilar Regulatory Requirements for Dissolution Similarity Assessment. The Example of Immediate-Release Dosage Forms.

PubMed

Jasińska-Stroschein, Magdalena; Kurczewska, Urszula; Orszulak-Michalak, Daria

2017-05-01

When performing in vitro dissolution testing, especially in the area of biowaivers, it is necessary to follow regulatory guidelines to minimize the risk of an unsafe or ineffective product being approved. The present study examines model-independent and model-dependent methods of comparing dissolution profiles based on various compared and contrasted international guidelines. Dissolution profiles for immediate release solid oral dosage forms were generated. The test material comprised tablets containing several substances, with at least 85% of the labeled amount dissolved within 15 min, 20-30 min, or 45 min. Dissolution profile similarity can vary with regard to the following criteria: time point selection (including the last time point), coefficient of variation, and statistical method selection. Variation between regulatory guidance and statistical methods can raise methodological questions and result potentially in a different outcome when reporting dissolution profile testing. The harmonization of existing guidelines would address existing problems concerning the interpretation of regulatory recommendations and research findings. Copyright © 2017 American Pharmacists Association®. Published by Elsevier Inc. All rights reserved.

Indomethacin-Kollidon VA64 Extrudates: A Mechanistic Study of pH-Dependent Controlled Release.

PubMed

Tres, Francesco; Treacher, Kevin; Booth, Jonathan; Hughes, Leslie P; Wren, Stephen A C; Aylott, Jonathan W; Burley, Jonathan C

2016-03-07

Because of its weakly acidic nature (pKa of 4.5), indomethacin presents an aqueous solubility that significantly increases when changing from acidic to neutral/alkaline pH (1.5 μg/mL at pH 1.2 and 105.2 μg/mL at pH 7.4). We have therefore investigated the impact of the dissolution medium pH on the dissolution performance of indomethacin:Kollidon VA64 extrudates. The impact of the drug loading on the dissolution properties of these systems was also examined (5%, 15%, 30%, 50%, 70%, and 90% drug loading). Time-resolved Raman spectroscopy along with in-line UV-vis spectrophotometry was employed to directly relate changes in dissolution behavior to physicochemical changes that occur to the extrudate during the test. The dissolution tests were performed in pH 2 HCl (to mimic the stomach conditions), and this was then switched during the experiment to pH 6.8 phosphate buffer (to simulate the poststomach conditions). The rotating disc dissolution rate test was also used to simultaneously measure the dissolution rate of both the drug and the polymer. We found that in pH 2 HCl buffer, for the 15% or higher drug-loaded extrudates, Kollidon VA64 preferentially dissolves from the exterior of the compact leaving an amorphous drug-rich hydrophobic shell, which, similarly to an enteric coating, inhibits the drug release. The in situ formation of an enteric coating has been previously hypothesized, and this has been the first time that is directly observed in a pH-variable dissolution test. The dissolution medium switch to pH 6.8 phosphate buffer, due to the large increase of the aqueous solubility of indomethacin at this pH, leads to rapid dissolution of the material forming the coating and therefore total drug release. In contrast, the 5% extrudate is fully hydrated and quickly dissolves at low pH pointing to a dissolution performance dependent on highly water-soluble Kollidon VA64.

Unstable Roche-Lobe Overflow of Gaseous Planets

NASA Astrophysics Data System (ADS)

Jackson, Brian

The discoveries of more than 100 roughly Earth-sized bodies with orbital periods less than 1 day, ultra-short-period planets or candidates (USPs), have challenged planet formation theories, and evidence suggests USPs may be the remnants of gaseous planets that shed their atmospheres. Indeed, many hot Jupiters are near Roche-Lobe overflow (RLO), and tidal decay can push them the rest of the way in. Recent work has shown stable RLO (atmospheres lost via a steady outflow and thin accretion disk) probably cannot produce USPs on its own but suggested unstable RLO (atmospheres quickly shed on dynamical timescales) may. In fact, stable RLO may drive overflowing hot Jupiters into unstable RLO, and by analogy with the common-envelope binaries, the core that remains can drive off the gaseous envelope at the cost of its orbital energy. Wellestablished mass-radius relations for gaseous planets, coupled to simple energy and angular momentum considerations, provide a connection between the observed masses and periods for USPs and their putative progenitor gaseous planets, with few free parameters. We propose to investigate the hypothesis that USPs originate through tidal decay and a combination of stable and unstable Roche-lobe overflow of short-period gaseous planets through the following studies: -We will explore the planetary masses, orbital periods, etc. that produce unstable RLO using the Modules for Experiments in Stellar Astrophysics (MESA) suite. -We will relate the observed periods and masses of USPs to their putative progenitor masses and periods to see whether they are consistent with the unstable RLO hypothesis. This proposal is directly relevant to the Exoplanets Research Program since it seeks to "understand the ... physical processes of exoplanets" and "improve understanding of [their] origins" through "theoretical studies ... and modeling'". We also expect that it will have broad impacts on a variety of astrophysical topics: -Ultra-short period planets could provide a glimpse inside gas giants. If our study corroborates the unstable RLO hypothesis, the properties of USPs may represent those of gaseous planet cores, which are almost entirely unconstrained. Even in our own solar system, estimates of the core masses for Jupiter (between 0 and 14 Earth masses) and Saturn (between 8 and 25 Earth masses) have large uncertainties. The upcoming Juno mission will clarify the situation for Jupiter, but it's unclear whether these constraints will directly bear on other planetary systems. -The TESS mission will probably find hundreds of ultra-short-period planets. The Transiting Exoplanet Survey Satellite (TESS) will launch in 2017 and look for shortperiod rocky planets around 500,000 nearby stars. Roughly 0.1% of Sun-like stars host USPs, so TESS should find hundreds of USPs. These planets would be ideal for followup, and a clear framework for their origins would motivate and guide additional TESS observations. -Even if we show they are not remnants of gaseous planets, ultra-short-period planets may serve as probes of the innermost protoplanetary gas disk and betray the presence of additional planets in their host systems. As we discuss below, one other obvious origin scenario involves dynamical interactions in a multi-planet system. Many USPs do not have observed siblings, so this scenario requires that there are additional, unseen planets in those systems. The exact location of USPs may be set, in part, by the inner edge of their maternal gas disk, a sensitive function of the host star's youthful properties.

Retigabine ameliorates acute stress-induced impairment of spatial memory retrieval through regulating USP2 signaling pathways in hippocampal CA1 area.

PubMed

Li, Cai; Zhang, Ji; Xu, Haiwei; Chang, Mujun; Lv, Chuntao; Xue, Wenhua; Song, Zhizhen; Zhang, Lizhen; Zhang, Xiaojian; Tian, Xin

2018-06-01

Acute stress could trigger maladaptive changes associated with stress-related cognitive and emotional deficits. Dysfunction of ion channel or receptor in the hippocampal area has been linked to the cognitive deficits induced by stress. It is known that Kv7 channel openers, including FDA-approved drug retigabine, show cognitive protective efficacy. However, the underlying molecular mechanisms remain elusive. Here we showed that exposing adult male rats to acute stress significantly impaired the spatial memory, a cognitive process controlled by the hippocampus. Concomitantly, significantly reduced AMPA receptor expression was found in hippocampal CA1 area from acute stressed rats. This effect relied on the down-regulation of deubiquitinating enzyme USP2 and its upstream regulators (PGC-1α and β-catenin), and the subsequent enhancement of mTOR-related autophagy which is regulated by USP2. These findings suggested that acute stress dampened AMPA receptor expression by controlling USP2-related signaling, which caused the detrimental effect on hippocampus-dependent cognitive processes. We also found that retigabine alleviated acute stress-induced spatial memory retrieval impairment through adjusting the aberrance of USP2, its upstream regulators (PGC-1α, E4BP4 and β-catenin) and its downstream targets (mTOR, autophagy and GluA1). Our results have identified USP2 as a key molecule that mediates stress-induced spatial memory retrieval impairment, which provides a framework for new druggable targets to conceptually treat stress-associated cognitive deficits. Copyright © 2018 Elsevier Ltd. All rights reserved.

Engineering Signal Peptides for Enhanced Protein Secretion from Lactococcus lactis

PubMed Central

Ng, Daphne T. W.

2013-01-01

Lactococcus lactis is an attractive vehicle for biotechnological production of proteins and clinical delivery of therapeutics. In many such applications using this host, it is desirable to maximize secretion of recombinant proteins into the extracellular space, which is typically achieved by using the native signal peptide from a major secreted lactococcal protein, Usp45. In order to further increase protein secretion from L. lactis, inherent limitations of the Usp45 signal peptide (Usp45sp) must be elucidated. Here, we performed extensive mutagenesis on Usp45sp to probe the effects of both the mRNA sequence (silent mutations) and the peptide sequence (amino acid substitutions) on secretion. We screened signal peptides based on their resulting secretion levels of Staphylococcus aureus nuclease and further evaluated them for secretion of Bacillus subtilis α-amylase. Silent mutations alone gave an increase of up to 16% in the secretion of α-amylase through a mechanism consistent with relaxed mRNA folding around the ribosome binding site and enhanced translation. Targeted amino acid mutagenesis in Usp45sp, combined with additional silent mutations from the best clone in the initial screen, yielded an increase of up to 51% in maximum secretion of α-amylase while maintaining secretion at lower induction levels. The best sequence from our screen preserves the tripartite structure of the native signal peptide but increases the positive charge of the n-region. Our study presents the first example of an engineered L. lactis signal peptide with a higher secretion yield than Usp45sp and, more generally, provides strategies for further enhancing protein secretion in bacterial hosts. PMID:23124224

Engineering signal peptides for enhanced protein secretion from Lactococcus lactis.

PubMed

Ng, Daphne T W; Sarkar, Casim A

2013-01-01

Lactococcus lactis is an attractive vehicle for biotechnological production of proteins and clinical delivery of therapeutics. In many such applications using this host, it is desirable to maximize secretion of recombinant proteins into the extracellular space, which is typically achieved by using the native signal peptide from a major secreted lactococcal protein, Usp45. In order to further increase protein secretion from L. lactis, inherent limitations of the Usp45 signal peptide (Usp45sp) must be elucidated. Here, we performed extensive mutagenesis on Usp45sp to probe the effects of both the mRNA sequence (silent mutations) and the peptide sequence (amino acid substitutions) on secretion. We screened signal peptides based on their resulting secretion levels of Staphylococcus aureus nuclease and further evaluated them for secretion of Bacillus subtilis α-amylase. Silent mutations alone gave an increase of up to 16% in the secretion of α-amylase through a mechanism consistent with relaxed mRNA folding around the ribosome binding site and enhanced translation. Targeted amino acid mutagenesis in Usp45sp, combined with additional silent mutations from the best clone in the initial screen, yielded an increase of up to 51% in maximum secretion of α-amylase while maintaining secretion at lower induction levels. The best sequence from our screen preserves the tripartite structure of the native signal peptide but increases the positive charge of the n-region. Our study presents the first example of an engineered L. lactis signal peptide with a higher secretion yield than Usp45sp and, more generally, provides strategies for further enhancing protein secretion in bacterial hosts.

27 CFR 21.78 - Formula No. 42.

Code of Federal Regulations, 2012 CFR

2012-04-01

...) Eighty grams of potassium iodide, U.S.P., and 109 grams of red mercuric iodide, N.F. XI; or (2) Ninety-five grams of thimerosal, U.S.P.; or (3) Seventy-six grams of any of the following: phenyl mercuric...

27 CFR 21.78 - Formula No. 42.

Code of Federal Regulations, 2014 CFR

2014-04-01

...) Eighty grams of potassium iodide, U.S.P., and 109 grams of red mercuric iodide, N.F. XI; or (2) Ninety-five grams of thimerosal, U.S.P.; or (3) Seventy-six grams of any of the following: phenyl mercuric...

27 CFR 21.78 - Formula No. 42.

Code of Federal Regulations, 2013 CFR

2013-04-01

...) Eighty grams of potassium iodide, U.S.P., and 109 grams of red mercuric iodide, N.F. XI; or (2) Ninety-five grams of thimerosal, U.S.P.; or (3) Seventy-six grams of any of the following: phenyl mercuric...

27 CFR 21.78 - Formula No. 42.

Code of Federal Regulations, 2010 CFR

2010-04-01

...) Eighty grams of potassium iodide, U.S.P., and 109 grams of red mercuric iodide, N.F. XI; or (2) Ninety-five grams of thimerosal, U.S.P.; or (3) Seventy-six grams of any of the following: phenyl mercuric...

27 CFR 21.78 - Formula No. 42.

Code of Federal Regulations, 2011 CFR

2011-04-01

...) Eighty grams of potassium iodide, U.S.P., and 109 grams of red mercuric iodide, N.F. XI; or (2) Ninety-five grams of thimerosal, U.S.P.; or (3) Seventy-six grams of any of the following: phenyl mercuric...

Evaluating bioequivalence of meloxicam tablets: is in-vitro dissolution test overdiscriminating?

PubMed

Jin, Chan; Zhao, Chenyao; Shen, Dachao; Dong, Wenxiang; Liu, Hongzhuo; He, Zhonggui

2018-02-01

The aim of the study was to assess the impact of the differences in dissolution profiles of meloxicam tablets on the in-vivo bioavailability parameters after oral administration. Compare in-vitro dissolution testing in the recommended media to evaluate in-vivo bioequivalence outcomes for the Biopharmaceutics Classification System Class II weak acidic drugs. Nine Beagle dogs received a single oral administration of each formulation (7.5 mg) in a three-way crossover design. The dissolution of meloxicam from both test products showed marked differences with that from the reference tablet in pH 1.0, 4.5 and 6.8 media at 50 or 75 rpm. Both formulations exhibiting slow or fast dissolution were then compared with the reference product for in-vivo bioequivalence study. Both products were bioequivalent with the reference tablet in either extent or rate of oral absorption. It indicated that the dissolution profiles which discriminated between the formulations in vitro did not accurately predict the in-vivo bioequivalence outcomes. Comparative dissolution profiles using similarity factor (f 2 ) in the recommended media should be relaxed to fulfil the requirements for the development, scale-up and postapproval changes to immediate release oral solid dosage forms of meloxicam. © 2017 Royal Pharmaceutical Society.

Accelerated dissolution testing for controlled release microspheres using the flow-through dissolution apparatus.

PubMed

Collier, Jarrod W; Thakare, Mohan; Garner, Solomon T; Israel, Bridg'ette; Ahmed, Hisham; Granade, Saundra; Strong, Deborah L; Price, James C; Capomacchia, A C

2009-01-01

Theophylline controlled release capsules (THEO-24 CR) were used as a model system to evaluate accelerated dissolution tests for process and quality control and formulation development of controlled release formulations. Dissolution test acceleration was provided by increasing temperature, pH, flow rate, or adding surfactant. Electron microscope studies on the theophylline microspheres subsequent to each experiment showed that at pH values of 6.6 and 7.6 the microspheres remained intact, but at pH 8.6 they showed deterioration. As temperature was increased from 37-57 degrees C, no change in microsphere integrity was noted. Increased flow rate also showed no detrimental effect on integrity. The effect of increased temperature was determined to be the statistically significant variable.

39 CFR 501.8 - Postage Evidencing System test and approval.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Service Web site at http://www.usps.com/postagesolutions/programdoc.html or requests for copies may be.... (b) As provided in § 501.11, the provider has a duty to report security weaknesses to the Postal... basic features or safeguards may be made except as authorized or ordered by the Postal Service in...

Development and validation of a dissolution test for lodenafil carbonate based on in vivo data.

PubMed

Codevilla, Cristiane Franco; Castilhos, Tamara dos Santos; Cirne, Carolina Araújo; Froehlich, Pedro Eduardo; Bergold, Ana Maria

2014-04-01

Lodenafil carbonate is a phosphodiesterase type 5 inhibitor used for the treatment of erectile dysfunction. Currently, there is no dissolution test reported for lodenafil carbonate and this drug is not listed in any pharmacopoeia. The present study focused on the development and validation of a dissolution test for lodenafil carbonate tablets, using a simulated absorption profile based on in vivo data. The appropriate conditions were determined after testing sink conditions. Different conditions as medium, surfactant concentration and rotation speed were evaluated. The percentage of dose absorbed was calculated by deconvolution, using the Wagner-Nelson method. According to the obtained results, the use of 0.1 M HCl + 1.5% SLS (900 mL, at 37 + 0.5 °C) as the dissolution medium, paddles at 25 rpm were considered adequate. The samples were quantified by UV spectroscopy at 295 nm and the validation was performed according to international guidelines. The method showed specificity, linearity, accuracy and precision, within the acceptable range. Kinetics of drug release was better described by the first-order model. The proposed dissolution test can be used for the routine quality control of lodenafil carbonate in tablets.

39 CFR 20.4 - Amendments to the International Mail Manual.

Code of Federal Regulations, 2010 CFR

2010-07-01

... incorporated by reference into this part and will be available at http://pe.usps.gov. The text of amendments to... Postal Bulletin, copies of which may be accessed at http://www.usps.com/cpim/ftp/bulletin/pb.htm. ...

39 CFR 20.4 - Amendments to the International Mail Manual.

Code of Federal Regulations, 2012 CFR

2012-07-01

... incorporated by reference into this part and will be available at http://pe.usps.gov. The text of amendments to... Postal Bulletin, copies of which may be accessed at http://www.usps.com/cpim/ftp/bulletin/pb.htm. ...

39 CFR 20.4 - Amendments to the International Mail Manual.

Code of Federal Regulations, 2011 CFR

2011-07-01

... incorporated by reference into this part and will be available at http://pe.usps.gov. The text of amendments to... Postal Bulletin, copies of which may be accessed at http://www.usps.com/cpim/ftp/bulletin/pb.htm. ...

39 CFR 20.4 - Amendments to the International Mail Manual.

Code of Federal Regulations, 2013 CFR

2013-07-01

... incorporated by reference into this part and will be available at http://pe.usps.gov. The text of amendments to... Postal Bulletin, copies of which may be accessed at http://www.usps.com/cpim/ftp/bulletin/pb.htm. ...

39 CFR 20.4 - Amendments to the International Mail Manual.

Code of Federal Regulations, 2014 CFR

2014-07-01

... incorporated by reference into this part and will be available at http://pe.usps.gov. The text of amendments to... Postal Bulletin, copies of which may be accessed at http://www.usps.com/cpim/ftp/bulletin/pb.htm. ...

Stabilization of the methyl-CpG binding protein ZBTB38 by the deubiquitinase USP9X limits the occurrence and toxicity of oxidative stress in human cells.

PubMed

Miotto, Benoit; Marchal, Claire; Adelmant, Guillaume; Guinot, Nadège; Xie, Ping; Marto, Jarrod A; Zhang, Lingqiang; Defossez, Pierre-Antoine

2018-05-18

Reactive oxygen species (ROS) are a byproduct of cell metabolism, and can also arise from environmental sources, such as toxins or radiation. Depending on dose and context, ROS have both beneficial and deleterious roles in mammalian development and disease, therefore it is crucial to understand how these molecules are generated, sensed, and detoxified. The question of how oxidative stress connects to the epigenome, in particular, is important yet incompletely understood. Here we show that an epigenetic regulator, the methyl-CpG-binding protein ZBTB38, limits the basal cellular production of ROS, is induced by ROS, and is required to mount a proper response to oxidative stress. Molecularly, these functions depend on a deubiquitinase, USP9X, which interacts with ZBTB38, deubiquitinates it, and stabilizes it. We find that USP9X is itself stabilized by oxidative stress, and is required together with ZBTB38 to limit the basal generation of ROS, as well as the toxicity of an acute oxidative stress. Our data uncover a new nuclear target of USP9X, show that the USP9X/ZBTB38 axis limits, senses and detoxifies ROS, and provide a molecular link between oxidative stress and the epigenome.

Crystal structure of the protein At3g01520, a eukaryotic universal stress protein-like protein from Arabidopsis thaliana in complex with AMP.

PubMed

Kim, Do Jin; Bitto, Eduard; Bingman, Craig A; Kim, Hyun-Jung; Han, Byung Woo; Phillips, George N

2015-07-01

Members of the universal stress protein (USP) family are conserved in a phylogenetically diverse range of prokaryotes, fungi, protists, and plants and confer abilities to respond to a wide range of environmental stresses. Arabidopsis thaliana contains 44 USP domain-containing proteins, and USP domain is found either in a small protein with unknown physiological function or in an N-terminal portion of a multi-domain protein, usually a protein kinase. Here, we report the first crystal structure of a eukaryotic USP-like protein encoded from the gene At3g01520. The crystal structure of the protein At3g01520 was determined by the single-wavelength anomalous dispersion method and refined to an R factor of 21.8% (Rfree = 26.1%) at 2.5 Å resolution. The crystal structure includes three At3g01520 protein dimers with one AMP molecule bound to each protomer, comprising a Rossmann-like α/β overall fold. The bound AMP and conservation of residues in the ATP-binding loop suggest that the protein At3g01520 also belongs to the ATP-binding USP subfamily members. © 2015 The Authors. Proteins: Structure, Function, and Bioinformatics Published by Wiley Periodicals, Inc.

A High-Confidence Interaction Map Identifies SIRT1 as a Mediator of Acetylation of USP22 and the SAGA Coactivator Complex

PubMed Central

Armour, Sean M.; Bennett, Eric J.; Braun, Craig R.; Zhang, Xiao-Yong; McMahon, Steven B.; Gygi, Steven P.; Harper, J. Wade

2013-01-01

Although many functions and targets have been attributed to the histone and protein deacetylase SIRT1, a comprehensive analysis of SIRT1 binding proteins yielding a high-confidence interaction map has not been established. Using a comparative statistical analysis of binding partners, we have assembled a high-confidence SIRT1 interactome. Employing this method, we identified the deubiquitinating enzyme ubiquitin-specific protease 22 (USP22), a component of the deubiquitinating module (DUBm) of the SAGA transcriptional coactivating complex, as a SIRT1-interacting partner. We found that this interaction is highly specific, requires the ZnF-UBP domain of USP22, and is disrupted by the inactivating H363Y mutation within SIRT1. Moreover, we show that USP22 is acetylated on multiple lysine residues and that alteration of a single lysine (K129) within the ZnF-UBP domain is sufficient to alter interaction of the DUBm with the core SAGA complex. Furthermore, USP22-mediated recruitment of SIRT1 activity promotes the deacetylation of individual SAGA complex components. Our results indicate an important role of SIRT1-mediated deacetylation in regulating the formation of DUBm subcomplexes within the larger SAGA complex. PMID:23382074

Aberrant Phosphorylation of SMAD4 Thr277-Mediated USP9x-SMAD4 Interaction by Free Fatty Acids Promotes Breast Cancer Metastasis.

PubMed

Wu, Yong; Yu, Xiaoting; Yi, Xianghua; Wu, Ke; Dwabe, Sami; Atefi, Mohammad; Elshimali, Yahya; Kemp, Kevin T; Bhat, Kruttika; Haro, Jesse; Sarkissyan, Marianna; Vadgama, Jaydutt V

2017-03-15

Obesity increases the risk of distant metastatic recurrence and reduces breast cancer survival. However, the mechanisms behind this pathology and identification of relevant therapeutic targets are poorly defined. Plasma free fatty acids (FFA) levels are elevated in obese individuals. Here we report that TGFβ transiently activates ERK and subsequently phosphorylates SMAD4 at Thr277, which facilitates a SMAD4-USP9x interaction, SMAD4 nuclear retention, and stimulates TGFβ/SMAD3-mediated transcription of Twist and Snail. USP9x inhibited the E3 ubiquitin-protein ligase TIF1γ from binding and monoubiquitinating SMAD4, hence maintaining the SMAD4 nuclear retention. FFA further facilitated TGFβ-induced ERK activation, SMAD4 phosphorylation, and nuclear retention, promoting TGFβ-dependent cancer progression. Inhibition of ERK and USP9x suppressed obesity-induced metastasis. In addition, clinical data indicated that phospho-ERK and -SMAD4 levels correlate with activated TGFβ signaling and metastasis in overweight/obese patient breast cancer specimens. Altogether, we demonstrate the vital interaction of USP9x and SMAD4 for governing TGFβ signaling and dyslipidemia-induced aberrant TGFβ activation during breast cancer metastasis. Cancer Res; 77(6); 1383-94. ©2017 AACR . ©2017 American Association for Cancer Research.

Ubiquitin-Specific Protease 2 Regulates Hepatic Gluconeogenesis and Diurnal Glucose Metabolism Through 11β-Hydroxysteroid Dehydrogenase 1

PubMed Central

Molusky, Matthew M.; Li, Siming; Ma, Di; Yu, Lei; Lin, Jiandie D.

2012-01-01

Hepatic gluconeogenesis is important for maintaining steady blood glucose levels during starvation and through light/dark cycles. The regulatory network that transduces hormonal and circadian signals serves to integrate these physiological cues and adjust glucose synthesis and secretion by the liver. In this study, we identified ubiquitin-specific protease 2 (USP2) as an inducible regulator of hepatic gluconeogenesis that responds to nutritional status and clock. Adenoviral-mediated expression of USP2 in the liver promotes hepatic glucose production and exacerbates glucose intolerance in diet-induced obese mice. In contrast, in vivo RNA interference (RNAi) knockdown of this factor improves systemic glycemic control. USP2 is a target gene of peroxisome proliferator–activated receptor γ coactivator-1α (PGC-1α), a coactivator that integrates clock and energy metabolism, and is required for maintaining diurnal glucose homeostasis during restricted feeding. At the mechanistic level, USP2 regulates hepatic glucose metabolism through its induction of 11β-hydroxysteroid dehydrogenase 1 (HSD1) and glucocorticoid signaling in the liver. Pharmacological inhibition and liver-specific RNAi knockdown of HSD1 significantly impair the stimulation of hepatic gluconeogenesis by USP2. Together, these studies delineate a novel pathway that links hormonal and circadian signals to gluconeogenesis and glucose homeostasis. PMID:22447855

Effect of drug loading method against drug dissolution mechanism of encapsulated amoxicillin trihydrate in matrix of semi-IPN chitosan-poly(N-vinylpyrrolidone) hydrogel with KHCO3 as pore forming agent in floating drug delivery system

NASA Astrophysics Data System (ADS)

Fimantari, Khansa; Budianto, Emil

2018-04-01

Helicobacterpylori infection can be treated using trihydrate amoxicillin. However, this treatment is not effective enough, as the conventional dosage treatment has a relatively short retention time in the human stomach. In the present study, the amoxicillin trihydrate drug will be encapsulated into a semi-IPN K-PNVP hydrogel matrix with 7,5% KHCO3 as a pore-forming agent. The encapsulated drug is tested with in vitro method to see the efficiency of its encapsulation and dissolution. The hydrogel in situ loading produces an encapsulation efficiency value. The values of the encapsulation efficiency are 95% and 98%, while post loading hydrogel yields an encapsulation efficiency value is 77% and the dissolution is 84%. The study of drug dissolution mechanism was done by using mathematical equation model to know its kinetics and its mechanism of dissolution. The post loading hydrogel was done by using thefirst-order model, while hydrogel in situ loading used Higuchi model. The Korsmeyer-Peppas model shows that post loading hydrogel dissolution mechanism is a mixture of diffusion and erosion, and in situ loading hydrogel in the form of diffusion. It is supported by the results of hydrogel characterization, before and after dissolution test with an optical microscope. The results of the optical microscope show that the hydrogel surface before and after the dissolution tested for both methods shows the change becomes rougher.

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.

Dose Uniformity of Scored and Unscored Tablets: Application of the FDA Tablet Scoring Guidance for Industry.

PubMed

Ciavarella, Anthony B; Khan, Mansoor A; Gupta, Abhay; Faustino, Patrick J

This U.S. Food and Drug Administration (FDA) laboratory study examines the impact of tablet splitting, the effect of tablet splitters, and the presence of a tablet score on the dose uniformity of two model drugs. Whole tablets were purchased from five manufacturers for amlodipine and six for gabapentin. Two splitters were used for each drug product, and the gabapentin tablets were also split by hand. Whole and split amlodipine tablets were tested for content uniformity following the general chapter of the United States Pharmacopeia (USP) Uniformity of Dosage Units <905>, which is a requirement of the new FDA Guidance for Industry on tablet scoring. The USP weight variation method was used for gabapentin split tablets based on the recommendation of the guidance. All whole tablets met the USP acceptance criteria for the Uniformity of Dosage Units. Variation in whole tablet content ranged from 0.5 to 2.1 standard deviation (SD) of the percent label claim. Splitting the unscored amlodipine tablets resulted in a significant increase in dose variability of 6.5-25.4 SD when compared to whole tablets. Split tablets from all amlodipine drug products did not meet the USP acceptance criteria for content uniformity. Variation in the weight for gabapentin split tablets was greater than the whole tablets, ranging from 1.3 to 9.3 SD. All fully scored gabapentin products met the USP acceptance criteria for weight variation. Size, shape, and the presence or absence of a tablet score can affect the content uniformity and weight variation of amlodipine and gabapentin tablets. Tablet splitting produced higher variability. Differences in dose variability and fragmentation were observed between tablet splitters and hand splitting. These results are consistent with the FDA's concerns that tablet splitting can have an effect on the amount of drug present in a split tablet and available for absorption. Tablet splitting has become a very common practice in the United States and throughout the world. Tablets are often split to modify dose strength, make swallowing easier, and reduce cost to the consumer. To better address product quality for this widely used practice, the U.S. Food and Drug Administration (FDA) published a Guidance for Industry that addresses tablet splitting. The guidance provides testing criteria for scored tablets, which is a part of the FDA review process for drugs. The model drugs selected for this study were amlodipine and gabapentin, which have different sizes, shapes, and tablet scores. Whole and split amlodipine tablets were tested for drug content because of a concern that the low-dose strength may cause greater variability. Whole and split gabapentin tablets were tested for weight variation because of their higher dosage strength of 600 mg. All whole tablets met the acceptance criteria for the Uniformity of Dosage Units based on the guidance recommendations. When unscored amlodipine tablets were split by a splitter, all formulations did not meet the acceptance criteria. When fully scored gabapentin tablets were split by hand and by splitter, they met the acceptance criteria. The findings of this FDA study indicated physical characteristics such as size, shape, and tablet score can affect the uniformity of split tablets. © PDA, Inc. 2016.

Discriminative Dissolution Method for Benzoyl Metronidazole Oral Suspension.

PubMed

da Silva, Aline Santos; da Rosa Silva, Carlos Eduardo; Paula, Fávero Reisdorfer; da Silva, Fabiana Ernestina Barcellos

2016-06-01

A dissolution method for benzoyl metronidazole (BMZ) oral suspensions was developed and validated using a high-performance liquid chromatography (HPLC) method. After determination of sink conditions, dissolution profiles were evaluated using different dissolution media and agitation speeds. The sample insertion mode in dissolution media was also evaluated. The best conditions were obtained using a paddle, 50 rpm stirring speed, simulated gastric fluid (without pepsin) as the dissolution medium, and sample insertion by a syringe. These conditions were suitable for providing sink conditions and discriminatory power between different formulations. Through the tested conditions, the results can be considered specific, linear, precise, accurate, and robust. The dissolution profiles of five samples were compared using the similarity factor (f 2) and dissolution efficiency. The dissolution kinetics were evaluated and described by the Weibull model. Whereas there is no monograph for this pharmaceutical formulation, the dissolution method proposed can be considered suitable for quality control and dissolution profile comparison of different commercial formulations.

Development and validation of dissolution study of sustained release dextromethorphan hydrobromide tablets.

PubMed

Rajan, Sekar; Colaco, Socorrina; Ramesh, N; Meyyanathan, Subramania Nainar; Elango, K

2014-02-01

This study describes the development and validation of dissolution tests for sustained release Dextromethorphan hydrobromide tablets using an HPLC method. Chromatographic separation was achieved on a C18 column utilizing 0.5% triethylamine (pH 7.5) and acetonitrile in the ratio of 50:50. The detection wavelength was 280 nm. The method was validated and response was found to be linear in the drug concentration range of 10-80 microg mL(-1). The suitable conditions were clearly decided after testing sink conditions, dissolution medium and agitation intensity. The most excellent dissolution conditions tested, for the Dextromethorphan hydrobromide was applied to appraise the dissolution profiles. The method was validated and response was found to be linear in the drug concentration range of 10-80 microg mL(-1). The method was established to have sufficient intermediate precision as similar separation was achieved on another instrument handled by different operators. Mean Recovery was 101.82%. Intra precisions for three different concentrations were 1.23, 1.10 0.72 and 1.57, 1.69, 0.95 and inter run precisions were % RSD 0.83, 1.36 and 1.57%, respectively. The method was successfully applied for dissolution study of the developed Dextromethorphan hydrobromide tablets.

Dissolution of pulp tissue by aqueous solution of chlorhexidine digluconate and chlorhexidine digluconate gel.

PubMed

Okino, L A; Siqueira, E L; Santos, M; Bombana, A C; Figueiredo, J A P

2004-01-01

To evaluate the activity of various root canal irrigants on bovine pulp tissue. The irrigants tested were: 0.5, 1.0 and 2.5% sodium hypochlorite; 2% aqueous solution of chlorhexidine digluconate; 2% chlorhexidine digluconate gel (Natrosol); and distilled water as control. Bovine pulp fragments were weighed and placed in contact with 20 mL of each tested substance in a centrifuge at 150 r.p.m. until total dissolution. Dissolution speed was calculated by dividing pulp weight by dissolution time. Statistical analysis was performed using the Kruskal-Wallis test. Distilled water and both solutions of chlorhexidine did not dissolve the pulp tissue within 6 h. Mean dissolution speeds for 0.5, 1.0 and 2.5% sodium hypochlorite solutions were 0.31, 0.43 and 0.55 mg min(-1), respectively. The solvent ability of chlorhexidine solutions was similar to that of distilled water. The results for sodium hypochlorite solutions, chlorhexidine solutions and distilled water were statistically different (P>0.01). Both chlorhexidine preparations and distilled water were not able to dissolve pulp tissue. All sodium hypochlorite solutions were efficient in dissolving pulp tissue; the dissolution speed varied with the concentration of the solution.

TRAF Family Member-associated NF-κB Activator (TANK) Inhibits Genotoxic Nuclear Factor κB Activation by Facilitating Deubiquitinase USP10-dependent Deubiquitination of TRAF6 Ligase*

PubMed Central

Wang, Wei; Huang, Xuan; Xin, Hong-Bo; Fu, Mingui; Xue, Aimin; Wu, Zhao-Hui

2015-01-01

DNA damage-induced NF-κB activation plays a critical role in regulating cellular response to genotoxic stress. However, the molecular mechanisms controlling the magnitude and duration of this genotoxic NF-κB signaling cascade are poorly understood. We recently demonstrated that genotoxic NF-κB activation is regulated by reversible ubiquitination of several essential mediators involved in this signaling pathway. Here we show that TRAF family member-associated NF-κB activator (TANK) negatively regulates NF-κB activation by DNA damage via inhibiting ubiquitination of TRAF6. Despite the lack of a deubiquitination enzyme domain, TANK has been shown to negatively regulate the ubiquitination of TRAF proteins. We found TANK formed a complex with MCPIP1 (also known as ZC3H12A) and a deubiquitinase, USP10, which was essential for the USP10-dependent deubiquitination of TRAF6 and the resolution of genotoxic NF-κB activation upon DNA damage. Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated deletion of TANK in human cells significantly enhanced NF-κB activation by genotoxic treatment, resulting in enhanced cell survival and increased inflammatory cytokine production. Furthermore, we found that the TANK-MCPIP1-USP10 complex also decreased TRAF6 ubiquitination in cells treated with IL-1β or LPS. In accordance, depletion of USP10 enhanced NF-κB activation induced by IL-1β or LPS. Collectively, our data demonstrate that TANK serves as an important negative regulator of NF-κB signaling cascades induced by genotoxic stress and IL-1R/Toll-like receptor stimulation in a manner dependent on MCPIP1/USP10-mediated TRAF6 deubiquitination. PMID:25861989

Accuracy of Cirrus HD-OCT and Topcon SP-3000P for measuring central corneal thickness.

PubMed

Calvo-Sanz, Jorge A; Ruiz-Alcocer, Javier; Sánchez-Tena, Miguel A

2017-02-18

To compare and analyze the interchangeability of three measuring systems, each based on a different technique, for central corneal thickness (CCT) analysis. CCT measurements were measured using optical coherence tomography (OCT), non-contact specular microscopy (NCSM), and ultrasonic pachymetry (USP) in 60 eyes of 60 healthy patients with a mean age of 66.5±15.0 years and a mean spherical equivalent of 0.43±1.14 D. Analysis of variations in measurement concordance and correlation among the three different methods were performed. Comparison of CCT measurements were done using Bland-Altman plots (with bias and 95% confidence intervals), intraclass correlation coefficient (ICC), and paired t-student analysis. Mean CCT values were: 549.20±26.91μm for USP (range 503-618μm), 514.20±27.49μm for NCSM (range 456-586μm) and 542.80±25.56μm for OCT (range 486-605μm). CCT values obtained with NCMS were significantly lower than those obtained with OCT and USP methods. NCMS CCT value was 36.08±10.72μm lower than USP value (p<0.05), and NCMS CCT value was 7.88±8.86μm lower than OCT value (p<0.05). ICC between USP-NCSM pair was 0.488 and 0.909 between USP-OCT pair. OCT and UPS offered highly comparable results, whereas NCSM offered lower mean CCT values compared to the other two methods. Therefore, NCSM should not be considered a reliable method for measuring CCT and should rather be considered for assessing longitudinal changes in the same patient. Copyright © 2017 Spanish General Council of Optometry. Published by Elsevier España, S.L.U. All rights reserved.

Enhanced bioavailability of process-induced fast-dissolving ibuprofen cogranulated with beta-cyclodextrin.

PubMed

Ghorab, Mohamed K; Adeyeye, Moji Christianah

2003-08-01

The objectives of this study were to evaluate the bioavailability of cogranulated and oven-dried ibuprofen (IBU) and beta-cyclodextrin (betaCD), in comparison to a physical mixture, and to examine the effect of endogenous bile on the bioavailability of the drug. In vitro dissolution studies were performed using USP type 2 apparatus. The granules and physical mixture were administered perorally in a crossover fashion, to male Wistar bile duct-nonligated rats. The granules were also perorally administered to bile duct-ligated rats. Blood samples were taken at different time intervals and the plasma analyzed for IBU. Dissolution of granules was faster than the physical mixture due to faster IBU-betaCD complex formation in solution from the former than the latter. The in vivo study showed that C(max), AUC(0-8), and the absolute bioavailability for the granules (49.0 microg/mL, 57.0 h x microg/mL and 80.6%, respectively) were almost one and half times that of the physical mixture (32.2 microg/mL, 38.4 h x microg/mL and 53.1%, respectively). However, in bile duct-ligated rats, lower C(max) and AUC(0-8) (15.9 microg/mL and 14.4 h x microg/mL, respectively) were obtained for the granules. Phase solubility study of IBU in an aqueous betaCD solution in the presence of the bile salt (sodium cholate), showed an increase in the solubility of IBU. Moreover, the stability constant value for the IBU-betaCD complex was also found to decrease as the sodium cholate concentration increased. These results indicated that the enhancement in the bioavailability of IBU was due to faster in-solution complex formation, and micelllar solubilization by the bile salt. Copyright 2003 Wiley-Liss, Inc.

An integrated assessment of soil erosion dynamics with special emphasis on gully erosion: Case studies from South Africa and Iran

NASA Astrophysics Data System (ADS)

Maerker, Michael; Sommer, Christian; Zakerinejad, Reza; Cama, Elena

2017-04-01

Soil erosion by water is a significant problem in arid and semi arid areas of large parts of Iran. Water erosion is one of the most effective phenomena that leads to decreasing soil productivity and pollution of water resources. Especially in semiarid areas like in the Mazayjan watershed in the Southwestern Fars province as well as in the Mkomazi catchment in Kwa Zulu Natal, South Africa, gully erosion contributes to the sediment dynamics in a significant way. Consequently, the intention of this research is to identify the different types of soil erosion processes acting in the area with a stochastic approach and to assess the process dynamics in an integrative way. Therefore, we applied GIS, and satellite image analysis techniques to derive input information for the numeric models. For sheet and rill erosion the Unit Stream Power-based Erosion Deposition Model (USPED) was utilized. The spatial distribution of gully erosion was assessed using a statistical approach which used three variables (stream power index, slope, and flow accumulation) to predict the spatial distribution of gullies in the study area. The eroded gully volumes were estimated for a multiple years period by fieldwork and Google Earth high resolution images as well as with structure for motion algorithm. Finally, the gully retreat rates were integrated into the USPED model. The results show that the integration of the SPI approach to quantify gully erosion with the USPED model is a suitable method to qualitatively and quantitatively assess water erosion processes in data scarce areas. The application of GIS and stochastic model approaches to spatialize the USPED model input yield valuable results for the prediction of soil erosion in the test areas. The results of this research help to develop an appropriate management of soil and water resources in the study areas.

Initial load-to-failure and failure analysis in single- and double-row repair techniques for rotator cuff repair

PubMed Central

Buchhorn, G. H.; Gilbert, F.; Spahn, G.; Schultz, W.; Klinger, H.-M.

2010-01-01

Aim This experimental study aimed to compare the load-to-failure rate and stiffness of single- versus double-row suture techniques for repairing rotator cuff lesions using two different suture materials. Additionally, the mode of failure of each repair was evaluated. Method In 32 sheep shoulders, a standardized tear of the infraspinatus tendon was created. Then, n = 8 specimen were randomized to four repair methods: (1) Double-row Anchor Ethibond® coupled with polyester sutures, USP No. 2; (2) Double-Row Anchor HiFi® with polyblend polyethylene sutures, USP No. 2; (3) Single-Row Anchor Ethibond® coupled with braided polyester sutures, USP No. 2; and (4) Single-Row Anchor HiFi® with braided polyblend polyethylene sutures, USP No. 2. Arthroscopic Mason–Allen stitches were placed (single-row) and combined with medial horizontal mattress stitches (double-row). All specimens were loaded to failure at a constant displacement rate on a material testing machine. Results Group 4 showed lowest load-to-failure result with 155.7 ± 31.1 N compared to group 1 (293.4 ± 16.1 N) and group 2 (397.7 ± 7.4 N) (P < 0.001). Stiffness was highest in group 2 (162 ± 7.3 N/mm) and lowest in group 4 (84.4 ± 19.9 mm) (P < 0.001). In group 4, the main cause of failure was due to the suture cutting through the tendon (n = 6), a failure case observed in only n = 1 specimen in group 2 (P < 0.001). Conclusions A double-row technique combined with arthroscopic Mason-Allen/horizontal mattress stitches provides high initial failure strength and may minimize the risk of the polyethylene sutures cutting through the tendon in rotator cuff repair when a single load force is used. PMID:20049605

Fuel Cells Provide Reliable Power to U.S. Postal Service Facility in Anchorage, Alaska

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

Parker, Steven

2003-01-01

Working together, the U.S. Postal Service (USPS) and Chugach Electric Association, partnering with the Department of Defense (DOD), Department of Energy (DOE), US Army Corps of Engineers Construction Engineering Research Laboratories (USA CERL), Electric Power Research Institute (EPRI), and National Rural Electric Cooperative Association (NRECA), developed and installed one of the largest fuel cell installations in the world. The one-megawatt fuel cell combined heat and power plant sits behind the Anchorage U.S. Postal Service Mail Processing and Distribution Facility. Chugach Electric owns, operates, and maintains the fuel cell power plant, which provides clean, reliable power to the USPS facility. Inmore » addition, heat recovered from the fuel cells, in the form of hot water, is used to heat the USPS Mail Processing and Distribution Facility. By taking a leadership role, the USPS will save over $800,000 in electricity and natural gas costs over the 5 1/2-year contract term with Chugach Electric.« less

Decoding the genetic basis of Cushing's disease: USP8 in the spotlight.

PubMed

Theodoropoulou, Marily; Reincke, Martin; Fassnacht, Martin; Komada, Masayuki

2015-10-01

Cushing's disease (CD) arises from pituitary-dependent glucocorticoid excess due to an ACTH-secreting corticotroph tumor. Genetic hits in oncogenes and tumor suppressor genes that afflict other pituitary tumor subtypes are not found in corticotrophinomas. Recently, a somatic mutational hotspot was found in up to half of corticotrophinomas in the USP8 gene that encodes a protein that impairs the downregulation of the epidermal growth factor receptor (EGFR) and enables its constitutive signaling. EGF is an important regulator of corticotroph function and its receptor is highly expressed in Cushing's pituitary tumors, where it leads to increased ACTH synthesis in vitro and in vivo. The mutational hotspot found in corticotrophinomas hyper-activates USP8, enabling it to rescue EGFR from lysosomal degradation and ensure its stimulatory signaling. This review presents new developments in the study of the genetics of CD and focuses on the USP8-EGFR system as trigger and target of corticotroph tumorigenesis. © 2015 European Society of Endocrinology.

USP8 regulates mitophagy by removing K6-linked ubiquitin conjugates from parkin

PubMed Central

Durcan, Thomas M; Tang, Matthew Y; Pérusse, Joëlle R; Dashti, Eman A; Aguileta, Miguel A; McLelland, Gian-Luca; Gros, Priti; Shaler, Thomas A; Faubert, Denis; Coulombe, Benoit; Fon, Edward A

2014-01-01

Mutations in the Park2 gene, encoding the E3 ubiquitin-ligase parkin, are responsible for a familial form of Parkinson's disease (PD). Parkin-mediated ubiquitination is critical for the efficient elimination of depolarized dysfunctional mitochondria by autophagy (mitophagy). As damaged mitochondria are a major source of toxic reactive oxygen species within the cell, this pathway is believed to be highly relevant to the pathogenesis of PD. Little is known about how parkin-mediated ubiquitination is regulated during mitophagy or about the nature of the ubiquitin conjugates involved. We report here that USP8/UBPY, a deubiquitinating enzyme not previously implicated in mitochondrial quality control, is critical for parkin-mediated mitophagy. USP8 preferentially removes non-canonical K6-linked ubiquitin chains from parkin, a process required for the efficient recruitment of parkin to depolarized mitochondria and for their subsequent elimination by mitophagy. This work uncovers a novel role for USP8-mediated deubiquitination of K6-linked ubiquitin conjugates from parkin in mitochondrial quality control. PMID:25216678

USP7/HAUSP: A SUMO deubiquitinase at the heart of DNA replication.

PubMed

Smits, Veronique A J; Freire, Raimundo

2016-09-01

DNA replication is both highly conserved and controlled. Problematic DNA replication can lead to genomic instability and therefore carcinogenesis. Numerous mechanisms work together to achieve this tight control and increasing evidence suggests that post-translational modifications (phosphorylation, ubiquitination, SUMOylation) of DNA replication proteins play a pivotal role in this process. Here we discuss such modifications in the light of a recent article that describes a novel role for the deubiquitinase (DUB) USP7/HAUSP in the control of DNA replication. USP7 achieves this function by an unusual and novel mechanism, namely deubiquitination of SUMOylated proteins at the replication fork, making USP7 also a SUMO DUB (SDUB). This work extends previous observations of increased levels of SUMO and low levels of ubiquitin at the on-going replication fork. Here, we discuss this novel study, its contribution to the DNA replication and genomic stability field and what questions arise from this work. © 2016 WILEY Periodicals, Inc.

USP7 Is a Tumor-Specific WNT Activator for APC-Mutated Colorectal Cancer by Mediating β-Catenin Deubiquitination.

PubMed

Novellasdemunt, Laura; Foglizzo, Valentina; Cuadrado, Laura; Antas, Pedro; Kucharska, Anna; Encheva, Vesela; Snijders, Ambrosius P; Li, Vivian S W

2017-10-17

The tumor suppressor gene adenomatous polyposis coli (APC) is mutated in most colorectal cancers (CRCs), resulting in constitutive Wnt activation. To understand the Wnt-activating mechanism of the APC mutation, we applied CRISPR/Cas9 technology to engineer various APC-truncated isogenic lines. We find that the β-catenin inhibitory domain (CID) in APC represents the threshold for pathological levels of Wnt activation and tumor transformation. Mechanistically, CID-deleted APC truncation promotes β-catenin deubiquitination through reverse binding of β-TrCP and USP7 to the destruction complex. USP7 depletion in APC-mutated CRC inhibits Wnt activation by restoring β-catenin ubiquitination, drives differentiation, and suppresses xenograft tumor growth. Finally, the Wnt-activating role of USP7 is specific to APC mutations; thus, it can be used as a tumor-specific therapeutic target for most CRCs. Copyright © 2017 The Francis Crick Institute. Published by Elsevier Inc. All rights reserved.

Oral Solid Dosage Form Disintegration Testing - The Forgotten Test.

PubMed

Al-Gousous, Jozef; Langguth, Peter

2015-09-01

Since its inception in the 1930s, disintegration testing has become an important quality control (QC) test in pharmaceutical industry, and disintegration test procedures for various dosage forms have been described by the different pharmacopoeias, with harmonization among them still not quite complete. However, because of the fact that complete disintegration does not necessarily imply complete dissolution, much more research has been focused on dissolution rather than on disintegration testing. Nevertheless, owing to its simplicity, disintegration testing seems to be an attractive replacement to dissolution testing as recognized by the International Conference on Harmonization guidelines, in some cases. Therefore, with proper research being carried out to overcome the associated challenges, the full potential of disintegration testing could be tapped saving considerable efforts allocated to QC testing and quality assurance. © 2014 Wiley Periodicals, Inc. and the American Pharmacists Association.

Integrating In Vitro, Modeling, and In Vivo Approaches to Investigate Warfarin Bioequivalence

PubMed Central

Wen, H; Fan, J; Vince, B; Li, T; Gao, W; Kinjo, M; Brown, J; Sun, W; Jiang, W; Lionberger, R

2017-01-01

We demonstrate the use of modeling and simulation to investigate bioequivalence (BE) concerns raised about generic warfarin products. To test the hypothesis that the loss of isopropyl alcohol and slow dissolution in acidic pH has significant impact on the pharmacokinetics of warfarin sodium tablets, we conducted physiologically based pharmacokinetic absorption modeling and simulation using formulation factors or in vitro dissolution profiles as input parameters. Sensitivity analyses indicated that warfarin pharmacokinetics was not sensitive to solubility, particle size, density, or dissolution rate in pH 4.5, but was affected by dissolution rate in pH 6.8 and potency. Virtual BE studies suggested that stressed warfarin sodium tablets with slow dissolution rate in pH 4.5 but having similar dissolution rate in pH 6.8 would be bioequivalent to the unstressed warfarin sodium tablets. A four‐way, crossover, single‐dose BE study in healthy subjects was conducted to test the same hypothesis and confirmed the simulation conclusion. PMID:28379643

Designing a dynamic dissolution method: a review of instrumental options and corresponding physiology of stomach and small intestine.

PubMed

Culen, Martin; Rezacova, Anna; Jampilek, Josef; Dohnal, Jiri

2013-09-01

Development of new pharmaceutical compounds and dosage forms often requires in vitro dissolution testing with the closest similarity to the human gastrointestinal (GI) tract. To create such conditions, one needs a suitable dissolution apparatus and the appropriate data on the human GI physiology. This review discusses technological approaches applicable in biorelevant dissolutions as well as the physiology of stomach and small intestine in both fasted and fed state, that is, volumes of contents, transit times for water/food and various solid oral dosage forms, pH, osmolality, surface tension, buffer capacity, and concentrations of bile salts, phospholipids, enzymes, and Ca(2+) ions. The information is aimed to provide clear suggestions on how these conditions should be set in a dynamic biorelevant dissolution test. Copyright © 2013 Wiley Periodicals, Inc.

77 FR 19391 - Notice of Proposed Intelligent Mail Indicia Performance Criteria With Request for Comments

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-30

... products designed to meet new customer needs for access to postage. In addition, changes within the United... opportunities for PES providers to propose new concepts, methods, and processes to enable customers to print pre... support the USPS PES Test and Evaluation Program (the ``Program''). The intent is for the volumes to fully...

[Evaluation of Dissolution Profiles of Famotidine from Over-the-counter Drugs].

PubMed

Saito, Yuji; Adachi, Naoki; Kato, Miki; Nadai, Masayuki

2018-03-27

  In recent years, self-medication has started to receive more attention in Japan owing to increasing medical costs and health awareness among people. One of the main roles of pharmacists in self-medication is to provide appropriate information regarding over-the-counter (OTC) drugs. However, pharmacists promoting the proper use of OTC drugs have little information on their formulation properties. In this study, we performed dissolution tests on both OTC drugs and ethical drug (ED) containing famotidine, and evaluated the differences in their dissolution profiles. Marked differences in dissolution profiles of OTC drugs were observed in test solutions at pH 1.2, 4.0, and 6.8 and in water. To evaluate the differences quantitatively, we calculated the lag time and dissolution rate constant from the dissolution profiles. Significant differences in lag times and dissolution rate constants between some OTC drugs and ED were observed. We also used similarity factor (f2), to quantify the similarity between dissolution profiles of OTC drugs and ED. f2 values less than 42 were observed in some OTC drugs, suggesting that these differences might influence absorption in vivo resulting in differences in their onset time and efficacy. The findings of this study will provide useful information for the promotion of proper use of OTC drugs.

[Comparison in dissolution behavior of ethical and over-the counter scopolamine butylbromide].

PubMed

Suzuki, Ichie; Miyazaki, Yasunori; Uchino, Tomonobu; Kagawa, Yoshiyuki

2011-01-01

Marketing authorization holders do not disclose any information on the pharmaceutical properties of over-the-counter drugs (OTC). When a drug is switched from a prescription drug to OTC, pharmacists can acquire that information from the corresponding ethical drug (ED) through the package insert, interview form, and so on. However, the pharmaceutical equivalence between ED and OTC is unclear. In this study, we examined the drug dissolution behavior of both ED and OTCs containing scopolamine butylbromide. Dissolution tests were performed by the paddle method using Japanese Pharmacopeia (JP) XV test fluids at pH 1.2, 4.0 and 6.8 and water based on the guidelines for bioequivalence studies of generic products. The dissolution profiles of OTCs differed significantly from ED showing a similarity factor (f2) value ranging from 8.9 to 42.9. Time until 85% dissolution ranged from 23 to 95 min and from 17 to 174 min at pH 1.2 and pH 6.8, respectively. Then JP XV disintegration tests were conducted to investigate differences in the disintegration process. The disintegration time of preparations showing delayed dissolution was prolonged compared to that of others, suggesting that the disintegration of the tablet or capsule is one of the important factors affecting the drug dissolution. These differences in the disintegration and drug dissolution might cause differences in the bioavailability of the drug. For patient safety, more detailed product information of OTCs should be supplied by the manufacturer, and not be assumed from that of corresponding ED.

77 FR 18707 - USPS Package Intercept-New Product Offerings

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-28

... service that replaced the former recall of mail process. Plans were announced to implement new features.... Additionally, customers using the electronic process will have the option of adding selected extra services to... POSTAL SERVICE 39 CFR Part 111 USPS Package Intercept--New Product Offerings AGENCY: Postal...

Modulation of the wettability of excipients by surfactant and its impacts on the disintegration and release of tablets.

PubMed

Yang, Baixue; Xu, Lu; Wang, Qiuxiao; Li, Sanming

2016-12-01

To investigate the modulation of the wettability of excipients by different types of surfactants and its impacts on the disintegration of tablets and drug release. The critical micelle concentration (CMC) of surfactants, including sodium dodecyl sulfate (SDS), sodium dodecyl benzene sulfonate (SDBS), dodecyl trimethyl ammonium bromide (DTAB), cetyltrimethyl ammonium bromide (CTAB) and polysorbate (Tween-20 and Tween-80), was obtained using the platinum ring method. Contact angles of surfactant solutions on the excipient compacts and double-distilled water on the mixture of surfactant and the other excipient (magnesium stearate (MgSt) or sodium alginate (SA)) were measured by the sessile drop technique. Besides, surface free energy of excipients was calculated by the Owens method. Finally, the disintegration of tablets and in vitro dissolution testing were performed according to the method described in USP. The wettability of excipients could be enhanced to different extent with low concentration of surfactant solutions and maintained stable basically after CMC. For MgSt (hydrophobic excipient), the shorter the hydrophobic chain (C 12 , including SDS and DTAB), the better the wettability with the addition of surfactant in the formulation, leading to the shorter disintegration time of tablets and higher drug release rate. In contrast, the wettability of SA (hydrophilic excipient) was reduced by adding surfactant, resulting in the longer disintegration time of tablets and lower release rate. The modulation of the wetting of pharmaceutical excipients by surfactant had changed the disintegration time of tablets and drug release rate to a greater extent.

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

Deubiquitinylase USP47 Promotes RelA Phosphorylation and Survival in Gastric Cancer Cells.

PubMed

Naghavi, Lara; Schwalbe, Martin; Ghanem, Ahmed; Naumann, Michael

2018-05-22

Every year, gastric cancer causes around 819,000 deaths worldwide. The incidence of gastric cancer in the western world is slowly declining, but the prognosis is unpromising. In Germany, the 5-year-survival rate is around 32%, and the average life span after diagnosis is 6 to 9 months. Therapy of gastric cancer patients comprises a gastrectomy and perioperative or adjuvant chemotherapy. However, resistance of gastric cancer cells to these agents is widespread; thus, improved chemotherapeutic approaches are required. Nuclear factor kappa B (NF-κB) transcription factors are associated with anti-apoptosis, carcinogenesis, and chemoresistance, and thus, constitute attractive targets for therapeutic intervention. In immunoblots, we show that ubiquitin specific protease 47 (USP47) promotes β-transducin repeat-containing protein (βTrCP) stability and phosphorylation of RelA. Furthermore, after knockdown of USP47 by RNA interference, we analyzed in gastric cancer cell lines metabolic activity/viability in an MTT assay, and apoptotic cell death by Annexin V staining and poly(ADP-Ribose) polymerase (PARP)-1, caspase 3, and caspase 8 cleavage, respectively. We found that USP47 contributes to cell viability and chemoresistance in NCI-N87 gastric carcinoma cells treated with etoposide and camptothecin. Inhibition of USP47 might be a suitable strategy to downregulate NF-κB activity, and to overcome chemoresistance in gastric cancer.

The Deubiquitinase USP47 Stabilizes MAPK by Counteracting the Function of the N-end Rule ligase POE/UBR4 in Drosophila.

PubMed

Ashton-Beaucage, Dariel; Lemieux, Caroline; Udell, Christian M; Sahmi, Malha; Rochette, Samuel; Therrien, Marc

2016-08-01

RAS-induced MAPK signaling is a central driver of the cell proliferation apparatus. Disruption of this pathway is widely observed in cancer and other pathologies. Consequently, considerable effort has been devoted to understanding the mechanistic aspects of RAS-MAPK signal transmission and regulation. While much information has been garnered on the steps leading up to the activation and inactivation of core pathway components, comparatively little is known on the mechanisms controlling their expression and turnover. We recently identified several factors that dictate Drosophila MAPK levels. Here, we describe the function of one of these, the deubiquitinase (DUB) USP47. We found that USP47 acts post-translationally to counteract a proteasome-mediated event that reduces MAPK half-life and thereby dampens signaling output. Using an RNAi-based genetic interaction screening strategy, we identified UBC6, POE/UBR4, and UFD4, respectively, as E2 and E3 enzymes that oppose USP47 activity. Further characterization of POE-associated factors uncovered KCMF1 as another key component modulating MAPK levels. Together, these results identify a novel protein degradation module that governs MAPK levels. Given the role of UBR4 as an N-recognin ubiquitin ligase, our findings suggest that RAS-MAPK signaling in Drosophila is controlled by the N-end rule pathway and that USP47 counteracts its activity.

A reproducible accelerated in vitro release testing method for PLGA microspheres.

PubMed

Shen, Jie; Lee, Kyulim; Choi, Stephanie; Qu, Wen; Wang, Yan; Burgess, Diane J

2016-02-10

The objective of the present study was to develop a discriminatory and reproducible accelerated in vitro release method for long-acting PLGA microspheres with inner structure/porosity differences. Risperidone was chosen as a model drug. Qualitatively and quantitatively equivalent PLGA microspheres with different inner structure/porosity were obtained using different manufacturing processes. Physicochemical properties as well as degradation profiles of the prepared microspheres were investigated. Furthermore, in vitro release testing of the prepared risperidone microspheres was performed using the most common in vitro release methods (i.e., sample-and-separate and flow through) for this type of product. The obtained compositionally equivalent risperidone microspheres had similar drug loading but different inner structure/porosity. When microsphere particle size appeared similar, porous risperidone microspheres showed faster microsphere degradation and drug release compared with less porous microspheres. Both in vitro release methods investigated were able to differentiate risperidone microsphere formulations with differences in porosity under real-time (37 °C) and accelerated (45 °C) testing conditions. Notably, only the accelerated USP apparatus 4 method showed good reproducibility for highly porous risperidone microspheres. These results indicated that the accelerated USP apparatus 4 method is an appropriate fast quality control tool for long-acting PLGA microspheres (even with porous structures). Copyright © 2015 Elsevier B.V. All rights reserved.

[Troubleshooting of bioinequivalence of compound valsartan tablets].

PubMed

Shao, Da; Zhang, Yi-Fan; Zhan, Yan; Chen, Xiao-Yan; Zhong, Da-Fang

2014-04-01

The study aims to evaluate the bioequivalence of valsartan hydrochlorothiazide tablets, and to investigate the potential cause of bioinequivalence. This was a single-center study with an open, randomized double-way crossover design. Test and reference preparations containing 160 mg of valsartan and 25 mg of hydrochlorothiazide were given to 36 healthy male volunteers. Plasma concentrations of valsartan and hydrochlorothiazide were determined simultaneously by LC-MS/MS. The pharmacokinetic parameters and relative bioavailability were calculated, while the bioequivalence between test and reference preparations were evaluated. The dissolution profiles of test and reference preparations in four different mediums were determined via dissolution test and HPLC. The similarity was investigated according to the similarity factors (f2). The F(o-t) and F(0-infinity) were (139.4 +/- 65.2)% and (137.5 +/- 61.2)% for valsartan of test preparations. It led to get the conclusion that test and reference preparations were not bioequivalent for valsartan. A significant difference was observed between test and reference tablets in the valsartan dissolution test of pH 1.2 hydrochloric acid solution. The key factor of the bioinequivalence might be that dissolution of valsartan in acid medium has marked difference between two preparations.

77 FR 38342 - Privacy Act of 1974; System of Records

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-27

... to adding postage to postage meters. III. Description of Changes to Systems of Records The Postal... Management Records USPS 300.000 SYSTEM NAME: Finance Records USPS 400.000 SYSTEM NAME: Supplier and Tenant...: Postage Meter and PC Postage Customer Data and Transaction Records Accordingly, for the reasons stated...

Recycling evaluation of new-generation environmentally benign pressure sensitive adhesives

Treesearch

Said M. Abubakr; Carl Houtman; Dave Bormett; Nancy Ross Sutherland; Joe Peng

1999-01-01

As a result of a United States Postal Service (USPS) initiative, a work team was formed consisting of representatives from USPS, Forest Products Laboratory (FPL), Specialized Technology Resources, Inc. (STR), and industry. The industries represented included papermakers, paper recyclers, paper collectors, equipment manufacturers, paper users, adhesive manufacturers and...

USP <800> Adds Significant Safety Standards: Facility Upgrades Needed to Protect Employees From Hazardous Drugs.

PubMed

Beans, Bruce E

2017-05-01

The new USP standard for handling hazardous drugs (HDs) will require millions of dollars in capital outlays for facility and equipment upgrades and also requires in-depth assessments of each HD that facilities handle, significant workflow and work practice changes, and thorough staff training.

Novel biorelevant dissolution medium as a prognostic tool for polysaccharide-based colon-targeted drug delivery system.

PubMed

Yadav, Ankit Kumar; Sadora, Manik; Singh, Sachin Kumar; Gulati, Monica; Maharshi, Peddi; Sharma, Abhinav; Kumar, Bimlesh; Rathee, Harish; Ghai, Deepak; Malik, Adil Hussain; Garg, Varun; Gowthamrajan, K

2017-01-01

To overcome the limitations of the conventionally used methods for evaluation of orally administered colon-targeted delivery systems, a novel dissolution method using probiotics has been recently reported. In the present study, universal suitability of this medium composed of five different probiotics is established. Different delivery systems - mini tablets, liquisolid compacts, and microspheres coated with different polysaccharides - were prepared and subjected to sequential dissolution testing in medium with and without microbiota. The results obtained from fluid thioglycollate medium (FTM)-based probiotic medium for all the polysaccharide-based formulations showed statistically similar dissolution profile to that in the rat and goat cecal content media. Hence, it can be concluded that the developed FTM-based probiotic medium, once established, may eliminate the need for further animal sacrifice in the dissolution testing of polysaccharide-based colon-targeted delivery system.

The effect of 8.25% sodium hypochlorite on dental pulp dissolution and dentin flexural strength and modulus.

PubMed

Cullen, James K T; Wealleans, James A; Kirkpatrick, Timothy C; Yaccino, John M

2015-06-01

The purpose of this study was to evaluate the effect of various concentrations of sodium hypochlorite (NaOCl), including 8.25%, on dental pulp dissolution and dentin flexural strength and modulus. Sixty dental pulp samples and 55 plane parallel dentin bars were retrieved from extracted human teeth. Five test groups (n = 10) were formed consisting of a pulp sample and dentin bar immersed in various NaOCl solutions. The negative control group (n = 5) consisted of pulp samples and dentin bars immersed in saline. The positive control group (n = 5) consisted of pulp samples immersed in 8.25% NaOCl without a dentin bar. Every 6 minutes for 1 hour, the solutions were refreshed. The dentin bars were tested for flexural strength and modulus with a 3-point bend test. The time until total pulp dissolution and any changes in dentin bar flexural strength and modulus for the different NaOCl solutions were statistically analyzed. An increase in NaOCl concentration showed a highly significant decrease in pulp dissolution time. The pulp dissolution property of 8.25% NaOCl was significantly faster than any other tested concentration of NaOCl. The presence of dentin did not have a significant effect on the dissolution capacity of NaOCl if the solutions were refreshed. NaOCl concentration did not have a statistically significant effect on dentin flexural strength or modulus. Dilution of NaOCl decreases its pulp dissolution capacity. Refreshing the solution is essential to counteract the effects of dentin. In this study, NaOCl did not have a significant effect on dentin flexural strength or modulus. Published by Elsevier Inc.

Development of a biphasic dissolution test for Deferasirox dispersible tablets and its application in establishing an in vitro-in vivo correlation.

PubMed

Al Durdunji, Amal; AlKhatib, Hatim S; Al-Ghazawi, Mutasim

2016-05-01

In a biphasic dissolution medium, the integration of the in vitro dissolution of a drug in an aqueous phase and its subsequent partitioning into an organic phase is hypothesized to simulate the in vivo drug absorption. Such a methodology is expected to improve the probability of achieving a successful in vitro-in vivo correlation. Dissolution of Dispersible tablets of Deferasirox, a biopharmaceutics classification system type II compound, was studied in a biphasic dissolution medium using a flow-through dissolution apparatus coupled to a paddle apparatus. The experimental parameters associated with dissolution were optimized to discriminate between Deferasirox dispersible tablets of different formulations. The dissolution profiles obtained from this system were subsequently used to construct a level A in vitro-in vivo correlation. Copyright © 2016 Elsevier B.V. All rights reserved.

Tissue dissolution by a novel multisonic ultracleaning system and sodium hypochlorite.

PubMed

Haapasalo, Markus; Wang, Zhejun; Shen, Ya; Curtis, Allison; Patel, Payal; Khakpour, Mehrzad

2014-08-01

This study aimed to evaluate the effectiveness of a novel Multisonic Ultracleaning System (Sonendo Inc, Laguna Hills, CA) in tissue dissolution in comparison with conventional irrigation devices. Pieces of bovine muscle tissue (68 ± 2 mg) were placed in 0.7-mL test tubes (height: 23.60 mm, inner diameter: 6.00 mm, outer diameter: 7.75 mm) and exposed to 5 minutes of irrigation by different devices. Endodontic devices included the Multisonic Ultracleaning System, the Piezon Master 700 (EMS, Dallas, TX) ultrasonic system with agitation, the EndoVac negative-pressure irrigation system (SybronEndo, Orange, CA), and a conventional positive-pressure 27-G irrigation needle at a flow rate of 10 mL/min. The systems were tested with 0.5%, 3%, and 6% sodium hypochlorite (NaOCl) at room temperature (21°C) as well as 40°C. Irrigation with sterile water was used as a control. The mass of tissue specimens was measured and recorded before and after the use of each device, and if the specimen was completely dissolved visually within 5 minutes, the dissolution time was recorded. The rate of tissue dissolution (%/s) was then calculated. The Multisonic Ultracleaning System had the fastest rate of tissue dissolution (P < .05), at 1.0% ± 0.1% per second using 0.5% NaOCl, 2.3% ± 0.9% per second using 3% NaOCl, and 2.9% ± 0.7% per second using 6% NaOCl. This tissue dissolution rate was more than 8 times greater than the second fastest device tested (P < .01), the Piezon Master 700 ultrasonic system, which resulted in a tissue dissolution rate of 0.328% ± 0.002% per second using 6% NaOCl at 40°C. For all irrigation devices tested, the rate of tissue dissolution increased with a higher concentration and temperature of the NaOCl solution. The novel Multisonic Ultracleaning System achieved a significantly faster tissue dissolution rate when compared with the other systems examined in vitro. Copyright © 2014 American Association of Endodontists. Published by Elsevier Inc. All rights reserved.

Formulation Predictive Dissolution (fPD) Testing to Advance Oral Drug Product Development: an Introduction to the US FDA Funded '21st Century BA/BE' Project.

PubMed

Hens, Bart; Sinko, Patrick; Job, Nicholas; Dean, Meagan; Al-Gousous, Jozef; Salehi, Niloufar; Ziff, Robert M; Tsume, Yasuhiro; Bermejo, Marival; Paixão, Paulo; Brasseur, James G; Yu, Alex; Talattof, Arjang; Benninghoff, Gail; Langguth, Peter; Lennernäs, Hans; Hasler, William L; Marciani, Luca; Dickens, Joseph; Shedden, Kerby; Sun, Duxin; Amidon, Gregory E; Amidon, Gordon L

2018-06-23

Over the past decade, formulation predictive dissolution (fPD) testing has gained increasing attention. Another mindset is pushed forward where scientists in our field are more confident to explore the in vivo behavior of an oral drug product by performing predictive in vitro dissolution studies. Similarly, there is an increasing interest in the application of modern computational fluid dynamics (CFD) frameworks and high-performance computing platforms to study the local processes underlying absorption within the gastrointestinal (GI) tract. In that way, CFD and computing platforms both can inform future PBPK-based in silico frameworks and determine the GI-motility-driven hydrodynamic impacts that should be incorporated into in vitro dissolution methods for in vivo relevance. Current compendial dissolution methods are not always reliable to predict the in vivo behavior, especially not for biopharmaceutics classification system (BCS) class 2/4 compounds suffering from a low aqueous solubility. Developing a predictive dissolution test will be more reliable, cost-effective and less time-consuming as long as the predictive power of the test is sufficiently strong. There is a need to develop a biorelevant, predictive dissolution method that can be applied by pharmaceutical drug companies to facilitate marketing access for generic and novel drug products. In 2014, Prof. Gordon L. Amidon and his team initiated a far-ranging research program designed to integrate (1) in vivo studies in humans in order to further improve the understanding of the intraluminal processing of oral dosage forms and dissolved drug along the gastrointestinal (GI) tract, (2) advancement of in vitro methodologies that incorporates higher levels of in vivo relevance and (3) computational experiments to study the local processes underlying dissolution, transport and absorption within the intestines performed with a new unique CFD based framework. Of particular importance is revealing the physiological variables determining the variability in in vivo dissolution and GI absorption from person to person in order to address (potential) in vivo BE failures. This paper provides an introduction to this multidisciplinary project, informs the reader about current achievements and outlines future directions. Copyright © 2018. Published by Elsevier B.V.

Silicon Isotopes doping experiments to measure quartz dissolution and precipitation rates at equilibrium and test the principle of detailed balance

NASA Astrophysics Data System (ADS)

Zhu, C.; Rimstidt, J. D.; Liu, Z.; Yuan, H.

2016-12-01

The principle of detailed balance (PDB) has been a cornerstone for irreversible thermodynamics and chemical kinetics for a long time, and its wide application in geochemistry has mostly been implicit and without experimental testing of its applicability. Nevertheless, many extrapolations based on PDB without experimental validation have far reaching impacts on society's mega environmental enterprises. Here we report an isotope doping method that independently measures simultaneous dissolution and precipitation rates and can test this principle. The technique reacts a solution enriched in a rare isotope of an element with a solid having natural isotopic abundances (Beck et al., 1992; Gaillardet, 2008; Gruber et al., 2013). Dissolution and precipitation rates are found from the changing isotopic ratios. Our quartz experiment doped with 29Si showed that the equilibrium dissolution rate remains unchanged at all degrees of undersaturation. We recommend this approach to test the validity of using the detailed balance relationship in rate equations for other substances.

Rehabilitative treatment of cleft lip and palate: experience of the Hospital for Rehabilitation of Craniofacial Anomalies/USP (HRAC/USP) - Part 4: Oral Rehabilitation

PubMed Central

FREITAS, José Alberto de Souza; de ALMEIDA, Ana Lúcia Pompéia Fraga; SOARES, Simone; NEVES, Lucimara Teixeira das; GARIB, Daniela Gamba; TRINDADE-SUEDAM, Ivy Kiemle; YAEDÚ, Renato Yassutaka Faria; LAURIS, Rita de Cássia Moura Carvalho; OLIVEIRA, Thais Marchini; PINTO, João Henrique Nogueira

2013-01-01

Treatment of patients with cleft lip and palate is completed with fixed prostheses, removable, total, implants and aims to restore aesthetics, phonetics and function and should be guided by the basic principles of oral rehabilitation, such as physiology, stability, aesthetics, hygiene and the expectations of the patient. In order to obtain longevity of a prosthetic rehabilitation, the periodontal and dental tissue as well as the biomechanics of the prosthesis are to be respected. The purpose of this article is to describe the types of prosthetics treatment, which are performed at HRAC/USP for the rehabilitation of cleft area in adult patients. PMID:23857655

Rehabilitative treatment of cleft lip and palate: experience of the Hospital for Rehabilitation of Craniofacial Anomalies/USP (HRAC/USP) - Part 4: oral rehabilitation.

PubMed

Freitas, José Alberto de Souza; Almeida, Ana Lúcia Pompéia Fraga de; Soares, Simone; Neves, Lucimara Teixeira das; Garib, Daniela Gamba; Trindade-Suedam, Ivy Kiemle; Yaedú, Renato Yassutaka Faria; Lauris, Rita de Cássia Moura Carvalho; Oliveira, Thais Marchini; Pinto, João Henrique Nogueira

2013-01-01

Treatment of patients with cleft lip and palate is completed with fixed prostheses, removable, total, implants and aims to restore aesthetics, phonetics and function and should be guided by the basic principles of oral rehabilitation, such as physiology, stability, aesthetics, hygiene and the expectations of the patient. In order to obtain longevity of a prosthetic rehabilitation, the periodontal and dental tissue as well as the biomechanics of the prosthesis are to be respected. The purpose of this article is to describe the types of prosthetics treatment, which are performed at HRAC/USP for the rehabilitation of cleft area in adult patients.

The influence of co-formers on the dissolution rates of co-amorphous sulfamerazine/excipient systems.

PubMed

Gniado, Katarzyna; Löbmann, Korbinian; Rades, Thomas; Erxleben, Andrea

2016-05-17

A comprehensive study on the dissolution properties of three co-amorphous sulfamerazine/excipient systems, namely sulfamerazine/deoxycholic acid, sulfamerazine/citric acid and sulfamerazine/sodium taurocholate (SMZ/DA, SMZ/CA and SMZ/NaTC; 1:1 molar ratio), is reported. While all three co-formers stabilize the amorphous state during storage, only co-amorphization with NaTC provides a dissolution advantage over crystalline SMZ and the reasons for this were analyzed. In the case of SMZ/DA extensive gelation of DA protects the amorphous phase from crystallization upon contact with buffer, but at the same time prevents the release of SMZ into solution. Disk dissolution studies showed an improved dissolution behavior of SMZ/CA compared to crystalline SMZ. However, enhanced dissolution properties were not seen in powder dissolution testing due to poor dispersibility. Co-amorphization of SMZ and NaTC resulted in a significant increase in dissolution rate, both in powder and disk dissolution studies. Copyright © 2016. Published by Elsevier B.V.

Development and validation of an HPLC method for tetracycline-related USP monographs.

PubMed

Hussien, Emad M

2014-09-01

A novel reversed-phase HPLC method was developed and validated for the assay of tetracycline hydrochloride and the limit of 4-epianhydrotetracycline hydrochloride impurity in tetracycline hydrochloride commercial bulk and pharmaceutical products. The method employed L1 (3 µm, 150 × 4.6 mm) columns, a mobile phase of 0.1% phosphoric acid and acetonitrile at a flow rate of 1.0 mL/min, and detection at 280 nm. The separation was performed in HPLC gradient mode. Forced degradation studies showed that tetracycline eluted as a spectrally pure peak and was well resolved from its degradation products. The fast degradation of tetracycline hydrochloride and 4-epianhydrotetracycline hydrochloride in solution was retarded by controlling the autosampler temperature at 4 °C and using 0.1% H3 PO4 as diluent. The robustness of the method was tested starting with the maximum variations allowed in the US Pharmacopeia (USP) general chapter Chromatography <621>. The method was linear over the range 80-120% of the assay concentration (0.1 mg/mL) for tetracycline hydrochloride and 50-150% of the acceptance criteria specified in the individual USP monographs for 4-epianhydrotetracycline hydrochloride. The limit of quantification for 4-epianhydrotetracycline hydrochloride was 0.1 µg/mL, 20 times lower than the acceptance criteria. The method was specific, precise, accurate and robust. Copyright © 2014 John Wiley & Sons, Ltd.

26 CFR 1.482-7A - Methods to determine taxable income in connection with a cost sharing arrangement.

Code of Federal Regulations, 2010 CFR

2010-04-01

... reasonable overhead costs attributable to the project. They also share the cost of a conference facility that... reasonable overhead costs attributable to the project. USP also incurs costs related to field testing of the... Unrelated Third Party (UTP) enter into a cost sharing arrangement to develop new audio technology. In the...

26 CFR 1.482-7A - Methods to determine taxable income in connection with a cost sharing arrangement.

Code of Federal Regulations, 2011 CFR

2011-04-01

... reasonable overhead costs attributable to the project. They also share the cost of a conference facility that... reasonable overhead costs attributable to the project. USP also incurs costs related to field testing of the... Unrelated Third Party (UTP) enter into a cost sharing arrangement to develop new audio technology. In the...

26 CFR 1.482-7A - Methods to determine taxable income in connection with a cost sharing arrangement.

Code of Federal Regulations, 2012 CFR

2012-04-01

... reasonable overhead costs attributable to the project. They also share the cost of a conference facility that... reasonable overhead costs attributable to the project. USP also incurs costs related to field testing of the... Unrelated Third Party (UTP) enter into a cost sharing arrangement to develop new audio technology. In the...

26 CFR 1.482-7A - Methods to determine taxable income in connection with a cost sharing arrangement.

Code of Federal Regulations, 2013 CFR

2013-04-01

... reasonable overhead costs attributable to the project. They also share the cost of a conference facility that... reasonable overhead costs attributable to the project. USP also incurs costs related to field testing of the... Unrelated Third Party (UTP) enter into a cost sharing arrangement to develop new audio technology. In the...

26 CFR 1.482-7A - Methods to determine taxable income in connection with a cost sharing arrangement.

Code of Federal Regulations, 2014 CFR

2014-04-01

... reasonable overhead costs attributable to the project. They also share the cost of a conference facility that... reasonable overhead costs attributable to the project. USP also incurs costs related to field testing of the... Unrelated Third Party (UTP) enter into a cost sharing arrangement to develop new audio technology. In the...

38 CFR 76.2 - Assistance allowance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... part of any month in which the veteran is training or competing in any event sponsored by the USP or the IPC; or (2) Residing at a USP training center in connection with any paralympic training or competition for the period certified under § 76.3. (b) In providing this allowance, VA will periodically...

27 CFR 21.60 - Formula No. 33.

Code of Federal Regulations, 2014 CFR

2014-04-01

... pounds of gentian violet or gentian violet, U.S.P. (b) Authorized uses. (1) As a solvent: 052.Inks (not including meat branding inks). 210.External pharmaceuticals, not U.S.P. or N.F. 249.Miscellaneous external...). (c) Conditions governing use. Meat branding inks made with Formula No. 33 do not meet U.S. Department...

27 CFR 21.60 - Formula No. 33.

Code of Federal Regulations, 2012 CFR

2012-04-01

... pounds of gentian violet or gentian violet, U.S.P. (b) Authorized uses. (1) As a solvent: 052.Inks (not including meat branding inks). 210.External pharmaceuticals, not U.S.P. or N.F. 249.Miscellaneous external...). (c) Conditions governing use. Meat branding inks made with Formula No. 33 do not meet U.S. Department...

27 CFR 21.60 - Formula No. 33.

Code of Federal Regulations, 2011 CFR

2011-04-01

... pounds of gentian violet or gentian violet, U.S.P. (b) Authorized uses. (1) As a solvent: 052.Inks (not including meat branding inks). 210.External pharmaceuticals, not U.S.P. or N.F. 249.Miscellaneous external...). (c) Conditions governing use. Meat branding inks made with Formula No. 33 do not meet U.S. Department...

27 CFR 21.60 - Formula No. 33.

Code of Federal Regulations, 2013 CFR

2013-04-01

... pounds of gentian violet or gentian violet, U.S.P. (b) Authorized uses. (1) As a solvent: 052.Inks (not including meat branding inks). 210.External pharmaceuticals, not U.S.P. or N.F. 249.Miscellaneous external...). (c) Conditions governing use. Meat branding inks made with Formula No. 33 do not meet U.S. Department...

75 FR 65515 - NRC Corporation, USPS Help Desk of Customer Care Center, Including On-Site Leased Workers of Volt...

Federal Register 2010, 2011, 2012, 2013, 2014

2010-10-25

... DEPARTMENT OF LABOR Employment and Training Administration [TA-W-74,347] NRC Corporation, USPS Help Desk of Customer Care Center, Including On-Site Leased Workers of Volt Consulting, West Columbia, SC; Notice of Affirmative Determination Regarding Application for Reconsideration By application...

USP7S-dependent inactivation of Mule regulates DNA damage signalling and repair.

PubMed

Khoronenkova, Svetlana V; Dianov, Grigory L

2013-02-01

The E3 ubiquitin ligase Mule/ARF-BP1 plays an important role in the cellular DNA damage response by controlling base excision repair and p53 protein levels. However, how the activity of Mule is regulated in response to DNA damage is currently unknown. Here, we report that the Ser18-containing isoform of the USP7 deubiquitylation enzyme (USP7S) controls Mule stability by preventing its self-ubiquitylation and subsequent proteasomal degradation. We find that in response to DNA damage, downregulation of USP7S leads to self-ubiquitylation and proteasomal degradation of Mule, which eventually leads to p53 accumulation. Cells that are unable to downregulate Mule show reduced ability to upregulate p53 levels in response to DNA damage. We also find that, as Mule inactivation is required for stabilization of base excision repair enzymes, the failure of cells to downregulate Mule after DNA damage results in deficient DNA repair. Our data describe a novel mechanism by which Mule is regulated in response to DNA damage and coordinates cellular DNA damage responses and DNA repair.

Comparative study on deposition of fluorine-doped tin dioxide thin films by conventional and ultrasonic spray pyrolysis methods for dye-sensitized solar modules

NASA Astrophysics Data System (ADS)

Icli, Kerem Cagatay; Kocaoglu, Bahadir Can; Ozenbas, Macit

2018-01-01

Fluorine-doped tin dioxide (FTO) thin films were produced via conventional spray pyrolysis and ultrasonic spray pyrolysis (USP) methods using alcohol-based solutions. The prepared films were compared in terms of crystal structure, morphology, surface roughness, visible light transmittance, and electronic properties. Upon investigation of the grain structures and morphologies, the films prepared using ultrasonic spray method provided relatively larger grains and due to this condition, carrier mobilities of these films exhibited slightly higher values. Dye-sensitized solar cells and 10×10 cm modules were prepared using commercially available and USP-deposited FTO/glass substrates, and solar performances were compared. It is observed that there exists no remarkable efficiency difference for both cells and modules, where module efficiency of the USP-deposited FTO glass substrates is 3.06% compared to commercial substrate giving 2.85% under identical conditions. We demonstrated that USP deposition is a low cost and versatile method of depositing commercial quality FTO thin films on large substrates employed in large area dye-sensitized solar modules or other thin film technologies.

Ubiquitin-specific protease 8 deubiquitinates Sec31A and decreases large COPII carriers and collagen IV secretion.

PubMed

Kawaguchi, Kohei; Endo, Akinori; Fukushima, Toshiaki; Madoka, Yuka; Tanaka, Toshiaki; Komada, Masayuki

2018-05-15

Nascent cargo proteins in the endoplasmic reticulum are transported to the Golgi by COPII carriers. Typical COPII vesicles are 60-70 nm in diameter, and much larger macromolecules, such as procollagen, are transported by atypical large COPII carriers in mammalian cells. The formation of large COPII carriers is enhanced by Cul3 ubiquitin ligase, which mono-ubiquitinates Sec31A, a COPII coat protein. However, the deubiquitinating enzyme for Sec31A was unclear. Here, we show that the deubiquitinating enzyme USP8 interacts with and deubiquitinates Sec31A. The interaction was mediated by the adaptor protein STAM1. USP8 overexpression inhibited the formation of large COPII carriers. By contrast, USP8 knockdown caused the accumulation of COPII coat proteins around the cis-Golgi, promoted the intracellular trafficking of procollagen IV from the endoplasmic reticulum to the Golgi, and increased collagen IV secretion. We concluded that USP8 deubiquitinates Sec31A and inhibits the formation of large COPII carriers, thereby suppressing collagen IV secretion. Copyright © 2018 Elsevier Inc. All rights reserved.

53BP1 and USP28 mediate p53-dependent cell cycle arrest in response to centrosome loss and prolonged mitosis.

PubMed

Fong, Chii Shyang; Mazo, Gregory; Das, Tuhin; Goodman, Joshua; Kim, Minhee; O'Rourke, Brian P; Izquierdo, Denisse; Tsou, Meng-Fu Bryan

2016-07-02

Mitosis occurs efficiently, but when it is disturbed or delayed, p53-dependent cell death or senescence is often triggered after mitotic exit. To characterize this process, we conducted CRISPR-mediated loss-of-function screens using a cell-based assay in which mitosis is consistently disturbed by centrosome loss. We identified 53BP1 and USP28 as essential components acting upstream of p53, evoking p21-dependent cell cycle arrest in response not only to centrosome loss, but also to other distinct defects causing prolonged mitosis. Intriguingly, 53BP1 mediates p53 activation independently of its DNA repair activity, but requiring its interacting protein USP28 that can directly deubiquitinate p53 in vitro and ectopically stabilize p53 in vivo. Moreover, 53BP1 can transduce prolonged mitosis to cell cycle arrest independently of the spindle assembly checkpoint (SAC), suggesting that while SAC protects mitotic accuracy by slowing down mitosis, 53BP1 and USP28 function in parallel to select against disturbed or delayed mitosis, promoting mitotic efficiency.

Phosphorylation and activation of ubiquitin-specific protease-14 by Akt regulates the ubiquitin-proteasome system

PubMed Central

Xu, Daichao; Shan, Bing; Lee, Byung-Hoon; Zhu, Kezhou; Zhang, Tao; Sun, Huawang; Liu, Min; Shi, Linyu; Liang, Wei; Qian, Lihui; Xiao, Juan; Wang, Lili; Pan, Lifeng; Finley, Daniel; Yuan, Junying

2015-01-01

Regulation of ubiquitin-proteasome system (UPS), which controls the turnover of short-lived proteins in eukaryotic cells, is critical in maintaining cellular proteostasis. Here we show that USP14, a major deubiquitinating enzyme that regulates the UPS, is a substrate of Akt, a serine/threonine-specific protein kinase critical in mediating intracellular signaling transducer for growth factors. We report that Akt-mediated phosphorylation of USP14 at Ser432, which normally blocks its catalytic site in the inactive conformation, activates its deubiquitinating activity in vitro and in cells. We also demonstrate that phosphorylation of USP14 is critical for Akt to regulate proteasome activity and consequently global protein degradation. Since Akt can be activated by a wide range of growth factors and is under negative control by phosphoinosotide phosphatase PTEN, we suggest that regulation of UPS by Akt-mediated phosphorylation of USP14 may provide a common mechanism for growth factors to control global proteostasis and for promoting tumorigenesis in PTEN-negative cancer cells. DOI: http://dx.doi.org/10.7554/eLife.10510.001 PMID:26523394

75 FR 8081 - Patrick J. Lais: Debarment Order

Federal Register 2010, 2011, 2012, 2013, 2014

2010-02-23

..., among other things, subpotent burn spray, aspirin that had failed dissolution testing, and antacid... as ``Uncoated Aspirin.'' This drug failed its final dissolution testing. Neither Mr. Lais nor the... coated the failed aspirin and renumbered the lot. Part of this lot then was packaged as ``Coated Aspirin...

Addition of Sodium Bicarbonate to Irrigation Solution May Assist in Dissolution of Uric Acid Fragments During Ureteroscopy.

PubMed

Paonessa, Jessica E; Williams, James C; Lingeman, James E

2018-04-01

We hypothesized that adding sodium bicarbonate (bicarb) to normal saline (NS) irrigation during ureteroscopy in patients with uric acid (UA) nephrolithiasis may assist in dissolving small stone fragments produced during laser lithotripsy. In vitro testing was performed to determine whether dissolution of UA fragments could be accomplished within 1 hour. In total 100% UA renal calculi were fragmented, filtered, and separated by size. Fragment sizes were <0.5 mm and 0.5 to 1 mm. Similar amounts of stone material were agitated in solution at room temperature. Four solutions were tested (NS, NS +1 ampule bicarb/L, NS +2, NS +3). Both groups were filtered to remove solutions after fixed periods. Filtered specimens were dried and weighed. Fragment dissolution rates were calculated as percent removed per hour. Additional testing was performed to determine whether increasing the temperature of solution affected dissolution rates. For fragments <0.5 mm, adding 2 or 3 bicarb ampules/L NS produced a dissolution rate averaging 91% ± 29% per hour. This rate averaged 226% faster than NS alone. With fragments 0.5 to 1 mm, addition of 2 or 3 bicarb ampules/L NS yielded a dissolution rate averaging 22% ± 7% per hour, which was nearly five times higher than NS alone. There was a trend for an increase in mean dissolution rate with higher temperature but this increase was not significant (p = 0.30). The addition of bicarbonate to NS more than doubles the dissolution rate of UA stone fragments and fragments less than 0.5 mm can be completely dissolved within 1 hour. Addition of bicarb to NS irrigation is a simple and inexpensive approach that may assist in the dissolution of UA fragments produced during ureteroscopic laser lithotripsy. Further studies are needed to determine whether a clinical benefit exists.

Inhibition of deubiquitinases primes glioblastoma cells to apoptosis in vitro and in vivo

PubMed Central

Karpel-Massler, Georg; Banu, Matei A.; Shu, Chang; Halatsch, Marc-Eric; Westhoff, Mike-Andrew; Bruce, Jeffrey N.; Canoll, Peter; Siegelin, Markus D.

2016-01-01

It remains a challenge in oncology to identify novel drug regimens to efficiently tackle glioblastoma, the most common primary brain tumor in adults. Here, we target deubiquitinases for glioblastoma therapy by utilizing the small-molecule inhibitor WP1130 which has been characterized as a deubiquitinase inhibitor that interferes with the function of Usp9X. Expression analysis data confirm that Usp9X expression is increased in glioblastoma compared to normal brain tissue indicating its potential as a therapeutic. Consistently, increasing concentrations of WP1130 decrease the cellular viability of established, patient-derived xenograft (PDX) and stem cell-like glioblastoma cells. Specific down-regulation of Usp9X reduces viability in glioblastoma cells mimicking the effects of WP1130. Mechanistically, WP1130 elicits apoptosis and increases activation of caspases. Moreover, WP1130 and siRNAs targeting Usp9X reduce the expression of anti-apoptotic Bcl-2 family members and Inhibitor of Apoptosis Proteins, XIAP and Survivin. Pharmacological and genetic interference with Usp9X efficiently sensitized glioblastoma cells to intrinsic and extrinsic apoptotic stimuli. In addition, single treatment with WP1130 elicited anti-glioma activity in an orthotopic proneural murine model of glioblastoma. Finally, the combination treatment of WP1130 and ABT263 inhibited tumor growth more efficiently than each reagent by its own in vivo without detectable side effects or organ toxicity. Taken together, these results suggest that targeting deubiquitinases for glioma therapy is feasible and effective. PMID:26872380

Internet cigarette vendor compliance with credit card payment and shipping bans.

PubMed

Williams, Rebecca S; Ribisl, Kurt M

2014-02-01

Most Internet cigarette sales have violated taxation and youth access laws, leading to landmark 2005 agreements with credit card companies, PayPal, and private shippers (United Parcel Service, Federal Express, DHL) to cease participation in these transactions. Despite their promise at the time, loopholes allowed for check payment and U.S. Postal Service (USPS) shipping. This study assessed actual vendor compliance with the payment and shipping bans using a purchase survey. In late 2007 and early 2008, an adult buyer attempted to order cigarettes from the 97 most popular Internet cigarette vendors (ICVs) using banned payment and shipping methods. When banned payment or shipping methods were unavailable, purchases were attempted with alternate methods (e.g., checks, e-checks, USPS). Twenty-seven of 100 orders were placed with (banned) credit cards; 23 were successfully received. Seventy-one orders were placed with checks (60 successfully received). Four orders were delivered using banned shippers; 79 of 83 successfully received orders were delivered by the USPS. About a quarter of ICVs violated the payment ban, others adapted by accepting checks. Most vendors complied with the shipping ban, perhaps because USPS was an easy substitute shipping option. Better enforcement of the bans is needed; the 2009 Prevent All Cigarette Trafficking Act closed the USPS loophole by making cigarettes nonmailable material; evaluation of enforcement efforts and adaptations by vendors are needed. These sorts of bans are a promising approach to controlling the sale of restricted goods online.

The molecular basis of conformational instability of the ecdysone receptor DNA binding domain studied by in silico and in vitro experiments.

PubMed

Szamborska-Gbur, Agnieszka; Rymarczyk, Grzegorz; Orłowski, Marek; Kuzynowski, Tomasz; Jakób, Michał; Dziedzic-Letka, Agnieszka; Górecki, Andrzej; Dobryszycki, Piotr; Ożyhar, Andrzej

2014-01-01

The heterodimer of the ecdysone receptor (EcR) and ultraspiracle (Usp), members of the nuclear receptors superfamily, regulates gene expression associated with molting and metamorphosis in insects. The DNA binding domains (DBDs) of the Usp and EcR play an important role in their DNA-dependent heterodimerization. Analysis of the crystal structure of the UspDBD/EcRDBD heterocomplex from Drosophila melanogaster on the hsp27 gene response element, suggested an appreciable similarity between both DBDs. However, the chemical denaturation experiments showed a categorically lower stability for the EcRDBD in contrast to the UspDBD. The aim of our study was an elucidation of the molecular basis of this intriguing instability. Toward this end, we mapped the EcRDBD amino acid sequence positions which have an impact on the stability of the EcRDBD. The computational protein design and in vitro analyses of the EcRDBD mutants indicate that non-conserved residues within the α-helix 2, forming the EcRDBD hydrophobic core, represent a specific structural element that contributes to instability. In particular, the L58 appears to be a key residue which differentiates the hydrophobic cores of UspDBD and EcRDBD and is the main reason for the low stability of the EcRDBD. Our results might serve as a benchmark for further studies of the intricate nature of the EcR molecule.

Molecular Weights of Bovine and Porcine Heparin Samples: Comparison of Chromatographic Methods and Results of a Collaborative Survey.

PubMed

Bertini, Sabrina; Risi, Giulia; Guerrini, Marco; Carrick, Kevin; Szajek, Anita Y; Mulloy, Barbara

2017-07-19

In a collaborative study involving six laboratories in the USA, Europe, and India the molecular weight distributions of a panel of heparin sodium samples were determined, in order to compare heparin sodium of bovine intestinal origin with that of bovine lung and porcine intestinal origin. Porcine samples met the current criteria as laid out in the USP Heparin Sodium monograph. Bovine lung heparin samples had consistently lower average molecular weights. Bovine intestinal heparin was variable in molecular weight; some samples fell below the USP limits, some fell within these limits and others fell above the upper limits. These data will inform the establishment of pharmacopeial acceptance criteria for heparin sodium derived from bovine intestinal mucosa. The method for MW determination as described in the USP monograph uses a single, broad standard calibrant to characterize the chromatographic profile of heparin sodium on high-resolution silica-based GPC columns. These columns may be short-lived in some laboratories. Using the panel of samples described above, methods based on the use of robust polymer-based columns have been developed. In addition to the use of the USP's broad standard calibrant for heparin sodium with these columns, a set of conditions have been devised that allow light-scattering detected molecular weight characterization of heparin sodium, giving results that agree well with the monograph method. These findings may facilitate the validation of variant chromatographic methods with some practical advantages over the USP monograph method.

Development and validation of an ICP-MS method for the determination of elemental impurities in TP-6076 active pharmaceutical ingredient (API) according to USP 〈232〉/〈233〉.

PubMed

Chahrour, Osama; Malone, John; Collins, Mark; Salmon, Vrushali; Greenan, Catherine; Bombardier, Amy; Ma, Zhongze; Dunwoody, Nick

2017-10-25

The new guidelines of the United States pharmacopeia (USP), European pharmacopeia (EP) and international conference on harmonization (ICH) regulating elemental impurities limits in pharmaceuticals signify the end of unspecific analysis of metals as outlined in USP 〈231〉. The new guidelines specify both daily doses and concentration/limits of elemental impurities in pharmaceutical final products, active pharmaceutical ingredients (API) and excipients. In chapter USP 〈233〉 method implementation, validation and quality control during the analytical process are described. We herein report the use of a stabilising matrix that overcomes low spike recovery problem encountered with Os and allows the determination of all USP required elemental impurities (As, Cd, Hg, Pb, V, Cr, Ni, Mo, Cu, Pt, Pd, Ru, Rh, Os and Ir) in a single analysis. The matrix was used in the validation of a method to determine elemental impurities in TP-6076 active pharmaceutical ingredient (API) by ICP-MS according to the procedures defined in USP〈233〉 and to GMP requirements. This validation will support the regulatory submission of TP-6076 which is a novel tetracycline analogue effective against the most urgent multidrug-resistant gram-negative bacteria. Evaluation of TP-6076 in IND-enabling toxicology studies has led to the initiation of a phase 1 clinical trial. Copyright © 2017 Elsevier B.V. All rights reserved.

TRAF Family Member-associated NF-κB Activator (TANK) Inhibits Genotoxic Nuclear Factor κB Activation by Facilitating Deubiquitinase USP10-dependent Deubiquitination of TRAF6 Ligase.

PubMed

Wang, Wei; Huang, Xuan; Xin, Hong-Bo; Fu, Mingui; Xue, Aimin; Wu, Zhao-Hui

2015-05-22

DNA damage-induced NF-κB activation plays a critical role in regulating cellular response to genotoxic stress. However, the molecular mechanisms controlling the magnitude and duration of this genotoxic NF-κB signaling cascade are poorly understood. We recently demonstrated that genotoxic NF-κB activation is regulated by reversible ubiquitination of several essential mediators involved in this signaling pathway. Here we show that TRAF family member-associated NF-κB activator (TANK) negatively regulates NF-κB activation by DNA damage via inhibiting ubiquitination of TRAF6. Despite the lack of a deubiquitination enzyme domain, TANK has been shown to negatively regulate the ubiquitination of TRAF proteins. We found TANK formed a complex with MCPIP1 (also known as ZC3H12A) and a deubiquitinase, USP10, which was essential for the USP10-dependent deubiquitination of TRAF6 and the resolution of genotoxic NF-κB activation upon DNA damage. Clustered regularly interspaced short palindromic repeats (CRISPR)/Cas9-mediated deletion of TANK in human cells significantly enhanced NF-κB activation by genotoxic treatment, resulting in enhanced cell survival and increased inflammatory cytokine production. Furthermore, we found that the TANK-MCPIP1-USP10 complex also decreased TRAF6 ubiquitination in cells treated with IL-1β or LPS. In accordance, depletion of USP10 enhanced NF-κB activation induced by IL-1β or LPS. Collectively, our data demonstrate that TANK serves as an important negative regulator of NF-κB signaling cascades induced by genotoxic stress and IL-1R/Toll-like receptor stimulation in a manner dependent on MCPIP1/USP10-mediated TRAF6 deubiquitination. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

Comparison of Central Corneal Thickness Measured by Standard Ultrasound Pachymetry, Corneal Topography, Tono-Pachymetry and Anterior Segment Optical Coherence Tomography.

PubMed

González-Pérez, Javier; Queiruga Piñeiro, Juan; Sánchez García, Ángelx; González Méijome, José Manuel

2018-04-10

To compare central corneal thickness (CCT) measured by standard ultrasound pachymetry (USP), and three non-contact devices in healthy eyes. A cross-sectional study of CCT measurement in 52 eyes of 52 healthy volunteers was done by a single examiner at Ocular Surface and Contact Lens Laboratory. Three consecutive measurements were done by standard USP, non-contact tono-pachymeter, Pentacam corneal topographer, and Anterior Segment Optical Coherence Tomography (AS-OCT). The mean values were used for assessment. The results were compared using multivariate ANOVA, linear regression, and Pearson correlation. Agreement among the devices was analyzed using mean differences and Bland-Altman analysis with 95% limits of agreement (LoA). Finally, reliability was analyzed using intraclass correlation coefficient (ICC). Mean CCT by ultrasound pachymeter, tono-pachymeter, corneal topographer and AS-OCT were 558.9 ± 31.2 µm, 525.8 ± 43.1 µm, 550.4 ± 30.5 µm, and 545.9 ± 30.5 µm respectively. There was a significant positive correlation between AS-OCT and USP (Pearson correlation = 0.957, p < 0.001), corneal topography and USP (Pearson correlation = 0.965, p < 0.001), and corneal topography and AS-OCT (Pearson correlation = 0.965, p < 0.001). There was a lower correlation between CT-1P tono-pachymeter and the other three modalities. Intraclass correlation coefficients show an excellent reliability between pairs except for CT-1P against the other three instruments that were found moderate. CT-1P tono-pachymeter underestimates CCT measurements compared to Scheimpflug system, AS-OCT device, and USP. Mean CCT among USP, Pentacam and AS-OCT were comparable and had significant linear correlations. In clinical practice, these three modalities could be interchangeable in healthy patients.

Investigation of the Dissolution Profile of Gliclazide Modified-Release Tablets Using Different Apparatuses and Dissolution Conditions.

PubMed

Skripnik, K K S; Riekes, M K; Pezzini, B R; Cardoso, S G; Stulzer, H K

2017-07-01

In the absence of an official dissolution method for modified-release tablets of gliclazide, dissolution parameters, such as apparatuses (1, 2, and 3), rotation speeds, pH, and composition of the dissolution medium were investigated. The results show that although the drug presents a pH-mediated solubility (pH 7.0 > 6.8 > 6.4 > 6.0 > 5.5 > 4.5), the in vitro release of the studied tablets was not dependent on this parameter, despite of the apparatus tested. On the other hand, the rotation speed demonstrated a greater influence (100 rpm >50 rpm). Using similar hydrodynamic conditions, the three different apparatuses were compared in pH 6.8 and provided the following trend: apparatus 1 at 100 rpm >2 at 50 rpm ≈3 at 10 dpm. As a complete, but slow release is expected from modified-release formulations, apparatus 2, in phosphate buffer pH 6.8 and 100 rpm, were selected as the optimized dissolution method. In comparison to apparatus 1 under the same conditions, the paddle avoids the stickiness of formulation excipients at the mesh of the basket, which could prejudice the release of gliclazide. Results obtained with biorelevant medium through the developed dissolution method were similar to the buffer solution pH 6.8. The application of the optimized method as a quality control test between two different brands of gliclazide modified-release tablets showed that both dissolution profiles were considered similar by the similarity factor (f2 = 51.8). The investigation of these dissolution profiles indicated a dissolution kinetic following first-order model.

38 CFR 76.4 - Amount of allowance.

Code of Federal Regulations, 2011 CFR

2011-07-01

... of the monthly rate to veterans who train or compete in USP or IPC sponsored events for each day of training or competition, or to veterans who reside at a USP training center, for each day of residence, or on a monthly basis at the monthly rate to veterans who train or compete continuously for a full month...

27 CFR 21.54 - Formula No. 27-B.

Code of Federal Regulations, 2012 CFR

2012-04-01

... gallon of lavender oil, N.F., and 100 pounds of green soap, U.S.P. Note. The requirements of this formula may be met by adding 1 gallon of lavender oil, N.F., and 66.5 pounds of U.S.P. quality soap... other biocides. (2) Miscellaneous uses: 812.Product development and pilot plant uses (own use only). ...

27 CFR 21.54 - Formula No. 27-B.

Code of Federal Regulations, 2011 CFR

2011-04-01

... gallon of lavender oil, N.F., and 100 pounds of green soap, U.S.P. Note. The requirements of this formula may be met by adding 1 gallon of lavender oil, N.F., and 66.5 pounds of U.S.P. quality soap... other biocides. (2) Miscellaneous uses: 812.Product development and pilot plant uses (own use only). ...

76 FR 52580 - Procedures To Adjudicate Claims for Personal Injury or Property Damage Arising Out of the...

Federal Register 2010, 2011, 2012, 2013, 2014

2011-08-23

..., Room 2400, St. Louis, MO 63155-9948. FOR FURTHER INFORMATION CONTACT: Ruth A. Przybeck, Chief Counsel... Center, USPS National Tort Center, 1720 Market Street, Room 2400, St. Louis, MO 63155-9948'' in its place... Counsel, Torts, General Law Service Center, USPS National Tort Center, 1720 Market Street, Room 2400, St...

The Ubiquitin-Specific Protease 14 (USP14) Is a Critical Regulator of Long-Term Memory Formation

ERIC Educational Resources Information Center

Jarome, Timothy J.; Kwapis, Janine L.; Hallengren, Jada J.; Wilson, Scott M.; Helmstetter, Fred J.

2014-01-01

Numerous studies have suggested a role for ubiquitin-proteasome-mediated protein degradation in learning-dependent synaptic plasticity; however, very little is known about how protein degradation is regulated at the level of the proteasome during memory formation. The ubiquitin-specific protease 14 (USP14) is a proteasomal deubiquitinating enzyme…

27 CFR 21.54 - Formula No. 27-B.

Code of Federal Regulations, 2013 CFR

2013-04-01

... concentrate containing 25 percent water to 100 gallons of alcohol and, after mixing, by adding thereto 33.5 pounds of water and again mixing. (b) Authorized uses. (1) As a solvent: 141.Shampoos. 210.External pharmaceuticals, not U.S.P. or N.F. 243.Liniments, U.S.P. or N.F. 410.Disinfectants insecticides, fungicides, and...

27 CFR 21.54 - Formula No. 27-B.

Code of Federal Regulations, 2014 CFR

2014-04-01

... concentrate containing 25 percent water to 100 gallons of alcohol and, after mixing, by adding thereto 33.5 pounds of water and again mixing. (b) Authorized uses. (1) As a solvent: 141.Shampoos. 210.External pharmaceuticals, not U.S.P. or N.F. 243.Liniments, U.S.P. or N.F. 410.Disinfectants insecticides, fungicides, and...

77 FR 46685 - In the Matter of: Steven Neal Greenoe, Currently Incarcerated at: Inmate #54450-056, USP Atlanta...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-08-06

... DEPARTMENT OF COMMERCE Bureau of Industry and Security In the Matter of: Steven Neal Greenoe, Currently Incarcerated at: Inmate 54450-056, USP Atlanta, U.S. Penitentiary, P.O. Box 1150160, Atlanta, GA... On January 10, 2012, in the U.S. District Court, District of North Carolina, Steven Neal Greenoe...

Low temperature dissolution flowsheet for plutonium metal

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

Daniel, W. E.; Almond, P. M.; Rudisill, T. S.

2016-05-01

The H-Canyon flowsheet used to dissolve Pu metal for PuO 2 production utilizes boiling HNO 3. SRNL was requested to develop a complementary dissolution flowsheet at two reduced temperature ranges. The dissolution and H 2 generation rates of Pu metal were investigated using a dissolving solution at ambient temperature (20-30 °C) and for an intermediate temperature of 50-60 °C. Additionally, the testing included an investigation of the dissolution rates and characterization of the off-gas generated from the ambient temperature dissolution of carbon steel cans and the nylon bags that contain the Pu metal when charged to the dissolver.

Development and validation of a discriminative dissolution test for nimesulide suspensions.

PubMed

da Fonseca, Laís Bastos; Labastie, Márcio; de Sousa, Valéria Pereira; Volpato, Nadia Maria

2009-01-01

The dissolution test for oral dosage forms has recently widened to a variety of special dosage forms such as suspensions. For class II drugs, such as nimesulide (NMS), this study is very important because formulation problems may compromise drug bioavailability. In the present work, tests with four brands of commercially available NMS (RA, TS, TB, and TC) have been performed in order to study their dissolution at different conditions. The suspensions have been characterized relatively to particle size, pH, and density besides NMS assay and the amount of drug in solution in the suspension vehicles. The dissolution study was conducted using the following media: simulated intestinal fluid, pH 6.8, containing polysorbate 80 (P80) or sodium lauryl sulfate (SLS); phosphate buffer, pH 7.4, with P80 and aqueous solution of SLS. Concerning the quantitative analysis, the UV-VIS spectrophotometry could have been used in substitution to high-performance liquid chromatography since the methodology had been adequately validated. The influence of the drug particle size distribution was significant on the dissolution profiles of NMS formulations, confirming to be a factor that should be strictly controlled in the development of oral suspensions.

Preparation and in vitro/in vivo Evaluation of Lacidipine by Adsorption onto Fumed Silica Using Supercritical Carbon Dioxide.

PubMed

Geng, Yajie; Fu, Qiang; Guo, Bei; Li, Yun; Zhang, Xiangrong; Wang, Xianglin; Zhang, Tianhong

2016-01-01

The aim of this study was to design a silica-supported solid dispersion of lacidipine (LCDP) to enhance the dissolution rate and oral absorption using supercritical CO2 (scCO2) as a solvent. The formulation was characterized using differential scanning calorimetry, powder X-ray diffraction, scanning electron microscopy and fourier transformed infrared spectroscopy. In the dissolution test, LCDP-scCO2 formulation showed a significantly enhanced dissolution compared with LCDPsilica physical mixture and a faster dissolution rate than Lacipil® under different dissolution conditions. In an in vivo test, the area under concentration-time curve and Cmax of LCDP-scCO2 formulation was 9.23 and 23.78 fold greater than LCDP-silica physical mixture (1:15, w/w), respectively, whereas the corresponding values were 1.92 and 2.80 fold greater than Lacipil®, respectively. Our results showed that the solid dispersion prepared by supercritical fluids technology is a feasible method to enhance the oral bioavailability of LCDP.

Microenvironmental pH measurement during sodium naproxenate dissolution in acidic medium by UV/vis imaging.

PubMed

Østergaard, Jesper; Jensen, Henrik; Larsen, Susan W; Larsen, Claus; Lenke, Jim

2014-11-01

Variable dissolution from sodium salts of drugs containing a carboxylic acid group after passing the acidic environment of the stomach may affect oral bioavailability. The aim of the present proof of concept study was to investigate pH effects in relation to the dissolution of sodium naproxenate in 0.01M hydrochloric acid. For this purpose a UV/vis imaging-based approach capable of measuring microenvironmental pH in the vicinity of the solid drug compact as well as monitoring drug dissolution was developed. Using a pH indicating dye real-time spatially resolved measurement of pH was achieved. Sodium naproxenate, can significantly alter the local pH of the dissolution medium, is eventually neutralized and precipitates as the acidic species naproxen. The developed approach is considered useful for detailed studies of pH dependent dissolution phenomena in dissolution testing. Copyright © 2014 Elsevier B.V. All rights reserved.

Initial dissolution kinetics of cocrystal of carbamazepine with nicotinamide.

PubMed

Hattori, Yusuke; Sato, Maiko; Otsuka, Makoto

2015-11-01

Objectives of this study are investigating the initial dissolution kinetics of the cocrystal of carbamazepine (CBZ) with nicotinamide (NIC) and understanding its initial dissolution process. Cocrystal solids of CBZ with NIC were prepared by co-milling and solvent evaporation methods. The formation of cocrystal solid was verified via X-ray diffraction measurement. Dissolution tests of the solids were performed using an original flow cell and ultraviolet-visible spectroscopic detector. The spectra monitored in situ were analyzed to determine the dissolved compounds separately using the classical least squares regression method. The initial dissolution profiles were interpreted using simultaneous model of dissolution and phase changes. In the initial dissolution, CBZ in the cocrystal structure dissolved in water and it was suggested that CBZ reached a metastable intermediate state simultaneously with dissolution. The cocrystal solid prepared by solvent evaporation provided a higher rate constant of the phase change than that prepared by co-milling. Our results thus support the use of evaporation as the method of choice to produce ordered cocrystal structures. We suggest that CBZ forms dihydrate during the dissolution process; however, during the initial phase of dissolution, CBZ changes to a metastable intermediate phase. © 2015 Royal Pharmaceutical Society.

Teaching Analytical Method Transfer through Developing and Validating Then Transferring Dissolution Testing Methods for Pharmaceuticals

ERIC Educational Resources Information Center

Kimaru, Irene; Koether, Marina; Chichester, Kimberly; Eaton, Lafayette

2017-01-01

Analytical method transfer (AMT) and dissolution testing are important topics required in industry that should be taught in analytical chemistry courses. Undergraduate students in senior level analytical chemistry laboratory courses at Kennesaw State University (KSU) and St. John Fisher College (SJFC) participated in development, validation, and…

Development of In Vitro-In Vivo Correlation/Relationship Modeling Approaches for Immediate Release Formulations Using Compartmental Dynamic Dissolution Data from “Golem”: A Novel Apparatus

PubMed Central

Tuszyński, Paweł K.; Polak, Sebastian; Jachowicz, Renata; Mendyk, Aleksander; Dohnal, Jiří

2015-01-01

Different batches of atorvastatin, represented by two immediate release formulation designs, were studied using a novel dynamic dissolution apparatus, simulating stomach and small intestine. A universal dissolution method was employed which simulated the physiology of human gastrointestinal tract, including the precise chyme transit behavior and biorelevant conditions. The multicompartmental dissolution data allowed direct observation and qualitative discrimination of the differences resulting from highly pH dependent dissolution behavior of the tested batches. Further evaluation of results was performed using IVIVC/IVIVR development. While satisfactory correlation could not be achieved using a conventional deconvolution based-model, promising results were obtained through the use of a nonconventional approach exploiting the complex compartmental dissolution data. PMID:26120580

Dissolution of Material and Test reactor Fuel in an H-Canyon Dissolver

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

Daniel, W. E.; Rudisill, T. S.; O'Rourke, P. E.

2017-01-26

In an amended record of decision for the management of spent nuclear fuel (SNF) at the Savannah River Site, the US Department of Energy has authorized the dissolution and recovery of U from 1000 bundles of Al-clad SNF. The SNF is fuel from domestic and foreign research reactors and is typically referred to as Material Test Reactor (MTR) fuel. Bundles of MTR fuel containing assemblies fabricated from U-Al alloys (or other U compounds) are currently dissolved using a Hg-catalyzed HNO3 flowsheet. Since the development of the existing flowsheet, improved experimental methods have been developed to more accurately characterize the offgasmore » composition and generation rate during laboratory dissolutions. Recently, these new techniques were successfully used to develop a flowsheet for the dissolution of High Flux Isotope Reactor (HFIR) fuel. Using the data from the HFIR dissolution flowsheet development and necessary laboratory experiments, the Savannah River National Laboratory (SRNL) was requested to define flowsheet conditions for the dissolution of MTR fuels. With improved offgas characterization techniques, SRNL will be able define the number of bundles of fuel which can be charged to an H-Canyon dissolver with much less conservatism.« less

Accelerated in vitro release testing of implantable PLGA microsphere/PVA hydrogel composite coatings

PubMed Central

Shen, Jie; Burgess, Diane J.

2011-01-01

Dexamethasone loaded poly(lactic-co-glycolic acid) (PLGA) microsphere/PVA hydrogel composites have been investigated as an outer drug-eluting coating for implantable devices such as glucose sensors to counter negative tissue responses to implants. The objective of this study was to develop a discriminatory, accelerated in vitro release testing method for this drug-eluting coating using United States Pharmacopeia (USP) apparatus 4. Polymer degradation and drug release kinetics were investigated under “real-time” and accelerated conditions (i.e. extreme pH, hydro-alcoholic solutions and elevated temperatures). Compared to “real-time” conditions, the initial burst and lag phases were similar using hydro-alcoholic solutions and extreme pH conditions, while the secondary apparent zero-order release phase was slightly accelerated. Elevated temperatures resulted in a significant acceleration of dexamethasone release. The accelerated release data were able to predict “real-time” release when applying the Arrhenius equation. Microsphere batches with faster and slower release profiles were investigated under “real-time” and elevated temperature (60°C) conditions to determine the discriminatory ability of the method. The results demonstrated both the feasibility and the discriminatory ability of this USP apparatus 4 method for in vitro release testing of drug loaded PLGA microsphere/PVA hydrogel composites. This method may be appropriate for similar drug/device combination products and drug delivery systems. PMID:22016033

Accelerated in vitro release testing of implantable PLGA microsphere/PVA hydrogel composite coatings.

PubMed

Shen, Jie; Burgess, Diane J

2012-01-17

Dexamethasone loaded poly(lactic-co-glycolic acid) (PLGA) microsphere/PVA hydrogel composites have been investigated as an outer drug-eluting coating for implantable devices such as glucose sensors to counter negative tissue responses to implants. The objective of this study was to develop a discriminatory, accelerated in vitro release testing method for this drug-eluting coating using United States Pharmacopeia (USP) apparatus 4. Polymer degradation and drug release kinetics were investigated under "real-time" and accelerated conditions (i.e. extreme pH, hydro-alcoholic solutions and elevated temperatures). Compared to "real-time" conditions, the initial burst and lag phases were similar using hydro-alcoholic solutions and extreme pH conditions, while the secondary apparent zero-order release phase was slightly accelerated. Elevated temperatures resulted in a significant acceleration of dexamethasone release. The accelerated release data were able to predict "real-time" release when applying the Arrhenius equation. Microsphere batches with faster and slower release profiles were investigated under "real-time" and elevated temperature (60°C) conditions to determine the discriminatory ability of the method. The results demonstrated both the feasibility and the discriminatory ability of this USP apparatus 4 method for in vitro release testing of drug loaded PLGA microsphere/PVA hydrogel composites. This method may be appropriate for similar drug/device combination products and drug delivery systems. Copyright © 2011 Elsevier B.V. All rights reserved.

Comparative evaluation of ICP sample introduction systems to be used in the metabolite profiling of chlorine-containing pharmaceuticals via HPLC-ICP-MS.

PubMed

Klencsár, Balázs; Sánchez, Carlos; Balcaen, Lieve; Todolí, José; Lynen, Frederic; Vanhaecke, Frank

2018-05-10

A systematic evaluation of four different ICP sample introduction systems to be used in the context of metabolite profiling of chlorine-containing pharmaceuticals via HPLC-ICP-MS was carried out using diclofenac and its major metabolite, 4'-hydroxy-diclofenac, as model compounds. The strict requirements for GMP validation of chromatographic methods in the pharmaceutical industry were adhered to in this context. The final aim of this investigation is an extension of the applicability and validatability of HPLC-ICP-MS in the field of pharmaceutical R&D. Five different gradient programmes were tested while the baseline peak width (w b ), peak capacity (P), USP tailing factor (A s ) and USP signal-to-noise ratio (USP S/N) were determined as major indicators of the chromatographic performance and the values obtained were compared to the corresponding FDA recommendations (if applicable). Four different ICP-MS sample introductions systems were investigated involving two units typically working at higher flow rates (∼1.0 mL min -1 ) and another two systems working at lower flow rates (∼0.1 mL min -1 ). Optimal conditions with potential for applicability under GMP conditions were found at a mobile phase flow rate of 1.0 mL min -1 by using a pneumatic micro-flow LC nebulizer mounted onto a Peltier-cooled cyclonic spray chamber cooled to -1 °C for sample introduction. Under these conditions, HPLC-ICP-MS provided a chromatographic performance similar to that of HPLC with UV detection. The peak shape (USP tailing factor = 1.1-1.4) was significantly improved compared to that obtained with the Peltier-cooled Scott-type spray chamber. Two alternative sample introduction systems - a POINT ® and a High-Temperature Torch-Integrated Sample Introduction System (hTISIS) - were also tested at a flow rate of 0.1 mL min -1 using a chromatographic column with 1.0 mm ID. Although these systems allowed the peak shape to be improved compared to that obtained with the traditional Scott-type spray chamber, the limits of detection and of quantification achievable were strongly compromised due to the significantly lower sensitivity observed for Cl. In addition to a comparison of the aforementioned sample introduction systems, also the effect of spray chamber temperature was evaluated and it was demonstrated that proper temperature control plays an essential role in the optimization of HPLC-ICP-MS methods. Copyright © 2018 Elsevier B.V. All rights reserved.

Two females with mutations in USP9X highlight the variable expressivity of the intellectual disability syndrome.

PubMed

Au, P Y B; Huang, L; Broley, S; Gallagher, L; Creede, E; Lahey, D; Ordorica, S; Mina, K; Boycott, K M; Baynam, G; Dyment, D A

2017-07-01

The genetic causes of intellectual disability (ID) are heterogeneous and include both chromosomal and monogenic etiologies. The X-chromosome is known to contain many ID-related genes and males show a marked predominance for intellectual disability. Here we report two females with syndromic intellectual disability. The first individual was relatively mild in her presentation with mild-moderate intellectual disability, hydronephrosis and altered pigmentation along the lines of Blaschko without additional congenital anomalies. A second female presented shortly after birth with dysmorphic facial features, post-axial polydactyly and, on follow-up assessment, demonstrated moderate intellectual disability. Chromosomal studies for Individual 1 identified an X-chromosome deletion due to a de novo pericentric inversion; the inversion breakpoint was associated with deletion of the 5'UTR of the USP9X, a gene which has been implicated in a syndromic intellectual disability affecting females. The second individual had a de novo frameshift mutation detected by whole-exome sequencing that was predicted to be deleterious, NM_001039590.2 (USP9X): c.4104_4105del (p.(Arg1368Serfs*2)). Haploinsufficiency of USP9X in females has been associated with ID and congenital malformations that include heart defects, scoliosis, dental abnormalities, anal atresia, polydactyly, Dandy Walker malformation and hypoplastic corpus callosum. The extent of the congenital malformations observed in Individual 1 was less striking than Individual 2 and other individuals previously reported in the literature, and suggests that USP9X mutations in females can have a wider spectrum of presentation than previously appreciated. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Increased acid ceramidase expression depends on upregulation of androgen-dependent deubiquitinases, USP2, in a human prostate cancer cell line, LNCaP.

PubMed

Mizutani, Naoki; Inoue, Minami; Omori, Yukari; Ito, Hiromi; Tamiya-Koizumi, Keiko; Takagi, Akira; Kojima, Tetsuhito; Nakamura, Mitsuhiro; Iwaki, Soichiro; Nakatochi, Masahiro; Suzuki, Motoshi; Nozawa, Yoshinori; Murate, Takashi

2015-10-01

Acid ceramidase (ACDase) metabolizes ceramide to sphingosine, leading to sphingosine 1-phosphate production. Reportedly, ACDase has been upregulated in prostate cancer. However, its regulatory mechanism remains unclear. LNCaP (androgen-sensitive prostate cancer cell line) but not PC3 and DU-145, (androgen-unresponsive cell lines) exhibited the highest ACDase protein. Among three cell lines, ASAH1 mRNA level was not correlated with ACDase protein expression, and the 5'-promoter activity did not show androgen dependency, suggesting the post-transcriptional regulation of ACDase in LNCaP cells. Based on these results, LNCaP was analysed further. Casodex, androgen receptor antagonist, and charcoal-stripped FCS (CS-FCS) decreased ACDase protein and activity, whereas dihydrotestosterone in CS-FCS culture increased ACDase protein and enzyme activity. MG132, a proteasome inhibitor, prevented the decrease of ACDase protein when cultured in CS-FCS, suggesting the involvement of ubiquitin/proteasome system. Reportedly, USP2, a deubiquitinase, plays an important role in LNCaP cells. USP2 siRNA decreased ACDase protein, whereas USP2 overexpression increased ACDase protein of LNCaP cells. However, SKP2, an ubiquitin E3 ligase known to be active in prostate cancer, did not affect androgen-dependent ACDase expression in LNCaP cells. Thus, ACDase regulation by androgen in androgen-sensitive LNCaP cells is mainly due to its prolonged protein half-life by androgen-stimulated USP2 expression. © The Authors 2015. Published by Oxford University Press on behalf of the Japanese Biochemical Society. All rights reserved.

Bauru School of Dentistry Tele-Health League: an educational strategy applied to research, teaching and extension among applications in tele-health

PubMed Central

da SILVA, Andressa Sharllene Carneiro; RIZZANTE, Fabio Antonio Piola; PICOLINI, Mirela Machado; de CAMPOS, Karis; CORRÊA, Camila de Castro; FRANCO, Elen Caroline; PARDO-FANTON, Cássia de Souza; BLASCA, Wanderléia Quinhoneiro; BERRETIN-FELIX, Giédre

2011-01-01

Tele-health is more than an innovative alternative; it is an excellent tool that enables access to health and education in health, making it possible to minimize distances, optimize time and reduce costs. Based on these advantages, some Brazilian Universities have used these actions in strategies of education, research and extension, aiming at the application of Tele-health in Brazil. In that way, the Bauru School of Dentistry - University of São Paulo (FOB-USP) has applied the use of information and communication technologies in health by means of a "Tele-Health League" (TL), in order to diagnose, prevent and treat diseases, in addition to educate the population and health services. Objective The present study aims to introduce the characteristics of the Tele-Health League of FOB-USP, as well as the development of its projects. Material and Methods The Tele-Health League consisted as a Diffusion Course approved by the Provost of Culture and Academic Extension of the University of São Paulo. It is composed as a large group enclosing professoriate coordinator, academician principal, contributing professors and league members, those, diversified between undergraduates students, graduated, health employees, technology and information areas. The participant members are evaluated by the presence frequency (minimum of 85%), and by the performance of tests and paperwork about the theoretical content provided. Results In four years of activities, the TLFOB-USP obtained a high satisfaction index (90%), an increased number of vacancies due to the interest to become a member, more commitment of the professors of the University and the accomplishment of association with other Brazilian leagues. It is emphasized that the approval percentage of the course results in approval from approximately half of its members. Also, it is important to identify and repair the causes related to the quitting of some members. Conclusions The results showed that the TLFOB-USP members, adjoining to the professor's participants, develop projects in Tele-helth, in Tele-aid and Tele-education areas, thus resulting in the involvement of the University and the community. PMID:22230993

Bauru School of Dentistry Tele-Health League: an educational strategy applied to research, teaching and extension among applications in tele-health.

PubMed

Silva, Andressa Sharllene Carneiro da; Rizzante, Fabio Antonio Piola; Picolini, Mirela Machado; Campos, Karis de; Corrêa, Camila de Castro; Franco, Elen Caroline; Pardo-Fanton, Cássia de Souza; Blasca, Wanderléia Quinhoneiro; Berretin-Felix, Giédre

2011-01-01

Tele-health is more than an innovative alternative; it is an excellent tool that enables access to health and education in health, making it possible to minimize distances, optimize time and reduce costs. Based on these advantages, some Brazilian Universities have used these actions in strategies of education, research and extension, aiming at the application of Tele-health in Brazil. In that way, the Bauru School of Dentistry - University of São Paulo (FOB-USP) has applied the use of information and communication technologies in health by means of a "Tele-Health League" (TL), in order to diagnose, prevent and treat diseases, in addition to educate the population and health services. The present study aims to introduce the characteristics of the Tele-Health League of FOB-USP, as well as the development of its projects. The Tele-Health League consisted as a Diffusion Course approved by the Provost of Culture and Academic Extension of the University of São Paulo. It is composed as a large group enclosing professoriate coordinator, academician principal, contributing professors and league members, those, diversified between undergraduates students, graduated, health employees, technology and information areas. The participant members are evaluated by the presence frequency (minimum of 85%), and by the performance of tests and paperwork about the theoretical content provided. In four years of activities, the TLFOB-USP obtained a high satisfaction index (90%), an increased number of vacancies due to the interest to become a member, more commitment of the professors of the University and the accomplishment of association with other Brazilian leagues. It is emphasized that the approval percentage of the course results in approval from approximately half of its members. Also, it is important to identify and repair the causes related to the quitting of some members. The results showed that the TLFOB-USP members, adjoining to the professor's participants, develop projects in Tele-helth, in Tele-aid and Tele-education areas, thus resulting in the involvement of the University and the community.

Field-scale prediction of enhanced DNAPL dissolution based on partitioning tracers.

PubMed

Wang, Fang; Annable, Michael D; Jawitz, James W

2013-09-01

The equilibrium streamtube model (EST) has demonstrated the ability to accurately predict dense nonaqueous phase liquid (DNAPL) dissolution in laboratory experiments and numerical simulations. Here the model is applied to predict DNAPL dissolution at a tetrachloroethylene (PCE)-contaminated dry cleaner site, located in Jacksonville, Florida. The EST model is an analytical solution with field-measurable input parameters. Measured data from a field-scale partitioning tracer test were used to parameterize the EST model and the predicted PCE dissolution was compared to measured data from an in-situ ethanol flood. In addition, a simulated partitioning tracer test from a calibrated, three-dimensional, spatially explicit multiphase flow model (UTCHEM) was also used to parameterize the EST analytical solution. The EST ethanol prediction based on both the field partitioning tracer test and the simulation closely matched the total recovery well field ethanol data with Nash-Sutcliffe efficiency E=0.96 and 0.90, respectively. The EST PCE predictions showed a peak shift to earlier arrival times for models based on either field-measured or simulated partitioning tracer tests, resulting in poorer matches to the field PCE data in both cases. The peak shifts were concluded to be caused by well screen interval differences between the field tracer test and ethanol flood. Both the EST model and UTCHEM were also used to predict PCE aqueous dissolution under natural gradient conditions, which has a much less complex flow pattern than the forced-gradient double five spot used for the ethanol flood. The natural gradient EST predictions based on parameters determined from tracer tests conducted with a complex flow pattern underestimated the UTCHEM-simulated natural gradient total mass removal by 12% after 170 pore volumes of water flushing indicating that some mass was not detected by the tracers likely due to stagnation zones in the flow field. These findings highlight the important influence of well configuration and the associated flow patterns on dissolution. © 2013.

Field-scale prediction of enhanced DNAPL dissolution based on partitioning tracers

NASA Astrophysics Data System (ADS)

Wang, Fang; Annable, Michael D.; Jawitz, James W.

2013-09-01

The equilibrium streamtube model (EST) has demonstrated the ability to accurately predict dense nonaqueous phase liquid (DNAPL) dissolution in laboratory experiments and numerical simulations. Here the model is applied to predict DNAPL dissolution at a tetrachloroethylene (PCE)-contaminated dry cleaner site, located in Jacksonville, Florida. The EST model is an analytical solution with field-measurable input parameters. Measured data from a field-scale partitioning tracer test were used to parameterize the EST model and the predicted PCE dissolution was compared to measured data from an in-situ ethanol flood. In addition, a simulated partitioning tracer test from a calibrated, three-dimensional, spatially explicit multiphase flow model (UTCHEM) was also used to parameterize the EST analytical solution. The EST ethanol prediction based on both the field partitioning tracer test and the simulation closely matched the total recovery well field ethanol data with Nash-Sutcliffe efficiency E = 0.96 and 0.90, respectively. The EST PCE predictions showed a peak shift to earlier arrival times for models based on either field-measured or simulated partitioning tracer tests, resulting in poorer matches to the field PCE data in both cases. The peak shifts were concluded to be caused by well screen interval differences between the field tracer test and ethanol flood. Both the EST model and UTCHEM were also used to predict PCE aqueous dissolution under natural gradient conditions, which has a much less complex flow pattern than the forced-gradient double five spot used for the ethanol flood. The natural gradient EST predictions based on parameters determined from tracer tests conducted with a complex flow pattern underestimated the UTCHEM-simulated natural gradient total mass removal by 12% after 170 pore volumes of water flushing indicating that some mass was not detected by the tracers likely due to stagnation zones in the flow field. These findings highlight the important influence of well configuration and the associated flow patterns on dissolution.

21 CFR 139.155 - Enriched noodle products.

Code of Federal Regulations, 2010 CFR

2010-04-01

... contain as an optional ingredient added vitamin D in such quantity that each pound of the finished food contains not less than 250 U.S.P. units and not more than 1000 U.S.P. units of vitamin D; (3) Each such... conform to the specifications of shape and size prescribed for egg macaroni in § 139.150(c). (d) Enriched...

27 CFR 17.132 - U.S.P., N.F., and H.P.U.S. preparations.

Code of Federal Regulations, 2011 CFR

2011-04-01

... NONBEVERAGE PRODUCTS Formulas and Samples Approval of Formulas § 17.132 U.S.P., N.F., and H.P.U.S..., formulas for compounds in which alcohol is a prescribed quantitative ingredient, which are stated in the... formulas and may be used as formulas for drawback products without the filing of TTB Form 5154.1. (b...

27 CFR 17.132 - U.S.P., N.F., and H.P.U.S. preparations.

Code of Federal Regulations, 2010 CFR

2010-04-01

... NONBEVERAGE PRODUCTS Formulas and Samples Approval of Formulas § 17.132 U.S.P., N.F., and H.P.U.S..., formulas for compounds in which alcohol is a prescribed quantitative ingredient, which are stated in the... formulas and may be used as formulas for drawback products without the filing of TTB Form 5154.1. (b...

27 CFR 17.132 - U.S.P., N.F., and H.P.U.S. preparations.

Code of Federal Regulations, 2013 CFR

2013-04-01

... NONBEVERAGE PRODUCTS Formulas and Samples Approval of Formulas § 17.132 U.S.P., N.F., and H.P.U.S..., formulas for compounds in which alcohol is a prescribed quantitative ingredient, which are stated in the... formulas and may be used as formulas for drawback products without the filing of TTB Form 5154.1. (b...