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1

The role of fillers and sodium metabisulfite on drug release from aged polyox tablets.  

PubMed

Abstract Polyethylene oxides (PEOs) are extensively used to control the release rate of drugs from matrices. Unfortunately, polyox polymers are prone to oxidation under high temperature and relative humidity. The aim of this study was to investigate the effect of sodium metabisulfite as an antioxidant to overcome the drug release changes from polyox matrices (PEO 301 and 303) when stored at 40?°C. The effect of different types of fillers (lactose, mannitol and dicalcium phosphate dihydrate) on stability of diltiazem HCl release profiles was also investigated. Generally, the presence of sodium metabisulfite stabilized the release of drug from PEO matrices stored at 40?°C for 8 weeks. Whilst the absence of metabisulfite caused an increase in drug release from polyox matrices when stored at 40?°C. The results indicate that all three concentrations (0.25, 0.5 and 1% w/w) of sodium metabisulfite were able to overcome structural changes of polyox samples hence stabilizing the drug release. The results also showed that the incorporation of fillers in polyox matrices reduced the sensitivity of drug release when stored at elevated temperature. This indicates that when these excipients were used there was no need to incorporate additional antioxidant. DSC results showed that there was no difference in the melting points of fresh polyox samples and aged polyox samples containing sodium metabisulfite, whereas the melting point of aged polyox samples without sodium metabisulfite were lower than fresh polyox samples. This indicates that the presence of metabisulfite is essential to stabilize polyox samples. PMID:23962147

Shojaee, Saeed; Nokhodchi, Ali; Cumming, Iain

2014-11-01

2

Formulation development and optimization of polyox based quick dissolving film of quetiapine  

PubMed Central

Quick dissolving film prepared by various grades of polyox like Polyox N10, N80, N750 and N205. Polyox having excellent film forming capacity with rapid hydration power which leads to rapid disintegration of film upon contact with saliva. Film is optimized for concentration of polymer and plasticizer using CCD design. The tensile Strength, folding Endurance, % drug released at 10 min (Y10) and disintegration time were selected as dependent variables. The data revealed that 2% of polyox N 750 and 15% of PEG 400 showed excellent film forming property with rapid drug release profile. PMID:23066190

Chaudhary, A. Sunita; Chaudhary, B. Ankit; Mehta, A. Tejal

2012-01-01

3

Polyox and carrageenan based composite film dressing containing anti-microbial and anti-inflammatory drugs for effective wound healing.  

PubMed

Polyethylene oxide (Polyox) and carrageenan based solvent cast films have been formulated as dressings for drug delivery to wounds. Films plasticised with glycerol were loaded with streptomycin (30%, w/w) and diclofenac (10%, w/w) for enhanced healing effects in chronic wounds. Blank and drug loaded films were characterised by texture analysis (for mechanical and mucoadhesive properties), scanning electron microscopy, differential scanning calorimetry, X-ray diffraction and Fourier transform infrared spectroscopy. In addition, swelling, in vitro drug release and antibacterial studies were conducted to further characterise the films. Both blank and drug loaded films showed a smooth, homogeneous surface morphology, excellent transparency, high elasticity and acceptable tensile (mechanical) properties. The drug loaded films showed a high capacity to absorb simulated wound fluid and significant mucoadhesion force which is expected to allow effective adherence to and protection of the wound. The films showed controlled release of both streptomycin and diclofenac for 72 h. These drug loaded films produced higher zones of inhibition against Staphylococcus aureus, Pseudomonas aeruginosa and Escherichia coli compared to the individual drugs zones of inhibition. Incorporation of streptomycin can prevent and treat chronic wound infections whereas diclofenac can target the inflammatory phase of wound healing to relieve pain and swelling. PMID:23228898

Boateng, Joshua S; Pawar, Harshavardhan V; Tetteh, John

2013-01-30

4

Hydrophilic matrices: application of Placket-Burman screening design to model the effect of POLYOX-carbopol blends on drug release.  

PubMed

The aim of the present study was to screen the effect of seven factors--POLYOX molecular weight (X(1)) and amount (X(2)); carbopol (X(3)), lactose (X(4)), sodium chloride (X(5)), citric acid (X(6)); compression pressure (X(7))--on (1) the release of theophylline from hydrophilic matrices, demonstrated by changes in dissolution rate, and (2) their impact on the release exponent [n] indicative of the drug transport mechanism through the diffusion matrix. This objective was accomplished utilizing the Placket-Burman screening design. Theophylline tablets were prepared according to a 7-factor-12-run statistical model and subjected to a 24-h dissolution study in phosphate buffer at pH 7.2. The primary response variable, Y(4), was the cumulative percent of theophylline dissolved in 12h. The regression equation for the response was Y(4)=66.2167 - 17.5833X(1) - 3.3833X(2) - 9.366X(3) - 1.1166X(4) - 0.6166X(5) + 2.6X(6) - 2.783X(7). This polynomial model was validated by the ANOVA and residual analysis. The results showed that only two factors (X(2) and X(3)) had significant effect (p-value<0.10) on theophylline release from the hydrophilic polymer matrix. Factors (X(2) and X(7)) had significant effect (p-value<0.10) on [n], the exponent. PMID:16413978

El-Malah, Yasser; Nazzal, Sami

2006-02-17

5

Study of Verapamil hydrochloride release from compressed hydrophilic Polyox-Wsr tablets.  

PubMed

This study deals with Verapamil hydrochloride release from tablets based on high molecular weight poly(ethylene oxide) (PEO). The drug release proceeds as a controlled diffusion (n=0.44-0.47), which rate is dependent on the molecular weight of PEO. Independent from it, under the conditions of the Half-change test, the drug release practically ceases after 4 h as a result of obtaining low soluble in the water base. The introduction of hydrophilic polymers with pH dependent solubility (Eudragit L, Eudispert hv and Carbopol 934) at concentrations of 10/50% with respect to PEO amount keeping constant the ratio drug: matrix insures relatively complete release both in alkali medium and under the conditions of the Half-change test. Meanwhile drug release kinetics also changes - the release of all models studied runs as a typical abnormal diffusion (a=0.66-0.87), i. e. like a diffusion-relaxation controlled process. The decrease in drug concentration leads not only to retarded release of the drug sample but also to changes in the kinetics of the process. At lower drug concentrations on the matrix from a typical abnormal diffusion it turns into a relaxation controlled diffusion (n(10%)=1). PMID:10518690

Dimitrov, M; Lambov, N

1999-10-28

6

Alexander Bort and the Bortian Blobs  

ERIC Educational Resources Information Center

Presents an imaginative story to be used to introduce elementary school students to the different properties and uses of "Polyox." Various ideas for using "Polyox" in elementary science are given. (MDR)

McCormack, Alan J.

1978-01-01

7

Growth Responses of Staphylococcus aureus and Streptococcus agalactiae to Corynebacterium bovis Metabolites1  

Microsoft Academic Search

Staphylococcus aureus and Strepto- coccus agalactiae growth responses to metabolites of Corynebacterium boris cultured in media containing polyox- yethylenesorbita n monolaurate, mono- oleate, or trioleate and milk were de- termined. Filter sterilized metabolites of 48-h C. boris cultures in synthetic media were added to cultures of Staph. aureus and Strep. agalactiae. Staphylococcus aureus and Strep. agalactiae were in- oculated into

J. S. Hogan; J. W. Pankey; A. H. Duthie

1987-01-01

8

Optimization studies on compression coated floating-pulsatile drug delivery of bisoprolol.  

PubMed

The purpose of the present work was to design and optimize compression coated floating pulsatile drug delivery systems of bisoprolol. Floating pulsatile concept was applied to increase the gastric residence of the dosage form having lag phase followed by a burst release. The prepared system consisted of two parts: a core tablet containing the active ingredient and an erodible outer shell with gas generating agent. The rapid release core tablet (RRCT) was prepared by using superdisintegrants with active ingredient. Press coating of optimized RRCT was done by polymer. A 3˛ full factorial design was used for optimization. The amount of Polyox WSR205 and Polyox WSR N12K was selected as independent variables. Lag period, drug release, and swelling index were selected as dependent variables. Floating pulsatile release formulation (FPRT) F13 at level 0 (55?mg) for Polyox WSR205 and level +1 (65?mg) for Polyox WSR N12K showed lag time of 4?h with >90% drug release. The data were statistically analyzed using ANOVA, and P < 0.05 was statistically significant. Release kinetics of the optimized formulation best fitted the zero order model. In vivo study confirms burst effect at 4?h in indicating the optimization of the dosage form. PMID:24367788

Jagdale, Swati C; Bari, Nilesh A; Kuchekar, Bhanudas S; Chabukswar, Aniruddha R

2013-01-01

9

Formulation and in vitro evaluation of floating tablets of hydroxypropyl methylcellulose and polyethylene oxide using ranitidine hydrochloride as a model drug.  

PubMed

The present study was carried out with an objective of preparation and in vitro evaluation of floating tablets of hydroxypropyl methyl cellulose (HPMC) and polyethylene oxide (PEO) using ranitidine hydrochloride as a model drug. The floating tablets were based on effervescent approach using sodium bicarbonate a gas generating agent. The tablets were prepared by dry granulation method. The effect of polymers concentration and viscosity grades of HPMC on drug release profile was evaluated. The effect of sodium bicarbonate and stearic acid on drug release profile and floating properties were also investigated. The result of in vitro dissolution study showed that the drug release profile could be sustained by increasing the concentration of HPMC K15MCR and Polyox WSR303. The formulation containing HPMC K15MCR and Polyox WSR303 at the concentration of 13.88% showed 91.2% drug release at the end of 24 hours. Changing the viscosity grade of HPMC from K15MCR to K100MCR had no significant effect on drug release profile. Sodium bicarbonate and stearic acid in combination showed no significant effect on drug release profile. The formulations containing sodium bicarbonate 20 mg per tablet showed desired buoyancy (floating lag time of about 2 minutes and total floating time of >24 hours). The present study shows that polymers like HPMC K15MCR and Polyox WSR303 in combination with sodium bicarbonate as a gas generating agent can be used to develop sustained release floating tablets of ranitidine hydrochloride. PMID:23493037

Gharti, Kp; Thapa, P; Budhathoki, U; Bhargava, A

2012-10-01

10

Formulation and in vitro evaluation of floating tablets of hydroxypropyl methylcellulose and polyethylene oxide using ranitidine hydrochloride as a model drug  

PubMed Central

The present study was carried out with an objective of preparation and in vitro evaluation of floating tablets of hydroxypropyl methyl cellulose (HPMC) and polyethylene oxide (PEO) using ranitidine hydrochloride as a model drug. The floating tablets were based on effervescent approach using sodium bicarbonate a gas generating agent. The tablets were prepared by dry granulation method. The effect of polymers concentration and viscosity grades of HPMC on drug release profile was evaluated. The effect of sodium bicarbonate and stearic acid on drug release profile and floating properties were also investigated. The result of in vitro dissolution study showed that the drug release profile could be sustained by increasing the concentration of HPMC K15MCR and Polyox WSR303. The formulation containing HPMC K15MCR and Polyox WSR303 at the concentration of 13.88% showed 91.2% drug release at the end of 24 hours. Changing the viscosity grade of HPMC from K15MCR to K100MCR had no significant effect on drug release profile. Sodium bicarbonate and stearic acid in combination showed no significant effect on drug release profile. The formulations containing sodium bicarbonate 20 mg per tablet showed desired buoyancy (floating lag time of about 2 minutes and total floating time of >24 hours). The present study shows that polymers like HPMC K15MCR and Polyox WSR303 in combination with sodium bicarbonate as a gas generating agent can be used to develop sustained release floating tablets of ranitidine hydrochloride. PMID:23493037

Gharti, KP; Thapa, P; Budhathoki, U; Bhargava, A

2012-01-01

11

Design of a novel bilayered gastric mucoadhesive system for localized and unidirectional release of lamotrigine  

PubMed Central

Lamotrigine is a BCS class II drug with pH dependent solubility. The bilayered gastric mucoadhesive tablets of lamotrigine were designed such that the drug and controlled release polymers were incorporated in the upper layer and the lower layer had the mucoadhesive polymers. The major ingredients selected for the upper layer were the drug and control release polymer (either HPMC K15M or polyox) while the lower MA layer predominantly comprised of Carbopol 974P. A 23 full factorial design was constructed for this study and the tablets were optimized for parameters like tablet size, shape, ex vivo mucoadhesive properties and unidirectional drug release. Oval tablets with an average size of 14 mm diameter were set optimum. Maximum mucoadhesive bond strength of 79.3 ± 0.91 * 103 dyn/cm2 was achieved with carbopol when used in combination with a synergistic resin polymer. All the tested formulations presented a mucoadhesion time of greater than 12 h. The incorporation of methacrylic polymers in the lower layer ensured unidirectional drug release from the bilayered tablets. The unidirectional drug release was confirmed after comparing the dissolution results of paddle method with those of a modified basket method. Model independent similarity and dissimilarity factor methods were used for the comparison of dissolution results. Controlled drug release profiles with zero order kinetics were obtained with polyox and HPMC K15M which reported t90% at 6th and 12th hours, respectively. The “n” value with polyox was 0.992 and that with HPMC K15M was 0.946 indicating an approximate case II transport. These two formulations showed the potential for oral administration of lamotrigine as bilayered gastric mucoadhesive tablets by yielding highest similarity factor values, 96.06 and 92.47, respectively, between the paddle and modified basket method dissolution release profiles apart from reporting the best tablet physical properties and maximum mucoadhesive strength. PMID:24109205

Mohana Raghava Srivalli, K.; Lakshmi, P.K.; Balasubramaniam, J.

2012-01-01

12

Decay of swirl in turbulent two phase flow  

E-print Network

water-soluble linear polymers known as poly- ethylene oxides. Union Carbide Chemicals Company manufactures a wide range of polymers having different average molecular weights, and these polymers are available under the trade name "Polyox" water... soluble resins (16). Since a supply of Union 21 Carbide USR 301 polymer was available it was an obvious choice for the tests conducted. This polymer has a molecular weight of 3. 4 X 10 , and its chemical formula is 6 ? 0 ? [CH ? CH ? 0] ? CH ? CH ? 0...

Neeley, Patrick Foster

2012-06-07

13

The Influence of Sodium Carboxymethylcellulose on Drug Release from Polyethylene Oxide Extended Release Matrices  

Microsoft Academic Search

Anionic polymer sodium carboxymethylcellulose (CELLOGEN® HP-HS and\\/or HP-12HS) was investigated for its ability to influence\\u000a the release of three model drugs propranolol hydrochloride, theophylline and ibuprofen from polyethylene oxide (POLYOX™ WSR\\u000a 1105 and\\/or Coagulant) hydrophilic matrices. For anionic ibuprofen and non-ionic theophylline, no unusual\\/unexpected release\\u000a profiles were obtained from tablets containing a mixture of two polymers. However, for cationic propranolol

Dasha Palmer; Marina Levina; Ali Nokhodchi; Dennis Douroumis; Tom Farrell; Ali Rajabi-Siahboomi

14

Development and optimization of press coated floating pulsatile drug delivery of sumatriptan succinate.  

PubMed

Floating pulsatile is combined approach designed according to circadian rhythm to deliver the drug at right time, in right quantity and at right site as per pathophysiological need of disease with prolong gastric residence and lag phase followed by burst release. As the migraine follows circadian rhythm in which headache is more painful at the awakening time, the dosage form should be given during night time to release drug when pain get worsen. Present work deals with formulation and optimization of floating pulsatile tablet of sumatriptan succinate. Core tablet containing crospovidone as superdisintegrant (10%) showed burst release. Lag time was maintained using swellable polymer as polyoxN12K and xanthum gum. 3(2) experimental design was carried out. Developed formulations were evaluated for physical characteristics, in vitro and in vivo study. Optimized batch F2 with concentration of polyox N12K (73.43%) and xanthum gum (26.56%) of total polymer weight showed floating lag time 15±2 sec, drug content 99.58±0.2 %, hardness 6±0.2 Kg/cm(2) and drug release 99.54±2% with pulsatile manner followed lag period of 7±0.1h. In vivo x-ray study confirms prolong gastric residence of system. Programmable pulsatile release has been achieved by formulation F2 which meet demand of chronotherapeutic objective of migraine. PMID:24893996

Jagdale, Swati C; Pawar, Chandrakala R

2014-01-01

15

Systematic screening of compressed ODT excipients: cellulosic versus non-cellulosic.  

PubMed

The successful development of compressed ODTs utilises low compression forces to create a porous structure whereby excipients are added to enhance wicking/swelling action or provide strength to the fragile tablet framework. In this work, a systematic investigation comparing materials from two different categories was employed to understand their functionality in binary mixture tablets of the most commonly used diluent mannitol. Cellulose based excipients such as HPC (SSL-SFP), L-HPC (NBD-022) and MCC (Avicel PH-102) were compared with non-cellulosic materials such as PEO (POLYOX WSR N-10) and Crospovidone (XL-10). Pure excipient properties were studied using Heckel Plot, compressibility profile, SEM and XRPD, whereas the prepared binary mixture compacts were studied for hardness, disintegration time and friability. Results from our investigation provide insight into differences encountered in product performance of ODT upon inclusion of additional materials. For example, non-cellulosic excipients Polyox and Crospovidone showed higher plasticity (Py values 588 and 450MPa) in pure form but not in binary mixtures of mannitol. Cellulosic excipients, nonetheless, offer faster disintegration (<30 sec) specifically L-HPC and MCC tablets. Disintegration time for tablets with fully substituted-HPC was prolonged (200-500 sec) upon increasing concentration between 1-10% due to gelation/ matrix formation. It can be concluded that despite the reasonably good plasticity of both cellulosic and noncellulosic excipients in pure form, the mechanical strength in binary mixtures is negatively impacted by the fragmentation/ fracture effect of mannitol. PMID:24655059

Al-Khattawi, Ali; Iyire, Affiong; Dennison, Tom; Dahmash, Eman; Bailey, Clifford J; Smith, Julian; Rue, Peter; Mohammed, Afzal R

2014-01-01

16

A novel bi-layer ascending release osmotic pump tablet: in vitro investigation and in vivo investigation in pharmacokinetic study and IVIVC evaluation.  

PubMed

This study was aimed to develop an ascending release push-pull osmotic pump (APOP) system with a novel mechanism and an easy manufacture process. Theoretical analysis showed that the key to obtain the non-zero order drug release was to break the balance between the drug suspension release rate in the drug layer and the swelling rate of the core, and an ascending drug release rate was achieved when the former was slower than the latter. A polymer (Polyox WSR N-12K) was introduced as a suspension agent in drug layer to slow down the hydration rate of drug layer. Influence of the composition of drug layer (PEO category, total amount, drug loading and fraction of NaCl), push layer (NaCl amount), and also the level of coating weight gain on the drug release profiles was investigated. Observation of hydration state was estimated by taking photos, and also was confirmed by the theories. Paliperidone was delivered successfully by APOP at an ascending release rate up to 20 h in vitro. The in vivo plasma concentration of paliperidone in beagle dogs increased gradually up to 19 h. The APOP with an easy manufacture process was a promising strategy to deliver drug at an ascending rate. PMID:24095815

Xu, Heming; Li, Zhao; Pan, Hao; Zhang, Zhihong; Liu, Dandan; Tian, Baocheng; Ma, Shilin; Song, Shilong; Pan, Weisan

2013-12-15

17

Tip vortex cavitation suppression via mass injection  

NASA Astrophysics Data System (ADS)

Tip vortex cavitation (TVC) suppression by mass injection in the core of the vortex was studied with an elliptical plan-form hydrofoil NACA-66 modified in a re-circulating water tunnel of known nuclei distribution. The chord based Re was O(106) for all experiments. Water and Polyox WSR 301 solution for a range of concentrations (10 to 500pmm) and relative flow rates (Qjet / Qcore of 0.033 to 0.27) were injected. Also, different injection port size and angle of attack were studied. It was found that the TVC suppression effect was different for inception and desinence. The baseline (no injection) inception cavitation number was more than the average negative pressure coefficient, -Cp of the vortex, while mass addition reduced the inception cavitation number to approximately the --Cp value. TVC desinence for the baseline case was found to match the estimated --Cp value and polymer injection provided some cavitation suppression. Flow measurements were made to understand the underlying physics of TVC. The mechanisms and scalability that lead to TVC suppression by mass injection are discussed.

Ganesh, Harish; Chang, Natasha; Yakushiji, Ryo; Ceccio, Steven

2009-11-01

18

Suppression of Tip Vortex Cavitation by Water and Polymer Injection  

NASA Astrophysics Data System (ADS)

Tip vortex cavitation (TVC) is typically the first form of cavitation observed in propellers; therefore a delay of its inception is desirable. In this study, TVC inception was delayed via mass injection from the tip of a modified NACA-66 elliptic plan-form hydrofoil. The injected mass used were water and Polyox WSR 301 solutions with concentrations from 10 to 500 ppm. The free-stream nuclei content was measured using a Cavitation Susceptibility Meter, and the TVC inception event rate was quantified with a light scattering system. The vortical flow field in the region of inception was characterized using Stereo Particle Imaging and Velocimetry (SPIV), with measurements taken from 0.25 to 1 chord length at various concentrations and injection rates. It was observed that TVC inception was delayed with injection by a ?? of 0.03 to 1.8 from a baseline of ? = 3.5. Injection with higher polymer concentrations and higher volume flux led to larger delays. A saturation effect for the TVC suppression was observed for both the polymer concentration (125ppm) and volume flux rate (Qj/Qc = 0.48). These effects are related to the SPIV flow field.

Chang, Natasha; Yakushiji, Ryo; Ceccio, Steven

2008-11-01

19

Swimming speed of an oscillating sheet in Newtonian and viscoelastic fluids  

NASA Astrophysics Data System (ADS)

We discuss a mechanical experimental model of a flexible sheet swimming with a prescribed wave pattern - a Taylor swimmer - through a fluid. Our study is motivated by a need for a fundamental understanding of microorganism locomotion through non-Newtonian fluids. In order to simplify the problem, we suspend a tall flexible cylindrical sheet concentric within a cylindrical tank filled with the fluid. Torque free boundary conditions are imposed by supporting the flexible sheet and the tank with friction-free ball-bearings. A traveling wave is imposed on the sheet with a pair of rollers in the azimuthal direction. We first demonstrate a linear response in the swimming velocity of the sheet with respect to its phase velocity in a viscous Newtonian fluid. Further, we show that the analytical system is essentially two dimensional by varying the height of fluid in the tank. We then discuss measurements of swimming speed in Polyox-water mixtures as a function of wave speed. We demonstrate that the swimming speed in this viscoelastic fluid decrease relative to the Newtonian case as wave speed is increased. We will further discuss the dependence of swimming speed on Deborah number and other characteristics of the fluid.

Dasgupta, Moumita; Berhanu, Michael; Kudrolli, Arshad; Fu, Henry; Breuer, Kenneth; Powers, Thomas

2011-03-01

20

D-optimal mixture design: optimization of ternary matrix blends for controlled zero-order drug release from oral dosage forms.  

PubMed

The objective of the present study was to develop a tablet formulation with a zero-order drug release profile based on a balanced blend of three matrix ingredients. To accomplish this goal, a 17-run, three-factor, two-level D-Optimal mixture design was employed to evaluate the effect of Polyox (X1), Carbopol (X2), and lactose (X3) concentrations on the release rate of theophylline from the matrices. Tablets were prepared by direct compression and were subjected to an in vitro dissolution study in phosphate buffer at pH 7.2. Polynomial models were generated for the responses Y4 (percent released in 8 h) and Y6 (similarity factor or f2). Fitted models were used to predict the composition of a formulation that would have a similar dissolution profile to an ideal zero-order release at a rate of 8.33% per hour. When tested, dissolution profile of the optimized formulation was comparable to the reference profile (f2 was 74.2, and n [release exponent] was 0.9). This study demonstrated that a balanced blend of matrix ingredients could be used to attain a zero-order release profile. Optimization was feasible by the application of response surface methodology, which proved efficient in designing controlled-release dosage forms. PMID:17090443

El-Malah, Yasser; Nazzal, Sami; Khanfar, Nile M

2006-01-01

21

The influence of sodium carboxymethylcellulose on drug release from polyethylene oxide extended release matrices.  

PubMed

Anionic polymer sodium carboxymethylcellulose (CELLOGEN® HP-HS and/or HP-12HS) was investigated for its ability to influence the release of three model drugs propranolol hydrochloride, theophylline and ibuprofen from polyethylene oxide (POLYOX™ WSR 1105 and/or Coagulant) hydrophilic matrices. For anionic ibuprofen and non-ionic theophylline, no unusual/unexpected release profiles were obtained from tablets containing a mixture of two polymers. However, for cationic propranolol HCl, a combination of polyethylene oxide (PEO) with sodium carboxymethylcellulose (NaCMC) produced a significantly slower drug release compared to the matrices with single polymers. The potential use of this synergistic interaction can be a design of new extended release pharmaceutical dosage forms with a more prolonged release (beyond 12 h) using lower polymer amount, which could be particularly beneficial for freely water-soluble drugs, preferably for once daily oral administration. In order to explain changes in the obtained drug release profiles, Fourier transform infrared absorption spectroscopy was performed. A possible explanation for the more prolonged propranolol HCl release from matrices based on both PEO and NaCMC may be due to a chemical bond (i.e. ionic/electrostatic intermolecular interaction) between amine group of the cationic drug and carboxyl group of the anionic polymer, leading to a formation of a new type/form of the active (i.e. salt) with sustained release pattern. PMID:21710334

Palmer, Dasha; Levina, Marina; Nokhodchi, Ali; Douroumis, Dennis; Farrell, Tom; Rajabi-Siahboomi, Ali

2011-09-01

22

Utilization of hydrophilic swellable polymers as carriers for sustained drug delivery from matrices and three layer tablet systems.  

PubMed

The purpose of this research was to develop and evaluate different sustained release preparations, using swellable polymers as carriers in the form of matrices and three-layer tablets. These preparations may offer a number of therapeutic advantages over immediate release dosage forms in drug delivery. The materials used for the fabrication of these systems were hydrophilic swellable polymers namely Metolose, Polyox, Xanthan gum and an erodible material Gantrez, acting as drug(diclofenac sodium) carriers. The powder characteristics determined for these polymers suggest good flowability with the exception of Gantrez. The addition of 1% of magnesium stearate resulted in improved flow properties for all polymers including Gantrez. Tablets were prepared by direct compression whereas three-layer tablets were prepared by compressing polymer barrier layers on both sides of the core containing the drug. Our findings show that both preparations exhibit sustained release characteristics; also the structure of the device considerably affects the drug release and the release rate. Furthermore erosion and swelling greatly influence the overall behavior, function and performance of the systems. Finally kinetic analysis studies indicated that the drug release mechanisms were also affected by these effects. PMID:20695845

Vlachou, Marilena; Naseef, Hani; Efentakis, Manuel

2010-10-01

23

Multifunctional medicated lyophilised wafer dressing for effective chronic wound healing.  

PubMed

Wafers combining weight ratios of Polyox with carrageenan (75/25) or sodium alginate (50/50) containing streptomycin and diclofenac were prepared to improve chronic wound healing. Gels were freeze-dried using a lyophilisation cycle incorporating an annealing step. Wafers were characterised for morphology, mechanical and in vitro functional (swelling, adhesion, drug release in the presence of simulated wound fluid) characteristics. Both blank (BLK) and drug-loaded (DL) wafers were soft, flexible, elegant in appearance and non-brittle in nature. Annealing helped to improve porous nature of wafers but was affected by the addition of drugs. Mechanical characterisation demonstrated that the wafers were strong enough to withstand normal stresses but also flexible to prevent damage to newly formed skin tissue. Differences in swelling, adhesion and drug release characteristics could be attributed to differences in pore size and sodium sulphate formed because of the salt forms of the two drugs. BLK wafers showed relatively higher swelling and adhesion than DL wafers with the latter showing controlled release of streptomycin and diclofenac. The optimised dressing has the potential to reduce bacterial infection and can also help to reduce swelling and pain associated with injury due to the anti-inflammatory action of diclofenac and help to achieve more rapid wound healing. PMID:24700434

Pawar, Harshavardhan V; Boateng, Joshua S; Ayensu, Isaac; Tetteh, John

2014-06-01

24

Design and development of polyethylene oxide based matrix tablets for verapamil hydrochloride.  

PubMed

In the present investigation an attempt has been made to increase therapeutic efficacy, reduced frequency of administration and improved patient compliance by developing controlled release matrix tablets of verapamil hydrochloride. Verapamil hydrochloride was formulated as oral controlled release matrix tablets by using the polyethylene oxides (Polyox WSR 303). The aim of this study was to investigate the influence of polymer level and type of fillers namely lactose (soluble filler), swellable filler (starch 1500), microcrystalline cellulose and dibasic calcium phosphate (insoluble fillers) on the release rate and mechanism of release for verapamil hydrochloride from matrix tablets prepared by direct compression process. Higher polymeric content in the matrix decreased the release rate of drug. On the other hand, replacement of lactose with anhydrous dibasic calcium phosphate and microcrystalline cellulose has significantly retarded the release rate of verapamil hydrochloride. Biopharmaceutical evaluation of satisfactory formulations were also carried out on New Zealand rabbits and parameters such as maximum plasma concentration, time to reach peak plasma concentration, area under the plasma concentration time curve(0-t) and area under first moment curve(0-t) were determined. In vivo pharmacokinetic study proves that the verapamil hydrochloride from matrix tablets showed prolonged release and were be able to sustain the therapeutic effect up to 24 h. PMID:24019567

Vidyadhara, S; Sasidhar, R L C; Nagaraju, R

2013-03-01

25

Swimming speed of an oscillating sheet in Newtonian and viscoelastic fluids  

NASA Astrophysics Data System (ADS)

We discuss a mechanical experimental model of a flexible sheet swimming with a prescribed wave pattern through a fluid. We are motivated by a need for a fundamental understanding of microorganism locomotion through non-Newtonian fluids. To simplify the problem, we suspend a tall flexible cylindrical sheet concentric within a cylindrical tank filled with the fluid. Torque free boundary conditions are imposed by supporting the flexible sheet and the tank with friction-free ball-bearings. A traveling wave is imposed on the sheet with a pair of rollers in the azimuthal direction. We first show that the swimming speed is linear with respect to the phase velocity of the traveling wave for a viscous Newtonian fluid. Then we show that the system is essentially two dimensional as the results do not depend on the height of fluid in the tank. We measure swimming speed in Polyox-water mixtures and Sodium CMC solutions as a function of wave speed. We again demonstrate linear response in the swimming speeds, which also decrease in these viscoelastic fluids relative to the Newtonian case as wave speed increases. Decrease in swimming speed is observed with increase in viscoelasticity of the fluids. We then discuss the dependence of swimming speed on the Deborah number of the fluids.

Dasgupta, Moumita; Berhanu, Michael; Kudrolli, Arshad; Liu, Bin; Breuer, Kenneth; Powers, Thomas

2011-11-01

26

Design and Development of Polyethylene Oxide Based Matrix Tablets for Verapamil Hydrochloride  

PubMed Central

In the present investigation an attempt has been made to increase therapeutic efficacy, reduced frequency of administration and improved patient compliance by developing controlled release matrix tablets of verapamil hydrochloride. Verapamil hydrochloride was formulated as oral controlled release matrix tablets by using the polyethylene oxides (Polyox WSR 303). The aim of this study was to investigate the influence of polymer level and type of fillers namely lactose (soluble filler), swellable filler (starch 1500), microcrystalline cellulose and dibasic calcium phosphate (insoluble fillers) on the release rate and mechanism of release for verapamil hydrochloride from matrix tablets prepared by direct compression process. Higher polymeric content in the matrix decreased the release rate of drug. On the other hand, replacement of lactose with anhydrous dibasic calcium phosphate and microcrystalline cellulose has significantly retarded the release rate of verapamil hydrochloride. Biopharmaceutical evaluation of satisfactory formulations were also carried out on New Zealand rabbits and parameters such as maximum plasma concentration, time to reach peak plasma concentration, area under the plasma concentration time curve(0-t) and area under first moment curve(0-t) were determined. In vivo pharmacokinetic study proves that the verapamil hydrochloride from matrix tablets showed prolonged release and were be able to sustain the therapeutic effect up to 24 h. PMID:24019567

Vidyadhara, S.; Sasidhar, R. L. C.; Nagaraju, R.

2013-01-01

27

Development of gastroretentive drug delivery system for cefuroxime axetil: in vitro and in vivo evaluation in human volunteers.  

PubMed

The objective of this investigation was to develop the cefuroxime axetil sustained-release floating tablets to prolong the gastric residence time and compare their pharmacokinetic behavior with marketed conventional tablets (Zocef). The floating tablets were developed using polymers like HPMC K4M and HPMC K100M alone, and polymer combination of HPMC K4M and Polyox WSR 303 by effervescent technique. Tablets were prepared by slugging method and evaluated for their physical characteristics, in vitro drug release, and buoyancy lag time. The best formulation (F10) was selected based on in vitro characteristics and used in vivo radiographic and bioavailability studies in healthy human volunteers. All the formulations could sustain drug release for 12 h. The dissolution profiles were subjected to various kinetic release models and it was found that the mechanism of drug release followed Peppas model. The in vivo radiographic studies revealed that the tablets remained in stomach for 225 ± 30 min. Based on in vivo performance, the developed floating tablets showed superior bioavailability than Zocef tablet. Based on in vivo performance significant difference was observed between Cmax, tmax, t1/2, AUC0-?, and mean residence time of test and reference (p<0.05). The increase in relative bioavailability of test was 1.61 fold when compared to reference. PMID:22348334

Bomma, Ramesh; Veerabrahma, Kishan

2013-01-01

28

Influence of Plasticizers on the Stability and Release of a Prodrug of ?9-Tetrahydrocannabinol Incorporated in Poly (Ethylene Oxide) Matrices  

PubMed Central

The objective of the present research was to stabilize a heat-labile novel prodrug of ?9-tetrahydrocannabinol (THC), THC-hemiglutarate (THC-HG), in polyethylene oxide (PEO) [PolyOx® WSR N-80 (PEO N-80), MW 200,000 Daltons] polymeric matrix systems produced by hot-melt fabrication for systemic delivery of THC through the oral transmucosal route. For this purpose, the effects of processing conditions (processing temperature and heating duration), plasticizer type and concentration and storage conditions on the stability of the prodrug were investigated. The selected plasticizers studied included vitamin E succinate (VES), acetyltributyl citrate (ATBC), triethyl citrate (TEC), triacetin and polyethylene glycol 8000 (PEG 8000). Furthermore, the influence of plasticizer concentration on drug release was also studied. The stability of THC-HG in PEO matrices was influenced by all of the aforementioned variables. Films processed at 110 °C for 7 min were found to be favorable for hot-melt processing with a post- processing drug content of 95%, while significant degradation of THC-HG (~42%) was observed in those processed at 200 °C for 15 min. The degradation of the prodrug during hot-melt fabrication and also upon storage was considerably reduced in the presence of the plasticizers investigated, VES being the most effective. Modulation of the microenvironmental pH to an acidic range via incorporation of citric acid in PEO-plasticizer matrices significantly improved the stability of the prodrug, with almost 90% of the theoretical drug remaining as opposed to only 15% remaining in PEO-only matrices when stored at 40 °C for up to 3 months. The release of drug from PEO matrices was influenced both by the plasticizer type and concentration. A faster release resulted from water-soluble plasticizers, PEG 8000 and triacetin, and with increasing concentration. However, a slower release was observed with an increase in concentration of water-insoluble plasticizers, VES and ATBC. PMID:18602993

Thumma, Sridhar; ElSohly, Mahmoud A.; Zhang, Shuang-Qing; Gul, Waseem; Repka, Michael A.

2008-01-01

29

Formulation and evaluation of micro hydrogel of Moxifloxacin hydrochloride.  

PubMed

The field of ocular drug delivery is one of the interesting and challenging endeavors facing the pharmaceutical scientist. Novel approaches for ophthalmic drug delivery need to be established to increase the ocular bioavailability by overcoming the inherent drawbacks of conventional dosage forms. In situ hydrogels are instilled as drops into the eye and undergoes a sol-to-gel transition in the cul-de-sac, improved ocular bioavailability by increasing the duration of contact with corneal tissue, thereby reducing the frequency of administration. The purpose of the present work was to develop an ophthalmic drug delivery system using three different gelling agents with different mechanisms for in situ gelation of Moxifloxacin hydrochloride, a fluoroquinolone antibiotic. polyox (a pH-sensitive gelling agent), sodium alginate (an ion-sensitive gelling agent), and poloxamer (a temperature-sensitive gelling agent) were employed for the formation of in situ hydrogel along with HPMC K4M as viscofying agent, which increases the residence time of the drug in the ocular cavity. The promising formulations MF(4), MF(5), and MF(9) were evaluated for pH, drug content, in vitro gelation, in vitro drug release, in vivo drug release, ocular irritation, and stability. Percent drug content of 98.2, 98.76, and 99.43%; viscosity of 15.724 × 100, 16.108 × 100, and 15.213 × 100 cP at 20 rpm, cumulative percent release of 75.364, 74.081, and 71.752%, and C (max) of 1,164.16, 1,187.09, and 1,220.58 ng/ml was observed for formulation MF(4), MF(5), and MF(9), respectively. The developed formulations were therapeutically efficacious, stable, and non-irritant and provided sustained release of the drug over 8 h. PMID:22015966

Nanjwade, Basavaraj K; Deshmukh, Rucha V; Gaikwad, Kishori R; Parikh, Kemy A; Manvi, F V

2012-06-01

30

Preparation, optimisation and characterisation of novel wound healing film dressings loaded with streptomycin and diclofenac.  

PubMed

Streptomycin (STP) and diclofenac (DLF) loaded film dressings were prepared by blending Polyox(®) (POL) with four hydrophilic polymers [hydroxypropylmethylcellulose (HPMC), carrageenan (CAR), sodium alginate (SA) or chitosan (CS)] using glycerol (GLY) as plasticiser. The films were characterised by scanning electron microscopy (SEM), differential scanning calorimetry (DSC), X-ray diffraction (XRD) and Fourier transform infrared (FTIR) spectroscopy, texture analysis (tensile and swelling characteristics) and in vitro dissolution profiles using Franz diffusion cell. SEM showed homogeneous morphology for both blank (BLK) and drug loaded (DL) films. Films prepared by blending of POL with the other polymers showed a reduction in the crystallisation of POL in descending order of SA>CS>HPMC>CAR respectively. DSC and XRD showed no crystalline peaks of STP and DLF suggesting molecular dispersion of both drugs as well as possible drug interaction with negatively charged sulphate ions present in CAR. The DL films did not show any IR bands of both drugs, confirming the DSC and XRD results. POL-CAR-BLK films showed higher tensile strength (12.32±1.40 MPa) than the POL-CAR-DL films (9.52±1.12 MPa). DL films plasticised with 25%w/w GLY revealed soft and tough (tensile strength 1.02±0.28 MPa, % elongation 1031.33±16.23) formulations. The swelling capacities of POL-CAR-BLK and POL-CAR-DL films were (733.17±25.78%) and (646.39±40.39%), increasing to (1072.71±80.30%) and (1051±86.68%) for POL-CAR-BLK-25% GLY and POL-CAR-DL-25% GLY respectively. POL-CAR-DL films showed significantly (n=3, p<0.0318) lower cumulative release of STP and DLF (52.11±1.34, 55.26±2.25) compared to POL-CAR-DL-25% GLY films (60.07±1.56, 63.39±1.92) respectively. PMID:23006557

Pawar, H V; Tetteh, J; Boateng, J S

2013-02-01