Current Issue : January - March Volume : 2016 Issue Number : 1 Articles : 5 Articles
A principle aim of this study was to establish the correlation between real time and accelerated in-vitro degradation of biodegradable polymer film composed of poly-L-lactic acid (PLLA) polymer. The effort of establishment of this correlation was to determine feasibility of carrying out accelerated in-vitro degradation study as a substitute of real time degradation study which was proven to be more time consuming. A degradation behavior of biodegradable PLLA polymer was evaluated on each stage of total degradation period up to six month and 15 days for real time and accelerated respectively during in-vitro degradation under simulated environment condition. Various series of samples were employed for study and degradation progress was investigated based on the change in mass loss, molecular weight, crystallinity and visual observation at each interval during degradation period by comparing with initial results. Reasonable evidence of results for degradation progress suggests the implementation of accelerated in-vitro degradation study as a fast quality control tool of PLLA properties evaluation....
Cephalexin is used as an anti-biotic. It is poorly soluble in water with erratic oral absorption and bioavailability less than 70%. More over cephalexin has a narrow therapeutic range and shows bioavailbility differences. In efforts to reduce the frequency of dosing required for chronic urinary tract infections and to decrease variability in plasma concentration, cephalexin can be formulated into controlled release systems. Even though several controlled release polymers are available, there is continuous need to develop safe, economical and biodegradable controlled release polymers. Hence, in the present investigation an attempt was made to develop a new controlled release polymer i.e., Azadirachta indica gum....
The aim of present study was to convert valacyclovir HCl (VH) into effervescent gastro retentive floating tablet (GRFT) and simultaneously to optimize the ratio of two grades of the synthetic polymer: hydroxy popyl methyl cellulose (HPMCK100M and HPMC K4M), in extending the release of VH until 12 h. The drug- excipients compatibility studies of VH and the polymers were carried by FTIR studies. The effervescent GRFT of VH was prepared by direct compression method. All Formulation blends and tablets were evaluated for pre-compression, post-compression, in vitro buoyancy studies and the optimized formulation was undergone accelerated stability studies for 3 months. The drug-excipients compatibility studies reveal that VH and the polymers used are compatible. Evaluation parameters were within the acceptable limits for all formulations. The drug release kinetics of optimized formulation F6 fitted best to the Zero-order (R2= 0.999). The (R2= 0.883) value in case of Higuchi release was found to be nearer to 0.9, suggesting that the drug release process is predominantly by diffusion. Korsmeyer-Peppa’s diffusion exponent value (n=0.972) for cylindrical shape, suggested the release mechanism of the drug is by Super Case II transport (as n > 0.89). Hence the ratio of HPMCK100M : HPMC K4M in 1:1 proportion is the optimized ratio and at the conc. of 10% w/w of each polymer, in better extending the release of VH until 12 h from its effervescent GRFT , to localize the drug at upper part of GIT, for improved absorption and oral bioavailability....
Aims: To pre-gelatinize, acetylate and characterize Dioscorea dumetorum (bitter yam) and Dioscorea oppositifolia (Chinese yam) starches using solid-state parameters such as differential scanning calorimetry (DSC), X-ray powder diffraction (PXRD), Fourier transform infrared spectroscopy (FT-IR), nuclear magnetic resonance spectroscope (1H-NMR) and scanning electron microscopy (SEM). The pH, swelling, density, flow and rheological properties of the starches were also determined. Commercial native corn and pre-gelatinized potato starches were used as standards. \nMethodology: Pregelatinization and acetylation were conducted by thermal and chemical modification respectively. Acetylated starches of bitter and Chinese yams with degrees of substitution of 2.56 and 2.70 respectively were obtained. The presence of acetyl groups was confirmed by FT-IR, 1H NMR spectroscopy, SEM, DSC and PXRD. \nResults: The DSC endotherms revealed that pre-gelatinized bitter and Chinese starches had higher gelatinization temperatures than the native forms (111.56 to 123.52Ã?°C and 101.14 to 108.88Ã?°C respectively), whereas the acetylated starches had lower gelatinization temperatures (84.69Ã?°C and 69.85Ã?°C respectively). The modified starches showed lower enthalpies (Ã?â?H values 154.0 to 91.91 J/g and 263.57 to 120.70 J/g for the respective pre-gelatinized starches; 8.09 J/g and 7.02 J/g for the respective acetylated starches). Acetylation was confirmed by FT-IR and NMR spectroscopy. The PXRD spectra showed characteristic semi-crystalline structures of the native starches (2Ã?¸ between 13Ã?°C and 23Ã?°C) were disrupted by acetylation and pregelatinization, forming amorphous structures. Viscosity of 5% slurry of the starches decreased with increasing shear rate; flow curves were typical of non-Newtonian shear thinning fluids. Bitter and Chinese yam starches had lower bulk density (0.33Ã?±0.02 and 0.38Ã?±0.01 gcm-3 respectively) and better compressibility (40Ã?±2.00 and 27.17Ã?±2.18% respectively) relative to commercial native corn, suggesting their potential effectiveness as binders in tablets. Pre-gelatinized yam starches had higher (p<0.01) swelling than their native forms and standards, suggesting their potential as disintegrants. Acetylation altered the nature of the starches from hydrophilic to hydrophobic and reduced swellability, suggesting their suitability for controlled release application.\nConclusion: Bitter and Chinese yam starches in their native, pre-gelatinized and acetylated forms could find applications as cheaper alternative excipients in various pharmaceutical formulations....
Purpose Currently, the FDA allows biowaivers for Class I\n(high solubility and high permeability) and Class III (high solubility\nand low permeability) compounds of the\nBiopharmaceutics Classification System (BCS). Scientific evidence\nshould be provided to support biowaivers for BCS Class\nI and Class III (high solubility and low permeability)\ncompounds.\nMethods Data on the effects of excipients on drug permeability\nare needed to demonstrate that commonly used excipients\ndo not affect the permeability of BCS Class III compounds,\nwhich would support the application of biowaivers to Class III\ncompounds. This study was designed to generate such data by\nassessing the permeability of four BCS Class III compounds\nand one Class I compound in the presence and absence of five\ncommonly used excipients.\nResults The permeability of each of the compounds was\nassessed, at three to five concentrations, with each excipient\nin two different models: Caco-2 cell monolayers, and in situ rat\nintestinal perfusion. No substantial increases in the permeability\nof any of the compounds were observed in the presence of\nany of the tested excipients in either of the models, with the\nexception of disruption of Caco-2 cell monolayer integrity by\nsodium lauryl sulfate at 0.1 mg/ml and higher.\nConclusion The results suggest that the absorption of these\nfour BCS Class III compounds would not be greatly affected\nby the tested excipients. This may have implications in\nsupporting biowaivers for BCS Class III compounds in\ngeneral....
Loading....