Rai Muhammad Sarfraz

Formulation and Evaluation of Mouth Disintegrating Tablets of Atenolol and Atorvastatin

In this study, mouth-disintegrating tablets of atenolol and atorvastatin combination were formulated using superdisintegrants to impart fast disintegration. Fifteen formulations were prepared based on different concentrations of two superdisintegrants, croscarmellose sodium and Kyron-T134. Three different techniques such as direct compression, effervescent and sublimation were used to study the effect of manufacturing processes, nature and concentration of superdisintegrants on various features of these tablets. Five formulations were made using each method. Precompression studies like bulk density, tapped density, angle of repose, Carrs compressibility index, Hausners ratio and compatibility studies such as Fourier transform infrared spectroscopy and differential scanning calorimetry were performed. Various features such as hardness, thickness, diameter, weight variation, friability, disintegration time, dissolution studies, wetting time, wetting volume, water absorption ratio, modified disintegration, uniformity of contents and stability were evaluated. Finally results were statistically analyzed by the application of one way ANOVA test. Formulation F13 containing Kyron-T134 (6%) and croscarmellose sodium (2%) was found to be the best among all fifteen formulations prepared in all aspects evaluated. Sublimation method is found to be the best among three methods of preparation used.

Formulation design and development of matrix diffusion controlled transdermal drug delivery of glimepiride

Background The present work was conducted to prepare and evaluate transdermal patches with optimization of suitable polymeric blend of poly(meth) acrylates (Eudragit®) (Ammonio Methacrylate Copolymer Ph Eur) for sustained transdermal delivery of glimepiride. Method Polymeric matrix transdermal films were prepared by using Ammonio Methacrylate Copolymer Ph Eur RL 100 and Ammonio Methacrylate Copolymer Ph Eur RS 100 as the film former, and dibutyl phthalate (30% w/w) as the plasticizer. Patches were characterized by physical appearance, thickness, weight variation, folding endurance, percentage erosion, swelling index, moisture content, and moisture uptake capacity. Fourier transform infrared spectroscopic studies and differential scanning calorimetry analysis of physical mixtures of contents were performed to identify any chemical and physical interaction between drug and excipients. Five different enhancers (isopropyl myristate [IPM], Span® 80, Tween® 20, eucalyptus oil, and limonene) were employed at three different concentrations of polymer (2%, 5%, and 10% w/w) in order to enhance permeation through rabbit skin. In vitro drug release studies were performed at pH 7.4, and scanning electron microscopy was conducted to elucidate surface morphology before and after the drug release. In vitro permeation studies through rabbit skin were performed on Franz diffusion cells and permeation kinetics followed the Higuchi model. Results Results of in vitro permeation studies revealed that these enhancers not only increased drug release but also augmented the skin permeation of glimepiride. Conclusion IPM was the most effective enhancer with the highest permeation flux of 51.763 μg/cm2/hr, and the enhancement effect of different enhancers on glimepiride permeation through rabbit skin was in the rank order of IPM > eucalyptus oil > Span® 80 > Tween® 20> limonene.

Development of β-cyclodextrin-based hydrogel microparticles for solubility enhancement of rosuvastatin: an in vitro and in vivo evaluation

The aim of this study was to enhance the solubility of rosuvastatin (RST) calcium by developing β-cyclodextrin-g-poly(2-acrylamido-2-methylpropane sulfonic acid [AMPS]) hydrogel microparticles through aqueous free-radical polymerization technique. Prepared hydrogel microparticles were characterized for percent entrapment efficiency, solubility studies, Fourier transform infrared spectroscopy, differential scanning calorimetry, thermal gravimetric analysis, powder X-ray diffraction, scanning electron microscopy, zeta size and potential, swelling and release studies. Formulations (HS1–HS9) have shown entrapment efficiency between 83.50%±0.30% and 88.50%±0.25%, and optimum release was offered by formulation HS7 at both pH levels, ie, 1.2 (89%) and 7.4 (92%). The majority of microparticles had a particle size of less than 500 µm and zeta potential of −37 mV. Similarly, optimum solubility, ie, 10.66-fold, was determined at pH 6.8 as compared to pure RST calcium, ie, 7.30-fold. In vivo studies on fabricated hydrogel microparticulate system in comparison to pure drug were carried out, and better results regarding pharmacokinetic parameters were seen in the case of hydrogel microparticles. A potential approach for solubility enhancement of RST calcium and other hydrophobic moieties was successfully developed.

Optimization and validation of high performance liquid chromatography-ultra violet method for quantitation of metoprolol in rabbit plasma: application to pharmacokinetic studies

Purpose: To develop a sensitive, simple and validated high performance liquid chromatography (HPLC) analytical method for the determination of metoprolol tartrate in rabbit plasma. Methods: Mobile phase of methanol and 50 mM ammonium dihydrogen phosphate solution (50:50) at pH 3.05 was used for separation of metoprolol on BDS hypersil C18 column at a wavelength of 223 nm. Flow rate and retention time were 0.6 mL/min and 7.4 min, respectively. For pharmacokinetic study, rabbits were given an oral dose of 8 mg/kg of metoprolol in solution form. Blood samples were taken from jugular vein of the rabbits after drug administration and analysed by HPLC. Results: Separation of metoprolol was not interfered with other components in plasma. The calibration curve was linear in the range of 25 - 1000 ng/mL (r 2 = 0.997). Lower limits of detection (LLOD) and quantitation (LLOQ) were 8.87 and 25 ng/mL, respectively. Relative standard deviation (RSD) of intraday and inter-day precision was < 14.27 and 7.61 %, respectively. Relative error of accuracy was between 4.85 and 14.37 %. Maximum plasma concentration (C max ), time to maximum plasma concentration (T max ) and half-life (t½) after metoprolol oral administration in rabbits were 186.29 ng/mL, 0.50 h and 2.27 h, respectively. Conclusion: A simple, accurate and precise HPLC-UV method for metoprolol determination in rabbit plasma has been successfully developed and applied to a pharmacokinetic study. Keywords: HPLC-UV, Metoprolol, Pharmacokinetics, Rabbit plasma, Liquid-liquid extraction, Validation