SOLUBILITY AND DISSOLUTION RATE ENHANCEMENT OF TELMISARTAN BY SOLID DISPERSION AND PELLETIZATION TECHNIQUES USING KOLLIDON VA 64 AS CARRIER

Objective: In the present investigation, an attempt was made to improve the surface characters and solubility of the drug by solid dispersion and coating it on the nonpareil sugar beads as pellets. Methods: Telmisartan solid dispersions were prepared by solvent evaporation technique using Kollidon VA64 as binder and solubility enhancer, Crospovidone as disintegrant and ethanol was used as the solvent. Telmisartan pellets were prepared by dissolving telmisartan, kollidonVA64, Crospovidone in ethanol in different ratios and coated on nonpareil sugar beads as a drug layer by pan coating technique. All the formulations were further evaluated for physicochemical parameters such as particle size, friability, angle of repose and drug content. In vitro dissolution studies were carried out in pH 7.5 phosphate buffer by using USP apparatus II. Results: It was observed that the dissolution rate of the solid dispersion formulation TSD5 showed a better dissolution rate to the extent of 1.113 folds and 1.979 folds when compared to a marketed formulation and pure drug, respectively. Similarly, the formulation TPL3containing 1:3 ratio of Telmisartan to Kollidon VA64 showed an improved dissolution rate to the extent of 1.150 folds and 2.045 folds when compared to the marketed formulation and pure drug, respectively. Majority of the formulations displayed first-order release kinetics and were found to be linear with R2 values in the range of 0.905 to 0.994. FTIR analysis and DSC analysis revealed that there was no major interaction between the drug and the excipients used in the design of the formulation. SEM analysis was performed for solid dispersions, pellet formulations and its polymers to determine the surface characteristics. Conclusion: From the present study, it was observed that the solubility of Telmisartan was enhanced by Kollidon VA 64 in pellet formulations when compared to solid dispersions

ESTIMATION OF PRIMIDONE IN COMMERCIAL DOSAGE FORMS USING A SIMPLE AND CONVENIENT HPLC METHOD

ABSTRACT A simple fast and precise reverse phase high performance liquid chromatographic method has been developed for the determination of Primidone Tablets. A symmetry (5µ, 150 x 4 .6mm column) in isocratic mode with methanol: Water (50:50) as mobile phase. The Flow rate is1.0ml/min and effluent is monitored at 210nm

A Validated RP-HPLC Method for the Estimation of Pizotifen in Pharmaceutical Dosage Form

A simple, selective, linear, precise, and accurate RP-HPLC method was developed and validated for rapid assay of Pizotifen in pharmaceutical dosage form. Isocratic elution at a flow rate of 1.0 mL/min was employed on Chromosil C18 (250 mm × 4.6 mm, 5 μm) column at ambient temperature. The mobile phase consists of methanol : acetonitrile in the ratio of 10 : 90 v/v. The UV detection wavelength was 230 nm, and 20 μL sample was injected. The retention time for Pizotifen was 2.019 min. The percent RSD for accuracy of the method was found to be 0.2603%. The method was validated as per the ICH guidelines. The method can be successfully applied for routine analysis of Pizotifen in the rapid and reliable determination of Pizotifen in pharmaceutical dosage form

Synthesis and reactions of 2-bis(methylthio)methylene-1-methyl-3-oxoindole: a facile access to benzo- and heterocyclo-fused carbazoles and indoles

The synthesis and reactions of 2-bis(methylthio)methylene-1-methyl-3-oxoindole 5 as a novel 3-carbon 1,3-bielectrophilic component are described. Thus cycloaromatization of 5 with allyl, methallyl and crotyl Grignard reagents affords substituted carbazoles 12a-c in good yields. Cycloaromatization of 5 with various anions derived from aryl / heteroaryl acetonitriles and antipyrine gives novel benzo[c]- (16), naphtho[1,2-c]- (19), indolo[3,2-a]- (21), thieno[2,3-c]- (23), pyrrolo[2,3-c]- (25) and pyrazolo[4,3-b]- (29) carbazole ring systems in good yields. Similarly heterocyclo[b]-fused indoles like pyrido[3,4-b]- (36), pyrido[3,2-b]- (39) indoles and indolo[3,2-b]quinolizinium salt 42 were synthesized by cyclization of 5 with lithioacetonitrile, lithioaminocrotonitrile, and 2-picolyl lithium respectively via our heteroaromatic annelation protocol

Development, validation of liquid chromatography-tandem mass spectrometry method for simultaneous determination of rosuvastatin and metformin in human plasma and its application to a pharmacokinetic study

A new, simple and accurate liquid chromatography-tandem mass spectrometry (LC-MS/MS) method for simultaneous determination of rosuvastatin (ROS) and metformin (MET) in human plasma was developed. The assay procedure involved simple protein precipitation with acetonitrile. Following precipitation, fraction of supernatant was decanted and evaporated under gentle stream of nitrogen at 40΀C. The residue was reconstituted in mobile phase and injected. The chromatographic separation was achieved with Thermo Hypurity C18 column (50 mm Χ 4.6 mm, 5 μ) using a mobile phase composition containing 0.1% v/v formic acid in water and acetonitrile (30:70, v/v) at a flow rate of 0.4 mL/min. The total run time was 3.5 min. The method showed good linearity in the range 0.5-200 ng/mL for ROS and 2-2000 ng/mL for MET with correlation coefficient (r) >0.9994 for both the analytes. The intra and inter-day precision values for ROS and MET met the acceptance criteria as per regulatory guidelines. The battery of stability studies viz., bench-top, freeze-thaw and long term stability were performed. The developed method was applied to a pharmacokinetic study

Shape Controlled Synthesis of Barium Carbonate Microclusters and Nanocrystallites using Natural Polysachharide -Gum Acacia

Abstract Different morphosynthesis strategies for BaCO 3 using natural polysaccharide-gum acacia (GA) as templating species are presented. The influence of GA with different functionalities such as -OH, -COOH and -NH 2 on the crystallization and structure formation was investigated. Some interesting morphologies, including rods, dumbbell, double-dumbbell and flower like clusters, can be readily generated by using GA as cooperative modifier in the mineralization process, under the conditions of 0.5%, 1% of templating species and at ambient temperature. The modifier GA and its concentration is the key factor in this system. In continuation, morphology was also examined for mixed metal carbonates (Ba-LaCO 3 , Ba-TbCO 3 ). The possible formation mechanism of the nanocrystallites is discussed. Structural characterization of the synthesized materials was investigated by Powder X-ray diffraction (XRD), Scanning Electron Microscopy (SEM), Energy Dispersive Analysis (EDAX), Transmission Electron Microscopy (TEM), Thermogravimetric analysis (TGA) coupled Mass (MS) and Fourier Transform Infrared spectroscopy (FT-IR)

Pd/C-mediated synthesis of (Z)-3-alkylidenephthalides of potential pharmacological interest

The coupling of o-bromobenzoic acid with terminal alkynes using 10% Pd/C–Et3N–CuI–PPh3 as a catalyst system leads to the synthesis of (Z)-3-alkylidenephthalides as the major product along with the traces of isocoumarin when the reaction was performed in 1,4-dioxane. The methodology afforded a range of compounds including (Z)-3-(4-(methylsulfonyl)benzylidene)isobenzofuran-1(3H)-one of potential pharmacological interest