Abstract

DEVELOPMENT OF SUSTAINED RELEASE TABLET OF VALSARTAN

Mohi Uddin*

ABSTRACT

The present study was aimed to develop sustained release matrix tablet of Valsartan and to evaluate its efficacy in reducing hypertension. In this experiment, sustained release matrix tablets were prepared by direct compression method and Methocel K4M CR and Methocel K100M CR were used as polymer. The evaluation involves three stages: the micromeritic properties evaluation of powder blend, physical property studies of tablets and in-vitro release kinetics studies. The powder blend was evaluated for angle of repose, loose bulk density, tapped bulk density, Carr’s index, Hausner’s ratio, moisture content and total porosity and the tablets were evaluated for hardness, friability, thickness, drug content and in vitro dissolution parameters. The weight variation was observed to be within the prescribed limits for each formulation. In vitro release studies were carried out using USP apparatus type II at 100 rpm and dissolution medium consisted of 0.1N hydrochloric acid for the first 2 hours and phosphate buffer pH 6.8 from 3 to 24 hours, maintained at 37±0.5°C. Drug release at different intervals was measured by UV-visible spectrophotometer at 249 nm. The release of drug was plotted in zero order, 1st order, Higuchi, Korsmeyer-Peppas and Hixson-Crowell release pattern. Kinetic modeling of in vitro dissolution profiles revealed that the drug release mechanism from all proposed formulations followed anomalous type or non-fickian transport. In this study formulation F8, F9 and F10 showed better drug release compared to others. Drug release from the matrix occurred by combination of two mechanism, diffusion and erosion of tablet.

Keywords: Valsartan, Antihypertensive drug, Sustained release tablet, Direct compression, HPMC, Sodium lauryl sulfate.