Comparative study of release profile of sustain release carvedilol matrix tablets using Methocel K100LV CR, Methocel K100M CR and xanthum gum polymer

Abstract

In present study an attempt was made to formulate and to evaluate the sustain release Carvedilol matrix tablets by using METHOCEL K100LV CR, METHOCEL K100M CR and Xanthum Gum polymer. The tablets were prepared by direct compression method. The granules were evaluated by angle of repose, bulk density, tapped density and compressibility index, surface P^H. The formulated tablets were evaluated by weight variation, thickness, diameter, hardness, friability and drug content. Drug content in formulation was determined by UV method. The granules showed satisfactory flow properties. The in-vitro release study of matrix tablets were carried out in 0.1N HCL using USP paddle method with sinker which was conducted for 8 hours and examined. Statistically significant differences were found among the drug release profile from different classes of polymeric matrix. Higher polymer content (30%) in the matrix decreased the rate of drug release due to the increase tortuosity and decrease porosity. At lower polymeric level (5%), the rate of drug release was elevated. METHOCEL K100M CR was found to cause the strong retardation of drug. On the other hand, highest release was found from Xanthum Gum while METHOCEL K100LV CR gave an intermediate release profile of Carvedilol. The release mechanism was explored and examined by Zero order; First order, Higuchi, korsmeyer-Peppas and Hixson-Crowell equation. The release of the drug from all the formulations was found to follow Higuchi model, as the plots showed high linearity. Also high viscosity METHOCEL grades mostly followed anomalous or non-ficking transport process. Therefore, the results generated in this study showed that the formulated sustained release matrix tablets deliver the drug through a combination of both diffusion and erosion controlled mechanism.