Design and Evaluation of Sustained Release Matrix Tablets of Etodolac

In recent years, plant derived polymers have evoked tremendous interest due to their diverse pharmaceutical applications such as diluent, binder, disintegrant in tablets, thickeners in oral liquids, protective colloids in suspensions, gelling agents in gels and bases in suppository. These polymers such as natural gums and mucilage are biocompatible, cheap and easily available and are preferred to semi synthetic and synthetic excipients. The main objective of the present work was to develop sustained release matrix tablets of water insoluble drug etodolac using natural polymers and gums like tamarind xyloglucan, gellan gum, sodium CMC and xanthan gum. Tablets were prepared by wet granulation method and evaluated for various physical parameters. The granules prepared were free flowing with good compressibility. FTIR and DSC studies revealed that there was no chemical interaction between the drug and the excipients. The hardness of all the formulated tablets were in the range of 6-7 kg/cm² and friability test was found to be less than 0.1% in all the cases and swelling index studies shown that increase in the concentration of polymer increases the swelling index of tablet. Tablets containing xanthan gum and sodium CMC showed highest swelling index. Drug release was faster from tablets prepared with gellan gum and sodium CMC as matrix forming material. However, tablets formulated with xanthan gum and tamarind xyloglucan it sustained drug release effectively for 12 hrs. And it is reveals that increase i n the polymer concentration decrease the release of Etodolac from matrix tablet. Among the formulation studied, formulation F16 containing xanthan gum (1:0.25) showed release of drug more than 12hrs was found to be the optimized combination. Optimized formulation F16 followed higuchi kinetics. The release co-efficient values 'n' indicated that the drug release followed non fickian anomalous mechanism based on formulation factors. Stability studies were carried out at 40°C±2°C/75%±5% RH for formulation F16 for 90 days. The results of stability studies indicated no significant changes with respect to physicochemical properties and in vitro drug release.