Influence of natural, synthetic polymers and fillers on sustainedrelease matrix tablets of sildenafil citrate

摘要

The purpose of the present investigation was to design and evaluate influence of natural, synthetic polymers and fillers on sustained release matrix tablets of sildenafil citrate and to select the best formulation based on pharmacokinetic of sildenafil citrate. The granules were evaluated for angle of repose, loose bulk density, tapped bulk density, compressibility index, and drug content. The tablets were subjected to various tests for physical parameters such as thickness, hardness and friability, and in vitro release studies. Release kinetics was evaluated by using United States Pharmacopeia (USP)-22 type II dissolution apparatus. The in vitro dissolution study was carried out for 12 hours. In 0.1 N hydrochloric acid (pH 1.2) for first 2hrs followed by phosphate buffer at pH 7.4 ±0.2 for remaining 10 hours. The results of dissolution studies indicated that formulations containing natural gum LBG and synthetic gum HPMC K100 showed better dissolution. The drug release data fit well to the zero order. Korsmeyer’s plot indicated that the drug release mechanism from the matrix tablet followed was Anomalous (non-Fickian) diffusion. It (F-3) showed that no change in physical appearance, drug content or dissolution pattern after storage at 400C temperature and relative humidity 75% for 90 days