Formulation and Evaluation of Sustained Release Tablets of Nateglinide by Using natural polymers

The purpose of this research work was to formulate and evaluate the sustained release tablets of Nateglinide 500mg, an antidiabetic drug. Nateglinide is an oral hypoglycemic agent. The tablets are prepared by direct compression method. The formulations were optimized by incorporating varying composition of Xanthan gum and guar gum as polymers, lactose as flow aid and magnesium stearate as lubricant. All the excipients are tested for compatibility with drug, which revealed that there was no physical and chemical interaction occurred. The Preformulation parameters such as bulk density, tapped density, compressibility index and Hausner’s ratio were analyzed. The friability, drug content, loss on drying, bulk density and percentage yield was evaluated for tablets. The effect of these variables on drug release also studied. The In-Vitro drug release studied were Performed in the USP dissolution apparatus-II using pH 0.1N HCl as dissolution media at 75 rpm speed and temperature of 37 o c ± 5 o c. The sampling was done at periodic time intervals of 1,4,8,12,16,20 and 24 hours and was replaced by equal volume of dissolution media after each withdrawal. The cumulative amount of drug release at different intervals is estimated using UV method. Based on the evaluation result the formulations F-7 was selected as best formulation. The tablets were found to follow first order kinetics and Higguchi mechanism of drug release, ‘n’ value is less than 0.5 which confirms that the drug release through the matrix was fickian diffusion.