Abstract

DEVELOPMENT AND EVALUATION OF EXTENDED RELEASE BILAYER TABLETS OF METFORMIN HYDROCHLORIDE AND ALPHA LIPOIC ACID

*B. Divya, S. Srinivasan, K. Kavitha, M. Rupesh kumar, Dr. Jagadeesh singh SD

East Point College of Pharmacy, Bidarhalli, Bangalore, Karnataka-560 049, India.

ABSTRACT

The objective of the work was to formulate and evaluate extended release bilayer tablets of Metformin Hydrochloride and Alpha Lipoic Acid. In this formulation the loading dose was incorporated in the immediate release layer i.e., Alpha Lipoic Acid so that the minimum effective concentration may be attained within a shorter period of time after this the maintenance dose level will be taken over by the drug release from the second layer i.e., Metformin Hydrochloride layer. Bilayer tablets containing Metformin Hydrochloride and Alpha Lipoic Acid layers were prepared by wet granulation method. MA 3 is considered to be the optimized formulation with the desired drug release. The polymer which have been used in the formulation of extended release layer is HPMC 4000, and Crospovidone as disintegrant in immediate release layer. The granules were evaluated for precompressional parameters. The tablets were subjected to weight variation, thickness, hardness, friability, drug content and in vitro release studies. The results of FTIR analysis of pure drug, drugpolymer and drug–excipient mixtures showed that there was no physical and chemical interaction. The stability studies of optimized formulation MA 3 at 40ºC/75% RH for 3 months did not show any variation in the tested parameters. The phenomenon of drug release shown that the release of optimized formulation (MA 3) follows zero order kinetics and Higuchi’s diffusion model.

Keywords: Metformin Hydrochloride; Alpha Lipoic Acid; Extended release; Wet granulation; Bilayer tablets.