Formulation and Release Characteristic of a Bilayer Matrix Tablet Containing Glimepride Immediate Release Component and Metformin Hydrochloride as Sustained Release Component

Abstract

 The aim of present study was to design the concept of bilayered tablets containing Glimepride for immediate release using sodium starch glycolate as super disintegrant and Metformin hydrochloride (HCl) for sustained release by using  Hydroxyl propyl methyl cellulose (HPMC K 4M) and Sodium Carboxy Methyl cellulose (SCMC) as the matrix forming polymer, and PVPK-30 as binder. The tablets were evaluated for physicochemical properties. All the values were found to be satisfactory. In vitro release studies were carried out as per USP in pH 1.2 with (0.1% sodium lauryl sulphate w/v) and phosphate buffer pH 6.8 using the apparatus I. The release kinetics of Metformin HCl was evaluated using the regression coefficient analysis. The formulated tablets (F5) shows zero order release and diffusion was the dominant mechanism of drug release. The polymer (HPMC K4M, SCMC) and binder PVPK-30 had significant effect on the release of Metformin HCl matrix tablets (F5). Thus formulated bilayer tablets provided immediate release of Glimepride and Metformin HCl as sustained release over a period of 8 hours.  Stability studies and FT-IR studies clearly indicated that there is no drug –polymer interaction.