FORMULATION AND IN-VITRO EVALUATION OF BILAYERED TABLETS CONTAINING METFORMIN HYDROCHLORIDE AND GLICLAZIDE

In the present investigation Bilayered extended release formulation of Metformin hydrochloride and Gliclazide based on monolithic - matrix technology was developed and evaluated. Tablets are prepared by wet granulation method (Gliclazide layer) and direct compression (Metformin layer). Bilayered Metformin and Gliclazide extended release tablet formulations were prepared with different compositions of polymers i.e. HPMC K4M, HPMC K15M, HPMC K100M, POLYOX WSR coagulant. Finally, one optimized formula F17 was selected and studied in detail. The developed formulation is equivalent to conventional marketed products in view of its’ in vitro release. The best formula was selected by physical evaluation of tablets, dissolution profile of Metformin hydrochloride was 99.6% whereas Exermet GZ 560 (innovator) was 100.4% aft er 24 hours and Gliclazide was 99.5%, Exermet GZ 560 (innovator) was 99.8% after 24h. Similarity factor (f2) correlation value is 97.6 for Metformin hydrochloride and 97.41 for Gliclazide when compared with the innovator product. The in vitro release data of bilayered tablet from the most satisfactory formulation F-17 fitted well with higher R 2 values in Higuchi as well as Peppas model, the ‘n’value of which showed that the bilayered tablet followed diffusion mechanism. The order of release was first order