FORMULATION AND DEVELOPMENT OF FLOATING DRUG DELIVERY SYSTEM OF METFORMIN HYDROCHLORIDE EXTENDED RELEASE AND GLIMEPIRIDE IMMEDIATE RELEASE INTO BILAYERED TABLET DOSAGE FORM: IN VITRO EVALUATION

*P.Shashidhar1 and G. Vidya sagar2

The purpose of the research work was formulation development and evaluation bi-layer floating tablets for metformin hydrochloride and glimepiride to improve the oral therapeutic efficacy Both these drugs exhibit pH dependent solubility and show good permeability from stomach and upper part of the small intestine into systemic circulation. Direct compression method form metformin hydrochloride layer and wet granulation method for glimepiride was used to formulate bi-layer floating tablets. The optimized formula F-5 of metformin layer exhibits float for more than 12 h and extend drug release above 12 h. Different grades of methocel (HPMC) was used as was used as drug release retarding agents in order to get the extended release profile of metformin hydrochloride over a period of 12 h. Glimepiride immediate release layer was formulation using different excipients. HPMC K100M based formulation 5 was showing drug release according to the USP specifications and was optimized and kept of stability studies. The drug release profiles at 1 month in 40???C and 75%RH suggesting that In various invitro drug release kinetics studies Higuchi model was found to be the best fitted in all dissolution profile having higher correlation coefficient 0.995 followed by Peppas model and first order release, Slope of vergnaurd model obtained is 0.399. Indicates fickian diffusion and the rate of matrix erosion of metformin hydrochloride tablets were found to 0.062 /min from the tablets