Formulation and evaluation of bilayer tablet of Metformin and vildagliptin

The Bilayered tablets containing Metformin SR and Vildagliptin IR were successfully prepared by direct compression method respectively. Various formulations were prepared and evaluated with an aim of presenting Metformin as sustained release and Vildagliptin as immediate release for improving the patient’s compliance. The prepared blend for IR layer tablets and SR layer tablets were also maintained the physiochemical properties of tablets such as thickness, hardness, weight variation, friability. The optimized formulation V6 in IR formulations contains the average thickness of 2.4mm, average hardness of 2.0 kg/cm 2 , average weight of 150mg, friability of 0.27%. The optimized formulation M5 in SR formulations contains the average thickness of 2.46mm, average hardness of 3.44kg/cm 2 , friability of 0.46%. The M5 formulation which releases the Metformin in sustained manner in 1 st hour it releases 18.26% but the remaining drug release was sustained up to 12 hours and Vildagliptin immediate release V6 formulation showed 98.3% drug release with in 60min.With the data of kinetic analysis, M5 formulation showed best linearity in Zero order plot indicating that the release of drug from matrix tablet follows Non Fickian diffusion. The dissolution study was carried out for optimized bilayer tablet and it correlates with the drug release of individual release layer formulations.