Formulation and Evaluation of Bilayered Tablets Containing Immediate Release Layer of Glimepiride Complexed with Mangifera indica Gum and Sustained Release Layer Containing Metformin HCL by Using HPMC as Release Retardant

In present investigation an attempt has been made to design and develop the Bilayered tablet of Glimepiride and Metformin using Mangifera Indica Gum (MIG) and HPMC as Immediate Release and Sustained Release Layer polymers. Glimepiride and Metformin are oral-hypoglycaemic drugs which lower blood glucose level and have been selected to prepare Bilayered tablets. Glimepiride immediate release layer was prepared using MIG by wet granulation technique and Metformin sustained release layer was prepared using HPMC by dry granulation technique. Prepared Bilayered tablets were evaluated for parameters like thickness, diameter, weight variation, hardness, friability, disintegration and in-vitro release studies. All the prepared tablets were of smooth surface and elegant texture. The weights of the tablets were in the range of 540±0.551 mg. The thicknesses of the tablet were in the range of 4±0.05mm. The drug content uniformity study showed uniform dispersion of drug throughout the formulation in the range of 97.16±0.50%. The hardness was in the range of 4.0±0.5 kg/cm2 and friability is in the range of 0.67±0.06%. The bilayered tablets were also subjected to model fitting analysis to know the order and mechanism of drug release from the formulation by treating the data according to zeroorder, first-order, Higuchi and peppas equations.The bioequivalence studies conducted between prepared and marketed (Glycomate) bilayered tablet showed the similarity factor value of 70.120 for IR layer and 57.689 for SR layer.