DESIGN AND FORMULATING GLICLAZIDE SOLID DISPERSION IMMEDIATE RELEASE LAYER AND METFORMIN SUSTAINED RELEASE LAYER IN BILAYER TABLET FOR THE EFFECTIVE POSTPRANDIAL MANAGEMENT OF DIABETES MELLITUS

In order to effectively manage the diabetic mellitus type-II hyperglycemic surge, bilayered tablets comprising of gliclazide in immediate release layer (IRL) and metformin in sustained release layer (SRL) have been designed and fabricated for years. Gliclazide suffers from reduced aqueous solubility of 0.19 mg/mL which remained a crucial problem for the biological effect as a result of reduced dissolution and bioavailability. Therefore, in this research an effort was done to improve the aqueous solubility of gliclazide in a bilayer tablet by forming solid dispersions which will provide prompt release to completely manage the postprandial effectually. In this study, a bilayer tablet of gliclazide solid dispersion in IRL and metformin in SRL were fabricated by direct compression method, with an intention that the IRL of the formulation will release the gliclazide at its earliest to combat the postprandial hyperglycemic level followed by a control of steady state plasma glucose by sustained release metformin. The compatibility studies, pre-compression studies, post-compression studies, disintegration studies, dissolution studies, and kinetic release studies were performed. The formulation B3 was found to be highly optimized and demonstrated the highest cumulative drug release where the metformin followed the either zero-order or first-order and the gliclazide followed anomalous diffusion. Therefore, the designed formulation will offer a better therapeutic regimen and provide patient friendly postprandial hypoglycemic management, where an immediate control and maintenance dose are required.