Design and Development of Sustained Release Bilayered Tablets of Glipizide

Glipizide, a second generation sulfonylurea is effective in controlling the blood glucose in patients with Non-Insulin Dependent Diabetes Mellitus. As Glipizide possess short biological half life (2-4 hrs), the concept of Bilayered tablet technology was used to formulate Glipizide as Sustained release tablet formulation. In order to overcome the disproportionate release of drug during intial period in case of general sustained release tablet formulations the concept of Bilayered tablets was utilized. Moreover by fabricating drugs in the form of Bilayered tablets, one can improve the Cmax and the speed of appearance of the drug in patient. Bilayered tablets formulated through Direct Compression was comprised of immediate, sustained release layers were formulated and evaluated through %Weight variation, Hardness, Friability, %Drug content, Swelling index and In-vitro drug release studies. 30% of the drug present in the immediate release layer was released within first 20 minutes and the remaining 70% of the drug release was sustained based on the polymer selected. The formulation comprised of HPC and HPMC as the polymers sustained the drug release for 12hrs and was found to be the best formulations.