Floating matrix tablets are designed to prolong the gastric residence time after oral administration, at a particular site and controlling the release of drug especially useful for achieving controlled plasma level as well as improving bioavailability. With this objective, floating dosage form containing glipizide as drug was designed for the management of type-II diabetes. Tablets were prepared by using release rate controlling and gel forming polymers such as hydroxypropyl methyl cellulose (HPMC K4M, HPMC K15M, HPMC K100M) in single by direct compression method. The study shows that tablet composition and mechanical strength have great influence on the floating properties and drug release. Incorporation of gas-generating agent like sodium bicarbonate together with polymer improved drug release, besides optimal floating (floating lag time <35 s; total floating time up to 12 h). Tablets were evaluated for their physical characteristics, viz., hardness, friability, and mass variation, drug content, swelling index and floating properties. Further, tablets were studied for in vitro drug release characteristics for 12 hours. The tablets exhibited controlled and prolonged drug release profiles while floating over the dissolution medium. Based on evaluating parameters, Formulation prepared by using 40% HPMC K4M and 20% sodium bicarbonate was selected as optimized formulation. Finally, Kinetic modeling correlation with zero order, first order and Higuchi equations was confirmed as the drug release mechanism from optimized formulation, indicating that water diffusion and polymer rearrangement played an essential role in drug release. Stability studies were carried out at 30OC/65% RH and 40OC/75% RH for optimized formulation for 2 months. Stability studies on the optimized formulation indicated that there was no significant change found in physical appearance, floating properties, and drug content of the tablets.
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