Once Daily Sustained Release Matrix Tablets of Glipizide: Formulation, Optimization and In vitro In vivo Correlation

The objective of present investigation was to formulate sustain release (SR) matrix tablets of Glipizide (GLZ) for treating type II Diabetes mellitus (T2DM). Different formulations were prepared by direct compression using Klucel HF (KLU HF) and Kollidon SR (KOL SR). Drug excipient interaction studies confirmed absence of any kind of interaction between the drug and the polymer. The powder blends were evaluated for their flow properties, compressibility, and particle size distribution. The tablets were evaluated for hardness, weight variation, friability and drug content uniformity. In vitro release of glipizide from the formulated tablets was performed in progressive pH media. These tablets were also evaluated for their swelling and erosion behaviour. Pharmacokinetic parameters of optimised formulation were compared with the immediate release and sustained release marketed formulations. Further, the formulations were evaluated for in vitro in vivo correlation and bioequivalence studies. The powder blends possessed good compressibility and flowability. The dissolution release profile demonstrated diffusion controlled release which was depicted from Higuchi and Korsmeyer Peppas model. However, swelling and erosion were also found to play profound role in the release kinetics. The in vivo studies along with in vitro in vivo correlation (IVIVC) elucidated that the optimized formulation was bioequivalent to the marketed formulation.