Abstract:
Metformin HCl matrix tablets were formulated and evaluated using different drug polymer (pectin/alginate) by direct compression method. The blends were evaluated for pre-compression and post-compression studies including swelling & erosion studies. In vitro release studies were carried out in acidic buffer (pH 1.2) and phosphate buffer (pH 6.8). The drug release was found to decrease with increase in the amount of polymer added in each formulation. Release studies also showed that the swelling and erosion of matrix tablets influenced the drug release and a bi-phasic release with an initial burst effect was observed with matrix tablets. The percent cumulative drug release was found to be sustained for all formulations and best formulation was A3 with 94.16% drug release in 11 hr. The kinetic studies revealed that the three formulations were good fitted into Korsmeyer-Peppas and six formulations were good fitted in Higuchi matrix model.

Keywords: Pectin, Sodium Alginate, Metformin HCl, Matrix Tablet, Drug Release, Swelling, Erosion, Cumulative Drug Release Kinetic, Formulations.