Abstract
The present research work was done to develop the formulation of two antidiabetic drugs i.e. Metformin HCl (500 mg) and Voglibose (0.3 mg) in bilayer tablet formulation. The tablet consist of two drug containing layers which comprises Metformin sustained release layer (blue colored layer with break line ) and an immediate release layer of Voglibose (white colored layer ) was optimized separately and constituted in bilayer tablet, a common analytical method by HPLC for quantitative combined drug evaluation (assay and dissolution ) was employed. Two different matrix formulations were developed, one matrix layer with hydrophilic swellable polymer and another with hydrophobic polymer. Hydroxypropylmethylcellulose and Colloidal silicon dioxide was used as polymers in order to get the sustained release profile for Metformin over a period of 24 h. Tablets were evaluated for physical properties as well as drug content (assay) and in vitro drug release (dissolution) were compared with standard commercial tablets. The excipients used in this formulation did not alter physicochemical properties of drug, as tested by HPLC. This formulation also best fitted formulation into zero order kinetics of the drug from the tablets was confirmed. The evaluation of bilayer tablet prepared from optimized formula was found to be best suited method for fixed dose combination of sustained release Metformin HCl and immediate release Voglibose as comparison to other marketed available formulation. The method of evaluation by HPLC was not developed separately, but it was common method used in laboratory for drug estimation in this combination.
