FORMULATION AND OPTIMIZATION OF LOSARTAN POTASSIUM SUSTAINED RELEASE TABLETS BY STATISTICAL EXPERIMENTAL DESIGN

The objective of the present study was to develop hydrophilic polymer and hydrophobic polymer based matrix Losartan potassium sustained release tablets which can release the drug up to time of 12 hrs in predetermined rate using 32 factorial design. The SR (sustained release) tablets of Losartan potassium were prepared employing different concentrations of HPMCK100 and ethyl cellulose in different combinations as rate retardants by Direct Compression technique. The quantity/ concentration of Polymers, HPMCK100 and ethyl cellulose required to achieve the desired drug release was selected as independent variables, X1 and X2 respectively whereas, drug release for 2hr (Y1), 12 hr (Y2) and time required for 50% (t50%) of drug dissolution (Y3) were selected as dependent variables which were restricted to 20-30%, NLT 80% and NLT 3 hrs respectively. Statistical elucidations of polynomials were established for all the responses. The formulations were evaluated for pre compression and post compression parameters. Contour plots and 3D surface plots revealed that desired drug release can be achieved (target) by maintaining factor X1 at high level and factor X2 at low level. From the kinetic and mathematical results, the drug release follows first order and Higuchis Fickian diffusion kinetics. The results demonstrated the effectiveness of the proposed design for development of Losartan potassium sustained release tablets with optimized properties. Keywords: Losartan potassium, DoE, HPMCK100, Ethyl cellulose Sustain release, Contour plots