DEVELOPMENT, OPTIMIZATION AND EVALUATION OF GASTRORETENTIVE TABLETS CONTAINING LOSARTAN POTASSIUM BY USING 32 FULL FACTORIAL DESIGN

Background: The present investigation was aimed at developing, optimize and evaluate gastroretentive floating tablets containing Losartan potassium to retain in the stomach for prolong and predictable period of time for hypertensive patients. In the present study, the effect of HPMC K15M showed prolong release of drug in gastric pH environment. Results: These formulations were evaluated for the parameters like drug excipient compatibility study, thickness, hardness, tablet density, floating lag time, total floating time, weight variation test, % friability, drug content, % swelling index and accelerated stability studies. On the basis of preliminary results, the amount of HPMC K15M (X₁) and the amount of MCC (X₂) were chosen as independent variables in 3² full factorial design while % Friability (%F) and Cumulative % drug release at 12 hrs (Q₁₂) were taken as dependent variables. Multiple linear regression analysis, ANOVA and graphical representation of the influence of factors by contour plots were performed using Design Expert. In-vitro release data were fitted to various models to ascertain kinetic of drug release. The release profile of the optimized batch was found to follow Higuchi model (r²=0.993). Check point batch was prepared to validate the evolved model. Conclusion: Batch F₇ was selected as an optimized batch because it showed friability less than 1 (0.80) and more % cumulative drug release (95.94) at 12 hrs. The optimized formulation was subjected to accelerated stability study and it was found to be stable.