Fabrication and optimization of floating tablets of antihypertensive drug losartan

Abstract

This study developed, optimized, and evaluated floating tablets containing Losartan potassium intended to provide prolonged gastric retention for hypertensive patients. HPMC K15M was found to effectively extend drug release in a gastric pH environment. Formulations were evaluated for drug-excipient compatibility, thickness, hardness, tablet density, floating lag time, total floating time, weight variation, friability, drug content, swelling index, and stability under accelerated conditions. Preliminary findings identified HPMC K15M (X1) and MCC (X2) as independent variables in a 3² full factorial design, with friability (%F) and cumulative drug release at 12 hours (Q12) as dependent variables. Multiple linear regression, ANOVA, and contour plots generated using Design Expert were employed to analyze factor effects. In vitro release data were fitted to kinetic models, with the optimized batch exhibiting a Higuchi release profile (r² = 0.993). A checkpoint batch validated the model. Batch F7 was identified as the optimized formulation, demonstrating friability below 1 (0.80) and 95.94% cumulative drug release at 12 hours. Accelerated stability testing confirmed the stability of the optimized formulation.