FORMULATION AND IN VITRO EVALUATION OF FUROSEMIDE FLOATING TABLETS

The present study was undertaken to formulate and evaluate gastroretentive floating tablets of furosemide to enhance gastric residence time and achieve sustained drug release. Tablets were prepared by Wet Granulation method using hydrophilic polymers HPMC K4M and HPMC K15M at concentrations of 20%, 30%, and 40%. Six formulations (FT-1 to FT-6) were developed, sodium bicarbonate and citric acid were incorporated as gas-generating agents to provide buoyancy. Preformulation studies indicated good flow properties of the powder blend, suggesting good compressibility. FTIR analysis confirmed the compatibility of furosemide with selected polymers, as no significant changes in characteristic peaks were observed. Post-compression evaluation showed that all formulations possessed acceptable physicochemical properties. Hardness ranged from 5.2 ± 1.13 to 5.6 ± 1.11 kg/cm², thickness from 3.4 ± 0.3 mm to 3.9 ± 0.2 mm, and friability remained below 1%. Drug content uniformity was within 96.51 ± 0.28% to 99.8 ± 0.34%. The swelling index increased from 120 ± 2% to 230 ± 4%, indicating enhanced hydration with higher polymer concentration. Floating studies revealed a floating lag time range from 124 to 133 seconds and total floating time is increases up to 12 hours. In vitro drug release studies demonstrated sustained release over 12 hours. Overall, formulations containing higher concentrations of HPMC K15M (FT-6) exhibited better swelling, floating behavior, and controlled drug release. The study concludes that furosemide floating tablets can be effectively developed to improve gastric retention and therapeutic performance.