Formulation and Evaluation of Famotidine Floating Microspheres for Gastro-retentive Drug Delivery

The present study focused on the design, formulation, and evaluation of gastroretentive floating microspheres of famotidine aimed at improving gastric residence time and providing sustained drug release. Famotidine, a histamine H₂-receptor antagonist, is conventionally used for the management of peptic ulcers, Zollinger–Ellison syndrome, and gastroesophageal reflux disease, but its short half-life (2.5–3.5 h) and narrow absorption window restrict its clinical efficacy. To overcome these limitations, floating microspheres of famotidine were prepared using sodium alginate and gelatin as polymers, sodium bicarbonate as a gas-generating agent, and calcium chloride as a cross-linker by ionotropic gelation method. A total of twelve formulations (F1–F12) were developed and evaluated for percentage yield, drug content, entrapment efficiency (EE%), floating behavior, buoyancy, swelling index, bulk density, particle size, in-vitro drug release, and drug release kinetics. Among the formulations, F10 was identified as the optimized batch, showing high yield (90.1%), drug content (98.3%), and entrapment efficiency (90.8%). Floating lag time was minimal (58 s), with buoyancy of 95.6% at 2 h and total floating time exceeding 12 h. The in-vitro dissolution profile demonstrated sustained release up to 12 h (97.8%), compared to a marketed tablet which released >90% drug within 1 h. Release kinetics indicated Higuchi and Korsmeyer–Peppas models best described the mechanism, with anomalous transport involving diffusion and polymer relaxation. Accelerated stability studies (ICH guidelines) confirmed F10 retained stability for 3 months under 40 °C/75% RH with no significant variation in physicochemical or functional parameters. These findings demonstrate that famotidine-loaded floating microspheres represent a promising gastroretentive controlled-release system, with potential clinical advantages such as reduced dosing frequency, enhanced patient compliance, and sustained therapeutic efficacy in peptic ulcer management.