LAUSR

Abstract Considering the benefits of stomach-specific delivery of H 2 -antagonists, the objective of the present investigation was to develop and characterize a floating in situ gel containing famotidine–chitosan (FM-CS) microspheres. FM-CS microspheres were prepared using the water-in-oil emulsion technique, with glutaraldehyde as the cross-linking agent. The microspheres were examined for drug loading, entrapment efficiency, particle size, water uptake, in vitro mucoadhesion, in vitro drug release, differential scanning calorimetry and surface morphology. The selected microsphere formulations, F3 (2% w/v CS, DD 81%) and F6 (2% w/v CS, DD 91%), were reconstituted with in situ gel developed using gellan gum. The formulations that were prepared were evaluated for in vitro gelation, in vitro floating behavior, viscosity, and in vitro release characteristics. The in vitro experiments suggested that the formulation G5 (Microsphere formulation F6 reconstituted with in situ gel containing 0.5% w/v gellan gum) remained buoyant and released drug in a sustained manner over 12 h. Thus, formulation G5 can deliver famotidine in a controlled and constant manner over 12 h and can be used for successful stomach-specific delivery of famotidine.