Formulation and optimisation of famotidine proniosomes: an in vitro and ex vivo study

The aim of the study was to develop a proniosomal system for famotidine (FAM), a potent H₂ receptor antagonist that could efficiently deliver entrapped drug over a prolonged period of time. The proniosomal system was formulated by selecting various ratios of Span 60 and cholesterol using a coacervation-phase separation method. The formulated systems were characterised for drug excipient compatibility studies by Fourier transform infrared spectroscopy (FTIR), vesicle size determination by the particle size analyser, % drug encapsulation, drug-release profiles, field emission scanning electron microscopy (FESEM) for surface morphology, X-ray diffraction (XRD) and vesicular stability at different storage conditions. By using this method, the % drug loading that resulted by the encapsulation of proniosome was found to be 78%–89%. Increase in cholesterol and surfactant concentration increases encapsulation efficiency, but further increment decreases encapsulation. In vitro drug-release studies showed prolonged release of entrapped famotidine. The highest % cumulative drug release was achieved in formulation FAM2 (96%) in 24 hours. The ex vivo data on the release of famotidine from proniosomal formulations have shown significantly increased per cent release and flux in comparison to the same dose of marketed preparation of famotidine. Stability studies were carried out in refrigerated conditions, and higher drug retention was observed. It is evident from this study that proniosomes are a promising prolonged delivery system for famotidine and have reasonably good stability characteristics.