Enhancement of the Anti-inflammatory Efficacy of Betamethasone Valerate via Niosomal Encapsulation

Betamethasone valerate-loaded niosomes were formulated to improve drug anti-inflammatory efficacy and reduce its systemic side effects by providing prolonged and localized drug delivery into the skin. Niosomes were prepared by thin-film hydration using different molar ratios of surfactant, cholesterol, and charge inducers. Formulations were characterized for entrapment efficiency, morphology, size, and zeta potential. In-vitro release and stability studies were conducted on selected formulations. Two niosomal gels were evaluated for spreadability, pH, rheological behavior, ex-vivo skin permeation, and in-vivo anti-inflammatory efficacy. Formulations showed high encapsulation efficiency reaching 92.03±1.88%. Vesicles were spherical in shape, ranging from 123.1 to 782 nm, and had large negative values of zeta-potential. They showed a biphasic release pattern which was more sustained than free drug suspension. Niosomes demonstrated good physicochemical stability under refrigeration for up to 3 months. Niosomal gels exhibited good spreadability, suitable pH values, favorable rheological behavior, and higher skin permeation than the plain gel. In-vivo studies revealed that niosomal gels showed a better sustained anti-inflammatory effect than drug plain gel and the marketed product, which was confirmed by further histopathological examination of paw tissues. Niosomal gels are promising formulations for sustained local delivery of betamethasone valerate.