Development and characterization of oleic acid vesicles for the topical delivery of fluconazole

Fatty acids have been widely used as adjuvant, vehicles in drug delivery viz penetration enhancers in topical delivery and in polymeric micelles to provide sustained release. However, the present investigation aims at exploring the potential of fatty acid vesicles for the topical delivery of fluconazole. Vesicles were prepared by film hydration method using oleic acid as a fatty acid principal component. Developed vesicles were characterized for size, size distribution, shape, in vitro release, pH dependent and storage stability, skin irritation study, and ex-vivo skin permeation. Penetration behavior of vesicles was further evaluated and elucidated using confocal microscopic study. Optical microscopy and TEM studies confirmed vesicular dispersion of fatty acid. The vesicles possessed higher entrapment efficiency (44.11%) with optimum vesicle size and homogeneity in regard to size distribution (PDI = 0.234 +/- 0.016) at 7:3 oleic acid-to-fluconazole ratio. In vitro drug release study suggested sustained release of drug from the vesicles. The release pattern followed Higuchian kinetics. The vesicles were fairly stable at refrigerated conditions. Ex-vivo skin permeation and confocal microscopic studies suggested that oleic acid vesicles penetrate the stratum corneum and retain the drug accumulated in the epidermal part of the skin. On the basis of sustained release behavior and skin retention it can be inferred that oleic acid vesicles can serve as a potential carrier for the topical localized delivery of bioactives.