Exploring the potential of oleic acid in nanotechnology-mediated dermal drug delivery: An up-to-date review

Oleic acid (OA), the naturally occurring fatty acid, is a multifunctional pharmaceutical excipient with penetration enhancing property for effective skin applications. Topical drug delivery via nano-carriers is also a widely used approach to improve dermal permeation and drug retention. Nano-carriers could achieve a sustainment drug release, hence reduce adverse effects such as skin irritation accompanied by the immediate release of some actives. The present review particularly emphasizes the synergy between both approaches for enhanced drug penetration, skin retention and therapeutic effectiveness in the treatment of several cutaneous diseases. Hence, defining exactly the characteristics of the various OA-based nanosystems; composition, viscosity, physicochemical properties, and focusing on their effects on enhanced dermal drug delivery are accentuated. Methods used to assess their effectiveness in skin delivery are thoroughly discussed. The overall in vitro, in vivo and/or clinical outcomes associated with these nano-platforms are highlighted based on literature during the last ten years.