Stability, oxidizability, and topical delivery of resveratrol encapsulated in octenyl succinic anhydride starch/chitosan complex-stabilized high internal phase Pickering emulsions.

High internal phase Pickering emulsions (HIPPEs) stabilized with octenyl succinic anhydride starch/chitosan complexes were examined as a topical delivery vehicle for resveratrol. All resveratrol-loaded HIPPEs showed stable gel-like network structures, with the droplet size and microrheological properties largely dependent on the complex concentrations. HIPPEs exhibited strong stability when subjected to light, high temperature, UV radiation and freeze-thaw treatment, and resveratrol retention was greatly improved with the increasing addition of complexes and resveratrol. High amounts of resveratrol facilitated the antioxidant activity of HIPPEs, whereas sustained release of resveratrol was mainly related to the existence of complex interfacial layers. Moreover, HIPPEs overcome the stratum corneum barrier, with an approximately 3-5-fold increase in resveratrol deposition in deep skin compared to bulk oil. In conclusion, the emulsion composition (especially at the particle level) was vital for the effectiveness of HIPPEs as a carrier, which may provide new opportunities to design topical delivery systems.