Prominent efficiency in skin delivery of resveratrol by novel sucrose oleate microemulsion

ObjectivesTo achieve an efficient skin delivery of resveratrol using sucrose fatty acid ester microemulsions and to clarify the mechanism of enhanced penetration. MethodsSkin delivery of resveratrol using different sucrose fatty acid ester microemulsions was examined in vitro. Vehicle-skin interaction was assessed by applying blank microemulsions to skin. Skin incorporation of microemulsion components was also assessed. Key findingsThe microemulsion consisting of sucrose oleate (SO), ethanol, isopropyl myristate (IPM) and water (MESO-E) showed a prominent increase in the amount of skin incorporation of resveratrol, which was more than 5-fold higher than those of all microemulsions we previously examined. Using MESO-E, resveratrol was rapidly incorporated into skin and mainly located in the dermis. When applied in the concentration range of 5-55 mm, the amount of skin incorporation of resveratrol increased with the applied concentration up to 30 mm, whereas skin incorporation efficiency was inversely proportional to the concentration. The microemulsion-skin interaction seemed to be involved in the enhanced skin delivery process of resveratrol by MESO-E. Stratum corneum modification due to the penetration of IPM, ethanol and SO is also involved in this interaction. ConclusionsMESO-E would be a promising vehicle for the efficient skin delivery of resveratrol, especially when applied at a low concentration.