Investigations on skin permeation of hyaluronic acid based nanoemulsion as transdermal carrier

An alcohol-free oil/water hyaluronic acid nanoemulsion was developed to be applied as transdermal carrier for active lipophilic ingredient. In vitro hemolysis, skin penetration and histological examinations were carried out using α-tocopherol as model ingredient to assess skin permeability and bioavailability. Without any chemical enhancers, nanoemuslion performed desirable skin permeable capacity, being able to penetrate across stratum corneum and diffuse deeper into dermis compared with the control group (ethanol solution) via follicular and intercellular pathway. Penetration mechanism was preliminarily studied and suggested to be closely concerned with transmembrane concentration gradient, carrier characteristics and penetration enhancers. No irritation has been found in dermis and skin surface indicated hyaluronic acid nanoemulsions could be successfully used as purcutaneous delivery carrier of active lipophilic ingredient and favorable for drug and cosmetic applications.