Topical L-Ascorbic Acid: Percutaneous Absorption Studies


  • H. Yang, MD, N. Monteiro-Riviere, PhD, H.V. DeBuys, MD, L.C. Walker, Y. Wang, MD, and M. Levine, MD have indicated no significant interest with commercial supporters. S.R. Pinnell, MD is a consultant for Skinceuticals (Dallas, TX). M. Omar, PhD is president of PhytoCeuticals (Elmwood Park, NJ).

Address correspondence and reprint requests to: Sheldon R. Pinnell, MD, Duke University Medical Center, Department of Medicine, Division of Dermatology, P.O. Box 3135, Durham, NC 27707, or e-mail:


Background. Reactive oxygen species generated by ultraviolet light result in photocarcinogenic and photoaging changes in the skin. Antioxidants protect skin from these insults.

Objective. This study defines formulation characteristics for delivering L-ascorbic acid into the skin to supplement the skin's natural antioxidant reservoir.

Methods. L-ascorbic acid or its derivatives were applied to pig skin. Skin levels of L-ascorbic acid were measured to determine percutaneous delivery.

Results. L-ascorbic acid must be formulated at pH levels less than 3.5 to enter the skin. Maximal concentration for optimal percutaneous absorption was 20%. Tissue levels were saturated after three daily applications; the half-life of tissue disappearance was about 4 days. Derivatives of ascorbic acid including magnesium ascorbyl phosphate, ascorbyl-6-palmitate, and dehydroascorbic acid did not increase skin levels of L-ascorbic acid.

Conclusions. Delivery of topical L-ascorbic acid into the skin is critically dependent on formulation characteristics.