Thesis

Topical Dehydroascorbic Acid (Oxidized Vitamin C) Permeates Stratum Corneum More Rapidly Than Ascorbic Acid

ABSTRACT Topical application of vitamin C has an established history of use in skincare. A large body of literature from clinical and laboratory studies supports a scientific basis for its use in improving both the appearance and health of the skin. Ascorbic acid (AA) is the naturally-occurring chemical form of vitamin C that is most familiar, and it is commonly used in topical products. But AA has limited permeation through the stratum corneum, and this has led to the use of very high concentrations that are associated with side effects such as tingling, irritation and redness in some people. Dehydroascorbic acid (DHAA) is the other naturally-occurring form of vitamin C, and has chemical properties that suggest its skin permeation rate would be higher than AA. In this study, the rates of AA and DHAA permeation were compared by a clinically relevant, in vivo method on human subjects. Specifically, a solution containing equal parts of AA and DHAA was applied in amounts and for time periods likely to be achieved in common use of a topical product by consumers. The amount absorbed was determined by subtracting the amount recoverable in skin washings. The results show that DHAA permeates stratum corneum at a rate up to 12 times faster than AA. This supports the concept that lower concentrations of DHAA in topical preparations can enhance skin vitamin C levels with less potential for side effects.

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Available from: Douglas Kitt, Jul 01, 2015
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