Clinical Evaluation of Topical Lotion Containing 2-Aza-8-Oxohypoxanthine on Skin Barrier Function against Water Loss

Abstract

A clinical study was conducted to evaluate the efficacy of 2-aza-8-oxohypoxanthine (AOH) on human skin in a double-blind, placebo-controlled, and split-face comparative trial. To this end, a topical lotion containing 0.1% of AOH and its placebo formulation were applied in 20 Japanese subjects (age: 41–58 years, average: 48.4 ± 4.7 years) to their faces daily for eight weeks. The moisture content in the stratum corneum and the trans-epidermal water loss (TEWL) were measured at the beginning of the study and after eight weeks. The results obtained upon comparing the data of the two measuring points showed that the 0.1% AOH lotion caused a statistically significant larger decrease in TEWL after eight weeks. Moreover, the 0.1% AOH lotion produced a larger increase in the moisture content in the stratum corneum after eight weeks, although there was no statistical difference between the two formulations. These results clearly indicate that AOH is effective as a cosmetic agent with a skin barrier function against water loss.