Facial application of high-concentration carbon dioxide prevents epidermal impairment associated with environmental changes

Katsuyuki Yuki, Sawako Kawano, Shinobu Mori, Takatoshi Murase

Biological Science Laboratories, Kao Corporation, Ichikai-machi, Haga-gun, Tochigi, Japan

Purpose: The transdermal application of carbon dioxide (CO₂) gas dissolved in a solution and bathing in carbonated springs have been known to improve circulatory disorders. We aimed to elucidate and profile the effects of CO₂ application on local skin function.
Patients and methods: A liquid formulation that included high-concentration CO₂ or a control formulation was applied to the face of healthy men for 8 weeks. Quantitative analysis was performed during the dry winter months.
Results: At the site where the control formulation was applied, transepidermal water loss (TEWL) increased while the moisturizing function (conductance) of facial skin decreased during the study period. However, at the CO₂-treated site, increases in TEWL and decreases in conductance were significantly suppressed. In addition, the deterioration in scaliness and wrinkles parameters were suppressed by ≥40% at the CO₂-treated site. There were no significant differences in skin surface pH or color properties between the control and test sites.
Conclusion: This study suggests that the continuous application of a high-concentration CO₂ formulation can affect skin physiology and has the potential to suppress reductions in the barrier and moisturizing functions of the stratum corneum accompanied by desquamation, which occurs during the winter.

Keywords: transepidermal water loss, stratum corneum, barrier, desquamation