Effects of 1,3-propanediol associated, or not, with butylene glycol and/or glycerol on skin hydration and skin barrier function.

Abstract

This study aimed to assess the effect of 1,3-propanediol at different concentrations (5%, 10%, or 15%), either applied alone or in combination with butylene glycol (BG) (5%) and/or glycerol (5%), on skin hydration and skin barrier function. The measurements were conducted using capacitance to determine skin hydration and trans epidermal water loss (TEWL) rates to evaluate skin barrier function. A total of 30 healthy female subjects participated in the study. Capacitance and TEWL measurements were conducted at multiple time points, including before application and at 15 min, 2 and 8 h after the humectants were applied to the forearms of the subjects. All the subjects provided written informed consent. The 1,3-propanediol in all concentrations and in all combinations (with BG and/or glycerol) increased skin hydration and improved skin barrier function 15 min, 2 and 8 h after application. Glycerol increased the hydration performance of 1,3-propanediol. The application of 1,3-propanediol at a concentration of 15%, either alone or in combination with other humectants, reduced the TEWL to a greater extent than lower concentrations of 1,3-propanediol. Furthermore, the addition of glycerol to 1,3-propanediol 15% improved the skin barrier and reduced TEWL when compared with 1,3-propanediol alone and with the combination of 1,3-propanediol + BG. The humectants significantly improved skin hydration and reduced TEWL throughout the 8-h time course. The increase in 1,3-propanediol concentration, as well as its combination with glycerol, provided a greater benefit to the skin, improving both hydration and the skin barrier function.