The ability of electrical measurements to predict skin moisturization. II. Correlation between one-hour measurements and long-term results.

We investigated the ability of short-term (one-hour) electrical measurements with three different commonly used instruments to predict the effects of long-term treatment with glycerin-containing formulations on moderately dry leg skin. We report the moisturizing effects of glycerin on healthy female adult skin in a two-week study as measured by electrical conductance and capacitance, transepidermal water loss (TEWL), and clinical grading of skin dryness. The test formulations contained 1.5% NaCl and levels of glycerin from 0% to 15%. Results obtained with a smaller cohort of ten subjects, one hour after treatment, were predictive of moisturizing efficacy in the two-week period among twenty subjects with dry leg skin. Our results show that single application tests can be predictive of longer-term results with humectant-based moisturizers and that electrical measurements of skin conditions correlate well with skin grades.