Anais Brasileiros de Dermatologia
On-line version ISSN 1806-4841
LEONARDI, Gislaine Ricci; GASPAR, Lorena Rigo and CAMPOS, Patrícia M. B. G. Maia. Study of pH variation on the skin using cosmetic formulation s with and without vitamins A, E or ceramide: by a non-invasive method. An. Bras. Dermatol. [online]. 2002, vol.77, n.5, pp. 563-569. ISSN 1806-4841. http://dx.doi.org/10.1590/S0365-05962002000500006.
BACKGROUND: Moisturizers are believed to improve the skin's condition by increasing the water content of the stratum corneum. Vitamins A and E and ceramides have been widely used in cosmetic moisturizing products, and these are one of the most important cosmetic and body care products. OBJECTIVE: The aim of this research was to evaluate the effects on the pH of human skin of an O/W emulsion (non ionic self-emulsifying base) with and without vitamin A palmitate, or vitamin E acetate, or ceramide III, using a non-invasive method. METHOD: The investigations were carried out on a group of 40 healthy female test subjects aged between 30 and 45 years old, using the Skin pH meter PH 900 PC. The measurements were performed on the forearm of volunteers at 7 and 30 days after daily use (twice a day) of the products used in the study. RESULTS AND CONCLUSION: The presence of vitamins A or E or ceramide III did not change the pH of the skin, consequently the formulations studied are suitable for cosmetic usage.
Keywords : lipids; vitamin A; vitamin E.