CINCINNATI—According to a new 35-day study by Proctor & Gamble, a niacinamide-containing moisturizer was better at providing rapid and prolonged improvement of cosmetic xerosis (aka dry skin) due to its functional improvement of stratum corneum barrier function (J Drugs Dermatol. 2012;11(1):22-29P). Sure marketplace shelves are stocked with numerous body moisturizers, but very few actually address the underline cause of dry skin.
“Because cosmetic skin dryness continues to be a leading skin problem for consumers, we wanted our research to focus on an ingredient formulation that would provide significant benefit to skin moisturization and barrier integrity," said Rolanda Johnson, Ph.D., a senior scientist at P&G Beauty & Grooming and co-author of the study. “When formulated in combination with humectants, such as glycerin—a well-known water-soluble, hydroscopic lipid—the niacinamide-containing moisturizers tested in these studies, Olay Advanced Healing Lotion and Olay Ultra Moisture Lotion, break the dry skin cycle and help heal the moisture barrier."
Therefore, a team of researchers at P&G performed two 35-day, randomized, untreated-controlled, nine test leg (including a not treatment) clinical studies to evaluate the ability of a variety of body moisturizers containing various levels of oils/lipids, humectants, as well as other ingredients (e.g., niacinamide) to improve stratum corneum integrity.
Two were performed on approximately 63 subjects each. Each study consisted of three phases: pre-treatment, treatment and regression. During the seven-day pre-treatment phase, subjects pre-conditioned their skin by using an Olay® bar soap in place of their usual products for bathing and showering. After pretreatment, subjects returned to the test facility to have the skin on their lower legs evaluated by an expert grader. Treatments were applied in a control setting by a clinical test manager. The two products’ major ingredient[s] were niacinamide/glycerin formula and heavy mineral oil formula. Following completion of the treatment phase, subjects began a six-day regression phase in which evaluations and procedures were performed on each site to assess product effectiveness and barrier integrity resulting from the application of the test products.
During the regression phase, no test products were applied to the sites. To assess product effectiveness, researchers performed visual dryness, skin hydration and skin (.i.e., stratum corneum) barrier integrity on each treatment site at during the regression (post-treatment) phase.
The results yielded four conclusion:
- There was insufficient evidence to detect a difference between the heavy mineral oil formula and no treatment for most endpoints.
- The heavy mineral oil showed more dryness five days after stopping treatment compared to the niacinamide/glycerin formula.
- The heavy mineral oil formula was consistently less hydrating and showed more dryness during the treatment phase than the niacinamide/glycerin formula.
- The niacinamide/glycerin formula showed higher moisturization at one week than any of the three weeks for the heavy mineral oil formula.
