Stability and Clinical Efficacy of Moisturizing Cosmetic Formulations Containing Vitamins C and E

The addition of different active substances in cosmetics, e.g. vitamins and their derivatives, has been quite frequent. In this way, it is fundamental to evaluate the stability and efficacy of cosmetic formulations containing these ingredients. The objective of this work was to evaluate the physical stability and the clinical efficacy of moisturizing cosmetic formulations based on panthenol, and containing ascorbyl tetraisopalmitate and α-tocopherol acetate. Formulations were developed with panthenol (FA), panthenol and ascorbyl tetraisopalmitate and α-tocopherol acetate (FBC). The latter was submitted to rheological behavior analysis and all were characterized as stable. Next, they were subjectively and objectively analyzed for clinical efficacy in 25 volunteers. Sensory evaluation and biophysical and skin imaging techniques were used to measure stratum corneum water content, transepidermal water loss (TEWL), and skin microrelief. These were carried out before application of the formulations and then after 3 hours. The formulations studied showed acceptable stability according to the physical aspects under consideration. In the clinical efficacy studies, both formulations significantly improved skin hydration and reduced TEWL. There was also improvement in skin microrelief but these results were not statistically significant. FBC received higher scores than FA in the sensory analysis as there was a significant improvement in the skin's smoothness, besides being preferred in purchase intent.