ABSTRACT
ABSTRACT Chronic exposure to solar radiation could contribute to premature skin aging and skin cancer. Skin presents its own antioxidant defense, however when defenses are out of balance, reactive oxygen species could damage biological structures. In the present work, an oil-in-water photoprotective emulsion was developed and Bauhinia microstachya var. massambabensis Vaz, Fabaceae, extracts at 1% (obtained by extraction with different solvents) were added to this emulsion. In vitro and in vivo efficacy and safety of the formulations were evaluated. Spectrophotometric methods and in vivo Colipa test were performed to evaluated efficacy of the formulations, through sun protection factor (SPF) determination and UVA protection factor assessment. To the in vitro safety assessment HET-CAM, CAM-TBS and Red Blood Cell tests were performed. Results showed that both extracts contributed to a higher in vivo photoprotection (SPF 18) when compared to the formulation without extract (SPF 13), this result could be attributed to the antioxidant activity of the plant extracts that act by capturing reactive oxygen species. Concerning safety, all formulations were considered non-irritant according to in vitro tests. Formulations containing extracts could be considered efficient and safe for cosmetic use since they presented higher sun protection factor and passed the toxicity tests.
ABSTRACT
The new generation of lipid nanoparticles with solid matrix are the NLC (Nanostructured lipid carriers), and these nanoparticles show increased chemical stability of drug, film formation, controlled occlusion, increased skin hydration, the bioavailability of the active skin is improved, increase the physical stability of lipid nanoparticles in topical formulations and lower toxicity. The NLC were produced by the technique of High Pressure Homogenization (HPH). The Accelerated Stability Test, also known as Normal Stability or exploratory, aims to provide data to predict product stability, shelf life and formulation compatibility with the packaging material. Therefore, this study aims: to evaluate the normal stability under varying conditions of temperature and luminosity over time as their physical and chemical characteristics in cosmetic formulation containing ursolic acid in free and nanoparticle forms. Based on the results, the ursolic acid in the nanostructured lipid carrier form achieved a better physical and chemical stability compared to ursolic acid in the free form in both variation of the viscosity and pH.