The influence of solid lipid nanoparticles on skin hydration and viscoelasticity--in vivo study.

Effects on skin hydration and viscoelasticity are important criteria during the development of novel cosmetic formulations. This study focuses on the in vivo performance of a conventional o/w cream and of the same cream enriched with solid lipid nanoparticles (SLN). Influences on skin hydration and viscoelastic properties were investigated with validated devices (Corneometer and Cutometer). After an application period of 4 weeks, significant changes in skin hydration were detected for both formulations. The SLN-enriched cream was significantly more effective than the conventional cream (+24% for the cream and +31% for the SLN-cream). The viscoelastic parameters UF and UA/UF remained almost unchanged, which is attributed to the young age of the volunteers. At this stage, SLN represent a promising compound for hydrating new cosmetic formulations.