S. Cambos, A. Roso
The aim of this study was to investigate the contribution of two oil-in-water emulsifiers with long C20-22 fatty chains to skin
benefits for end-users, from minimalist emulsions compared to the appropriate reference. Complementary evaluations were
conducted, using classical measurements such as corneometry for moisturizing effect, dosage of heavy metals in skin stripping
to measure potential protection from pollution, advanced spectroscopy, and the latest visualization imaging technology to
evaluate effects on the skin surface, such as potential skin roughness or mattifying properties. A second part was dedicated
to better understanding the mechanism of action of each emulsifier by exploring what happens to the emulsion after application using scanning microscopy or X-Ray microdiffraction: does the formulation have film-forming properties? What is the interaction of the emulsion with the stratum corneum? The results demonstrated different benefits according to the emulsifier structure and pointed out their interest versus reference emulsifiers. The anionic structure forms a matte film which increases water resistance and protects the skin from atmospheric pollutants. The non-ionic structure strengthens the skin barrier by gently inserting itself within the stratum corneum lipid lamellar structure, resulting in reduced skin roughness and increased moisturisation up to five hours after application.