ascorbic-acid and 2-naphthol-orange

The aim of the study was the comparison of photo-activity of three types of titanium dioxide (TiO2) micro-dispersions intended for use as UV filters for cosmetic sunscreen products. The dispersions were also investigated with regard to their influence on the stability of photo-protective systems in cosmetic emulsions, their skin penetration/absorption and their photo-toxicity for humans and skin bacterial flora. All the tested micro-dispersions of rutile TiO2 type (agglomerates with diameter 120-150 nm), with primary particle size lower than 100 nm, demonstrated no phototoxic effect and insignificant antimicrobial behaviour. On the other hand, TiO2 with insufficient deactivation of photo-activity had significant negative impact on the stability of other organic UV filters and therefore on the stability of declared UV protective factors (SPF, UVA-PF). The study demonstrated that the level of deactivation of TiO2 is one of the highly important factors for evaluation of UV filters used as sunscreens.

Topics: 3T3 Cells; Animals; Anti-Bacterial Agents; Ascorbic Acid; Azo Compounds; Benzenesulfonates; Chemistry, Pharmaceutical; Coloring Agents; Escherichia coli; Female; In Vitro Techniques; Mice; Myristates; Nanoparticles; Particle Size; Skin; Skin Absorption; Staphylococcus epidermidis; Sunscreening Agents; Swine; Titanium; Ultraviolet Rays; Water