Deeper layers of the stratum corneum were devoid of TiO2. Biopsy specimens were taken from areas where the horny layer had been removed by tape stripping. In isolated areas, a penetration of coated TiO2 was observed in the orifice of the follicle. The amount of TiO2 found in any given follicle was less than 1% of the applied total amount of sunscreen. Penetration of microparticles into the viable skin tissue was not detected.