Nanoparticles in cosmetic creams may not penetrate skin

A new study conducted by scientists at the University of Bath has revealed that nanoparticles, which are used in sunscreens and some cosmetic and pharmaceutical creams, may not penetrate the skin’s surface at all.

The scientists discovered that even the tiniest of nanoparticles did not penetrate the skin’s surface, even when the skin sample had been partially compromised by stripping the outer layers with adhesive tape.

The research challenges claims that nanoparticles are able to transport and deliver active ingredients to deeper layers of the skin and may have implications for cosmetic companies and pharmaceutical researchers that use nanoparticles in their products for this purpose.

Professor Richard Guy, who led the study, said: “Previous studies have reached conflicting conclusions over whether nanoparticles can penetrate the skin or not. Using confocal microscopy has allowed us to unambiguously visualise and objectively assess what happens to nanoparticles on an uneven skin surface. Whereas earlier work has suggested that nanoparticles appear to penetrate the skin, our results indicate that they may in fact have simply been deposited into a deep crease within the skin sample.

“The skin’s role is to act as a barrier to potentially dangerous chemicals and to reduce water loss from the body. Our study shows that it is doing a good job of this. So, while an unsuspecting consumer may draw the conclusion that nanoparticles in their skin creams are ‘carrying’ an active ingredient deep into the skin, our research shows this is patently not the case.”