In Vitro Photostability Dynamic approach

One paradox of sunscreen products is that in order for them to protect against UV radiation, they must be exposed to it, which induces their photo-degradation and, in turn, a progressive loss in efficacy. The present dynamic method measures photo-stability based on the residual efficacies of UVA+B parts in a formula. By using a reproducible substrate, an automated spreading and different doses of UV exposure, samples also could be ranked in order of stability-potentially providing new label claims.