Stratum corneum biomarkers after in vivo repeated exposure to sub-erythemal dosages of ultraviolet radiation in unprotected and sunscreen (SPF 50+) protected skin.

Background: There is a need for non-invasive biomarkers to assess in vivo efficacy of protective measures aiming at reducing ultraviolet radiation (UVR) exposure. Stratum corneum (SC) biomarkers showed to be promising markers for internal UVR dose and immune response.

Purpose: To establish a dose-response relationship for SC biomarkers and explore their suitability for in vivo assessment of the blocking effect of two sunscreens with a high sun protection factor (SPF) (50+).