Method for screening sunscreen cream formulations by determination of in vitro SPF and PA values using UV transmission spectroscopy and texture profile analysis.

Formulation of sunscreen products to obtain high values of sun protection factor (SPF) and protection from ultraviolet A (PA) is challenging work for cosmetic chemists. This study aimed to study factors affecting SPF and PA values using ultraviolet transmission spectroscopy as well as texture profiles of sunscreen formulations using 23 factorial designs. Results demonstrate that the correlation coefficient between the labeled SPF values of counter-brand sunscreen products and the in vitro SPF values was 0.