In vitro determination of the sun protection factor of sunscreens through photoacoustic spectroscopy: A new approach
Instituto de Pesquisa & Desenvolvimento (IP&D), Universidade do Vale do Paraíba (UNIVAP), Av. Shishima Hifumi 2911, São José dos Campos, SP, 12244-000, Brazil
2 State University of Campinas (UNICAMP), Gleb Wataghin Physics Institute (IFGW), Cidade Universitária Zeferino Vaz, Campinas, SP, 13083-970, Brazil
3 Universidade Estadual do Norte Fluminense (UENF), Laboratório de Ciências Físicas, Campos dos Goytacazes, RJ, 28013-600, Brazil
Corresponding author: email@example.com
The investigation of the sun protection factor (SPF) and the efficacy of ultraviolet absorber ingredients are extremely important items for the cosmetic industry. The development of new efficient in vitro methodologies for these investigations is an essential condition for the evolution of sunscreens. The most accepted test for assessing the efficacy of sunscreens is the in vivo (in humans) SPF determination, following validated and worldwide adopted methodologies like those regulated by FDA (USA), COLIPA (Europe) and JCIA (Japan). However, due to the high costs and time consumption of in vivo SPF determination, the constant development of in vitro methods able to predict the in vivo SPF is very important. The present study evaluates different experimental methods for in vitro SPF determination – photoacoustic spectroscopy (PAS) and transmission spectroscopy (TS), employing different substrates (PMMA and VitroSkin®) and concentrations (0.8 mg/cm2 and 2 mg/cm2). Results are compared to the labeled SPF. The high correlation between the labeled SPF and the SPF determined by PAS expands the application of this technique in the photobiology field.
© EDP Sciences, Springer-Verlag, 2008