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Copyright @ Pol J Cosmetol
Pol J Cosmetol 2016, 19(2): 90-97pl  The use of in vitro methods for evaluating sunscreen productsJustyna Popiół, Agnieszka Gunia-Krzyżak, Dorota Żelaszczyk, Anna Waszkielewicz Pracownia Chemii Kosmetycznej, Zakład Chemii Bioorganicznej, Katedra Chemii Organicznej, Wydział Farmaceutyczny, Collegium Medicum Uniwersytet Jagielloński w Krakowie Summary Ultraviolet radiation that reaches the earth is divided into UVA I, UVA II and UVB rays. Excessive exposure to sunlight has carcinogenic influence, causes many other adverse changes in the skin, such as photoaging, immunosuppression and photodermatoses. Therefore it is necessary to protect skin against ultraviolet radiation by using, for example, photoprotective formulations. These cosmetics should provide protection against the complete spectrum of ultraviolet radiation and protection against UVA should be at least 1/3 of protection against UVB. Photoprotection parameters (SPF, UVAPF) are determined using in vivo methods, but these studies are expensive and time-consuming. In addition they require the employment of a large number of volunteers, and also exclude the study of new, unknown compounds. This stimulates a search for alternative in vitro methods. This test is based on measuring absorption spectrum in the ultraviolet (290-400 nm) through thin layer of cosmetic which is spreaded on a transparent for ultraviolet radiation substrate. The received absorption curve gives a lot of important information on the spectral properties of the final product and allows to determine the SPF, UVAPF and critical wavelength. So far, in the European Union in vitro method is recommended only for determining the UVA protection factor. Despite this, many researchers use in vitro methods for determining UVB protection factor and they indicate that obtained results have a high correlation with in vivo studies. These methods may also be used in other studies of very relevant properties of photoprotective products, such as water resistance and photostability. Key words: photoprotection, SPF, SPF in vitro, photoprotective cosmetics |