Garoli Denis, Pelizzo Maria Guglielmina, Nicolosi Piergiorgio, Peserico Andrea, Tonin Elena, Alaibac Mauro
CNR-INFM LUXOR via Gradenigo, 6B, Padua 35131, Italy.
J Dermatol Sci. 2009 Nov;56(2):89-98. doi: 10.1016/j.jdermsci.2009.07.015. Epub 2009 Aug 22.
In vitro measurements of sunscreen products are used to assess their reliability in terms of photoprotection and photo-stability.
In this study, several substrates have been fully characterized for in vitro sunscreen testing.
The following different substrates have been utilised in the study: roughened PMMA plates, Transpore, Vitro-Skin, roughened quartz plate and a laboratory prepared roughened PTFE plate. The suitability of these substrates for SPF evaluation has been investigated by performing total absorbance measurements of seven sunscreen products with different SPF values produced by the same manufacturer.
Application of sunscreen products on Transpore, roughened quartz plate, PMMA, PTFE and Vitro-Skin was performed efficiently. With regard to photo-stability of the substrate materials, only PMMA plate, PTFE and roughened quartz plate showed to be photo-stable after UV irradiation. With regard to SPF tests, our results indicate that Transpore, roughened quartz plate and Vitro-Skin are preferable to assess SPF values because of a better correlation between in vitro and in vivo measurements. Our study also confirms that an initial calibration must be performed for sunscreen products labelled with different SPF values. Finally, the results of our measurements demonstrate that, although a correlation between in vitro and in vivo SPF results can be established, it is never exactly 1:1.
防晒产品的体外测量用于评估其在光防护和光稳定性方面的可靠性。
在本研究中，对几种用于体外防晒测试的底物进行了全面表征。
本研究使用了以下不同的底物：粗糙的聚甲基丙烯酸甲酯（PMMA）板、透气胶带、体外皮肤模型、粗糙的石英板和实验室制备的粗糙聚四氟乙烯（PTFE）板。通过对同一制造商生产的七种不同防晒系数（SPF）值的防晒产品进行总吸光度测量，研究了这些底物对SPF评估的适用性。
防晒产品能有效地应用于透气胶带、粗糙的石英板、PMMA、PTFE和体外皮肤模型上。关于底物材料的光稳定性，只有PMMA板、PTFE和粗糙的石英板在紫外线照射后显示出光稳定性。关于SPF测试，我们的结果表明，由于体外和体内测量之间具有更好的相关性，透气胶带、粗糙的石英板和体外皮肤模型更适合用于评估SPF值。我们的研究还证实，对于标有不同SPF值的防晒产品必须进行初始校准。最后，我们的测量结果表明，虽然可以建立体外和体内SPF结果之间的相关性，但它从来都不是完全1:1的。
