Shiseido Research Center, Tsuzuki-ku, Yokohama-shi, Japan.
Photochem Photobiol. 2012 Jul-Aug;88(4):1005-11. doi: 10.1111/j.1751-1097.2012.01155.x. Epub 2012 May 14.
Irradiation from an artificial solar simulator that matches the relative cumulative erythema effectiveness (RCEE) of sunlight is used for in vivo sun protection factor (SPF) testing, whereas irradiation that matches the spectrum of natural sunlight (NS) is generally used for in vitro SPF testing. This study was designed to clarify whether this difference is important. Eight sunscreens spread on artificial substrates and several optical filters as sunscreen mimics were used. Their in vitro SPF values were evaluated using RCEE-compliant and NS spectrum-matching light sources in calculation. The calculated in vitro SPF values obtained using NS light (SPF [NS]) were lower than those obtained using RCEE light (SPF [RCEE]). The in vitro SPF (RCEE) values showed a better correlation and better agreement with in vivo SPF values, as compared with the in vitro SPF (NS) values. A marked difference between in vitro SPF values obtained with the two light sources in calculation was found for sunscreens showing low transmittance in the ultraviolet B region. To obtain in vitro SPF values that correspond well to in vivo SPF values measured with currently accepted methodology, it is important to use an RCEE-compliant light source.
采用符合相对累积红斑效应（RCEE）的人工太阳模拟器辐照进行体内防晒因子（SPF）测试，而采用匹配自然光（NS）光谱的辐照通常用于体外 SPF 测试。本研究旨在阐明这种差异是否重要。使用人工基底上涂抹的八种防晒霜和几种防晒霜模拟光学滤光片。使用符合 RCEE 的光源和 NS 光谱匹配光源计算评估其体外 SPF 值。使用 NS 光（SPF [NS]）计算得到的体外 SPF 值低于使用 RCEE 光（SPF [RCEE]）计算得到的值。与体外 SPF（NS）值相比，体外 SPF（RCEE）值与体内 SPF 值具有更好的相关性和一致性。在计算中，对于在紫外线 B 区域透射率低的防晒霜，两种光源的体外 SPF 值存在显著差异。为了获得与当前接受的方法测量的体内 SPF 值很好对应的体外 SPF 值，使用符合 RCEE 的光源很重要。
