Center of Experimental and Applied Cutaneous Physiology, Department of Dermatology, Charité - Universitätsmedizin Berlin, Berlin, Germany.
Skin Pharmacol Physiol. 2012;25(3):118-23. doi: 10.1159/000336246. Epub 2012 Feb 16.
The inhomogeneous distribution of topically applied substances due to decisive differences in the skin structure (furrows and wrinkles) affects the efficacy of cosmetic products, in particular sunscreens. The combination of tape stripping and optical spectroscopy results in absorption data, which reflect ex vivo the inhomogeneity of the in vivo distribution of topically applied substances. Based on these data, a factor of inhomogeneity is defined describing the individual distribution of formulations on the skin surface of volunteers. Thus, the influence of different skin surface structures and the influence of different formulations on the distribution of the topically applied substances can be determined. Analyzing the inhomogeneity data on 6 volunteers (5 sunscreens per volunteer), it was found that the influence on the distribution of sunscreens caused by the formulation was higher than the inhomogeneity originating from the differences in the skin surface structure of the volunteers. The method is well suited to characterize, for example, sunscreens and antiaging creams in the process of development, as well as for the evaluation of the final products.
由于皮肤结构（皱纹和褶皱）存在显著差异，局部应用物质的分布不均匀会影响化妆品的功效，尤其是防晒霜。胶带剥离和光谱光学技术的结合产生吸收数据，这些数据反映了体外局部应用物质分布的不均匀性。基于这些数据，定义了一个不均匀性因子，用于描述志愿者皮肤表面制剂的个体分布。因此，可以确定不同皮肤表面结构和不同制剂对局部应用物质分布的影响。对 6 名志愿者（每名志愿者 5 种防晒霜）的不均匀性数据进行分析后发现，制剂对防晒霜分布的影响高于志愿者皮肤表面结构差异引起的不均匀性。该方法非常适合在开发过程中对防晒霜和抗衰老霜等进行特征描述，也适用于评估最终产品。
