Institut für Pharmazeutische Technologie, Mendelssohnstraße 1, D-38106 Braunschweig, Germany.
Int J Cosmet Sci. 2001 Feb;23(1):25-34. doi: 10.1046/j.1467-2494.2001.00054.x.
Ingredients of topically applied skin care formulations have not only positive effects on the appearance of human skin but can also disturb the Stratum corneum (SC) lipid barrier. In the present study, the influence of silicones (PDMS), as often used cosmetic ingredients, on the microstructure of SC lipids was investigated. For this purpose the interactions of four different PDMS with excised human SC were examined first using differential scanning calorimetry (DSC) and wide angle X-ray diffraction for physical characterization. Because the physical properties of human stratum corneum strongly depend on the lipid composition, showing inter-and intra-individual differences, the interactions with an in vitro model lipid system containing SC fatty acids were also studied, using polarized light microscopy, transmission electron microscopy, small angle X-ray diffraction and DSC. The results revealed that the investigated PDMS do not change either the microstructure of excised human SC or the biphasic lamellar/inverse hexagonal structure of the in vitro model. We concluded that PDMS will not cause any side-effects when topically applied and that our simplified in vitro model could be helpful for estimating interactions between cosmetic ingredients and other topically applied substances and the skin barrier at an early moment of formulation development.
局部应用于皮肤的护理制剂的成分不仅对人体皮肤的外观有积极的影响，而且还可以干扰角质层 (SC) 脂质屏障。在本研究中，研究了硅酮 (PDMS) 等常用化妆品成分对 SC 脂质微观结构的影响。为此，首先使用差示扫描量热法 (DSC) 和广角 X 射线衍射对四种不同的 PDMS 与离体人 SC 的相互作用进行了物理特性研究。由于人体角质层的物理性质强烈依赖于脂质组成，具有个体间和个体内的差异，因此还使用偏光显微镜、透射电子显微镜、小角 X 射线衍射和 DSC 研究了它们与含有 SC 脂肪酸的体外模型脂质系统的相互作用。结果表明，所研究的 PDMS 既不会改变离体人 SC 的微观结构，也不会改变体外模型的双相层状/反六方结构。我们得出结论，PDMS 局部应用时不会产生任何副作用，并且我们简化的体外模型可以帮助在配方开发的早期阶段估计化妆品成分与其他局部应用物质和皮肤屏障之间的相互作用。
