Evonik Operations GmbH, Essen, Germany.
Department of Organic Technology, Faculty of Chemical Technology, University of Chemistry and Technology Prague, Prague, Czech Republic.
Int J Cosmet Sci. 2024 Aug;46(4):526-543. doi: 10.1111/ics.12972.
Ceramides are a family of lipids constituted by a sphingoid base and a fatty acid. In the skin, they are mainly present in the stratum corneum where, with cholesterol and free fatty acids, they constitute the inter-corneocyte lipids. With the other lipid groups, they play a key role in the formation of dense lamellar structures between adjacent corneocytes, collectively ensuring the vital efficient barrier to water evaporation and protection from foreign agents´ penetration. Changes in ceramide level and relative composition, with potential impairment of lipid arrangement, have been evidenced in different skin conditions and skin diseases. Therefore, use of suitably formulated ceramides has been proposed for topical treatment to help re-structure damaged lipid arrangement and repair impaired skin barrier function. Nonetheless, the formulation of ceramides in products necessitates specific processes such as heating to high temperature before their introduction in the final formula. In this review on the structure, the role and the potential of ceramides for skincare, we point out the necessity of rigorous process when formulating ceramides into the final product. We demonstrate the counterproductive effects of undissolved ceramides on skin barrier repair capacity of the formulas, when assessed in different in vitro models of disrupted skin barrier.
神经酰胺是由神经鞘氨醇和脂肪酸组成的脂质家族。在皮肤中，它们主要存在于角质层中，与胆固醇和游离脂肪酸一起构成细胞间脂质。与其他脂质组一起，它们在相邻角质细胞之间形成密集的层状结构中起关键作用，共同确保了水蒸发和防止外来物质渗透的有效高效屏障。在不同的皮肤状况和皮肤疾病中，已经证实了神经酰胺水平和相对组成的变化，可能会损害脂质排列。因此，已经提出使用适当配方的神经酰胺进行局部治疗，以帮助重建受损的脂质排列并修复受损的皮肤屏障功能。然而，产品中神经酰胺的配方需要特定的过程，例如在将其引入最终配方之前加热至高温。在本综述中，我们讨论了神经酰胺的结构、作用以及其在护肤方面的潜力，强调了在将神经酰胺配方成最终产品时严格控制过程的必要性。我们展示了当在不同的体外皮肤屏障受损模型中评估时，配方中未溶解的神经酰胺对配方修复皮肤屏障能力的反作用。
