Epidermal lipids are polar lipids located above the granular layer. They form large lamellae which provide intercorneocytory cement. Epidermal lipids thus play a major role in the skin barrier function and in the maintaining of skin hydration.
The purpose of this assay is to evaluate the effects of compounds (active ingredients or formulations) on lipid neosynthesis in reconstructed human epidermis by measuring [14C]-acetate incorporation into various lipid species (total lipids, ceramides, cerebrosides, cholesterol sulfate, etc.).