The epidermis provides a physical and permeability barrier which is continuously regenerated by the epidermal keratinocyte differentiation process. Multiple components can impact the barrier function quality including protein structure (claudin, desmoglein, filaggrin, etc.), lipids (ceramides) and proteases. When properly differentiated, the epidermis prevents water loss and provides a barrier to epidermal invasion of pollutants, toxins, allergens and bacteria.
The purpose of this assay is to evaluate, via radiodetection, the capacity of compounds (active ingredients or formulations) to reinforce the human reconstructed epidermis barrier function by analyzing caffeine diffusion.