Stratum corneum (epidermal physical barrier)

The \"physical barrier on epidermal surface\" refers to the stratum corneum, the outermost layer of the epidermis, which provides a highly effective barrier to environmental insults, water loss, and pathogen invasion. This barrier is structured as interlocking layers of dead, highly keratinized corneocytes embedded in a matrix of lipids—principally ceramides, cholesterol, and free fatty acids—that forms tightly packed lamellae. The structural integrity and function of this barrier depend on the regulated synthesis of proteins (such as involucrin, filaggrin, and loricrin) and lipids, along with specialized cell junctions like desmosomes and tight junctions deeper in the epidermis. Barrier defects are associated with a range of skin diseases, particularly atopic dermatitis, where altered lipid composition and/or protein dysfunction can lead to increased water loss, heightened allergen penetration, and immune activation.

Other names

Physical skin barrierepidermal barriercutaneous barrierskin permeability barrier

Restoration of lipid matrix, normalization of skin pH, reduction of inflammation, enhancement of barrier lipid composition, inhibition of protease activity