The skin is a complex organ with a delicate balance. It consists of 3 cutaneous layers: the epidermis, dermis and hypodermis. On the surface of the epidermis, the layer that comes into contact with the external environment, called the corneal layer (stratum corneum), is covered by the hydrolipid film. This section (corneal layer + hydrolipid film) forms a natural protection, it is the skin’s barrier. It is therefore essential to maintain the integrity of the hydrolipidic film to preserve the protective function of the skin barrier.