ABSTRACT
The skin surface is an ecosystem, stable for a given body region, within which interfacial tension and friction phenomena play a major role because of the important forces they bring into action, especially in ruling the physical interactions between hydrophilic and hydrophobic substances. Examples of these interactions are the sorption of water by stratum corneum and the spreading of water and lipidic liquids, which influences skin absorption, thermal loss, as well as transcutaneous pressure of water vapor, carbon dioxide, and oxygen. The production of a sweat/sebum emulsion as well as the behavior and effect of topical drugs or cosmetics are also under the influence of these interactions (2).
