title: Controlling the hydration of the skin though the application of occluding barrier creams.
abstract: The skin is a barrier membrane that separates environments with profoundly different water contents. The barrier properties are assured by the outer layer of the skin, the stratum corneum (SC), which controls the transepidermal water loss. The SC acts as a responding membrane, since its hydration and permeability vary with the boundary condition, which is the activity of water at the outer surface of the skin. We show how this boundary condition can be changed by the application of a barrier cream that makes a film with a high resistance to the transport of water. We present a quantitative model that predicts hydration and water transport in SC that is covered by such a film. We also develop an experimental method for measuring the specific resistance to water transport of films made of occluding barrier creams. Finally, we combine the theoretical model with the measured properties of the barrier creams to predict how a film of cream changes the activity of water at the outer surface of the SC. Using the known variations of SC permeability and hydration with the water activity in its environment (i.e. the relative humidity), we can thus predict how a film of barrier cream changes SC hydration.
authors.affiliation: Physical Chemistry, Lund University, , PO Box 124, 22100 Lund, Sweden. emma.sparr@fkem1.lu.se
authors.forename: Emma
authors.initials: E
authors.lastname: Sparr
authors.forename: Danielle
authors.initials: D
authors.lastname: Millecamps
authors.forename: Muriel
authors.initials: M
authors.lastname: Isoir
authors.forename: Véronique
authors.initials: V
authors.lastname: Burnier
authors.forename: Åsa
authors.initials: Å
authors.lastname: Larsson
authors.forename: Bernard
authors.initials: B
authors.lastname: Cabane
mesh_terms: D000818:Animals; D001693:Biological Transport, Active / Q000187:drug effects; D006801:Humans; D008954:Models, Biological; D051381:Rats; D012867:Skin / Q000378:metabolism*; D063465:Skin Cream / Q000009:adverse effects* / Q000494:pharmacology; D013552:Swine; D014867:Water / Q000378:metabolism*
chemical_list: D014867:Water