title: In vivo investigations on the penetration of various oils and their influence on the skin barrier.
abstract: BACKGROUND
  The skin represents a potent barrier to the environment, which can be enhanced by the topical application of skin care products, such as oil and oil-based formulations by moisturizing the skin.
  
  
  METHODS
  The aim of this study was the investigation of the penetration behaviour of four vegetable oils and of paraffin oil into the stratum corneum by laser scanning microscopy. In addition, the occlusion capacity of these substances was assessed by transepidermal water loss (TEWL) measurements. Petrolatum served as a positive control for skin occlusion. The study was conducted in vivo and included six healthy volunteers.
  
  
  RESULTS
  Paraffin oil, as well as the vegetable oils, penetrated only into the first upper layers of the stratum corneum. TEWL measurements indicated that the application of the vegetable oils (except jojoba oil) as well as paraffin oil, led to a similar occlusion of the skin surface. The most effective occlusion was found for petrolatum.
  
  
  CONCLUSIONS
  For the investigated oils, a deeper penetration than into the first upper layers of the stratum corneum could be excluded. The decreased TEWL values indicate that the application of the oils leads to a semi-occlusion of the skin surface as it is intended by the use of oils to retain moisture in skin.
authors.affiliation: Charité - Universitätsmedizin Berlin, Department of Dermatology, Venerology and Allergology, Center of Experimental and Applied Cutaneous Physiology, Berlin, Germany. alexa.patzelt@charite.de
authors.forename: A
authors.initials: A
authors.lastname: Patzelt
authors.forename: J
authors.initials: J
authors.lastname: Lademann
authors.forename: H
authors.initials: H
authors.lastname: Richter
authors.forename: M E
authors.initials: ME
authors.lastname: Darvin
authors.forename: S
authors.initials: S
authors.lastname: Schanzer
authors.forename: G
authors.initials: G
authors.lastname: Thiede
authors.forename: W
authors.initials: W
authors.lastname: Sterry
authors.forename: T
authors.initials: T
authors.lastname: Vergou
authors.forename: M
authors.initials: M
authors.lastname: Hauser
mesh_terms: D000328:Adult; D006801:Humans; D008297:Male; D008875:Middle Aged; D010232:Paraffin / Q000493:pharmacokinetics* / Q000494:pharmacology*; D010938:Plant Oils / Q000493:pharmacokinetics* / Q000494:pharmacology*; D012869:Skin Absorption / Q000187:drug effects* / Q000502:physiology*
chemical_list: D010938:Plant Oils; D010232:Paraffin