title: Influence of cholesterol on liposome fluidity by EPR. Relationship with percutaneous absorption.
abstract: The influence of liposome composition on bilayer fluidity and its effect on the percutaneous absorption into the skin were investigated. Liposomes formed with saturated or unsaturated phospholipids (H-PC or PC) with varying amounts of cholesterol were prepared and their penetration behaviour into the stratum corneum was followed up by means of the stripping method. The order and dynamics of the hydrophobic domain of the vesicles were studied using electron paramagnetic resonance (EPR) methodology. Phospholipid composition and the amount of cholesterol exert a considerable influence on the penetration behaviour of the probe encapsulated in the liposomes. This behaviour is closely related to the fluidity characteristics of these liposomes studied by EPR. Therefore, a penetration mechanism of the vesicles into the skin, based on the incorporation of lipids into the skin lipids and on fluidity behaviour, is suggested.
authors.affiliation: IIQAB, (CSIC), Jordi Girona 18-26, 08034, Barcelona, Spain. lcnesl@cid.csic.es
authors.forename: L
authors.initials: L
authors.lastname: Coderch
authors.forename: J
authors.initials: J
authors.lastname: Fonollosa
authors.forename: M
authors.initials: M
authors.lastname: De Pera
authors.forename: J
authors.initials: J
authors.lastname: Estelrich
authors.forename: A
authors.initials: A
authors.lastname: De La Maza
authors.forename: J L
authors.initials: JL
authors.lastname: Parra
mesh_terms: D000279:Administration, Cutaneous; D000328:Adult; D002784:Cholesterol / Q000008:administration & dosage / Q000493:pharmacokinetics*; D004337:Drug Carriers; D004578:Electron Spin Resonance Spectroscopy / Q000379:methods; D005260:Female; D006801:Humans; D008051:Lipid Bilayers / Q000008:administration & dosage / Q000493:pharmacokinetics*; D008081:Liposomes / Q000737:chemistry / Q000493:pharmacokinetics*; D012869:Skin Absorption / Q000187:drug effects*
chemical_list: D004337:Drug Carriers; D008051:Lipid Bilayers; D008081:Liposomes; D002784:Cholesterol