title: Simultaneous analysis of skin penetration of surfactant and active drug from fluorosurfactant-based microemulsions.
abstract: The purpose of this study was to investigate the penetrated amount of the incorporated model drug diclofenac-sodium and of a fluorosurfactant as specific vehicle constituent of topically applied microemulsions at the same time. To this end, the penetration depth of each compound was elucidated through tape stripping studies by the simultaneous quantification of diclofenac-sodium and the fluorosurfactant from the same sample. A new approach was made by using the very sensitive and specific (19)F NMR (nuclear magnetic resonance) for quantification of the fluorinated vehicle component. The tape stripping experiments with the microemulsions showed an almost similar penetration velocity of diclofenac-sodium and fluorosurfactant, suggesting that the surfactant within the microemulsion-structure intensified the stratum corneum uptake of the incorporated active constituent. Moreover, ATR-FTIR studies on porcine ear skin revealed significant shifts of the CH₂ stretching absorbances, which are associated with an enhanced disorder of the SC lipids resulting in a decreased skin barrier function, after application of the microemulsions. However, the application of pure fluorosurfactant did not cause any shifts in the CH₂ stretching absorbances. It can be thereby concluded that the prepared microemulsions exerted specific effects on skin integrity resulting in a "push" of diclofenac-sodium penetration.
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria.
authors.forename: Denise
authors.initials: D
authors.lastname: Mahrhauser
authors.affiliation: Research Platform "Characterisation of Drug Delivery Systems on Skin and Investigations of Involved Mechanisms", University of Vienna, Vienna, Austria.
authors.forename: Magdalena
authors.initials: M
authors.lastname: Hoppel
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria.
authors.forename: Judith
authors.initials: J
authors.lastname: Schöll
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria.
authors.forename: Lisa
authors.initials: L
authors.lastname: Binder
authors.affiliation: Research Platform "Characterisation of Drug Delivery Systems on Skin and Investigations of Involved Mechanisms", University of Vienna, Vienna, Austria; Institute of Organic Chemistry, University of Vienna, Vienna, Austria.
authors.forename: Hanspeter
authors.initials: H
authors.lastname: Kählig
authors.affiliation: Department of Pharmaceutical Technology and Biopharmaceutics, University of Vienna, Vienna, Austria; Research Platform "Characterisation of Drug Delivery Systems on Skin and Investigations of Involved Mechanisms", University of Vienna, Vienna, Austria. Electronic address: claudia.valenta@univie.ac.at.
authors.forename: Claudia
authors.initials: C
authors.lastname: Valenta
mesh_terms: D000818:Animals; D002851:Chromatography, High Pressure Liquid; D004008:Diclofenac / Q000737:chemistry; D016503:Drug Delivery Systems; D004431:Ear, External / Q000187:drug effects; D004655:Emulsions; D005461:Fluorine; D008055:Lipids / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D019301:Oleic Acid / Q000737:chemistry; D012212:Rheology; D012867:Skin / Q000187:drug effects*; D012869:Skin Absorption; D012964:Sodium / Q000737:chemistry; D017550:Spectroscopy, Fourier Transform Infrared; D013501:Surface-Active Agents / Q000008:administration & dosage* / Q000737:chemistry; D013552:Swine
chemical_list: D004655:Emulsions; D008055:Lipids; D013501:Surface-Active Agents; D004008:Diclofenac; D005461:Fluorine; D019301:Oleic Acid; D012964:Sodium
keywords: (19)F NMR; ATR-FTIR; Fluorosurfactant; Microemulsion; Simultaneous analysis; Vehicle penetration