title: Development and validation of a high-performance liquid chromatographic method for the determination of cyproterone acetate in human skin.
abstract: In the framework of a preliminary study on the transdermal penetration of cyproterone acetate (CPA), a simple and rapid procedure involving an extraction step coupled to a HPLC-UV determination has been developed for the separation and quantification of CPA in the two main skin layers-epidermis and dermis-after local application. The separation of epidermis and dermis layers was carefully carried out by means of a sharp spatula after skin immersion in heated water at 65 degrees C. The two skin layers were then treated separately according to the same process: (1) sample homogenization by vibration after freezing with liquid nitrogen in a Mikro-Dismembrator; (2) CPA extraction with methanol after addition of the internal standard (betamethasone dipropionate); (3) centrifugation; (4) evaporation of a supernatant aliquot; (5) dissolution of the dry residue in methanol and addition of water; (6) centrifugation; (7) injection of a supernatant aliquot into the HPLC system. The separation was achieved on octadecylsilica stationary phase using a mobile phase consisting in a mixture of acetonitrile and water (40:60 (v/v)). The method was then validated using a new approach based on accuracy profiles over a CPA concentration range from 33 to 667 ng/ml for each skin layer. Finally, the method was successfully applied to the determination of CPA to several skin samples after topical application of different gel formulations containing CPA.
authors.affiliation: Department of Pharmaceutical Technology, Institute of Pharmacy, University of Liège, CHU, B36, Liège B-4000, Belgium.
authors.forename: Sandrine
authors.initials: S
authors.lastname: Henry de Hassonville
authors.forename: Patrice
authors.initials: P
authors.lastname: Chiap
authors.forename: Jean-François
authors.initials: JF
authors.lastname: Liégeois
authors.forename: Brigitte
authors.initials: B
authors.lastname: Evrard
authors.forename: Luc
authors.initials: L
authors.lastname: Delattre
authors.forename: Jacques
authors.initials: J
authors.lastname: Crommen
authors.forename: Géraldine
authors.initials: G
authors.lastname: Piel
authors.forename: Philippe
authors.initials: P
authors.lastname: Hubert
mesh_terms: D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D017373:Cyproterone Acetate / Q000032:analysis* / Q000493:pharmacokinetics; D005260:Female; D006801:Humans; D066298:In Vitro Techniques; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012867:Skin / Q000737:chemistry* / Q000378:metabolism; D012869:Skin Absorption; D013048:Specimen Handling
chemical_list: D017373:Cyproterone Acetate