title: Linear free energy relationship analysis of retention factors in cerasome electrokinetic chromatography intended for predicting drug skin permeation.
abstract: The retention factors of neutral, positively charged, and negatively charged solutes were determined in a liposome electrokinetic chromatography (EKC) system, where cerasome was used as the investigated liposome. The Abraham linear free energy relationship (LFER) for neutral and ionized solutes gave a good account of the retention factors (N = 71, R(2) = 0.814, and SD = 0.29 log units). It was shown that the calculated retention factors for 16 neutral acids were about four times higher than those of the corresponding anions, whereas the calculated retention factors for neutral bases were less than those for the corresponding cations by a factor of 0.36. The LFER equation for neutral species, anions, and cations was compared with those for partition from water into a number of solvents and for n-octanol-water distribution coefficients. It was shown that the cerasome EKC system is substantially different to the other systems and consequently it could be a very useful additional model system, possibly for predicting skin permeation. It was further shown that there are considerable advantages in the use of Abraham LFERs that can encompass not only neutral molecules but also ionic species.
authors: Department of Pharmaceutical Technology, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany.
authors: Keda
authors: K
authors: Zhang
authors: Department of Pharmaceutical Technology, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany.
authors: Ming
authors: M
authors: Chen
authors: Department of Pharmaceutical Chemistry, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany.
authors: Gerhard K E
authors: GKE
authors: Scriba
authors: Department of Chemistry, University College London, London WC1H 0AJ, UK. Electronic address: m.h.abraham@ucl.ac.uk.
authors: Michael H
authors: MH
authors: Abraham
authors: Department of Pharmaceutical Technology, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany.
authors: Alfred
authors: A
authors: Fahr
authors: Department of Pharmaceutical Technology, Friedrich-Schiller-Universität Jena, 07743 Jena, Germany. Electronic address: Xiangli.Liu@uni-jena.de.
authors: Xiangli
authors: X
authors: Liu
mesh_terms: D002518:Ceramides / Q000737:chemistry; D020374:Chromatography, Micellar Electrokinetic Capillary; D006801:Humans; D018499:Linear Energy Transfer; D008081:Liposomes; D008954:Models, Biological; D010539:Permeability; D004364:Pharmaceutical Preparations / Q000008:administration & dosage / Q000737:chemistry* / Q000378:metabolism; D012869:Skin Absorption; D012996:Solutions; D013329:Structure-Activity Relationship
chemical_list: D002518:Ceramides; D008081:Liposomes; D004364:Pharmaceutical Preparations; D012996:Solutions