title: N-in-one permeability studies of heterogeneous sets of compounds across Caco-2 cell monolayers.
abstract: OBJECTIVE
  The purpose of the study was to evaluate several n-in-one cocktails of heterogeneous compounds to increase the throughput of permeability studies across Caco-2 monolayers, to investigate the reliability and applicability of the method, and to develop fast and sensitive analysis for the compounds. Compounds with potential interactions in efflux and/or active transport were chosen.
  
  
  METHODS
  Permeability experiments with verapamil, propranolol, midazolam, hydroxyzine, timolol, buspirone, procaine, naproxen, ketoprofen, and antipyrine as single compounds and in cocktails of 5-10 compounds were performed at 50 microM concentration both in the apical-to-basolateral and basolateral-to-apical direction. The compounds were quantified by liquid chromatography-electrospray tandem mass spectrometry (LC-ESI/MS/MS). Toxicity tests were performed to determine cellular damage.
  
  
  RESULTS
  The analytical method was sensitive, accurate, and rapid. The individual permeabilities of compounds in cocktails correlated well with permeabilities as single compounds. No significant interactions between the compounds within the mixtures were observed, except for acidic compounds. The studied mixtures did not show any toxicity.
  
  
  CONCLUSIONS
  The use of n-in-one cocktails is a suitable method to improve the capacity in routine permeability experiments and higher throughput screening of drug candidates, although potential interactions should always be borne in mind. The use of LC-ESI/MS/MS technology provides an excellent tool in fast and accurate analysis of small amounts of heterogeneous compounds.
authors.affiliation: Viikki Drug Discovery Technology Center (DDTC), Department of Pharmacy, University of Helsinki, P.O. Box 56, Fin-00014 University of Helsinki, Finland.
authors.forename: Leena
authors.initials: L
authors.lastname: Laitinen
authors.forename: Heli
authors.initials: H
authors.lastname: Kangas
authors.forename: Ann Marie
authors.initials: AM
authors.lastname: Kaukonen
authors.forename: Kati
authors.initials: K
authors.lastname: Hakala
authors.forename: Tapio
authors.initials: T
authors.lastname: Kotiaho
authors.forename: Risto
authors.initials: R
authors.lastname: Kostiainen
authors.forename: Jouni
authors.initials: J
authors.lastname: Hirvonen
mesh_terms: D001692:Biological Transport / Q000502:physiology; D018938:Caco-2 Cells / Q000378:metabolism*; D006801:Humans; D010539:Permeability; D004364:Pharmaceutical Preparations / Q000032:analysis* / Q000737:chemistry / Q000378:metabolism*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods
chemical_list: D004364:Pharmaceutical Preparations