title: Separation and determination of warfarin enantiomers in human plasma using a novel polymeric surfactant for micellar electrokinetic chromatography-mass spectrometry.
abstract: Warfarin is a widely used oral anticoagulant which is mostly administrated as a racemic mixture containing equal amount of R- and S-enantiomers. The two enantiomers are shown to exhibit significant differences in pharmacokinetics and pharmacodynamics. In this study, a new chiral micellar electrokinetic chromatography-mass spectrometry (MEKC-MS) method has been developed using a polymeric chiral surfactant, polysodium N-undecenoyl-L,L-leucyl-valinate (poly-L,L-SULV), as a pseudostationary phase for the chiral separation of (+/-)-warfarin (WAR) and (+/-)-coumachlor (COU, internal standard). Under optimum MEKC-MS conditions, the enantio-separation of both (+/-)-WAR and (+/-)-COU was achieved within 23 min. Calibration curves were linear (R=0.995 for (R)-WAR and R=0.989 for (S)-WAR) over the concentration range 0.25-5.0 microg/mL. The MS detection was found to be superior over the commonly used UV detection in terms of selectivity and sensitivity with LOD as low as 0.1 microg/mL in human plasma. The method was successfully applied to determine WAR enantiomeric ratio in patients' plasma undergoing warfarin therapy.
authors.affiliation: Department of Chemistry, Center of Biotechnology and Drug Design, Georgia State University, Atlanta, GA 30303, USA.
authors.forename: Jingguo
authors.initials: J
authors.lastname: Hou
authors.forename: Jie
authors.initials: J
authors.lastname: Zheng
authors.forename: Shahab A
authors.initials: SA
authors.lastname: Shamsi
mesh_terms: D002138:Calibration; D020374:Chromatography, Micellar Electrokinetic Capillary / Q000295:instrumentation / Q000379:methods*; D003374:Coumarins / Q000737:chemistry / Q000592:standards; D004151:Dipeptides / Q000737:chemistry*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D013058:Mass Spectrometry / Q000295:instrumentation / Q000379:methods*; D015394:Molecular Structure; D011108:Polymers / Q000737:chemistry; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism; D013501:Surface-Active Agents / Q000737:chemistry*; D014859:Warfarin / Q000097:blood* / Q000737:chemistry* / Q000302:isolation & purification
chemical_list: D003374:Coumarins; D004151:Dipeptides; D011108:Polymers; D013501:Surface-Active Agents; C111876:sodium N-undecylenyl-valine-leucine; D014859:Warfarin; C412550:coumachlor