title: Simultaneous enantiospecific separation and quantitation of mephenytoin and its metabolites nirvanol and 4'-hydroxymephenytoin in human plasma by liquid chromatography.
abstract: A high-performance liquid chromatographic method for the enantiospecific quantitation of S- and R-mephenytoin and its metabolites S- and R-nirvanol and S- and R-4'-hydroxymephenytoin in plasma is described. The compounds were separated using a reversed-phase C(2) column in tandem with a chiral alpha(1)-acid glycoprotein column and were detected using ultraviolet detection at 205 nm. The lower limit of quantification was 10 ng/ml for all compounds using 0.5 ml human plasma (intra-day coefficient of variation <13%, accuracy <+/-20%). The method was validated for human plasma in the concentration range 10-2000 ng/ml for each of the six compounds. The method allows for the simultaneous characterisation of the metabolic capacity of two human drug-metabolising enzymes, CYP2C19 and CYP2B6, and may be used when investigating polymorphisms or changes in activity of these two enzymes.
authors.affiliation: Division of Pharmacokinetics and Drug Therapy, Department of Biopharmaceutical Sciences, Uppsala University, BMC, Box 591, SE-751 24 Uppsala, Sweden.
authors.forename: Britt
authors.initials: B
authors.lastname: Jansson
authors.forename: Ulrika S H
authors.initials: US
authors.lastname: Simonsson
authors.forename: Michael
authors.initials: M
authors.lastname: Ashton
mesh_terms: D001189:Aryl Hydrocarbon Hydroxylases / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid; D065702:Cytochrome P-450 CYP2B6; D065731:Cytochrome P-450 CYP2C19; D006801:Humans; D008617:Mephenytoin / Q000031:analogs & derivatives* / Q000097:blood* / Q000302:isolation & purification; D006899:Mixed Function Oxygenases / Q000378:metabolism; D010089:Oxidoreductases, N-Demethylating / Q000378:metabolism; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013056:Spectrophotometry, Ultraviolet; D013237:Stereoisomerism
chemical_list: C014544:ethylphenylhydantoin; C025687:4-hydroxymephenytoin; D006899:Mixed Function Oxygenases; D001189:Aryl Hydrocarbon Hydroxylases; C585599:CYP2B6 protein, human; C045793:CYP2C19 protein, human; D065702:Cytochrome P-450 CYP2B6; D065731:Cytochrome P-450 CYP2C19; D010089:Oxidoreductases, N-Demethylating; D008617:Mephenytoin