title: Determination of a catechol-O-methyltransferase inhibitor, nitecapone, in human plasma and urine by liquid chromatography.
abstract: Methods based on reversed-phase liquid chromatography with amperometric detection have been developed for determination of nitecapone, 3-(3,4-dihydroxy-5-nitrobenzylidene)-2,4-pentanedione, a COMT inhibitor, in human plasma and urine. Nitecapone was extracted with ethyl acetate-hexane mixtures from plasma after acidification with hydrochloric acid and from urine as the tetrabutylammonium ion-pair of its diphenylborate derivative. The recoveries of both methods exceeded 70% and the relative standard deviations for within-day precision were less than 4% and 8% at 50 ng ml-1 and at the quantitation limits, respectively. The methods are selective, sensitive and precise enough for determination of 4-5 ng ml-1 of nitecapone in plasma and urine and are thus suitable for the kind of pharmacokinetic studies exemplified in this paper.
authors.affiliation: Orion Pharmaceutica, Research Center, Espoo, Finland.
authors.forename: T
authors.initials: T
authors.lastname: Wikberg
authors.forename: J
authors.initials: J
authors.lastname: Taskinen
mesh_terms: D002138:Calibration; D065098:Catechol O-Methyltransferase Inhibitors; D002396:Catechols / Q000032:analysis* / Q000097:blood / Q000652:urine; D002853:Chromatography, Liquid; D004355:Drug Stability; D006801:Humans; D010422:Pentanones / Q000032:analysis* / Q000097:blood / Q000652:urine
chemical_list: D065098:Catechol O-Methyltransferase Inhibitors; D002396:Catechols; D010422:Pentanones; C057364:nitecapone