title: A sensitive HPLC method for the determination of fluoxetine and norfluoxetine in human plasma with fluorescence detection.
abstract: A selective, sensitive, and precise HPLC method for the simultaneous determination of fluoxetine (FL) and its N-demethylated metabolite norfluoxetine (NFL) in human plasma has been developed. Following extraction with n-hexane, FL, NFL, and fluvoxamine (internal standard) were derivatized with 7-chloro-4-nitrobenzofurazan (NBD-Cl) under weakly alkaline conditions. NBD derivatives were extracted with chloroform after acidification and chromatographed on a reversed-phase column with gradient elution using acetonitrile and 0.1 mol/L nitric acid (pH 3) solution. Calibration curves were linear over the range of 1.0-100.0 ng/mL and 0.1-50.0 ng/mL for FL and NFL, respectively, with inter- and intraassay precision given by a relative standard deviation (RSD%) of less than 9.2%. The lower limits of quantification were 1.0 ng/mL for FL and 0.1 ng/mL for NFL. Recoveries of FL and NFL from plasma at three different concentrations were assessed. Average recovery was about 100% for both substances. The assay was applied to pharmacokinetic study in 2 healthy volunteers after a single oral administration of 40 mg of FL.
authors.affiliation: Department of Analytical Chemistry, Istanbul University, Faculty of Pharmacy, 34116 Istanbul, Turkey. serturk@yahoo.com
authors.forename: Sidika
authors.initials: S
authors.lastname: Ertürk
authors.forename: Sevil Müge
authors.initials: SM
authors.lastname: Cetin
authors.forename: Sedef
authors.initials: S
authors.lastname: Atmaca
authors.forename: Lale
authors.initials: L
authors.lastname: Ersoy
authors.forename: Gül
authors.initials: G
authors.lastname: Baktr
mesh_terms: D000284:Administration, Oral; D019540:Area Under Curve; D001572:Benzofurans / Q000737:chemistry / Q000378:metabolism; D002851:Chromatography, High Pressure Liquid / Q000379:methods* / Q000639:trends*; D004334:Drug Administration Schedule; D016903:Drug Monitoring / Q000379:methods; D005473:Fluoxetine / Q000031:analogs & derivatives / Q000097:blood* / Q000494:pharmacology; D016666:Fluvoxamine / Q000737:chemistry; D006207:Half-Life; D006586:Hexanes; D006801:Humans; D007700:Kinetics; D012015:Reference Standards; D012680:Sensitivity and Specificity
chemical_list: D001572:Benzofurans; D006586:Hexanes; D005473:Fluoxetine; C043708:7-chloro-4-nitrobenzofuran; C026385:n-hexane; D016666:Fluvoxamine