title: Determination of esomeprazole and its two main metabolites in human, rat and dog plasma by liquid chromatography with tandem mass spectrometry.
abstract: A LC-MS/MS method was developed for quantitative determination of esomeprazole, and its two main metabolites 5-hydroxyesomeprazole and omeprazole sulphone in 25 microL human, rat or dog plasma. The analytes and their internal standards were extracted from plasma into methyl tert-butyl ether - dichloromethane (3:2, v/v). After evaporation and reconstitution of the organic extract the analytes were separated on a reversed-phase LC column and measured by atmospheric-pressure positive ionisation MS. The linearity range was 20-20,000 nmol/L for esomeprazole and omeprazole sulphone, and 20-4000 nmol/L for 5-hydroxyesomeprazole. The extraction recoveries ranged between 80 and 105%. The intra- and inter-day imprecision were less than 9.5% with accuracy between 97.7% and 100.1% for all analytes.
authors.affiliation: Development DMPK & Bioanalysis, AstraZeneca R&D Mölndal, SE-431 83 Mölndal, Sweden.
authors.forename: Ia
authors.initials: Ia
authors.lastname: Hultman
authors.forename: Helene
authors.initials: H
authors.lastname: Stenhoff
authors.forename: Mathias
authors.initials: M
authors.lastname: Liljeblad
mesh_terms: D000818:Animals; D002138:Calibration; D002853:Chromatography, Liquid / Q000379:methods*; D004285:Dogs; D064098:Esomeprazole / Q000097:blood*; D006801:Humans; D015394:Molecular Structure; D009853:Omeprazole / Q000031:analogs & derivatives / Q000097:blood; D051381:Rats; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: C040450:omeprazole sulfone; D009853:Omeprazole; D064098:Esomeprazole