title: Stereoselective determination of venlafaxine and its three demethylated metabolites in human plasma and whole blood by liquid chromatography with electrospray tandem mass spectrometric detection and solid phase extraction.
abstract: A stereoselective method is described for simultaneous determination of the S- and R-enantiomers of venlafaxine and its three demethylated metabolites in human plasma and whole blood samples. This validated method involved LC/MS/MS with positive electrospray ionization and solid phase extraction. Chromatographic separation was performed on a 250 mm x 2.1mm Chirobiotic V column with a total run time of 35 min. In plasma, calibration curves were in the range of 1-1000 nM for the S- and R-enantiomers of venlafaxine and O-desmethylvenlafaxine, and 0.5-500 nM for N-desmethylvenlafaxine and N,O-didesmethylvenlafaxine. In whole blood the corresponding concentrations were 10-4000 and 5-2000 nM, respectively. The intra-day precision was <6.3% and the inter-day precision was <9.9% for plasma and <15% and <19% for whole blood. LLOQ ranged between 0.25 and 0.5 nM. No ion suppression/enhancement or other matrix effects were observed. The method was successfully applied for determination of venlafaxine and its metabolites in plasma from patients and whole blood samples from forensic autopsy cases.
authors.affiliation: Department of Medical and Health Sciences, Division of Drug Research, Faculty of Health Sciences, Linköping University, SE-581 85 Linköping, Sweden.
authors.forename: Maria
authors.initials: M
authors.lastname: Kingbäck
authors.forename: Martin
authors.initials: M
authors.lastname: Josefsson
authors.forename: Louise
authors.initials: L
authors.lastname: Karlsson
authors.forename: Johan
authors.initials: J
authors.lastname: Ahlner
authors.forename: Finn
authors.initials: F
authors.lastname: Bengtsson
authors.forename: Fredrik C
authors.initials: FC
authors.lastname: Kugelberg
authors.forename: Björn
authors.initials: B
authors.lastname: Carlsson
mesh_terms: D002853:Chromatography, Liquid / Q000379:methods*; D003511:Cyclohexanols / Q000097:blood* / Q000737:chemistry; D000069468:Desvenlafaxine Succinate; D004355:Drug Stability; D006801:Humans; D017367:Selective Serotonin Reuptake Inhibitors / Q000097:blood*; D052616:Solid Phase Extraction / Q000379:methods*; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D013237:Stereoisomerism; D000069470:Venlafaxine Hydrochloride
chemical_list: D003511:Cyclohexanols; D000069468:Desvenlafaxine Succinate; D017367:Selective Serotonin Reuptake Inhibitors; D000069470:Venlafaxine Hydrochloride; C434332:N-desmethylvenlafaxine; C434333:N,O-didesmethylvenlafaxine