title: Gas chromatographic-mass spectrometric method for quantitative determination of ketotifen in human plasma after enzyme hydrolysis of conjugated ketotifen.
abstract: A validated method for determination of total amount of ketotifen (unchanged and conjugated) in human plasma has been presented. An enzyme hydrolysis of conjugated ketotifen was conducted with combination of beta-glucuronidase and arylsulfatase. After the enzyme hydrolysis a solid-phase extraction was applied as a cleaning step. The quantitative determination by gas chromatography with mass-spectrometry detection (GC-MS) was performed. Pizotifen has been used as an internal standard. A reliable hydrolysis as well as a satisfactory accuracy, improved precision in the linear region from 0.500 to 10.0 ng/ml plasma, limit of detection of 0.010 ng/ml and prolonged capillary column life have been achieved.
authors.affiliation: NIFARMA '98 SA, Sofia, Bulgaria.
authors.forename: S
authors.initials: S
authors.lastname: Tzvetanov
authors.forename: M
authors.initials: M
authors.lastname: Vatsova
authors.forename: A
authors.initials: A
authors.lastname: Drenska
authors.forename: J
authors.initials: J
authors.lastname: Gorantcheva
authors.forename: N
authors.initials: N
authors.lastname: Tyutyulkova
mesh_terms: D002138:Calibration; D004355:Drug Stability; D008401:Gas Chromatography-Mass Spectrometry / Q000379:methods*; D006634:Histamine H1 Antagonists / Q000097:blood*; D006801:Humans; D006868:Hydrolysis; D007665:Ketotifen / Q000097:blood*; D011786:Quality Control
chemical_list: D006634:Histamine H1 Antagonists; D007665:Ketotifen