title: Determination of ziprasidone in human plasma by liquid chromatography-electrospray tandem mass spectrometry and its application to plasma level determination in schizophrenia patients.
abstract: An accurate, rapid and simple liquid chromatography-tandem mass spectrometry (LC-MS-MS) assay method was developed for the determination of ziprasidone (ZIP) in the plasma of schizophrenia patients. A simple one step liquid-liquid extraction with 20% methylene dichloride in pentane was used to isolate ZIP and the internal standard from the plasma matrix. The compounds were separated on a C-18 column by an isocratic elution and the eluted compounds were analyzed by a triple quadrupole mass spectrometer with a TurboIon spray interface using the positive ion atmospheric pressure electrospray ionization method and detected using multiple reaction monitoring mode. The ZIP standard calibration curve was linear over the range of 0.25-500ng/ml when 0.5ml of plasma was used for the analysis (r(2)>0.998). The intra-assay (within-day) and inter-assay (between-day) variations were less than 12% for the spiked standard curve and quality control samples. The absolute extraction efficiency was 82% for ZIP and 68% for INS-RSP. The analysis time for each sample was less than 3min and useful for high turnaround plasma level determinations. This LC-MS-MS assay method for ZIP is highly specific, sensitive, accurate and rapid and is currently being used for the plasma level determination of ZIP in schizophrenia patients treated with various daily oral doses of ZIP. The data showed large inter-individual variations.
authors.affiliation: Veterans Administration Greater Los Angeles Healthcare System, UCLA, Los Angeles, CA, USA. kannan@ucla.edu
authors.forename: Manickam
authors.initials: M
authors.lastname: Aravagiri
authors.forename: Stephen R
authors.initials: SR
authors.lastname: Marder
authors.forename: Bruce
authors.initials: B
authors.lastname: Pollock
mesh_terms: D000328:Adult; D000368:Aged; D002853:Chromatography, Liquid / Q000379:methods*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D015394:Molecular Structure; D010879:Piperazines / Q000097:blood* / Q000737:chemistry; D015203:Reproducibility of Results; D012559:Schizophrenia / Q000097:blood*; D053719:Tandem Mass Spectrometry / Q000379:methods*; D013844:Thiazoles / Q000097:blood* / Q000737:chemistry
chemical_list: D010879:Piperazines; D013844:Thiazoles; C092292:ziprasidone