title: Simultaneous determination of clofarabine and cytarabine in human plasma by LC-MS/MS.
abstract: Combination of cytostatic agents is a basic principle in the treatment of cancer. For the treatment of acute myeloid leukemia (AML), purine analogs, like clofarabine and cytarabine act synergistically. Little is known, however, on their interaction in vivo. We developed a method for the simultaneous determination of clofarabine and cytarabine in human plasma. The substances were extracted from plasma samples by protein precipitation with acetonitrile. Cladribine was the internal standard (IS). The analytes were separated on Synergi HydroRP column (150mm×2.0mm, 4μm) and a triple-quadrupole mass spectrometry with an electrospray ionisation (ESI) source was applied for detection. The mobile phase consisted of acetonitrile, ammonium acetate 2mM and 0.5% formic acid in a gradient mode at a flow rate of 0.5ml/min. The injection volume was 10μl and the total run time was 6.0min. Retention times were 2.46min for clofarabine, 0.97min for cytarabine and 2.43min for the IS. Calibration ranges were 8-1000ng/ml for clofarabine and 20-2500ng/ml for cytarabine. The intra-day and inter-day precision was less than 15% and the relative standard deviation was all within ±15%. This new method allows a rapid and simple determination of both clofarabine and cytarabine in human plasma. It was applied to a pharmacokinetic investigation within a hematological trial in adult patients with AML.
authors.affiliation: Klinik-Apotheke, Universitätsklinikum Carl Gustav Carus der TU Dresden, Germany. Electronic address: bozena.buettner@uniklinikum-dresden.de.
authors.forename: Božena
authors.initials: B
authors.lastname: Büttner
authors.affiliation: Institut für Klinische Pharmakologie, Medizinische Fakultät Carl Gustav Carus der TU Dresden, Germany.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Oertel
authors.affiliation: Medizinische Klinik und Poliklinik I, Universitätsklinikum Carl Gustav Carus der TU Dresden, Germany; DKMS, German Bone Marrow Donor Center, Germany.
authors.forename: Johannes
authors.initials: J
authors.lastname: Schetelig
authors.affiliation: Medizinische Klinik und Poliklinik I, Universitätsklinikum Carl Gustav Carus der TU Dresden, Germany.
authors.forename: Jan Moritz
authors.initials: JM
authors.lastname: Middeke
authors.affiliation: Medizinische Klinik und Poliklinik I, Universitätsklinikum Carl Gustav Carus der TU Dresden, Germany.
authors.forename: Martin
authors.initials: M
authors.lastname: Bornhäuser
authors.affiliation: Institut für Pharmazie, Friedrich-Schiller-Universität Jena, Germany.
authors.forename: Andreas
authors.initials: A
authors.lastname: Seeling
authors.affiliation: Klinik-Apotheke, Universitätsklinikum Carl Gustav Carus der TU Dresden, Germany.
authors.forename: Holger
authors.initials: H
authors.lastname: Knoth
mesh_terms: D000227:Adenine Nucleotides / Q000097:blood*; D001087:Arabinonucleosides / Q000097:blood*; D002853:Chromatography, Liquid / Q000379:methods*; D000077866:Clofarabine; D003561:Cytarabine / Q000097:blood*; D006801:Humans; D057230:Limit of Detection; D015203:Reproducibility of Results; D053719:Tandem Mass Spectrometry / Q000379:methods*
chemical_list: D000227:Adenine Nucleotides; D001087:Arabinonucleosides; D003561:Cytarabine; D000077866:Clofarabine
keywords: Clofarabine; Cytarabine; Human plasma; LC–MS/MS; Pharmacokinetic investigation