title: Simultaneous quantification of fludarabine and cyclophosphamide in human plasma by high-performance liquid chromatography coupled with electrospray ionization tandem mass spectrometry.
abstract: Fludarabine and cyclophosphamide are anticancer agents mainly used in the treatment of hematologic malignancies. We have developed and validated an assay using high-performance liquid chromatography (HPLC) coupled with electrospray ionization tandem mass spectrometry for the quantification of fludarabine in combination with cyclophosphamide in human heparin and human EDTA plasma. Sample pre-treatment consisted of a protein precipitation with cold acetonitrile (-20 degrees C) using 250 microL of plasma. Separation was performed on an Extend C18 column (150 x 2.1 mm i.d.; 5 microm) with a stepwise gradient using 1 mM ammonia solution and acetonitrile at a flow rate of 400 microL/min. The analytical run time was 12 min. The triple quadrupole mass spectrometer was operated in the positive ion mode and multiple reaction monitoring was used for drug quantification. The method was validated over a concentration range of 1 to 100 ng/mL for fludarabine and cyclophosphamide in human heparin and human EDTA plasma. The coefficients of variation were <13.9% for inter- and intra-day precisions. Mean accuracies were also within the designated limits (+/-15%). The analytes were stable in plasma, processed extracts and in stock solution under all relevant conditions.
authors.affiliation: Department of Pharmacy and Pharmacology, Slotervaart Hospital/The Netherlands Cancer Institute, Louwesweg 6, 1066 EC Amsterdam, The Netherlands.
authors.forename: L H H
authors.initials: LH
authors.lastname: Silvertand
authors.forename: F
authors.initials: F
authors.lastname: Vazvaei
authors.forename: P
authors.initials: P
authors.lastname: Weigl
authors.forename: H
authors.initials: H
authors.lastname: Rosing
authors.forename: M J X
authors.initials: MJ
authors.lastname: Hillebrand
authors.forename: M J
authors.initials: MJ
authors.lastname: van Maanen
authors.forename: J H
authors.initials: JH
authors.lastname: Beijnen
mesh_terms: D000970:Antineoplastic Agents / Q000097:blood*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D017338:Cladribine / Q000097:blood; D003520:Cyclophosphamide / Q000031:analogs & derivatives / Q000097:blood*; D006801:Humans; D015394:Molecular Structure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D021241:Spectrometry, Mass, Electrospray Ionization / Q000379:methods*; D014740:Vidarabine / Q000031:analogs & derivatives* / Q000097:blood
chemical_list: D000970:Antineoplastic Agents; C508633:d4-cyclophosphamide; D017338:Cladribine; D003520:Cyclophosphamide; D014740:Vidarabine; C024352:fludarabine