title: Liquid chromatographic-tandem mass spectrometric assay for the simultaneous quantification of Camptosar and its metabolite SN-38 in mouse plasma and tissues.
abstract: A simple, rapid and sensitive LC-MS/MS bioanalytical method has been developed to simultaneously quantify Camptosar (CPT-11) and its active metabolite, SN-38, in mouse plasma and tissues. A single step protein precipitation with acetonitrile in 96-well plates was used for sample preparation. Camptothecin (CPT) was used as the internal standard. Fast separation of SN-38, CPT-11 and CPT was carried out isocratically on a C18, 2 mm x 50 mm, 5 microm HPLC column with a mobile phase containing acetonitrile and 20 mM ammonium acetate (pH 3.5) and a 2.5 min chromatographic run time. The API 4000 MS/MS system was operated in positive ionization multiple reaction monitoring mode, and the transitions for SN-38, CPT-11 and CPT were 393.4 --> 349.3, 587.6 --> 167.2 and 349.3 --> 305.3, respectively. The SN-38 and CPT-11 concentrations in samples were calculated from a standard curve of peak area ratios of the analyte to that of the internal standard using a 1/chi2 weighted linear regression. The quantitation limit of 0.5 ng/mL was achieved by using a low sample volume (100 microL) of plasma or tissue homogenates. The assay was linear over the concentration range of 0.5-500 ng/mL with acceptable precision and accuracy. The method was used for the quantification of CPT-11 and SN-38 in plasma and tissues to support a preclinical pharmacokinetics and tissue distribution study of CPT-11 in mice.
authors.affiliation: Pharmacokinetics, Safety, and Efficacy Department, Research and Development, NeoPharm, Inc., 1850 Lakeside Drive, Waukegan, IL 60085, USA.
authors.forename: Sofia
authors.initials: S
authors.lastname: Bardin
authors.forename: Wei
authors.initials: W
authors.lastname: Guo
authors.forename: Jenifer L
authors.initials: JL
authors.lastname: Johnson
authors.forename: Sumsullah
authors.initials: S
authors.lastname: Khan
authors.forename: Ateeq
authors.initials: A
authors.lastname: Ahmad
authors.forename: Jeffrey X
authors.initials: JX
authors.lastname: Duggan
authors.forename: Jennifer
authors.initials: J
authors.lastname: Ayoub
authors.forename: Imran
authors.initials: I
authors.lastname: Ahmad
mesh_terms: D000818:Animals; D000972:Antineoplastic Agents, Phytogenic / Q000097:blood / Q000493:pharmacokinetics*; D002166:Camptothecin / Q000031:analogs & derivatives* / Q000097:blood / Q000493:pharmacokinetics*; D002851:Chromatography, High Pressure Liquid / Q000379:methods*; D000077146:Irinotecan; D013058:Mass Spectrometry / Q000379:methods*; D051379:Mice; D012015:Reference Standards; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014018:Tissue Distribution
chemical_list: D000972:Antineoplastic Agents, Phytogenic; D000077146:Irinotecan; D002166:Camptothecin