Application of a liquid chromatography-tandem mass spectrometry (LC/MS/MS) method to the pharmacokinetics of ON01910 in brain tumor-bearing mice

ON01910 is a small molecular weight benzyl styryl sulfone currently under investigation as a novel anticancer agent. The purpose of the investigation was to develop a sensitive and reproducible liquid chromatography-tandem mass spectrometry (LC/MS/MS) method to quantitate levels of ON01910 in small amounts of five biological matrices; mouse plasma, feces, urine, normal brain and brain tumor. For all matrices, protein precipitation sample preparation was used that led to linear calibration curves with coefficients of determination greater than 0.99. The lower limit of quantitation (LLOQ) for all matrices was 5. ng/ml except that for mouse urine which was 10. ng/ml. The calibration standard curves were reproducible for all matrices with inter- and intra-day variability in precision and accuracy being less than 15% at all quality control concentrations except for the LLOQ in mouse plasma for which the accuracy was within 17%. The assay was successfully applied to characterize the systemic pharmacokinetics of ON01910 as well as its disposition in brain and brain tumor in mice. ON01910 exhibited a clearance of 3.61 ± 0.85 l/h/kg and a half life of 8.66 ± 3.30 h at 50 mg/kg dose given I.V.