Determination of Puquitinib in Human Plasma by HPLC–ESI MS/MS: Application to Pharmacokinetic Study

BACKGROUND AND OBJECTIVE: Puquitinib mesylate (XC-302) is a new multiple-target anticancer inhibitor, which directly suppresses the activity of phosphatidylinositol 3-kinase (PI3K). This study was aimed to develop a sensitive and specific liquid chromatography electrospray ionization tandem mass spectrometry (HPLC–ESI MS/MS) method for the quantification and pharmacokinetic investigation of plasma puquitinib in cancer patients. METHODS: The analytes of human plasma were prepared by liquid–liquid extraction using methyl-t-butyl ether (MTBE). The plasma analytes were separated by HPLC on Thermo ODS Hypersil column (2.1 × 150 mm; 3 μm) at 25 °C with 5 mmol/L ammonium acetate (A)-acetonitrile (B) (30:70, v/v) as the mobile phase. RESULTS: The total run time was 3.5 min and the elution of puquitinib was at 1.38 min. The detection were analyzed by multiple reaction monitoring (MRM) mode with positive-ion electrospray ionization (ESI) interface using the respective [M + H](+) ions: m/z 318.2 → 261.1 for puquitinib and m/z 258.2 → 121.0 for the internal standard (etofesalamide). The optimized method provided a good linear relation over the concentration range of 1.00-500.00 ng/mL (r = 0.9944) for puquitinib. The intra-day and inter-day precision (relative standard deviation [RSD%]) were within 9.83%, and the intra-day and inter-day accuracy ranged from 91.05 to 103.26%. The lower limit of quantitation (LLOQ) was 1.00 ng/mL. The absolute extraction recovery was on an average of 50.43% for puquitinib and 49.3% for internal standard. In addition, the maximum plasma concentration (C(max)) of puquitinib in dosage from 50 to 800 mg/m(2) in the human study showed an increased linearly (57.1–1289.2 ng/mL), which displayed that the concentrations had reached effective levels. CONCLUSIONS: The optimized method was successfully applied to the pharmacokinetic profile study in human cancer patient plasma after the oral administration of puquitinib.