Abstract
An LC-ESI-MS/MS method using high-throughput solid-phase extraction (SPE) was developed and validated to measure crizotinib in human and mouse plasma to support ongoing clinical and preclinical pharmacokinetic studies. Chromatographic separation of mouse or human plasma extracts was performed on a Supelco Discovery c18 column (50 mm × 2.1mm, 5.0 μ) with gradient elution using a combination of acidified aqueous and methanol (MeOH) mobile phases. The mass-to-charge transition monitored for detection and quantitation of crizotinib was m/z 450.2>260.2 while the stable label internal standard (ISTD) was monitored at m/z 457.2>267.3. The validation studies demonstrated that the assay is both precise and accurate with %CV<9% and accuracies within 8% of nominal target concentration across all concentrations tested for both the human and mouse plasma matrices. Sample volumes required for analysis were 50 and 25 μL for human plasma and mouse plasma, respectively. Calibration curves were linear over a range of 5-5,000 ng/mL for human plasma and 2-2,000 ng/mL for mouse plasma. The use of a 96-well plate format enabled rapid extraction as well as compatibility with automated workflows. The method was successfully applied to analyze crizotinib concentrations in plasma samples collected from children enrolled on a phase I pediatric study investigating the use of crizotinib for treatment of pediatric brain tumors.