A validated UPLC-MS/MS method for the determination of CX3002 in human plasma and its application to a pharmacokinetic study.

A simple, selective, rapid, and reliable ultra-high performance liquid chromatography-tandem mass spectrometry (UPLC-MS/MS) method was developed and validated to determine CX3002 in human plasma using CX3002-d3 as the internal standard (IS). After a rapid protein precipitation with acetonitrile (3:1, v/v), the chromatographic separation of CX3002 and IS was performed on a Thermo Hypersil GOLD C18 column (2.1 mm × 50 mm, 1.9 μm) with gradient elution at a flow rate of 0.4 ml/min. Gradient elution was achieved with mobile phase A consisting of water containing 0.1% formic acid and 5 mmol/L ammonium formate and mobile phase B consisting of methanol containing 0.1% formic acid. The detection was performed on AB SCIEX QTRAP® 5500 tandem mass spectrometry in the positive ion mode. Multiple reactions monitoring (MRM) was used for quantitative analysis at transition of m/z 460.3 → 199.3 for CX3002 and m/z 463.3 → 202.3 m/z for IS. The method was fully validated and displayed good linearity over a concentration range of 0.2-400 ng/mL with the correlation coefficient above 0.997. The intra-run and inter-run precision (coefficient of variation, CV) ranged from 0.60%-16.46% and the accuracy bias ranged from -7.09%-9.75%. The mean IS-normalized extraction recovery ranged from 98.30% to 104.52%. The CV(%) of IS-normalized matrix factors at the low and high QC concentration were 4.09% and 1.68%, respectively. The storage stability under different conditions was in accordance with the bioanalytical guidelines. The method was successfully applied to the pharmacokinetic study of CX3002 (30 mg) in healthy Chinese subjects.