Objective: Apatinib, a novel small-molecule Tyrosine Kinase Inhibitor (TKI), is under development
to treat advanced gastric cancer. For the pharmacokinetic evaluation and routine drug monitoring
of apatinib, a quantitative ultra-performance liquid chromatography coupled with tandem mass
spectrometry (UPLC-MS/MS) method in rat plasma was developed with tinidazole used as an internal
Methods: Protein precipitation (PPT) was selected as a sample pre-treatment method to extract apatinib.
Then, chromatography was performed on a Kinetex C8 column (2.1×100 mm, 2.6 μm) using a constant
mobile phase including 0.2% formic acid and 10 mM ammonium acetate in water and methanol
(30:70, v/v) with a gradient flow rate from 0.2 mL/min to 0.4 mL/min. Chromatographic analysis was
performed in only 4.5 min. Mass spectrometric detection was carried on positive electrospray ionization
(ESI+) mode with Multiple-Reaction Monitoring (MRM).
Results: The standard calibration curve showed good linearity in 2-1000 ng/mL with the correlation
coefficient (R2) > 0.99. The Lower Limit of Quantitation (LLOQ) was 2 ng/mL. The precision, accuracy,
extraction recovery, matrix effect, stability and carryover were all within the acceptable range.
Conclusion: This method was simple, accurate, selective and successfully used for a pharmacokinetic
study following seven rats orally administrated a single of 60 mg/kg apatinib.