Imatinib quantification in human serum with LC-MS3 as an effective way of protein kinase inhibitor analysis in biological matrices

LC–MS3 Strategy for Quantification of Carbamazepine in Human Plasma and Its Application in Therapeutic Drug Monitoring

This study developed a detection method based on the strategy of HPLC/MS³ and verified its suitability by quantifying carbamazepine in human plasma. The high-performance liquid chromatography–tandem mass spectrometry (HPLC/MS³) system was performed using a Shimadzu UFLC XR liquid chromatography and a SCIEX QTRAP^® 5500 linear ion trap triple quadrupole mass spectrometer. The specific operation was as follows: the sample protein was firstly precipitated using methanol, then carbamazepine and carbamazepine-D₂N¹⁵ were separated on an ACQUITY UPLC HSS T3 column using the gradient elution with solvent A (0.1% formic acid) and solvent B (0.1% formic acid in acetonitrile) at a flow rate of 0.25 mL/min. Each sample was run for 7 min. This method was validated for various parameters including accuracy, precision, selectivity, linearity, LLOQ, etc. Only 5 μL of sample plasma could obtain the result of LLOD 0.5 µg/mL. The intra-day and inter-day precision was <8.23%, and accuracy was between −1.74% and 2.92%. This method was successfully used for monitoring the blood concentration of epilepsy patients after carbamazepine treatment.

A Rapid and Selective UPLC-MS/MS Assay for Accurate Analysis of Apatinib in Rat Plasma and its Application to a Pharmacokinetic Study

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 standard (IS).

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.