Rapid and sensitive pyrotinib quantification in rat plasma via UHPLC-Q-Orbitrap MS for comprehensive pharmacokinetic studies

Pyrotinib, a potent tyrosine kinase inhibitor, is pivotal in treating human epidermal growth factor receptor 2-positive breast cancer. This research established and validated an ultrasensitive and selective UHPLC-Q-Orbitrap MS method for plasma pyrotinib quantification. Utilizing an Acquity UPLC BEH C 18 column (100 × 2.1 mm, 1.7 μm), the method achieved efficient separation of pyrotinib and the internal standard imatinib through a gradient elution system with methanol (A) and water with 0.2% formic acid (B). Operating in positive ion mode, the Q-Orbitrap mass spectrometer employed full MS/dd-MS2 scans for comprehensive data acquisition, ensuring high analytical precision and accuracy. Pyrotinib was efficiently separated from plasma matrices within 5 min, demonstrating a robust linear range from 2 to 2,000 μg L −1 , with a low quantification limit of 2 μg L −1 . The method displayed excellent precision and accuracy below 5%, coupled with plasma extraction recoveries for pyrotinib consistently between 88.25% and 92.25%. This study presents a highly efficient analytical tool for pyrotinib quantification, which was successfully applied in the precise pharmacokinetic profiling of pyrotinib in rats after an oral dose of 5 mg kg −1 .