A high-performance liquid chromatography–mass spectrometry assay for quantitation of the tyrosine kinase inhibitor nilotinib in human plasma and serum

Nilotinib (AMN-107, Tasigna™) is a small-molecule inhibitor of BCR/ABL, approved for chronic myelogenous leukemia. We developed and validated, according to FDA-guidelines, an LC–MS assay for sensitive, accurate and precise quantitation of nilotinib in 0.2 mL human plasma or serum. After acetonitrile protein precipitation, separation is achieved with a hydro-Synergi column and a 0.1% formic acid in methanol/water-gradient. Detection uses electrospray, positive-mode ionization mass spectrometry. Between 5 (LLOQ) and 5000 ng/mL, accuracy (92.1–109.5%), intra-assay precision (2.5–7.8%), and inter-assay precision (0–5.6%)) were within FDA limits. We demonstrated the suitability of this assay by quantitating plasma concentrations of nilotinib in a healthy volunteer after oral administration of 400 mg nilotinib.