Hybrid solid-phase extraction to overcome interference due to phospholipids for determination of neratinib in human plasma using UPLC-MS/MS.

A reliable and robust bioanalytical method was developed to quantify neratinib, a tyrosine kinase inhibitor in human plasma, using UPLC-MS/MS. The extraction of neratinib and its deuterated internal standard, neratinib-d6, was successfully performed on hybrid solid-phase extraction ultra-cartridges to remove the interference of phospholipids and proteins. Chromatographic analysis was performed on a UPLC BEH C18 (50 × 2.1 mm, 1.7 μm) column using 0.1% formic acid and acetonitrile under gradient conditions. The total analysis time was 1.5 min. Neratinib was quantified using electrospray ionization source operated in the positive-ion multiple reaction monitoring mode. The mass transitions of neratinib and neratinib-d6 were m/z 557.3/112.1 and m/z 563.1/118.2, respectively. The linear concentration range for neratinib was 0.5-500 ng/mL, which adequately covers concentration levels expected in real subject samples. The assay was extensively validated for various validation parameters following standard guidelines for a bioanalytical assay. The intra- and inter-batch precision was ≤4.6%, and neratinib was found to be stable under various stability conditions. The mean internal standard-normalized matrix factor and recovery were 0.997 and 95.4%, respectively. The validated method was successfully applied to a pharmacokinetic study in healthy subjects with different doses.