Development and Validation of LC–MS/MS Method for the Quantitation of Infliximab in Human Serum

Abstract

Liquid chromatography tandem mass spectrometry (LC–MS/MS), especially triple-quadrupole mass spectrometry, has become an attractive alternative method to ligand binding assays for therapeutic monoclonal antibody quantification in biological samples, but the use of an internal standard with infliximab LC–MS/MS assays has not been reported yet. In this study, an improved LC–MS/MS method for quantification of infliximab in human serum was developed and validated. A surrogate peptide was used as a representative of infliximab which was cleaved for the quantification of infliximab based on LC–MS/MS assay. A stable isotope-labeled signature peptide was used as the internal standard (IS). The results showed linearity in the range of 0.39–100 μg mL−1; the lower limit of quantification (LLOQ), and the lower limit of detection were 0.39 and 0.0975 μg mL−1, respectively. The quality control (QC) data showed that the within-run, between-run precision (%RSD) and accuracy (%RE) conformed to the acceptance criteria of ±15 % for calibration standards and QCs (±20 % at the LLOQ). Other validation parameters including selectivity, methanol precipitation efficiency, serum matrix effect, stability, and auto-sampler carry-over were also evaluated. This improved LC–MS/MS method might be a promising LC–MS-based methodology for pharmacokinetic studies of other recombinant monoclonal antibodies.