Quantitative Determination of Imatinib in Human Plasma with High-Performance Liquid Chromatography and Ultraviolet Detection

A simple and sensitive high-performance liquid chromatography (HPLC) method was developed to quantitate imatinib in human plasma. Imatinib and the internal standard dasatinib were separated using a mobile phase of 0.5% KH2PO4 (pH3.5)-acetonitrile-methanol (55:25:20, v/v/v) on a CAPCELL PAK C18 MG II column (250 mm x 4.6 mm) at a flow rate of 0.5 ml/min and measurement at UV 265 nm. Analysis required 100 mu L of plasma and involved a solid phase extraction with an Oasis HLB cartridge, which gave recoveries of imatinib from 73% to 76%. The lower limit of quantification for imatinib was 10 ng/ml. The linear range of this assay was between 10 and 5000 ng/mL (regression line r(2) > 0.9992). Inter- and intra-day coefficients of variation were less than 11.9% and accuracies were within 8.3% over the linear range. The plasma concentrations of imatinib obtained by our present method were almost the same as those assayed by an LC-MS-MS method at the bray Research Center, Inc. This method can be applied effectively to measure imatinib concentrations in clinical samples.