Simultaneous Determination of Imatinib and N-desmethyl Imatinib in Human Plasma by Two-Dimensional Liquid Chromatography and Its Clinical Application

OBJECTIVE To establish a simple and sensitive method based on two-dimensional liquid chromatography for the determination of imatinib and N-desmethyl imatinib in human plasma. METHODS Samples were directly injected and analyzed after simple deproteinization pretreatment. Samples were preliminarily extracted and separated with on the one-dimensional chromatographic column Aston SX1(3.5 mm×25 mm, 5 μm), and transferred from the one-dimension chromatographic column to the two-dimension chromatographic column as Aston SCB(4.6 mm×125 mm, 5 μm) through the intermediate column Aston SCB(4.6 mm×10 mm, 3.5 μm) for secondary separation analysis. The one-dimensional mobile phase was CAA-1D extractant with the flow rate of 0.8 mL·min^-1 and the two-dimensional mobile phase was imatinib-2D flowing phase with the flow rate of 1.2 mL·min^-1, the column temperature was 40℃. The concentration of imatinib and N-desmethyl imatinib were tested under the the wavelength of 264/235 nm. RESULTS It was found that the plasma concentration of imatinib and N-desmethyl imatinib showed a good linear relationship with their peak areas over the concentration range of 13.44-1 400 ng·mL^-1 and 13.17-1 372 ng·mL^-1, respectively(r²=0.999 9, r²=0.999 9). The mean recoveries obtained from three concentrations of imatinib(33.60, 896, 1 120 ng·mL^-1) and N-desmethyl imatinib(32.93, 878.08, 1 097.6 ng·mL^-1) were higher than 96% and 98%, respectively. The intra-day and inter-day RSD for imatinib and N-desmethyl imatinib were both <5.0%. CONCLUSION The method showed good accuracy, good reproducibility and high degree of automation. This method is more superior than traditional HPLC and can be applied to determine the clinical plasma concentration of imatinib and its pharmacokinetic studies.