Detection of Two Genotoxic Impurities in Drug Substance and Preparation of Imatinib Mesylate by LC-MS/MS

摘要

As a potential DNA damaging substance, genotoxic impurities have been concerned by regulatory authorities in various countries. Two genotoxic impurities were found in imatinib mesylate which was a classical small molecule inhibitor of tyrosine kinase, and the analysis method has never been reported. A LC-MS/MS method was developed for the analysis of two genotoxic impurity materials: N-(5-amino-2-methylphenyl)-4-(3-pyridyl)-2-aminopyrimidine (IMA) and N-(2-methyl-5-nitrophenyl)-4-(pyridin-3-yl) pyrimidin-2-amine (IMN). The HPLC method utilized an ACQUITY UPLC HSS T3 C18 (150 x 2.1 mm, 1.7 mu m) maintained at 40 degrees C. The mobile phase consisted of 0.02 M ammonium formate buffer (pH 3.4) and acetonitrile (containing 0.05% formic acid) in gradient elution mode. Detection was performed by triple quadrupole mass spectrometry fitted with ESI probe functioning in the positive ion mode and the following m/z 278/106 and 308/262 were used as qualifier and quantifier transitions. Flow rate was 0.4 mL min(-1). The validation data demonstrated that the method had high sensitivity and selectivity. A linear calibration curve (correlation coefficient, r > 0.998) was obtained at the concentration range of 0.02-35.27 and 0.02-28.86 ng mL(-1), respectively. The LOD of IMA in drug substances, tablets, and capsules were 0.0039, 0.0043, and 0.0044 ng mL(-1), and LOD of IMN were 0.0034, 0.0035, and 0.0036 ng mL(-1), respectively. Precision and accuracy were within the acceptable limit. The drug substances, tablets, and capsules from three manufacturers were used for inspection and all samples met the requirements. The developed LC-MS/MS method is robust and can be applied to detect the genotoxic impurities in imatinib mesylate.