Application of an LC-MS/MS Method in Quantification of Hexyl Chloroformate Content in Dabigatran Etexilate Mesylate
Application of an LC–MS/MS Method in Quantification of Hexyl Chloroformate Content in Dabigatran Etexilate Mesylate
A selective and sensitive liquid chromatography–mass spectrometry (AB SCIEX QTRAP 5500) method was developed for quantitative determination of genotoxic impurity, hexyl chloroformate, in drug substance. The method was developed by derivatizing the hexyl chloroformate (HCF) to complex compound hexyl benzylcarbamate (HBC) by reaction with benzylamine. This method provided good sensitivity for quantification of hexyl chloroformate at a concentration of 10 ppm in 10 mg/mL DEM sample solution. The compounds were chromatographed under isocratic condition on poroshell EC-C18 (2.7 μm particle packed in 4.6 x 50 mm column) column with mobile phase of 0.1% v/v ammonium hydroxide in water (pH adjusted to 6 using acetic acid) and acetonitrile in ratio of 1:1 v/v at the flow rate of 1.0 ml/minute with triple quadrupole Q-Trap 5500 mass spectrometer operated in multiple reaction monitoring mode (MRM). To produce transition ion of 236/152 the molecular mass of 236(M+H) was used as molecular ion. Positive mode electro spray ionization (ESI) was employed as the ionization source. The developed method was validated in terms of specificity, limit of detection (LOD), limit of quantification (LOQ), linearity, precision, accuracy, and robustness. The LOD & LOQ were found at 2.1 and 4.2 ppm, respectively.