METHOD DEVELOPMENT AND VALIDATION STUDY FOR QUANTITATIVE DETERMINATION OF GENOTOXIC IMPURITY AND ITS PRECURSOR IN FLUCONAZOLE SAMPLE BY LIQUID CHROMATOGRAPHY–TANDEM MASS SPECTROMETRY

Objective: The objective of this work is method development and validation study for quantitative determination of 1-[2-(2,4-difluorophenyl)-2,3-epoxypropyl]-1H-1,2,4-triazole, a genotoxic impurity and its precursor in a fluconazole drug sample by liquid chromatography–tandem mass spectrometry. Methods: LC-MS/MS analysis of these impurities was performed on Hypersil BDS C18 (100 mm x 4.0 mm, 3 µm) column. 5 mmol ammonium acetate and acetonitrile in the ratio of 65:35 (v/v) was used as the mobile phase with a flow rate of 0.4 ml/min. The developed method was accomplished with a short run time of 10 min. Triple quadrupole mass detector coupled with positive electrospray ionization was used for the quantification of genotoxic impurities in multiple reaction monitoring (MRM). Results: The method was validated as per International Conference on Harmonization (ICH) guidelines. The method was linear in the range of 0.30 µg/g to 11.37 µg/g for impurity A and 0.30 µg/g to 11.34 µg/g for impurity B with a correlation coefficient of 0.999. The accuracy of the method was in the range of 98.25 % to 100.53 % for both impurities. Conclusion: A specific, selective, highly sensitive and more accurate analytical method using LC-MS/MS coupled with positive electrospray ionization has been developed for the quantification of genotoxic impurity (1-[2-(2,4-difluorophenyl)-2,3-epoxypropyl]-1H-1,2,4-triazole) and its precursor (1-(2,4-difluorophenyl)-2-[1,2,4]triazol-1-yl-ethanone) at 0.3 µg/g with respect to the 5.0 mg/ml of fluconazole.