Development and validation of an analytical method for quantitative determination of three potentially genotoxic impurities in vildagliptin drug material using HPLC-MS.

Abstract

A novel high-performance liquid chromatography-mass spectrometry method was developed to determine the quantities of pyridine, 4-dimethylaminopyridine, and N, N-dimethylaniline impurities in vildagliptin drug material. These impurities are reactive bases that may be used in synthesis of vildagliptin pharmaceutical ingredients. They are considered as potentially genotoxic impurities since they contain electrophilic functional groups. Therefore, these impurities should be monitored at the allowed limits in vildagliptin. Hence a high-performance liquid chromatography-mass spectrometry method was developed to quantify the amounts of these impurities in vildagliptin. The column was KROMASIL CN (250mm × 3.9mm, 3.5μm) in reversed-phase mode. The mobile phase was a mixture of water-methanol (55:45) containing 2.5mM ammonium acetate and 0.1% formic acid. The mass spectrometer was used to detect the amounts of impurities using selected ionization monitoring mode at m/z=80, 122, and 123 for pyridine, N, N-dimethylaniline, and 4-dimethylaminopyridine, respectively. The flow rate was 0.5mL/min. The sensitivity of the method was excellent at levels very less than the allowed limits. The method had excellent linearity in the concentration ranges of limit of quantification-150% of the permitted level with coefficients of determination above 0.9990. The recovery ratios were in the range of 93.70-108.63%. Results showed good linearity, precision, accuracy, sensitivity, selectivity, robustness, and solution stability.