Toxicity estimation using QSAR methodology and analytical approach for the accurate determination of two potential genotoxic impurities in Abacavir Sulfate antiviral drug at TTC level by liquid chromatography-mass spectrometry (LC-MS/MS)

Abstract

Toxicity estimation of N-(2-amino-4,6-dichloropyrimidin-5-yl) formamide (FADCP) and 2-Amino-5-Nitroso Pyrimidine-4,6-diol (N NITROSO) impurities were done using Case ultra-software and both the impurities found Mutagenic under the class 3. The sensitive analytical method was established and validated for the potential genotoxic impurities, FADCP, and N NITROSO in the Abacavir Sulfate drug sample using Liquid chromatography-tandem mass spectrometry (LC-MS/MS). Zorbax SB Phenyl (250mm x 4.6mm, 5.0μm) column was used to quantify the genotoxic impurities using LC-MS/MS. Formic acid (0.1%) was used as mobile phase A and acetonitrile (LCMS grade) was used as mobile phase B in gradient mode. The flow rate and run time of the developed quantification method were 0.5 mL/min and 45minutes. A tandem mass spectrometer consisting of triple quadrupole coupled with an electrospray ionization source, multiple reaction monitoring targeted approach of LC-MS/MS with the positive ionization mode was used to quantify the potential genotoxic impurities. The linearity range covered in the developed method was 0.76ppm to 3.79ppm for N-(2-amino-4,6-dichloropyrimidin-5-yl) formamide (FADCP) and 0.75ppm to 3.76ppm for 2-Amino-5-nitroso Pyrimidine-4,6-diol (N NITROSO) with respect to Abacavir Sulfate drug sample concentration with a correlation coefficient 1.000 & 0.9996 respectively. The accuracy of the method was in the range of 101.73% to 104.33% for FADCP impurity and 111.68% to 98.66% for N NITROSO impurity. This developed LC-MS/MS method is validated as per the International Council on Harmonization (ICH) guidelines and is able to quantify the potential genotoxic impurities at minimal levels.