GTIs evaluation: analytical tactic to quantitate the GTIs at the Threshold of Toxicological Concern level

The toxicity of Abacavir sulfate API impurities, N NITROSO [2-Amino-5-nitroso-4,6-pyrimidinediol] and FADCP [2-Amino-4,6-Dichloro-5-Formamido Pyrimidine] were checked by the software model Case Ultra and the study result was class 3 potential genotoxic impurities (GTIs). A delicate analysis method was developed for the impurity’s quantification followed by the validation study, employing an electrospray ionization probe with a triple quadrupole liquid chromatography mass spectrometer. Multiple reaction monitoring tactics were selected in positive ionization for the impurity’s quantification of Abacavir sulfate. A gradient mode system was used by employing, 1.0ml of formic acid in water and organic solvent acetonitrile (LCMS grade) as a mobile phase A and B separately with SB Phenyl Zorbax (5.0μm, 4.6mm x 250mm) analytical column. The developed quantification method flow rate was set at 0.5 mL/min whereas 45 minutes was the run time. The developed method linearity range for FADCP started from 0.76ppm and ended at 3.79ppm. For N NITROSO, it started from 0.75ppm and ended at 3.76ppm when compared with the concentration of Abacavir sulfate drug, showing 1.0 and 0.9996 correlation coefficients separately. The method recovery was 111.7% to 98.7% for N NITROSO impurity and 101.7% to 104.3% for FADCP impurity.