Validated Chromatographic Method for the Determination of Process Related Genotoxic Impurity in Lansoprazole

An LC-MS method for the simultaneous determination of process related impurity of 2-Chloromethyl-3-methyl-4-(2, 2, 2-trifluoroethoxy) pyridine Hydrochloride (CMTP, 1) and RP-LC method for the routine determination of 1 in Lansoprazole (2) was presented. In LC-MS, Hypersil BDS C-18 (150 X 4.6 mm, 5 μm) column was used with mobile phase containing buffer (0.01 M ammonium acetate), acetonitrile, and methanol in 50:45:5 v/v ratios. The flow rate was 0.8 mL min⁻¹ and elution was monitored at 205 nm. LC analysis of 1 was done on Synergi polar RP-80A (250 X 4.6 mm, 4 μm) column using mobile phase containing buffer (0.1% triethyl amine) and acetonitrile in 65:35 v/v ratio. The flow rate was 0.8 mL min⁻¹ and elution was monitored at 205 nm. Both methods were validated as per International Conference on Harmonization (ICH) guidelines. LC-MS is able to quantitate up to 0.9 ppm, whereas with RP-LC up to 30 ppm of 1 could be quantitated.