STABILITY-INDICATING HPLC METHOD FOR THE DETERMINATION OF RELATED SUBSTANCES IN LANSOPRAZOLE INTERMEDIATE

A novel, reversed-phase liquid chromatographic method was developed and validated for the determination of related substances in lansoprazole intermediate. Symmetric peak shape was on a C18 stationary phase with the dimensions of 250 mm column length, 4.6 mm as internal diameter, 5 microns particles with an economical and straightforward mass-compatible mobile phase combination of formic acid/triethylamine and acetonitrile delivered in gradient mode at a flow rate of 1.0 mL/min at 260 nm. The resolution between lansoprazole intermediate (LAN20) and its impurities (LAN20-I & LAN20-II) in the developed method was more than 2.0, indicating a significant separation. Regression analysis shows a correlation coefficient greater than 0.999 for lansoprazole intermediate and its related substances. The detection and quantitation limits of lansoprazole intermediate and its impurities are 0.01% and 0.005%. This method indicates that the recovery at different levels is 90 to 110% accurate. The test solution was stable in the diluent for 48 h and subjected to stress conditions. The mass balance was close to 99.5%