Identification, characterization and quantification of new impurities by LC-ESI/MS/MS and LC-UV methods in rivastigmine tartrate active pharmaceutical ingredient.

Six impurities were detected at trace level in rivastigmine tartrate drug substance by a newly developed high performance liquid chromatography method. Three impurities were characterized rapidly and three impurities were found to be unknown. The unknown impurities were enriched and identified with a combination of semi-preparative HPLC and LC/MS/MS techniques.