Identification, characterization and quantification of a new impurity in deferasirox active pharmaceutical ingredient by LC-ESI-QT/MS/MS.

An unknown impurity was detected in deferasirox drug substance by a newly developed high performance liquid chromatography (HPLC) method. The unknown impurity was identified by liquid chromatography-tandem mass spectrometry using electrospray ionization source and Q-trap mass analyzer (LC-ESI-QT/MS/MS). Based on LC-MS/MS data and knowledge of the synthetic scheme of deferasirox, this impurity was proposed as the regio-isomer of deferasirox.