Characterization of a novel process-related impurity in commercial bendazac lysine eye drops by LC-ESI-QTOF/MS/MS and NMR

- Two impurities of bendazac lysine eye drops were identified by LC-MS.
- A known impurity was characterized rapidly by comparison with reference standard.
- A new impurity was confirmed by QTOF MS and NMR after preparative isolation.
- The mechanism for the formation of the two impurities was discussed.