Synonyms: Ondansetron Hydrochloride Dihydrate Imp. G (EP), Ondansetron Imp. G (EP), (3RS)-3-[(1H-Imidazol-1-yl)methyl]-9-methyl-1,2,3,9-tetrahydro-4H-carbazol-4-one, C-Demethylondansetron, Ondansetron Hydrochloride Dihydrate Impurity G, Ondansetron Impurity G