Azelastine EP Impurity BMethylazepan benzohydrazideAzelastine EP Impurity B DiHCln'-(1-Methylazepan-4-yl)benzohydrazideN'-(1-methylazepan-4-yl)benzohydrazide hydrochloride1-Benzoyl-2-(1-methylhexahydro-1H-azepin-4-yl)diazaneN''-[(4RS)-1-Methylhexahydro-1H-azepin-4-yl]benzohydrazide1-Benzoyl-2-[(4RS)-1-methylhexahydro-1H-azepin-4-yl]diazaneBenzoic acid, 2-(hexahydro-1-Methyl-1H-azepin-4-yl)hydrazide