4-(5-(bis(2-chloroethyl-1,1,2,2-d4)amino)-1-methyl-1H-benzo[d] imidazol-2-yl)butanoic acid, hydrochloride,4-(5-(bis(2-chloroethyl-1,1,2,2-d4)amino)-1-methyl-1H-benzo[d] imidazol-2-yl)butanoic acid, hydrochloride,"Labeled Bendamustine, intended for use as an internal standard for the quantification of Bendamustine by GC- or LC-mass spectrometry.",Bendamustine Stable Isotopes