» Iobenguane I 131 Injection is a sterile solution containing iobenguane sulfate in which a portion of the molecules contain radioactive iodine (¹³¹I) in the molecular structure. Iobenguane I 131 Injection contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of ¹³¹I as iobenguane sulfate expressed in megabecquerels (or in millicuries) per mL at the time indicated in the labeling. It may contain preservatives or stabilizers.