» Thallous Chloride Tl 201 Injection is a sterile, isotonic, aqueous solution of radioactive thallium (²⁰¹Tl) in the form of thallous chloride suitable for intravenous administration. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of ²⁰¹Tl as chloride, expressed in megabecquerels (microcuries or millicuries) per mL, at the time indicated in the labeling. Other chemical forms of radioactivity do not exceed 5.0 percent of the total radioactivity. It may contain a preservative or stabilizer.