» Xenon Xe 133 Injection is a sterile, isotonic solution of Xenon 133 in Sodium Chloride Injection suitable for intravenous administration. Xenon 133 is a radioactive nuclide prepared from the fission of uranium 235. It contains not less than 90.0 percent and not more than 110.0 percent of the labeled amount of Xenon 133 at the date and time stated on the label.