The Nuclear Regulatory Commission (NRC) is amending its regulations to permit NRC licensees to distribute a radioactive drug containing one microcurie of carbon-14 urea to any person for ``in vivo'' diagnostic use. The NRC has determined that the radioactive component of such a drug in capsule form presents an insignificant radiation risk and, therefore, regulatory control of the drug for radiation safety is not necessary. This amendment makes the drug more widely available and reduces costs to patients, insurers, and the health care industry. This action grants a petition for rulemaking (PRM-35-12) from Tri-Med Specialties, Inc. and completes action on the petition.