According to the USP, what is the minimum radiochemical purity percentage for most 99mTc-labeled radiopharmaceuticals to be administered to patients?

The correct percentage for the minimum radiochemical purity required for most 99mTc-labeled radiopharmaceuticals to be administered to patients is 90%. Ensuring a minimum radiochemical purity is crucial for the safety and effectiveness of radiopharmaceuticals. A radiochemical purity of 90% means that at least 90% of the administered radiopharmaceutical consists of the desired radiolabeled compound, ensuring reliable imaging and diagnostic results while minimizing potential adverse effects from impurities that could alter pharmacokinetics or biodistribution.

By establishing this threshold, the United States Pharmacopeia (USP) aims to promote standardization and quality in radiopharmaceutical preparation, allowing clinicians to have confidence in the integrity of the products they administer. A purity lower than 90% could lead to inconsistent results and potentially harmful side effects, which is why this standard is critical in nuclear medicine practice.