The Establishment of the Enterprise Internal Control Quality Standard for No-carrier-added Lutetium ¹⁷⁷Lu Chloride Solution

To establish the stable and reliable analytical methods and the enterprise internal control quality standard for no-carrier-added lutetium ¹⁷⁷Lu chloride solution which is a key material of therapeutic radiopharmaceuticals, the radiochemical purity, radionuclidic purity, radioactivity concentration, element impurities, endotoxin, etc. of lutetium ¹⁷⁷Lu chloride solution were tested, and these analytical methods were verified. Three batches of lutetium ¹⁷⁷Lu chloride solution were tested, and the results met the requirements. The radiochemical purity were greater than 99%, ¹⁷⁶Yb and other γ impurities were not detected in radionuclidic purity test, the contents of impurity elements met the corresponding requirement, bacterial endotoxin was less than 2.00 EU/mL, the main γ energy peaks of ¹⁷⁷Lu were presented at 0.113 MeV and 0.208 MeV, and the radioactivity concentration was 90.0%-110.0% of the concentration declared on the label. The internal control quality standard was established based on the development and verification of the analytical methods and the test results of three batches. The analytical methods and internal control quality standard of no-carrier-added lutetium ¹⁷⁷Lu chloride solution have been successfully established, which laid a foundation for the preparation and translational researches of ¹⁷⁷Lu therapeutic radiopharmaceuticals.