Facile radiochemical separation of clinical-grade 90Y from 90Sr by selective precipitation for targeted radionuclide therapy

Abstract Introduction The widespread clinical utilization of 90 Y for preparation of target specific radiopharmaceuticals demands development of a facile, efficient and cost-effective method for radiochemical separation of 90 Y from 90 Sr via 90 Sr/ 90 Y generator. In this article, we describe an efficient and facile method for radiochemical separation of 90 Y from 90 Sr for preparation of radiopharmaceuticals by exploiting the large difference in the solubility product constants (K sp ) of Y(OH) 3 and Sr(OH) 2 . Methods A two-step radiochemical separation procedure based on selective precipitation of 90 Y under alkaline conditions from 90 Sr/ 90 Y equilibrium mixture was developed. The 90 Y(OH) 3 colloid formed at pH ~ 10 was selectively trapped in 0.22 μm sterile filter and was subsequently retrieved by dissolution in HCl solution. Detailed quality control analyses of obtained 90 Y were carried out and its utility towards preparation of different radiopharmaceuticals was assessed. Results Using the same feed solution of 90 Sr (3.7 GBq), consistent and repeated separation of 90 Y could be achieved in different batches with >85% yield and >99.999% radionuclidic purity. Yttrium-90 obtained from this process was found suitable for preparation of therapeutically relevant doses of three different radiopharmaceutical formulations, namely, 90 Y-DOTA-TATE, 90 Y-PSMA-617 and 90 Y-CHX-A″-DTPA-Cetuximab with >95% radiochemical purity. Conclusions The promising results obtained in this study would facilitate implementation of the developed technique for obtaining 90 Y in adequate quantity and of required purity from a centralized radiopharmacy setup.