90Y and 105Rh labelled preparations: Potential therapeutic agents

90Y and 105Rh formulations were studied with an aim to prepare therapeutic radiopharmaceuticals. 90Y obtained from a 90Sr-90Y generator as chloride was complexed with known ligands such as DTPA, EDTMP and DOTA as well as a few other phosphonate ligands. Particulates such as 90Y labelled ferric hydroxide macroaggregates (FHMA) and 105Rh-sulphur colloid were prepared and studied for their stability in buffers and human serum. The studies on the complexation of 90Y and the preparation of radiolabelled particulates are described. 90Y complexed nearly quantitatively with DTPA, DOTA and EDTMP under optimised conditions of reaction pH, temperature and ligand concentrations. Both 90Y-FHMA and 105Rh-S colloid could be prepared in high yields under optimised conditions. The labelled particulates were measuring 20-100 μm and 1-20 μm, respectively and were found to be very stable in buffers as well as human serum at 37 deg. C. The particulates have the potential for use as radiosynovectomy agents and for therapy of cancers such as hepatomas. (author)