Production, chemical separation and characterization of 186+188Re, 153Sm and 99Mo, products of radiopharmaceutical use

Full text: The development of therapeutic and diagnosis radiopharmaceuticals involves the production and radiochemical processing of the isotopes, synthesis of ligands, complex studies with radiometals, conjugation of the ligands complexes with carrier molecules and bio-evaluation in suitable animal models. The work carried out for the preparation of radionuclides and products of radiopharmaceutical used for the development of therapeutic radiopharmaceuticals is discussed in this paper. 186+188Re and 153Sm are two strong beta and weak gamma-emitters having short half-lives and are intensely studied as promising radionuclides for radiotherapy. They are used for bimolecular or other agent labelling. 99Mo is a gamma-emitter and 99mTc, the 'daughter' from 99Mo-99mTc generator, is used for preparation of diagnosis radiopharmaceuticals. 186+188Re, 153Sm and 99Mo have been obtained by irradiation in the 14 MW TRIGA-SSR-Reactor at INR-Pitesti. 10 mg of natural metal rhenium powder of analytical purity, having the isotopic composition 185Re - 37.1 % and 187Re - 62.9 %, was irradiated for one week at 5 x 1013 n/cm2. The target was dissolved in H2O2 by gentle warming and stirring and then treated with sodium hydroxide until the 6 pH value. 10 mg of natural samarium trioxide and 100 mg molybdenum trioxidatum powder of analytical purity were irradiated in same conditions. After that the samarium target was dissolved in HCl and the molybdenite target in sodium hydroxide solution. The final products (Na 186,188ReO4; 153SmCl3; Na299MoO4) were characterised. The radiometrological, physico-chemical, biological and microbiological parameters were checked by measuring the activity, radionuclidic and radiochemical purity, and pH value. (authors)