Cyclen-containing phosphonic acids as components of osteotropic 68Ga radiopharmaceuticals

The known methods of preparation of cyclen-containing phosphonic acids, promising components of radiopharmaceuticals, have been improved, and new approaches have been developed. Application of D-31 and D-13 NMR spectroscopy for initial screening of complex formation between cyclen-containing phosphonic acids and Ga3+ in D2O has been demonstrated. The conditions of Ga-68 complex formation with cyclencontaining phosphonic acids and estimation of their radiochemical yield in water by means of thin-layer chromatography have been elaborated. A correlation between the NMR and TLC data has been found. Biological distribution of the selected Ga-68 radiopharmaceuticals has been determined in vivo from the positron emission tomography data. The obtained standardized uptake values point at the osteotropicity of the Ga-68 compounds.