HYDROXAMAMIDE AS A CHELATING MOIETY FOR THE PREPARATION OF TC-99M RADIOPHARMACEUTICALS .2. THE TC-99M COMPLEXES OF HYDROXAMAMIDE DERIVATIVES

In a search for a basic ligand structure to coordinate with the radiom etal technetium (Tc), three different hydroxamamide derivatives, benzo hydroxamamide, p-toluhydroxainamide and 4-pyridylhydroxamamide were sy nthesized. Radiolabeling was carried out easily using the stannous tar trate method and high yields or complexes with Tc-99m at room temperat ure over a wide pH range were obtained. The Tc-99m-complexes formed wi th each ligand showed good stability and their organ distribution, blo od clearance and urinary excretion in mice were screened. The presence of the substituted group showed little effect on the in vitro or in v ivo stability of these Tc-99m complexes. Thus, the hydroxamamide-based ligand may be a useful new chelating moiety for designing Tc-99m radi opharmaceuticals.