99mTc-labelling studies of solubilized ligands—Part I

Abstract

The 99mTc labelling of a homologous series of some 2,3-diaminoalkanes has been studied with a view to obtaining their in vivo distribution in animal models. In this ligand series, hydrophilicity decreases to higher members and technetium labelling in aqueous medium becomes difficult. However, when individual ligands were first solubilized with the aid of Tween 80, technetium cationic complexes were afforded in good yield. The surfactant itself did not label under the conditions at which high percentage technetium ligand complexes were obtained, but the labelling seems to depend on a particular Tween-to-ligand concentration ratio. The 99mTc-diamine complexes were found to be stable not only within a wide range of pH but also for over 24 h after preparation. The partition coefficients and protein binding of the complexes were also measured and presented.