Chemical and biological evaluation of 99mTc (CO)3 and 99mTc complexes of some IDA derivatives

The confirmation that N-substituted imidodiacetic acids, as small and simple ligand systems containing amines and carboxylic acids, could be coordinated to the tricarbonyl core and form inert complexes with [99mTc (CO)3(H2O)3]+, is demonstrated. The HPLC quality control results of 99mTc-carbonyl tagged IDA molecules, performed by gradient HPLC, have shown that HIDA, EHIDA and p-butyl-IDA form complexes with [99mTc(CO)3(H2O)3]+, with a labeling yield of ~90% for each of 99mTc(CO)3 IDA derivatives. However, the changes in the structure of labeled compounds, e.g., EHIDA, influence the changes in the biological behavior. In comparison with 99mTc-EHIDA, the biliary excretion of 99mTc(CO)3 EHIDA was lower, but the urinary excretion higher.