Striking medium effects on the kinetics of decomposition of macrocyclic Cu2+ complexes: Additional considerations to be taken when designing Copper-64 radiopharmaceuticals

The kinetics of decomposition of a macrocyclic Cu2+ complex is strongly dependent on the anions in solution. In particular, chloride anions accelerate significantly the decomposition process, even out of the stopped-flow time scale. Given the different Cl− concentrations in biological media, the possibility of changes in the decomposition kinetics must be considered when designing 64Cu radiopharmaceuticals.