Synthesis of 188Re-MDP complex using carrier-free 188Re

The synthesis of a rhenium-MDP labelled compound using carrier-free 188Re from the 188W/188Re generator was investigated. Stannous chloride was used as the reducing agent for the reduction of rhenium. Dependence of the yield of Re-MDP upon the concentration of reducing agent, reaction time, antioxidant, pH, temperature, ionic strength and adding the carrier was examined. Under optimum conditions, the yields of Re-MDP were 85–89% using carrier-free 188Re and 92–95% using carrier-added 188Re. Furthermore, the stability of Re-MDP at different pHs was studied.