Preparation and characterization of [99mTc(DMPE)2X2]+, X = Cl, Br (DMPE = 1,2-bis(dimethylphosphino)ethane).

The preparation of "no-carrier-added" [99mTc(DMPE)2X2]+ (X = Cl, Br) in greater than 95% radiochemical purity, suitable for in vivo evaluation as a myocardial imaging agent, is described. Reaction parameters that lead to the formation of the desired products, as well as those that lead to the formation of the major impurities, are delineated. These 99mTc species are characterized by HPLC using the known 99Tc analogs as standards. Myocardial images obtained in mongrel dogs with [99mTc(DMPE)2X2]+ (X = Cl, Br) are briefly discussed.