The chemistry underlying the kit formulation of 99mTcMAG3, a new radiopharmaceutical for renal function studies

99mTcMAG3, a potential replacement for 123I and 131I 0-iodohippuran in renal function studies, is now available via a cold kit formulation that provides a product of excellent radiochemical purity and stability. The chemistry that underlies this kit formulation includes (1) characterization of the structure and properties both of TcMAG3 and of Tc-containing impurities present in early kit formulations, (2) a new approach to the synthesis of the MAG3 ligand to eliminate the source of potential radiolabeled impurities, and (3) detailed modifications of earlier generation kit formulations