Stability of the radiopharmaceutical []DMSA: Study of the ligand exchange reaction with [99Tc]EDTA

Abstract A kinetic study was made of the ligand exchange reaction between [ 99 m Tc]EDTA and DMSA. The results of this study indicate that this exchange reaction is closely related to temperature and pH. Kinetic and thermodynamic parameters demonstrate that both complexes—[ 99 m Tc]EDTA and [ 99 m Tc]DMSA—have a similar stability. Furthermore, the existence of an acid-basic catalysis for the global exchange reaction was established, and the catalytic parameters were calculated. These data were obtained by radiochromatography and visible spectrophotometry.