Preparation of the renal function and imaging agent 99mTc-MAG3 starting from S-unprotected mercaptoacetyltriglycine

A new approach that obviates inconvenient heating of the labelling solution when preparing the renal function and imaging agent 99mTc-MAG3 is described. The labelling procedure involves reduction of 99mTc-generator eluate with stannous chloride in alkaline solution in the presence of S-unprotected mercaptoacetyltriglycine (MAG3) and the co-ligand sodium tartrate, followed by neutralization with a phosphate buffer solution. After optimization of the kit preparation the radiochemical purity of the radiopharmaceutical amounts to greater than 98%. During the labelling process intermediate Tc-species occur.