Electroless semi-automatic synthesis of 225Ac-labeled PSMA-derivatives for clinical application and evaluation of rechelation capability

INTRODUCTION: Ac. METHODS: An iQS module was equipped with sterile single-use components and an already automated radiolabeling process was adopted to the semi-automatic system. Three validation batches for two different mcp-based PSMA derivatives were produced including quality control with criteria fulfilling clinical standards. RESULTS: ) led to similar retention times combined with a higher resolution in the radio-HPLC chromatograms. The effect of rechelation was carefully evaluated using an excess amount of precursor. It was found that, with increasing concentration, a rechelation of free progenies occurred from 22 to 144 h. Either the reaction solution or the diluted product solution was analyzed by TLC and HPLC. CONCLUSIONS: Ac-labeled macropa-containing peptides without electricity. ADVANCES IN KNOWLEDGE: Ac-radiopharmaceuticals with 10× increased molar activity compared to DOTA- or DOTAGA-based precursors and diluted product solution leads to higher stability and lesser radiolysis due to the rechelation effect compared to the reaction solutions.