An HPLC and UHPLC-HRMS approach to study PSMA-11 instability in aqueous solution

Abstract Background The stability of precursors and reagents is utmost importance for developing a robust radiolabelling method that provides high constant radiochemical yield purity. While performing the QC [ 68 Ga]Ga-PSMA-11 injectable solutions according to Ph. Eur. Monograph has recently been published, trend instability standard PSMA-11, same used as precursor radiosynthesis, observed. This led formation side product in time-dependent manner. this compound, besides making implementation analytical more difficult, negatively influenced purity by increasing gallium-68 colloidal ionic forms. Results nature was investigated adding chelators, such EDTA, PSMA-11 using combination UHPLC-HRMS. results definition structure, nat Fe-PSMA-11, from high-affinity chelator HBED-CC, present molecule environmental Fe (III). Conclusions Strategies reduce risk low radiolabeling yields increase an aqueous solution were also discussed.