Development of a high‐performance liquid chromatography method for rapid radiochemical purity measurement of [<sup>18</sup>F]PSMA‐1007, a PET radiopharmaceutical for detection of prostate cancer
Joseph A. Ioppolo, Eva Alvárez de Eulate, Danica Cullen, Shifaza Mohamed, Laurence Morandeau
Abstract
Since first becoming commercially available in 2018, the PET radiopharmaceutical [ 18 F]PSMA‐1007 has been used widely for the diagnosis and staging of prostate cancer. A pharmacopoeia monograph first became available in 2021, prescribing a radiochemical purity specification of >91%, based on analytical results from both TLC (for [ 18 F]fluoride impurity alone) and HPLC (for all other 18 F‐impurities). Though this monograph has provided clarity for the quality control testing of [ 18 F]PSMA‐1007, it prescribes a HPLC method using phosphate buffer mobile phase that may present a risk of precipitation of phosphate salts in the HPLC system. The method also requires specialised hardware not immediately available to all laboratories. This work describes the development of a simple, rapid reversed‐phase HPLC method utilising 0.1 M ammonium formate mobile phase for the accurate assessment of both [ 18 F]fluoride impurity and overall radiochemical purity in a single test. This method is especially useful for assessment of product stability over time. A more accurate TLC method for [ 18 F]fluoride impurity is also described.