Published methods for radiolabelling of 1,4,7-triazacyclononane-1,4,7-triacetic acid ubiquicidin (NOTA-UBI) 29-41 to date describe manual or kit-based procedures. The purpose of this study was to develop an automated synthesis method for the synthesis of [ 68 Ga]Ga-NOTA-UBI. NOTA-UBI was successfully labelled with gallium-68 using the three different automated procedures. The use of radical scavengers to improve radiochemical purity is also discussed. The automated procedures showed a high degree of robustness and repeatability. The validated automated synthesis protocols using a Scintomics GRP Module will contribute to provide GMP-compliant [ 68 Ga]Ga-NOTA-UBI for clinical infection imaging.

No abstract

The labeling of peptides with gallium-68 is often initially performed by manual labeling, but with high clinical demand, other alternatives are needed. Coldkits or automated synthesis are viable options for standardized methods and deemed pharmaceutically more acceptable. This study compares these [ 68 Ga] Ga-PSMA-11 production methods. Data from 40 kit-based and 40 automated syntheses of [ 68 Ga]Ga-PSMA-11 were analyzed. Pre-set criteria were evaluated including radiochemical purity, radionuclidic purity, chemical purity, physiological acceptability and sterility. The operator time and radiation dose received were measured. The robustness and repeatability of each method were assessed and a comparison of the running costs of each method is also provided. For both the methods all the analyzed products met the release criteria. No differences were found in radiochemical purity, radiochemical identity, radionuclidic purity, and sterility. However, radiochemical yield and apparent molar activity showed significant differences. For both methods, whole body radiation exposure to operators was lower than with manual labeling (25-40 μSv). The exposure during kit-based labeling (14.5 ± μSv) was seven times higher than that of automated synthesis (2.05 ± 0.99 μSv). The automated synthesis was the more expensive method. Both methods are sound alternatives to manual synthesis and offer higher quality, better radiation protection and a more reliable manufacturing of radiopharmaceuticals.

The single vial kit formulations met the quality release specifications for human administration and appear to be highly advantageous over using peptide stock solutions in terms of stability and user-friendliness.