Large-Scale Production of 119mTe and 119Sb for Radiopharmaceutical Applications

Radionuclides find widespread use in medical technologies for treating and diagnosing disease. Among successful and emerging radiotherapeutics, 119 Sb has unique potential in targeted therapeutic applications for low-energy electron-emitting isotopes. Unfortunately, developing 119 Sb-based drugs has been slow in comparison to other radionuclides, primarily due to limited accessibility. Herein is a production method that overcomes this challenge and expands the available time for large-scale distribution and use. Our approach exploits high flux and fluence from high-energy proton sources to produce longer lived 119m Te. This parent isotope slowly decays to 119 Sb, which in turn provides access to 119 Sb for longer time periods (in comparison to direct 119 Sb production routes). We contribute the target design, irradiation conditions, and a rapid procedure for isolating the 119m Te/ 119 Sb pair. To guide process development and to understand why the procedure was successful, we characterized the Te/Sb separation using Te and Sb K-edge X-ray absorption spectroscopy. The procedure provides low-volume aqueous solutions that have high 119m Te-and consequently 119 Sb-specific activity in a chemically pure form. This procedure has been demonstrated at large-scale (production-sized, Ci quantities), and the product has potential to meet stringent Food and Drug Administration requirements for a 119m Te/ 119 Sb active pharmaceutical ingredient.