Changes In The Radiochemical Purity Of [18f]Fdg Radiopharmaceutical According To The Amount Of Ethanol Added

Background: we aimed to find the optimal level of ethanol that can be added such that the radiochemical purity of [F-18]FDG is increased and the MFDS and USP stipulated guidelines are met. Materials and Methods: Changes in the radiochemical purity of [F-18]FDG were analyzed according to changes in the concentrations of ethanol added. The study used 1 L of 99.9% pure ethanol. The ethanol concentrations used were 0.0% (0 mu L) for the control group and 0.1% (1 mu L), 0.2% (2 mu L), and 0.3% (3 mu L) for the experimental groups. Since the radiochemical purity of [18F]FDG may differ according to the radioactive concentrations used, four different radioactive concentrations were prepared: 1580 mCi/16 mL, 3320 mCi/16 mL, 4840 mCi/16 mL, and 6470 mCi/16 mL. Results: The radiochemical purity of [F-18]FDG increased significantly when ethanol was added to it at different radioactive concentrations in comparison to when ethanol was not added. When ethanol concentrations of 0.1%, 0.2%, and 0.3% were added, the radiochemical purity increased at all radioactive concentrations (100 mCi/mL, 200 mCi/mL, 300 mCi/mL, and 400 mCi/mL) while meeting the KP and USP standards even after 10 hours following the EOS. Conclusion: It was determined in our study that adding ethanol at the concentration of 0.1% to [F-18]FDG is most suitable as it generates the least residual ethanol while maintaining the radiochemical purity of [18F]FDG at stable levels that meet the KP and USP standards.