Direct Labeling Method of Lomefloxacin With ⁹⁹Tc^m

The purpose of this study was to determine the best conditions in synthesis of ⁹⁹Tc^m lomefloxacin.Lomefloxacin was directly labeled by Na⁹⁹Tc^mO₄, the effects on labeling yield by lomefloxacin, stannous chloride, pH and temperature were evaluated, the labeling yield, stability, and lipid/water partition coefficient were analyzed. The results showed that the labeling yield was more than 95% and the radiochemical purity of ⁹⁹Tc^m-lomefloxacin was 96.98%. The optimized synthesis conditions of ⁹⁹Tc^m-lomefloxacin were containing 3 mg lomefloxacin, 150 μg SnCl₂·2H₂O, pH 6, 10 min and 60 ℃. ⁹⁹Tc^m lomefloxacin has an excellent radiochemical characters. ⁹⁹Tc^m-lomefloxacin was fat soluble. These results demonstrated that the direct labeling method of ⁹⁹Tc^m-
lomefloxacin was easy and efficient.