Technetium-99m labeling and freeze-dried kit formulation of levofloxacin (L-Flox): A novel agent for detecting sites of infection

In this study, the labeling method of levofloxacin with technetium-99m and its biological evaluation were described. Tc-99m-L-Flox was synthesized via direct complexation with technetium-99m in the presence of stannous chloride dihydrate as reducing agent. The optimum amounts of the reactants are: 1-2 mg levofloxacin, 150 mu g stannous chloride dihydrate and 48-1490 MBq pertechnetate. The reaction mixture was bring to pH 6 and kept at room temperature for 30 min. The labeled levofloxacin was stable for more than 8 h. The in vivo evaluation of Tc-99m-L-Flox in man-induced inflammation models showed that this tracer was localized with different values. The live E. Coli model had the highest value which was 2.9%, the heat killed E. coli model had a value of 2.0%, and the turpentine oil model had a value of 1.2% at 24 post injection, while the non-inflamed muscle had activity of 0.5%. All the gathered biological data support the usefulness of Tc-99m-L-Flox as infection imaging agent. The freeze-dried form of Sn-L-Flox was prepared and found meet all the radiochemical and biological tests. Copyright (c) 2007 John Wiley & Sons, Ltd.