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. ^99mTc‐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 µg 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 ^99mTc‐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 ^99mTc‐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 © 2007 John Wiley & Sons, Ltd.