Levofloxacin was labeled with 99mTc using cysteine\cdot HCl as co-ligand and SnCl2.2H2O as reducing agent. The influence of various parameters such as amount of cysteine\cdot HCl, reducing agent, pH value, and reaction time on labeling process was studied. After optimizing the conditions the labeling was performed at pH 5 using 1 mg of levofloxacin, 500 m g of cysteine\cdot HCl, 50 m g of SnCl2.2H2O, and 15 min reaction time. The radiochemical purity was determined with the help of instant thin layer chromatography (ITLC) and reverse phase high performance liquid chromatography (RP-HPLC) which was more than 95% and was stable for up to 6 h. Biodistribution of 99mTc-levofloxacin (99mTc-lefx) was studied in infection induced rat models using live Staphylococcus aureus and heat killed S. aureus (sterile inflammation model). In the case of the live S. aureus induced abscess model, the accumulation of 99mTc-lefx at target was 3.96, which was higher than that of 99mTc-ciprofloxacin (99mTc-cifx), taken as the control.

Levofloxacin was labeled with 99mTc using cysteine\cdot HCl as co-ligand and SnCl2.2H2O as reducing agent. The influence of various parameters such as amount of cysteine\cdot HCl, reducing agent, pH value, and reaction time on labeling process was studied. After optimizing the conditions the labeling was performed at pH 5 using 1 mg of levofloxacin, 500 m g of cysteine\cdot HCl, 50 m g of SnCl2.2H2O, and 15 min reaction time. The radiochemical purity was determined with the help of instant thin layer chromatography (ITLC) and reverse phase high performance liquid chromatography (RP-HPLC) which was more than 95% and was stable for up to 6 h. Biodistribution of 99mTc-levofloxacin (99mTc-lefx) was studied in infection induced rat models using live Staphylococcus aureus and heat killed S. aureus (sterile inflammation model). In the case of the live S. aureus induced abscess model, the accumulation of 99mTc-lefx at target was 3.96, which was higher than that of 99mTc-ciprofloxacin (99mTc-cifx), taken as the control.