Ciprofloxacin-99mTc: labeling and biodistribution in infection diagnostic

Labeling and biodistribution studies with the antibiotic ciprofloxacin were done using as radio marker Tc-99m. The aims were to optimize the labeling procedures as well as to analyze its efficacy in the diagnosis of infection sites, healthy and experimentally infected animals were employed to this purpose. On basis of optimized parameters a freeze-dried could be formulated containing 2 mg ciprofloxacin, 30 μg SnCl2HO and 5 mg ascorbic acid. This preparation could be easily activated by the addiction of Na99mTc)4 a maximum value of 3700 MBq after a reaction time of 10 minutes only. Yield of the labeling technique higher than 95%, radiochemical stability reached 6 hours after preparation, and shelf life till 2 months was demonstrated. Biodistribution investigations revealed high renal excretion, low concentration in liver and soft tissues, along with affinity for the bacterial focus 1.7-2.4 times higher than for normal tissues. This protocol demonstrated the potential of ciprofloxacin-99mTcs a diagnostic agent for infections process. (author)