Preparation, Biodistribution, and Scintigraphic Evaluation of 99mTc-Clindamycin: an Infection Imaging Agent

Bacterial infection is found to be the cause of death throughout the world. Nuclear medicine imaging with the help of radiopharmaceuticals has great potential for treating infections. In the present work, clindamycin, a lincosamide antibiotic, was labeled with technetium-99 m (similar to 380 MBq). Clindamycin has been proven to be efficient for treating serious infections caused by bacteria such as Staphylococcus aureus. Quality control, characterization, biodistribution, and scintigraphy of radiolabeled clindamycin were done, and labeling efficiency was determined by ascending paper chromatography. More than 95 % labeling efficiency with technetium-99 m (Tc-99m) was achieved at pH 6-7 while using 2.5-3 mu g SnCl2 center dot H2O as a reducing agent and 100 mu g of ligand at room temperature. The characterization of the compound was performed by using electrophoresis, HPLC and shake flask assay. Electrophoresis indicates the neutral behavior of Tc-99m-clindamycin. HPLC analysis confirms the single specie of the labeled compound, while shake flask assay confirms high lipophilicity. The biodistribution studies of Tc-99m-clindamycin were performed Sprague Dawley rats bearing bacterial infection. Scintigraphy and biodistribution studies showed a high uptake of Tc-99m-clindamycin in the liver, heart, lung, and stomach as well as at S. aureus-infected sites in rabbits.