Comparative Biological Evaluation of 99mTc-Timonacic Acid Prepared Using Different Reducing Agents as a Complex for Hepatobiliary Imaging.

Timonacic acid (TCA) was labeled with 99mTc in the presence of three different reducing agents: NaBH4, Na2S2O4, and SnCl2·2H2O. The optimum conditions were as follows: with Na2S2O4, pH 8, 7 mg of Na2S2O4, room temperature, 2 mg of TCA, 30 min (radiochemical yield 98 ± 0.3%, complex was stable for 24 h); with NaBH4, pH 8, 10 mg of NaBH4, room temperature, 2 mg of TCA, 30 min (radiochemical yield 95 ± 0.3%, complex was stable for 6 h). The biodistribution of the complex in mice was studied. The liver uptake depends on the reducing agent used, reaching in 30 min 33.5 ± 0.3, 18.4 ± 0.18, and 22.3 ± 0.3% ID/g for the complexes prepared using Na2S2O4, NaBH4, and SnCl2·2H2O, respectively. [ABSTRACT FROM AUTHOR]