Radiosynthesis and biological evaluation of 111In-tris [8-Hydroxy-2-methylquinoline] complex as a possible imaging agent

Introduction: Due to the interesting pharmacological properties of radiolabeled metal oxine derivatives such as cell internalization, tumor avidity and antiproteosome activity, 111In-tris[8-Hydroxy-2-methylquinoline] (111In-HMQ) was developed in this study. Methods: 111In-HMQ was prepared using 111InCl3 and 8-Hydroxy-2-methylquinoline (HMQ) for 60 min at 100°C (radiochemical purity: >99% ITLC, >99% HPLC, specific activity: 13-14 GBq/mmol). Stability of the complex was checked in final formulation and in the presence of human serum for 48 h. The partition coefficient was calculated for the compound (log P=0.68). Results: The biodistribution of the labeled compound in vital organs of wild-type rats was studied using scarification studies and SPECT up to 24 h. A detailed comparative pharmacokinetic study for 111In cation and 111In-HMQ are performed up to 24h. Conclusion: The complex is mostly cleaned from the circulation by kidneys and is a compound rapidly washing from the circulation. The biodistribution of the complex in tumor models is on-going.