Preparation and biodistribution of novel 99m Tc(CO) 3 ‐CNR complexes for myocardial imaging

We evaluated lipophilicity and biodistribution of a series of 99m Tc(CO) 3 ‐ether isonitrile complexes to determine whether different lipophilicity and structure of isonitrile ligands would improve the imaging properties of the radiopharmaceutical for the heart. Novel 99m Tc(CO) 3 ‐MIBI analogs were prepared and analyzed by radio‐HPLC, and their lipophilicity was determined. These new complexes could be bi‐ or tri‐substituted in specified pH conditions like 99m Tc(CO) 3 ‐MIBI. These new complexes exhibited low liver, lungs and blood uptake compared with [ 99m Tc(CO) 3 (MIBI) 3 ] + though their heart uptake was not so high. Among these complexes, [ 99m Tc(CO) 3 (EPI) 2 (OH 2 )] + showed higher target to non‐target ratios at 5 and 30 min post‐injection than that of [ 99m Tc(CO) 3 (MIBI) 3 ] + . Copyright © 2007 John Wiley & Sons, Ltd.