Preparation,characterization and biodistribution of a new technetium‐99 m nitrido complex with 2‐methoxyisobutylisonitrile and comparison with 99mTc–MIBI

The preparation of complex ^99mTcN–MIBI was carried out using two alternative procedures that led to the formation of the complex with high radiochemical purity (>90%). The partition coefficient, electrophoresis and cationic resin exchange experiments showed that the ^99mTcN–MIBI is a lipophilic and neutral complex, the structure of this complex is six‐coordinate distorted octahedral, its composition may be [^99mTcNCl₂(MIBI)₃], and the optimized geometry of this complex was calculated by using Gaussian 98 for Window (G98W) program. The biodistribution of ^99mTcN–MIBI shows high myocardial uptake and good target/non‐target ratios in mice at early post‐injection time, for 5 min post‐injection the heart‐to‐blood, heart‐to‐lungs and heart‐to‐liver ratios are 3.18, 1.72 and 1.42, respectively. In respect of the relatively good rations after 5 min and the rapid clearance from non‐target, the complex ^99mTcN–MIBI may be suitable for instant myocardial imaging. In addition, the lyophilized kit enables the convenient preparation of this complex for clinical use. Based on these promising properties, ^99mTcN–MIBI should be a new potential myocardial perfusion‐imaging agent. Copyright © 2002 John Wiley & Sons, Ltd.