99mTc-hexakis(2-methoxy-isobutyl-isonitrile)(99mTc-MIBI) a new myocardial imaging agent: synthesis of MIBI, optimising conditions for radiolabelling with 99mTc at high radiochemical purity and in vivo behavior

99mTc-MIBI is a promising radiopharmaceutical for myocardial perfusion imaging agent, but it has also shown good results in identifying several types of tumors, such as breast, lung and thyroid cancers. It is a lipophilic, cationic technetium (1) complex. In this paper a complete study on the synthesis of 2-metohy-isobutyl-isonitrile (MIBI) as well as a formulation of a lyophilized kit for labeling with 99mTc is presented. Investigation on effective factors as well as finding out the optimum parameters to obtain the highest labelling efficiency and radiochemical purity of 99mTc-MIBI complex were performed. The radiochemical purity of the labelled preparation was high (>95%). Biodistribution study performed in health male Wistar rats showed satisfactory biokinetics results. 99mTc-MIBI was accumulated in sufficient amount into the hearth tissue for myocardial perfusion imaging. MIBI in kit formulation was found to be stable and also safe for administration. (author)