Preparation and evaluation of modified composition for lyophilized kits of [Cu(MIBI)4]BF4 for [99mTc] technetium labeling

Abstract

The [Cu(MIBI)4]BF4 complex was synthesized and different formulations for lyophilized kits that could be cost-effectively used with different routines in nuclear medicine laboratories were investigated. In one preparation the kit components were kept similar to the Cardiolite® , except that the SnCl2.2H2O concentration was increased to 0.150 mg. In a second formulation, component concentrations were reduced to 1/5 of the original value and the SnCl2.2H2O concentration was adjusted to 0.04 mg. These products were labeled with maximum activities of 55.5 GBq and 8.14 GBq, respectively, and have shown an average radiochemical purity of 95 %. Biodistribution of the products was assessed by dissection in mice and in rabbits, and did not show any statistical difference when compared to Cardiolite®. In the synthesis of [Cu(MIBI)4]BF4 a new procedure was introduced for the synthesis of N-(2-methyl-propenyl)-formamide, with the use of microwave radiation as heat source. This modification reduced the reaction time to 25 seconds, while maintaining a yield of 68%.