The aim of this work was to develop a new radiopharmaceutical for lung perfusion scintigraphy that does not carries, contrary to radiopharmaceuticals derived from human albumin currently used, the risk of transmitting infectious agents. For this purpose, a new starch-based microparticulate system has been conceived. In order to form stable complexes with Technetium-99m, the starch microparticles were modified by oxidation and functionalized with a polyamine ligand. Optimization of the formulation was carried out using experimental plans. The starch-based microparticles (SBMP) were characterized and the subject of in vitro and in vivo Technetium-99m labeling stability studies. The most promising SBMP formulation was investigated during further biodistribution and imaging studies on healthy animals and in a model of pulmonary embolism. With an average size between 20 and 30 μm, a high radiochemical purity (> 95%), the ability to be formulated as ready-to-use kits and to be sterilized by gamma radiation, the SBMP possess also a good labeling stability and meet therefore the requisites of an effective radiopharmaceutical for lung perfusion scintigraphy.
