Encapsulation of Superparamagnetic Iron Oxide Nanoparticles by the Supercritical Antisolvent Process

The aim of the experiments in this research was to produce a coated superparamagnetic iron oxide nanoparticle (SPION) product that may be used as a contrasting agent for MRI. There are several methods that can be employed to coat SPIONs. However, many of the current methods employ toxic organic solvents which can be difficult to remove from the product solution. The encapsulation and characterization of SPIONs in Eudragit was done using a supercritical antisolvent system (SAS) with ethanol as the solvent and supercritical carbon dioxide (SC-CO2) as the antisolvent. Particles of diameters less than 200 nm were produced which had preserved superparamagnetic properties. An encapsulation efficiency of 70 % was achieved.