Production of Nanostructured Microspheres Biopolymer-Active Principle-Magnetic Nanoparticles by Supercritical Assisted Atomization

Supercritical Assisted Atomization (SAA) has been applied to the production of nanostructured microspheres ampicillin-chitosan-magnetic nanoparticles (AMP-CH-NMPs). Several ampicillin/chitosan (AMP/CH) ratios with a fixed content of NMPs were processed in acid water solutions, to produce microspheres with different size, drug content and amount of NMPs. To verify the successful formation of microparticles, drug content and nanoparticle dispersion, they were characterized by SEM (Scanning Electron Microscope), EDX (Energy Dispersive X-ray), TGA (ThermoGravimetric Analysis), HPLC (High Performance Liquid Chromatography), UV-vis obtaining information on morphology, particle size distribution, nanostructure, loading of active principle in the polymeric matrix and drug release rate. Spherical microparticles were obtained, with a maximum particle size of 2 mu m and loading efficiencies up to 99%. The microspheres produced by SAA showed a controlled release of the drug over about 72 h.