One-pot Synthesis and Encapsulation of Hydrophilic Drug in Uniform Microparticles for Controlled Release

The route for single step synthesis and encapsulation of a model hydrophilic drug onto homogeneous microparticles for controlled release applications is described. The microfluidic spray drying technique, able to handle complex fluids, was used to produce uniform particles with adjustable functionality. Here, an aqueous polymeric dispersion of Eudragit NE was used as the controlled release matrix, with no organic solvent required. This study investigated the effects of additives in the form of lactose and silica nanoparticles on the release properties of the microparticles. Depending on precursor composition, the evaporation-induced self-assembly during drying resulted in a heterogeneous spatial distribution of drug and matrix materials. Accordingly, these particulate systems demonstrated intricate release kinetics compared with the behavior of a single material system. We demonstrated that the release properties, whether immediate or sustained, could be directly tuned using this route as an effective approach to design new spray-dried pharmaceutical systems.