Micronization of Levan, a Fructose-based Amphiphilic Polymer, using Supercritical CO2 as Antisolvent

Abstract

Levan is a fructose polysaccharide with potential applications in biomedicine and the food industry, as it can form particles in water (approximately 120 nm) through a self-assembly process. Despite this phenomenon, the levan size in powdered form cannot be controlled using conventional techniques, which hinders its use in various applications where the powdered form is required.
Based on the previous fact, the supercritical antisolvent technique (SAS) was used to process levan (previously synthesized with a cell-free methodology) to obtain the polymer in powdered form with a controlled particle size distribution. Specifically, particles ranging from 300 to 500 nm were obtained depending on the experimental conditions (pressure and temperature), but always working above the mixture critical point of the solvent-antisolvent system (CO₂-DMSO). Moreover, nimesulide as a model drug was coprecipitated with the polymer, obtaining a controlled-release drug delivery system. These results highlighted that amphiphilic polymers (levan) can be processed with supercritical CO₂ to control the particle size of the polymer in powdered form.