Continuous supercritical fluid extraction of emulsions to produce nanocapsules of vitamin E in polycaprolactone

Vitamin E in polycaprolactone nanoparticles was continuously produced by supercritical fluid extraction of emulsions using a high-pressure packing column in countercurrent mode. This operating mode reduces the amount of solvent required, increases production capacity and enables lower residual organic solvent concentrations in the raffinate. At 8.0�MPa and 313�K, with a packing height of 2�m, and a solvent to feed ratio of 5�kg�L⁻¹, the residual acetone concentration was 1400�ppm, far below 5000�ppm, and therefore suitable for pharmaceutical applications. The process was also simulated with Aspen Plus. It would be necessary to increase the packing height to 3.5�m or the CO₂flow rate to 60�g�min⁻¹in order to get a residual acetone concentration suitable for food applications (50�ppm). The nanoparticles produced were non-aggregated spheres, which had an encapsulation efficiency higher than 70% and particle size at the nanoscale.