Supercritical antisolvent precipitation from an emulsion: β-Carotene nanoparticle formation

Supercritical antisolvent precipitation of β-carotene from an oil-in-water emulsion in which the solute is dissolved in the droplets that confirm the dispersed phase has been studied, with the objective of producing particles with a mean particle size in the nanometer scale. The aim of the current research work was to confirm the possibility to control the particle size of the carotene + surfactant suspensions obtained with this process, with the initial drop size present in the emulsions. The final products were formed by particles with a mean size below 400 nm in suspension in an aqueous media, which was also the mean droplet size of the emulsion. This result suggests that produced particles are encapsulated in surfactant micelles. The final suspension was then lyophilized and observed by means of a scanning electron microscopy. In order to obtain a better comprehension of the process, a mass transfer model was developed. This model is based on previous observations of the evolution of the organic phase drop and the solute, obtained with a view cell.