In this study we demonstrate the use of flash evaporation to rapidly remove tetrahydrofuran (THF) from a mixed solvent stream used to produce block copolymer stabilized nanoparticles by Flash NanoPrecipitation (Johnson & Prud'homme, 2003). The effectiveness of the solvent removal by flash evaporation is, in part, due to the strong non-ideality in the THF:water vapor-liquid equilibrium. The application has been demonstrated for the nanoparticle-formulation of model hydrophobic solute, β-carotene stabilized by PEO-b-PS (3k-b-1k) block copolymer. The dependence of stability of nanoparticles on the fraction of solvent present and degree of supersaturation have been analyzed.
Vacuum flash evaporation is especially well suited as the solvent removal process coupled with nanoparticle formation by Flash NanoPrecipitation. The process can easily scale from the laboratory-scale preparation of research samples, to large scale production.