A new technology to form nanoparticles of hydrophobic organic actives at high concentration and yield, as well as methods to characterize the process, are presented. In Flash NanoPrecipitation, an organic active and an amphiphilic diblock copolymer are molecularly dissolved in an organic phase and mixed rapidly with a miscible anti-solvent to afford precipitation of the active with a tunable, narrow submicron particle size distribution from 1 µm to 80 nm. The enabling components are a novel ‘analytical’ (quantified mixing time) confined impinging jets (CIJ) mixer for millisecond stream homogenization and amphiphilic diblock copolymers which alter the organic nucleation and growth, provide steric stabilization for the particles, and offer a functional surface for the particle. Applications in enhanced pharmaceutical delivery, dye preparation, and pesticide formulation are specifically targeted.

Hydrophobic ion pairing has emerged as a method to modulate the solubility of charged hydrophilic molecules ranging in class from small molecules to large enzymes. Here we review the application of hydrophobic ion pairing for encapsulating charged hydrophilic molecules into nanocarriers.