Flash NanoPrecipitation (FNP)is a new technology for the preparation
of multifunctional nanoparticles (NPs) via rapid solvent
displacement using amphiphilic diblock copolymers to direct precipitation
of hydrophobic species. The process is composed of
two steps: (1) the hydrophobic actives along with amphiphilic
diblock copolymers are dissolved in a water miscible organic solvent
such as tetrahydrofuran or acetone; and (2) the organic
phase is rapidly mixed with an antisolvent (water) in a multiinlet
vortex mixer (MIVM) to create homogeneous mixing on the
order of milliseconds. Details of the design of the MIVM apparatus
have been described elsewhere [13–15]. In the process, high
supersaturation is induced by the rapid mixing which drives the
hydrophobic actives and the hydrophobic block ofthe copolymer to
precipitate simultaneously. All hydrophobic components are kinetically
trapped in the core. The NPs are sterically stabilized by the
hydrophilic block of the copolymer as it precipitates onto the surface
of the aggregating core components. The block copolymer
adsorption arrests aggregation, affording nanoparticles with narrow
size distributions. In contrast to slow equilibrium processes,
FNP offers high loading capacity, control over size and incorporation
of multiple actives in the same nanoparticle. A wide range of
successful applications of FNP have been demonstrated for encapsulation
of various hydrophobic drugs, peptides, imaging agents, or
a combination of both therapeutics and inorganic colloids [16–20]