A process, method and/or system for preparing polymer-coated nanoparticles
and/or other ultrafine particles utilizing a supercritical fluid, e.g.,
supercritical carbon dioxide (SC CO.sub.2), as an antisolvent that may be
added to a solution of a polymer and an organic solvent in which
insoluble nanoparticles or the like are suspended. The coating process
occurs when the supercritical fluid (e.g., SC CO.sub.2) and the
nanoparticle-containing suspension are combined to cause the suspended
nanoparticles to precipitate as coated nanoparticles. Processing
parameters for optimizing and/or enhancing the efficacy and/or efficiency
of the coating process, method and/or system and for controlling the
coating and/or agglomeration of coated particles are also described. The
process, method and/or system has wide ranging applicability, e.g., for
coating and/or encapsulation of pharmaceuticals, cosmetics, food
products, chemicals, agrochemicals, pesticides, polymers, coatings,
catalysts and the like.