Classic processes for particle coating usually work with organic
solvents to bring in the coating substances and use high temperatures
to evaporate these solvents (organic phase separation, spray
drying, solvent separation and emulsification/solvent evaporation).
Both, high temperatures and residuals of organic solvents are problematic
in case of drug treatment, since organic solvents might be
harmful, not only for the human beings but also for the environment,
and many pharmaceutical products are temperature sensible
and will suffer fromhigh processing temperatures. Therefore, there
has been a continuing growth of interest in replacing conventional
organic solvents with environmentally friendly supercritical solvents
in encapsulation processes. As a result, particle design has
become an important part of supercritical fluids (SCF) applications
in pharmaceutics, as well as in food, cosmetics, and several areas
of industrial chemistry. The need for high-purity products together
with the lowcost and easy recoverability of carbon dioxide makes it
an attractive solvent in the industrial processing of pharmaceuticals