Supercritical antisolvent micronization of some biopolymers

We processed various biopolymers by semi-continuous supercritical antisolve nt precipitation (SAS) to evaluate the possibility of producing nano and mi cro-particles of controlled size and distribution. First, some liquid expan sion curves were experimentally produced to study the general behavior of t he ternary systems antisolvent-solvent-biopolymer. A condition that guarant ees a successful SAS micronization is that solute does not modify the expan sion curves of the solvent-antisolvent binary system. SAS experiments were performed by varying the process parameters; we mainly studied the influenc e of pressure, temperature and liquid solution concentrations. SEM images o f the processed material were used to study morphologies, mean particle siz e and particle size distribution. We successfully processed by SAS dextran, poly-L-lactide (PLLA) and poly-(hydroxypropylmethacrylamide) (HPMA), using dimethylsulfoxide (DMSO) and dichloromethane (DCM) as liquid solvents. (C) 2000 Elsevier Science B.V. All rights reserved.