Recently, supercritical fluids (SFs) have been used in applications closely related to biotechnology. For example, they have been proposed as media for processing biocompatible polymers to develop new products for medical and pharmaceutical applications (1 ). It was shown that SFs are suitable for the micronization of pharmaceuticals to obtain controlled drug-delivery systems characterized by particles with a desired small size, a narrow size distribution, and uniformly impregnated by the drug (2 ).