Micronization of drugs using supercritical carbon dioxide

Particles from gas saturated solutions, a novel method for high pressure material processing, has been used for micronization of practically insoluble calcium-channel blockers nifedipine and felodipine and the hypolipidemic agent fenofibrate with the aim of increasing their dissolution rate and hence their bioavailability. Dependent on the pre-expansion conditions, a mean particle size of between 15 and 30 mu m was achieved for micronized nifedipine and 42 mu m for micronized felodipine. The particle size of processed fenofibrate, on the other hand, increased due to agglomeration. The highest dissolution rate was achieved by preparation of drug coprecipitates with PEG 4000. (C) 1999 Elsevier Science B.V. All rights reserved.