Micronization of aztreonam with supercritical anti-solvent process

The ultra-fine particles of antibiotic aztreonam have been successfully prepared via a supercritical anti-solvent (SAS) process, by using the mixtures of dimethyl sulfoxide (DMSO) and ethanol as solvents and carbon dioxide as an anti-solvent. A series of precipitation experiments was conducted at different pressures, temperatures, and concentrations of the mixed solvents to explore the influence of these process parameters on the characteristics of the resultant particles. The experimental results reveal that submicron aztreonam particles with narrow size distribution were generated in supercritical region, while expanded micro-spheroids were formed in superheated vapor region.

► Supercritical anti-solvent technique has been used for micronization of aztreonam.
► Phase behavior plays an important role to control the size of particulate products.
► Uniform submicro-metric particles can be generated in supercritical phase region.