Formation of salbutamol sulphate microparticles using solution enhanced dispersion by supercritical carbon dioxide

Salbutamol sulphate (SS) was precipitated by supercritical carbon dioxide (SC-CO2) using a homemade system at two different pressures. This process is characterized by spraying a methanolic solution of the drug into the supercritical fluid (SCF), extraction of the solvent by SC-CO2 and formation of drug particles. The morphology and size distribution of precipitated SS particles were characterized using scanning electron microscope and laser diffraction particle size analyzer respectively. FTIR spectra were used before and after processing to asses crystal modifications. Depending on the processing conditions, needle-like and flake-like particles with different size distributions were observed. The average size of the flake like particles was less than needle-like particles and the span parameter showed a narrower size distribution of the processed in comparison with the unprocessed materials. Analysis by FTIR showed that there was no significant effect on the structure of the drug under these processing conditions.