RESEARCH NOTES: Production of Submicroparticles of beta-Sitosterol Using an Aerosol Solvent Extraction System

The submicroparticles of beta-sitosterol were produced by using an aerosol solvent extraction system (ASES) and characterized by scanning electronic microscope (SEM), X-ray diffraction (XRD), and Fourier transform infrared (FT-IR) analysis. The effects of operational parameters including pressure, temperature, solution concentration, and ratio of flow rate (CO2/solution, r) on particle size (PS), yield, and morphology were investigated. The results showed that microparticles of beta-sitosterol (less than 1000 nm size and larger than 70% yield) could be obtained at 10-15 MPa, 35-50 deg C, 15 mg*ml-1, 10/1(r); beta-sitosterol particles were found to occur as three mophologies: flakes, rods, and spheres by varying ratio of flow rate or solution concentration. In contrast, the crystallinity of beta-sitosterol decreased, whereas its molecular structure remained almost unchanged after being ASES-treated. Therefore, ASES was an effective method to produce submicroparticles of beta-sitosterol.