Solid solubility measurement of ipriflavone in supercritical carbon dioxide and microparticle production through the rapid expansion of supercritical solutions process

Abstract In this study, the solid solubilities of ipriflavone in supercritical CO2 were measured by using a semi-flow apparatus. The Chrastil equation, Mendez-Santiago and Teja equation, and a solution model developed from the regular solution model and Flory–Huggins equation were adopted to correlate the measured solubility data. Because the solubility in mole fraction of ipriflavone can be as high as 10−4, the rapid expansion of supercritical solutions (RESS) process was adopted to produce ipriflavone microparticles. The effects of the operating parameters of the RESS process on the mean particle size of ipriflavone were evaluated and discussed. In addition, based on the results of powder X-ray diffraction, differential scanning calorimetry, and Fourier-transform infrared spectrometry analysis, particulate ipriflavone exhibited consistency with the unprocessed sample in terms of crystal structure, melting temperature, and spectrometric properties.