Abstract
In this study, hydroxypropyl-beta-cyclodextrin (HP-β-CD) particles were produced using supercritical assisted atomization (SAA) with carbon dioxide as the spraying medium or co-solute and aqueous ethanol solution as the solvent. The effects of several key factors on the morphology and size of the HP-β-CD particles were investigated. These factors included the solvent effect, temperatures of the precipitator and saturator, concentration of the HP-β-CD solution, and flow rate ratio of carbon dioxide to the HP-β-CD solution. The conducive conditions for producing fine spherical particles were 54.2% (w/w) aqueous ethanol as the solvent; precipitator and saturator temperatures of 373.2 K and 353.2 K, respectively; a flow rate ratio of carbon dioxide to HP-β-CD solution of 1.8; and low concentrations of HP-β-CD solution. The addition of leucine (LEU) enhanced the aerosol performance of the HP-β-CD particles, and the fine particle fraction (FPF) of the HP-β-CD particles with the addition of 13.0 mass% LEU was 1.8 times higher than that of the HP-β-CD particles without LEU. This study shows that LEU can act as a dispersion enhancer and that HP-β-CD particles produced using SAA can be used as pulmonary drug carriers.