Powder coating and dissolution rate modification of L-leucine supplements with hydrophilic fumed SiO2 nanoparticles by ultrasonic irradiation in high-pressure liquid CO2

Abstract The dissolution properties of L-leucine (L-Leu) supplements with hydrophobic surfaces were improved by coating particles with hydrophilic fumed SiO2 nanoparticles (Aerosil 200FAD) using ultrasonic irradiation in high-pressure liquid carbon dioxide (CO2). Shock waves generated by the collapse of cavitation bubbles induced by ultrasonic irradiation accelerated the deagglomeration and dispersion of SiO2 nanoparticles and achieved dry-particle coating in high-pressure liquid CO2. The dissolution rate of the L-Leu microparticles was increased by coating with SiO2 nanoparticles. The effects of the experimental conditions (size and concentration of the SiO2 nanoparticles, coating method, depressurizing method, and ultrasonic irradiation time) on the morphology and dissolution rate of the composite particles were also investigated.