Micronization of luteolin using supercritical carbon dioxide: characterization of particles and biological activity in vitro

Abstract The reduction in particle size alters the physical structure of the compound, modifying its dissolution rate, solubility, and bioavailability. Luteolin is a flavonoid that can be found particularly in fruits and vegetables; in addition to its antioxidant and anti-inflammatory activity, it has relevant effects in some types of cancer and diseases caused by insufficiency of neurotransmitters, however, its low solubility and bioavailability limit its functional applications. In this context, the objective was to study micronization by GAS to evaluate in vitro improvements in the properties of luteolin. The process reduced the average particle size by 10 times; PXRD and DSC demonstrated the modification in the crystal structure and FTIR proved the preservation of the compound. In vitro tests showed an increase in water solubility, in addition to increases in dissolution rate and antioxidant activity. GAS potentiated in vitro therapeutic effects, enabling in vivo tests and pharmaceutical and food applications.