Study of aerodynamic and release properties of inhaled particles containing cyclodextrins

The aim of this study was to investigate the influence of different cyclodextrins (CyD) on physical characteristics of inhalation dry powders. The particle size was characterised by Aerosizer^® LD and aerodynamic behaviour of inhaled complexes assessed by twin-stage liquid impinger. The in vitro release profile of the powders was studied through Franz cell modified method. Produced particles showed a suitable size for pulmonary delivery, ranging between 1 and 5 μm. The nature of the CyD affected the powders performance on reaching the lower compartment (“Lungs”), mainly by the altering their aerodynamic properties, which is reflected on the different percentages of their emitted respirable fractions. HP-γ-CyD:fluticasone propionate complex showed a fast release of corticosteroid while γ-CyD had a constant release throughout time. The best characteristics for pulmonary delivery were obtained with acetyl-γ-CyD:fluticasone propionate complex.