β-Cyclodextrin Inclusion Complexes of Budesonide with Enhanced Bioavailability for COPD Treatment

Chronic obstructive pulmonary disease (COPD) is a life-threatening disease of the respiratory system, affecting many patients worldwide. Budesonide (BUD), a synthetic glucocorticosteroid applied for the treatment of COPD patients, is a hydrophobic compound with low bioavailability. The formation of inclusion complexes of hydrophobic compounds with β-cyclodextrin (CD) through the solvent evaporation technique is an appealing method for the amelioration of the compounds’ in vitro release behavior. In the present study, CD–BUD complexes were prepared through the solvent evaporation technique. The effect of the applied solvent was evaluated through FTIR, scanning electron microscopy (SEM), X-ray diffraction (XRD) analysis, and in vitro release behavior measurements. It was found that the optimum complexes with the minimum degree of crystallinity and the optimum in vitro release behavior are prepared in the solvent ratio H2O/EtOH 80/20 v/v. In a further step, the formation of CD–BUD complexes containing different amounts of BUD was prepared. Through XRD measurements, the degree of crystallinity of the samples was calculated confirming the diminished crystallinity of BUD in CD complexes. The in vitro release of the samples showed the improved release behavior of BUD from the complexes in comparison to neat BUD while a direct correlation between the degree of crystallinity and in vitro release behavior was demonstrated.