Influence of the preparation method on the physicochemical properties of econazole-β-cyclodextrin complexes

Econazole (C18H15Cl3N2O) is one of the common antifungal agents whose poor aqueous solubility restricts its use for the treatment of oropharyngeal candidiasis, which is the first symptom of HIV infection. Therefore, the aim of the current study was to investigate the effect of different preparation methods (i.e. kneading, coevaporation, sealed-heating, and supercritical carbon dioxide (SC CO2)) for obtaining solid inclusion complexes between beta-cyclodextrin and econazole. The physico-chemical properties of the different products were characterized by differential scanning calorimetry (DSC), Fourier transform infrared spectroscopy (FTIR) and powder X-ray diffractometry (PXRD). For the complexes prepared by the SC CO2 method, the effects of temperature and pressure have also been investigated and related to the solubility of econazole in SC CO2. Results suggested the validity of the SC CO2 method for preparing solid complexes between cyclodextrins and econazole, avoiding the use of organic solvents and problems of their complete removal. Moreover, temperature played a major role in promoting drug-carrier interactions, whereas pressure had limited effects.