Formation and antimycotic effect of cyclodextrin inclusion complexes of econazole and miconazole

The stability constants between β-cyclodextrin (β-CD) and the two antimycotic imidazole derivatives, miconazole and econazole were measured. Increased ionization of the imidazole derivatives decreased the size of the stability constants. The same phenomenon was observed for miconazole and hydroxypropyl-β-cyclodextrin. In addition, the type of solubility diagram obtained was dependent on the degree of ionization of the imidazole derivatives. A type Bs solubility diagram was obtained for econazole and β-CD in buffer solution, pH 7.1. An econazole β-CD complex with a molar ratio of 1:1 was isolated. In a fluid medium the antimycotic effect of the econazole β-CD complex against a strain of Candida albicans was superior to the effect of a physical mixture of the two compounds. A small inhibitory effect of β-CD on the growth of the test organism was observed.