Introduction: The aim of this study is to characterize the interaction in solution between the antimycotic bifonazole and two cyclodextrins: random methyl-beta-cyclodextrin and beta-cyclodextrin.
Material and method: The interaction in solution between bifonazole and random methyl-beta-cyclodextrin/beta-cyclodextrin was characterized using dissolution studies and phase solubility studies. The dissolution of bifonazole was characterized through the index of the rate of dissolution and the dissolution efficiency, and from the phase solubility study we calculated the apparent stability constant of the complex.
Results: The bifonazole – random methyl beta-cyclodextrin binary systems revealed better dissolution properties as compared to bifonazole alone, and to the bifonazole – beta-cyclodextrin binary systems. The phase solubility studies revealed the formation of soluble complexes in the cyclodextrin concentration range, and an apparent stability constant of 17956 M-1 for bifonazole – random methyl-beta-cyclodextrin complex, and of 873 M-1 for bifonazole – beta-cyclodextrin complex.
Discussions: The dissolution studies and the phase solubility studies demonstrated an improvement of the wettability of the particles of bifonazole, due to a better contact between bifonazole and cyclodextrin, and the formation of soluble complexes in the dissolution medium.
Conclusions: The complexation with cyclodextrins determined the increase in the dissolution properties of bifonazole. The best results were obtained with random methyl-beta-cyclodextrin, which demonstrates a better interaction within the components in the liquid medium and the better solubilization properties of this cyclodextrin.