Complexation of Doxorubicin with β and γ-Cyclodextrins

Abstract

The binding of β and γ-cyclodextrins with the anti-cancer drug doxorubicin has been examined with the use of fluorescence and absorbance spectroscopy, circular dichroism measurements, and proton NMR spectroscopy. The stoichiometry of the complexes formed and their apparent formation constants have been estimated with the use of various approaches. The stoichiometrics for both the β-cyclodextrin-doxorubicin complex and the γ-cyclodextrin-doxorubicin complex have been determined to be predominantly 1:1. The strength of the interaction of the drug with γ-cyclodextrin is stronger than that with β-cyclodextrin. The effect of varying the pH on the calculated formation constants of the complexes has also been investigated.