Cyclodextrins as diethylstilbestrol carrier system: Characterization of diethylstilbestrol-cyclodextrins complexes

Purpose. The in vitro formation of DES-cyclodextrins inclusion complexes wa s characterized using lipoxygenase as enzymatic system. Methods. DES-cyclodextrins complexes were obtained in aqueous solution. Results. The addition of cyclodextrins to the reaction medium had an inhibi tory effect on DES oxidation by lipoxygenase due to the drug's complexation into the cyclodextrin cavity. This inhibitory effect depends on the comple xation constant between DES and the cyclodextrins type used. In this case, beta-. 2-hydroxypropyl-beta- and gamma-cyclodextrins have similar complexat ion constants and therefore produce the same inhibitory effect. Moreover, d epending on the type of cyclodextrins used, the solubility of DES can be en hanced up to 956 times, while the lipoxygenase activity remains constant. Conclusions. These results suggest that the system described may be used as a controlled-release delivery system for DES, since it may diminish the lo cal and systemic adverse side effects caused by high concentrations of the drug.