New polyfunctional derivatives of ß-cyclodextrin suited for the formulation of drug release systems

New functional derivatives of beta-cyclodextrin were obtained by grafting beta-cyclodextrin with epoxides of protected polyols, such as glycidylisopropylideneglycerol, glycidyldiisopropylidenexylitol and glycidyldiisopropylidenearabitol. The glycidyl ether of 2-pyrrolidone was also used. The reaction products have a degree of substitution per glucose residue included between 0.5 and 1. Selective removal of protecting groups from cyclodextrin substituents, carried out under conditions not affecting the integrity of the cyclodextrin ring, gave rise to hydrosoluble cyclodextrin derivatives whose hydrophilic/hydrophobic balance was modulated by controlling the extent of deprotection. The unusual solubility in water, greater than 350%, for both protected and deprotected derivatives, represents a breakthrough for a wide variety of applications requiring polymeric materials with remarkable water solubility.