This work deals with the bioactive agent release from dextran-alpha-naphthylacetic and dextran-naproxen adducts, in which the bioactive agent is linked to the dextran carrier through a spacer. Water absorption characteristics of these adducts have been studied. The hydrolysis in the heterogeneous phase showed autocatalytic effects and the release of the active compound is dependent upon the hydrophilic character of the adduct as well as the pH value of the medium.