The mucoadhesive properties of polymer compounds can be considerably improved by the covalent binding of thiol partial structures to said compounds, because as a result disulfide bridge bonds are formed having mucus glycoproteins. By converting the free thiol groups on such polymers into disulfides having mercaptonicotin amides or mercaptopyridoxines, said thiol groups become comparatively more reactive, so that the mucoadhesive properties of said polymers are considerably higher. In addition, polymers that comprise the disulfide partial structures having mercaptonicotin amides or mercaptopyridoxines do not have to be protected from oxidation and have comparatively higher permeation-accelerating properties.
