Patent ID: 8840951

Claim:
A method for the preparation of a controlled release system which is a three-dimensionally cross-linked polymer network comprising active ingredient molecules covalently coupled through a linker to and entrapped in said three-dimensionally cross-linked polymer network, the method comprising the steps of: (i) mixing under conditions that do not result in cross-linking (a) active ingredient molecules coupled through said linker to a polymerisable moiety with (b) an aqueous solution or dispersion comprising polymer chains, said polymer chains forming a non-cross-linked matrix and comprising polymerisable moieties that will polymerise under cross-linking conditions with the polymerisable moiety linked to the active ingredient molecules to entrap the active ingredient molecules within the polymer matrix, the polymer chains comprising polymerisable moieties that will result in cross-linking intra- or intermolecularly under cross-linking conditions thus non-covalently entrapping said active ingredient molecules in the non-cross-linked polymer matrix; and (ii) subjecting this mixture to cross-linking conditions, thereby forming a three-dimensionally cross-linked polymer network simultaneously with covalently coupling the molecules of the active ingredient both to the polymer network and to other active ingredient molecules included in said network; wherein said cross-linking conditions include a polymerisation initiator and wherein the controlled release system of polymer chains and active ingredient molecules is stabilized.