The invention is directed to a three-dimensional polymer network for encapsulating a pharmaceutical ingredient, said polymer network comprising (a) at least one first polymer and (b) at least one cross-linking agent. Said three-dimensional polymer network is remarkable in that said at least one first polymer comprises a first polyuronate derivative, said first polyuronate derivative being modified with a hydrophobic moiety and in that said at least one cross-linking agent is calcium chloride and/or a cyclodextrin derivative.
