The invention relates to a method for producing injectable medicament preparations containing a therapeutically and/or diagnostically effective substance which is comprised of an active agent, of a spacer molecule and of at least one protein-binding molecule. After being brought into contact with the body, said therapeutically and/or diagnostically effective substance covalently bonds to the body fluid constituents or tissue constituents via the protein-binding molecule, thus providing a form of transport of the active agent that an be hydrolytically or enzymatically cleaved, according to pH, in the body while releasing the active agent.