Composition consisting of a dendrimer and an active substance

A compn. for controlled drug release consists of a dendrimer provided with blocking agents and an active substance occluded in the dendrimer. A blocking agent is a compd. which is sterically of sufficient size, which readily enters into a chem. bond with the terminal groups of a dendrimer and which can also be split off from the dendrimer or be modified without affecting the chem. structure of the dendrimer and the active substance. The blocking agent can be provided with protective groups. Such conjugates have the advantage of control of the time at which the releasing of the active substance starts. As an example, 3,5-dinitrobenzoic acid was occluded in a NH2-terminated polypropylamine dendrimer of the fifth generation (64-cascade: 1,4-diaminobutane[4]/(1-azabutylidene)60/propylamine)