A nanoparticulate composition is disclosed for the targeted therapeutic treatment of tumours. The stable self assembled nanocomposition according to the invention comprises (i) a carrier and targeting system comprising an optionally modified polyanion, and optionally a polycation, which may also be modified at least one targeting agent which is linked to either the polycation/modified polycation or the polyanion/modified polyanion, or both (ii) an active compound selected from the group of epirubicin and its pharmaceutically acceptable salts, especially hydrochloride and optionally (iii) at least one complexing agent, metal ion and stabilizer/formulating agent. The invention furthermore relates to a process for the preparation of the above-mentioned composition, the therapeutic uses thereof, and pharmaceutical compositions containing the nanocomposition according to the invention.