The invention concerns a system for biocompatible drug release comprising: (i) a polymer matrix; (ii) an inorganic component located inside said matrix and characterized by a lamellar structure with a net positive or negative charge able to intercalate (iii) a pharmacologically active principle into said lamellar structure, by establishing an ionic type of bond with it and thereby obtaining an intercalation compound. The preparation process for the release system comprises the stages of: treating the lamellar solid in such a way as to give it a net positive or negative charge, then combining it with the chosen active principle, also in an ionic form, to obtain an intercalation compound which is then mixed with the polymer matrix. The release system can be employed in making medical devices, like sutures, membranes, osteosynthesis plaques, multilayered devices, gels and drug delivery systems.