Abstract: The present invention relates to a subcutaneous delivery system comprising a biodegradable polymeric matrix and at least one of the pharmacologically active substances of general formula (I): wherein A represents an amino group —NH2 or an ammonium group —NH3+ or a residue of general formula (II): wherein each of X1 to X5 represents, independently, an hydrogen atom, a linear or branched C1 to C6 alkyl group, a linear or branched C1 to C6 alkyloxy group, a hydroxyl group —OH, an amino group —NH2, a primary or secondary C1 to C6 alkylamino group, a halogen atom, a nitro group —NO2; said substance being embedded into said matrix. It relates also to a process for its preparation and to its use for the preparation of a medicament.