A stabilised composition having antibacterial, antiviral and/or antifungal activity, said composition comprising silver ions and a ligand, characterised in that the composition comprises a complex of silver and a ligand selected from the group consisting of 5,5-disubstituted hydantoins in which the substituents do not comprise conjugated unsaturated bonds and barbituric acid and derivatives thereof stabilising silver ions against reduction to free silver in a hydrophilic environment, and that the composition has a solubility in water higher than 10 mg Ag/l is stable during sterilisation and retains the activity without giving rise to darkening or discoloration of the dressing during storage.