A solid material including a matrix, dispersed in which are microparticles of at least one antimicrobial agent for preventing, limiting and/or eliminating the contamination of the material and/or the contamination of a composition which is in contact with the material for at least a given time, and/or preventing, eliminating and/or slowing down the formation of biofilms on the surface of the material, wherein the antimicrobial agent is an oxide of at least one positively charged metal ion and the antimicrobial agent does not migrate out of the material. Also, the use of such material for manufacturing an article, to the process for manufacturing the article, and to the article obtained. In particular, the article is selected from stoppers, lids, seals, caps, covers, plugs and valves intended for sealing bottles, flasks, jars, cans, canisters, barrels, tanks, or various containers used for packaging and/or storing food products, dietetic products, cosmetic products, dermatological products or pharmaceutical products.