Methods for increasing the effectiveness of one or more antimicrobial agents incorporated in polymeric films are described. The methods involve adding an antimicrobial agent promoter to the polymer prior to or when forming the film. The antimicrobial agent promoter is a blowing agent, a hydrophilic wetting agent, and/or both. Also described are polymeric films comprising antimicrobial agents and such promoters, and multilayer barrier assemblies using such films. The multilayer barrier assemblies find wide application in the medical field. Also described are multilayered polymeric films comprising a first skin layer that includes at least one gas and vapor barrier organic polymer, a core layer that comprises at least one elastomeric organic polymer, and a second skin layer that comprises at least one sealable organic polymer and at least one antimicrobial agent. Articles comprising the film are useful in various applications to include medical and health care applications. A method to provide a gas and vapor barrier and antimicrobial activity in an article comprises manufacturing an article in which the article comprises the film.Linvention concerne des procédés daugmentation de lefficacité dun ou plusieurs agents antimicrobiens incorporés dans des films polymères. Les procédés mettent en jeu laddition dun promoteur dagent antimicrobien au polymère avant ou pendant la formation du film. Le promoteur dagent antimicrobien est un agent gonflant, un agent mouillant hydrophile et/ou les deux. Linvention concerne également des films polymères comprenant des agents antimicrobiens et de tels promoteurs et des ensembles barrière à multicouche utilisant de tels films. Les ensembles barrière à multicouche trouvent une large application dans le domaine médical. Linvention concerne également des films polymères multicouches comprenant une première couche de peau qui comprend au moins un polymère organique de barrière aux gaz et à la vapeur, une couche centrale qui comprend au moi
