Surface-active, non-leaching antimicrobial film forming compositions and methods for their application to preferably medical device surfaces are provided. The compositions form durable coatings with long-lasting antimicrobial efficacy without formation of a zone of inhibition. Optionally the films can be hydrophilic. Specific long-chain molecules of certain chemical reactivity are covalently bonded into a polymeric matrix. They maintain a long-term anti-microbial efficacy without being leached out into the aqueous environment. The polymeric matrix of the compositions contain functional groups, which covalently bond to an amine, thiol, carboxyl, aldehyde or hydroxyl active group of selected long chain quaternary ammonium compounds. Upon formation of a covalent bonding with the polymeric matrix the long chain compounds become immobilized but still maintain antimicrobial efficacy. They do not leach out over extended period of time into the aqueous environment and maintain an anti-microbial efficacy against microorganisms. The coating is useful to prevent bacterial colonization on a variety of surface including surfaces of medical devices.
