Biofilm implant-related infections cost the US healthcare system billions of dollars each year. For several decades, device coatings have been developed that actively release antimicrobial compounds in an attempt to prevent these infections from developing. To date, few coatings have been put into clinical use. These have shown limited to no efficacy in clinical trials. Recent data have shown the in vitro and in vivo efficacy of a novel active release coating that may address the limitations of coatings that are used clinically. In this study, the novel active release coating was characterized to gain an understanding of the effects of combining an antimicrobial additive, cationic steroid antimicrobial-13 (CSA-13), to a medical grade polydimethylsiloxane (PDMS) material. Results indicated that the addition of CSA-13 did influence the physical properties of the PDMS, but not with adverse effects to the desired material properties. Furthermore, there was no indication of chemical reactivity. It was shown that CSA-13 was uniformly dispersed as small particles throughout the PDMS matrix. These particles were able to dissolve and elute out of the PDMS within a 30-day period. The results of this work suggested that the PDMS with CSA-13 was thermally, chemically and physically stable when used as a device coating to treat local infection and/or prevent biofilm implant-related infections from developing. © 2013 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2013.