When we think of commonly used rubber compounds for use in medical devices, silicone may come to mind. However, silicone is not always the best of choices. A more favorable option might be a synthetic polymer such as SSBR and BIIR. Both types of polymers provide high density and low permeability and are essential in a wide variety of medical devices including syringe stoppers, infusion containers, injection and blood collection vials, plungers, pre-filled syringes, and so much more.