butyl rubber
Achieve a high level of cleanliness and gas/moisture barrier in pharmaceutical stoppers and seals
More than 90% of antibiotic, infusion and biomedical stoppers made in Europe, the United States and Asia are based on halobutyl rubber. Exxon™ halobutyl rubber is ideal for stoppers and seals because of its high cleanliness and chemical resistance as well as low permeability to air, gases and moisture.
Exxon halobutyl rubber offers a number of other advantages over natural rubber and other synthetic rubbers in pharmaceutical packaging, including:
- Chemically and biologically inertness
- Low extractables due to low level of additives and high curing efficiency
- Resistance to heat, ozone and oxygen
- Good self-sealing and fragmentation performance
- Vulcanizable by low level of sulfur-free and/or zinc-free curatives
Because halobutyl rubber is chemically inert and nonpolar, absorption of drugs or water is low. Studies indicate that bromobutyl rubber-based stoppers have much lower drug turbidity than regular butyl stoppers.
Another option for high-end applications is Exxpro™ specialty elastomer, a brominated isobutylene paramethyl-styrene terpolymer (BIMSM). It is the cleanest elastomer available that is suitable for pharmaceutical applications. Exxpro specialty elastomer-based stoppers have been shown to exhibit similar drug turbidity performance in comparison to a coated stopper.
