CLEVELAND—With all the polymer choices available for the health care industry, it's important to make sure all parties involved with medical device development understand the application and regulatory hurdles involved.
That's what the International Elastomer Conference's Advanced Elastomers for Health Care seminar, held recently in Cleveland, sought to clear up—identifying the key applications for some of the core rubber materials and educating companies on the regulatory hurdles involved.
"It's a little bit of a new direction for the Rubber Division, coming from a tire background and moving into health care," said Judit Puskas, professor of chemical and biomolecular engineering at the University of Akron and chair of the seminar, as well as the recipient of the 2017 Charles Goodyear Medal.
"But even I didn't realize that some of the rubber processing companies around this area have now over 50 percent of their business in health care. I think this is a very important meeting."
Dow Chemical's Uma Kale said the global health care market is growing at 4-6 percent annually with emerging geographies exceeding that. However, the American and European regions account for about 75 percent of the health care market, which Kale estimates to exceed $300 billion.
Aging population and the rise of chronic diseases are driving this growth, but Kale said advancement in science, materials and a shift to outpatient/home care is driving the need for stronger regulations.
"The modern medical devices are much more sophisticated than what you had about 50 or 60 years ago," Kale said. "Those devices were primarily tools to aid the diagnosis and treatment of diseases. What you see now are medical devices that have evolved into being minimally invasive and can be adjusted very precisely without needing surgery and the risks associated with that surgery."
Variety of rubbers
Many different types of rubber compounds have made their way into the health care industry—butyl, butadiene and isoprene rubbers in addition to both high consistency and liquid silicones. Dana Adkinson, technical development manager within Arlanxeo's Tire and Specialty Rubber business unit, outlined that butyl rubber lends itself to a number of applications, namely rubber stoppers, plungers and sealing applications.
While the specific type of butyl rubber varies depending on the application, Adkinson said butyl is usually the best choice when strong impermeability, low water absorption and excellent resistance to mineral oils is required.
Comparatively, butadiene and isoprene rubber lack in their resistance to gas and moisture, but have low-water absorption properties, she said. If the drug vial is to be penetrated multiple times by a needle, isoprene's strength is that is has excellent re-fragmentation resistance.
These compounds also need to have strong resistance to sterilization chemicals.
"All of these different kinds of medical parts undergo at least one sterilization step in their lifecycle," Adkinson said. "Different sterilization techniques include steam, radiation and ethylene oxide, but they can undergo anywhere from one type of sterilization to multiple types of sterilizations from when they actually make the stopper to when it's in its final form."
Adkinson added that while butyl and other kinds of rubbers are excellent for some applications, their main weakness is that they cannot be used for implantable medical device applications. Silicone, however, does not share that problem and its biocompatibility is one of the reasons it's widely used in many short- and long-term implantable applications.