RTPMexico’s Plásticos y Materias Primas (PyMPSA), a leading manufacturer of medical devices and components for the healthcare industry worldwide, was able to develop an epidural catheter using a custom RTP 2900 Series polyether-block-amide (PEBA) thermoplastic elastomer compound that is radiopaque, so it can be easily observed during x-ray imaging to ensure proper placement.
In a recent report entitled The Safety Net, Josh Blackmore, global healthcare manager at US polymer compounder RTP Company, has written about the recent uptick in medical device product recalls due to patient safety issues. He provides advice for medical device manufacturers on how to increase overall patient and product safety through materials selection and enhanced product performance. The report also looks at additives specific to drug delivery devices, as well as high-temperature and other performance properties.
Josh begins the report with an interesting reference. According to the FDA, there were 49 Class I medical device recalls in 2012. The FDA defines a Class I recall as “a situation in which there is a reasonable probability that the use of or exposure to a violative product will cause serious adverse health consequences or death.” In addition, there were hundreds of Class II and Class III recalls in 2012.
The report is reproduced below.
The Safety Net: Selecting thermoplastic materials for the development of safe and effective medical devices
By Josh Blackmore, Global Healthcare Manager, RTP Company
According to the US Food and Drug Administration (FDA), there were 49 Class I medical device recalls in 2012. The FDA defines a Class I recall as “a situation in which there is a reasonable probability that the use of or exposure to a violative product will cause serious adverse health consequences or death.” In addition, there were hundreds of Class II and Class III recalls in 2012.
While recalls are often necessary to protect patient safety, they can be extremely damaging to consumer confidence and a company’s brand. With this in mind, it is no surprise that a primary focus of the medical device industry is patient safety.
During the design stage, key areas to look at include material specification and performance. The ideal material supplier can collaborate with an OEM to provide design and engineering input, and materials science expertise, demonstrating a pattern of concern for safety.
Effective in the field: The performance of a finished medical device is vital to patient safety. To enhance this, compounds used to develop medical devices can be formulated with additives to achieve specific performance properties to ensure the functional and commercial success of the device. Examples within the healthcare industry can include coloured, conductive and wear resistant compounds.
Colour-coded for the ER: Colour can play an important role in medical device safety. Colour coded medical devices can indicate size, type and function for quick identification during surgical and emergency procedures. Emergency and operating room nurses report that colour coding allows them to quickly locate the right devices, reducing the risk of human error.
However, it is essential for manufacturers to know that not all colorants are equal. In an effort to reduce potential safety risks, the FDA and other regulatory bodies throughout the world have recently begun to look more closely at colorants, specifically at the biologic testing performed on pigments used in medical device materials. Manufacturers must understand the biologic testing requirements of a medical device in order to choose the right colorant. An experienced colour compounder with medical device market and biologic testing expertise can utilize pre-tested ISO 10993 resin and pigment options to ensure the finished product can meet all the biological testing requirements.
Standing up to sterilization
Used to eliminate infection-causing microbials from the surface of medical devices and instruments, modern sterilization techniques are extremely effective methods for increasing patient safety, but they can have a detrimental effect on some polymers. Many medical devices must be able to withstand harsh environments associated with various sterilization techniques, such as steam autoclave, ethylene oxide (EtO), hospital chemical cleansers and gamma radiation.
Typically reaching temperatures up to 134°C, autoclave sterilization can result in polymer melting, warping, and deformation. Adequate temperature resistance, through the right compound formulation, is necessary to increase the durability of polymers exposed to a steam autoclave. Resin systems such as polyphenylsulfone (PPSU), polysulfone (PSU), and polyetheretherketone (PEEK) can readily accept these high temperatures without damage. To further fortify these compounds, additives or “reinforcements” such as glass fibers (both chopped and long fibers) and carbon fibers can be added.
Low temperature sterilization methods such as ethylene oxide (EtO) and gamma radiation are becoming the preferred method to sterilize polymeric medical devices in high volume – specifically pre-packaged disposables. However, repeated exposure to EtO or gamma radiation can result in gradual degradation to a polymer, including cross-linking and chain scission. The right biopolymer must be formulated with the right stabilization package to ensure the integrity of finished medical devices continually exposed to EtO or gamma radiation sterilization.
When delivered through dry powder inhalers (DPI) or pressurized metered dose inhalers (pMDI), the flow of powdered or aerosol drugs over traditional plastic surfaces can generate high levels of static electricity that can cause the drug particles to adhere to the device’s drug flow paths. This can result in the patient receiving an inaccurate dosage of the drug. Anti-static compound formulations can reduce these effects, preventing the drugs from obstructing the drug flow path and ensuring the delivery of a proper dose. A supplier with a complete portfolio of solutions can provide innovative anti-static compounds that can greatly increase the effectiveness of these drug delivery devices.
Keeping moving parts lubricated
Prolonged contact motion can have a detrimental effect on medical devices, decreasing their ability for safe use. Materials for components, such as valves or gaskets, formulated with a biocompatible internal lubricant can reduce friction rates, vibration and noise. Internal lubricants can also eliminate the need for a topical applied external oil-based lubricant. A competent materials supplier knows that compounds formulated with internal lubricants extend the useful life of medical devices and reduce the amount of timely and costly maintenance to keep them running safely.
Product recalls, while often necessary to protect the general public, are extremely damaging to a medical device manufacturer’s brand and reputation. In order to increase the overall performance of a medical device, it is vital to demonstrate a pattern of concern for safety from the earliest design stages and throughout the lifecycle of a finished product. This can be accomplished by working with a material supplier that is experienced in developing compounds for medical devices.
About the author:
Josh Blackmore is the global healthcare manager at RTP Company, responsible for strategy creation and implementation, managing the healthcare sales force, and providing healthcare industry expertise.
RTP Company, headquartered in Winona, Minnesota, USA, is a global compounder of custom engineered thermoplastics. The company has 12 manufacturing plants on three continents, plus sales representatives throughout the Americas, Europe, and Asia. RTP Company's engineers develop customized thermoplastic compounds in over 60 different engineering resin systems for applications requiring colour, conductive, elastomeric, flame retardant, high temperature, structural, and wear resistant properties.
 Hanson, Scott & Turner, Pachel. “Where Color Meets Clarity.” Medical Device & Diagnostic Industry, July 2010.