There is a burgeoning market for antimicrobial protected tubing in the medical industry in response to hospital-acquired infections (HAI), and Loveland-Colo.-based Eldon James, (www.eldonjames.com) is responding to it. The Center for Disease Control in Atlanta reports that healthcare-associated infections account for an estimated 1.7 million infections and 99,000 associated deaths each year. Of these, 32% are urinary tract cases, 22% are surgical site infections, 15% are pneumonia (lung infections), and 14% are bloodstream infections.

By some reports, there are about 25 state laws that require public reporting of hospital-acquired infection rates. And to make matters worse, Medicare no longer provides hospitals with reimbursement for secondary conditions acquired during hospital stays, and which Medicare deems preventable.

The demand for medical devices that inhibit colonization and growth of bacteria, while serving their intended purpose will continue to grow, says Eldon James President Marcia Coulson.

Her company incorporates silver-based antimicrobial materials from Wakefield, Mass.-based Agion, (www.agion-tech.com) into its MFXAG Flexelene USP Class VI medical and pharmaceutical tubing. “The silver ions actually attack the bacteria cells, choke off the oxygen supply, and keep it from multiplying,” says Coulson. “It's 99.9999% effective agains many of the bacteria, yeast, fungi, and molds we have tested. Because silver is inorganic, it reduces the risk of antibiotic resistance.”

The MFXAG's pliable polyethylene-based material is engineered specifically for medical use. The tubing can be sterilized using EtO (ethylene oxide) and irradiation.

“We offer the antimicrobial tubing as well as antimicrobial luer connectors,” says Coulsen. “Nurses and technicians are constantly touching connections so it makes sense that the luers be antimicrobially protected as well.”

Coulson says the MFXAG Flexelene tubing is often used for IV applications in hospitals and healthcare facilities.

“Hospitals need to show that they're being proactive when it comes guarding against HAIs,” says Coulson. “And so do medical-device makers and their suppliers.” She adds that the tubing could also be used by pharmacies where the antimicrobial protection could limit the growth of bacteria in tubes used to mix medications post filter.

Teamwork solves problems

As a manufacturer of custom profile extrusions made from porous polytetrafluoroethylene (PTFE) and a variety of melt thermoplastic materials, Tempe, Ariz.-based International Polymer Engineering, www.ipeweb.com, is increasingly being called in on the front end of new product design or redesign efforts, according to IPE Melt Thermoplastics Specialist Jonathan Jurgaitis.

“A lot of medical-device engineers aren't experienced in designing extruded parts,” says Jurgaitis. “We have that experience. So suppliers, like us, prefer to get involved in the early stages of a product design. That way, together with the medical-device manufacturer, we're able to effectively factor in the extrudable part. The earlier technical suppliers are involved, the better, because if the part design moves too far along in the approval process and without our specialized input, the design may end up with a drawing showing difficult-to-extrude parts, leading to changes, and higher project costs. But when suppliers can make suggestions at the front end, they can develop less expensive parts with greater capability.”

Jurgaitis says the extrusions make it possible to form unusual shapes and contours that may require less space and material.

He tells of one recent example that occurred recently when his design team was called in early on a project involving a delivery device used in arthroscopic surgery.

“The tube we designed ended up being nestled between two larger tubes,” says Jurgaitis. “What came of the effort was the most unusual shape with which I've ever been involved. It looks like the Batman symbol, but instead of multiple scallops at the bottom, it has two scallops that meet together in a point with a slight curve over the top.” The design lets the manufacturer reduce the overall size of its device, an important objective in arthroscopic procedures.

Jurgaitis continues: “This part demonstrates what can happen when a customer and supplier tackle a challenge together. We're able to use our capabilities and get creative results.”

RoHS compliant

Parker TexLoc, Fort Worth, Texas, (www.texloc.com) is supplying RoHS-compliant fluorinated ethylene propylene (FEP) tubing made from resins and colors that are certified as being free of hazardous substances in accordance with the EU's RoHS directive. RoHS compliant products must be free of mercury, cadmium, hexavelant chromium, lead, polybrominated biphenyls and flame retardants such as polybrominated diphenyl ethers.

“Buyers are driving demand because everything sold to the European Union must be RoHS compliant,” says Gil Oats, Parker's plant and manufacturing engineering manager.

Parker adds color or radiopaque compounds and produces the tubing as a heat shrink for catheter applications. Class 10,000 clean-room capabilities ensures cleanliness. The RoHS compliant FEP tubing features a Teflon non-stick surface and is non-leaching. Also, RoHS-compliant etching can be added to aid in bonding because the Teflon tubing will not adhere to anything but itself until the chemical structure of the surface is changed.

RoHS-compliant products pose challenges in terms of heat profiles, screw speeds, and color, says Oats. “The heat profiles are different because the melt flows are different. If the customer allows it, a single or double through-pass is typically necessary. The screw speeds depend on the materials's residence time in the barrel, but the screw speeds are definitely affected as is the tooling design. As for the materials' elements, colors seem to be the only elements affected, unless carbon or a black derivative is used.” Oats says Parker is able to meet customers' color demands while remaining RoHS compliant.

Suppliers can teach old materials new tricks

The next generation of silicones will possess antimicrobial properties to protect patients from hospital acquired infections, especially those caused by drug-resistant microbes. Such silicones will kill these infecting organisms.

Silicones, the family of polymers that includes siloxanes and silanes, possess many physical properties for integrated components in healthcare applications. Silicones are hypo-allergenic, almost bio-inert, they can be sterilized using steam or dry heat, and they're gas permeable. Selected grades of silicone rubber are approved according to USP Class VI and ISO 10993 standards. Silicones also can be optically clear, and most grades are translucent to transparent, making them a valuable component in tubing production. Lastly, silicone rubber is inherently soft and flexible and does not require plasticizers to impart these qualities.

Silicones have long been used in tubing for intravenous drug delivery systems and heart devices because of their resistance to bacteria, and they sterilize easily.

— Gregory Dull, marketing manager and Theodore Johnson, technical service manager, Wacker Chemical Corporation, Adrian, Mich., (www.wacker.com).