Plastic Mirrors Glass, but without the Cracks

Artegraft’s new flat-sided tubes use Eastman Chemical’s Eastar copolyester to resist cracks.

Artegraft Inc. (North Brunswick, NJ) was growing tired of the occasional crack fracturing glass bottles of its Artegraft collagen vascular graft. Not only would the cracks threaten product integrity, but they also would allow the liquid preserving the natural collagen matrix to leak, saturating other products and their packaging during transit. The firm would eventually find a copolyester to be a suitable alternative and be able to improve the design the 21-in. bottle.

Cathy VanDerVeer, Artegraft’s director of operations, had enlisted O. Berk Co.’s (Union, NJ) help to redesign its packaging for the graft, often used as a hemodialysis graft or for peripheral bypass. She had found the package supplier through industry contacts, and Artegraft’s team worked closely with David Gotler, director technical services from O.Berk.

“We had a number of preliminary ideas for the redesign,” explains Laurence A. Potter, vice president of scientific affairs from Artegraft. “The redesign process was pretty arduous, lasting a couple of years, and it had a lot of false starts. We had trouble finding the material, design, and process. Until it actually got made, we were crossing our fingers.” After following formal design controls and reviews, Artegraft arrived at a nearly cylindrical bottle measuring the same size but with a flat side and a wide neck. “The final design met our requirements in terms of cost and function as well as our user requirements,” Potter says.

O.Berk suggested that Artegraft try Eastar Copolyester from Eastman Chemical Co. “Eastar’s proven alcohol resistance ensures the plastic will not absorb into Artegraft’s sensitive product,” says Gotler. “Essentially we found a plastic that mirrored the advantages of glass.” Says Potter: “O.Berk was instrumental in facilitating the use of Eastman’s expertise.”

O.Berk worked with FGH Systems Inc., a designer and manufacturer of extrusion blow molds, who supplied the culture tube samples that the customer used for extraction and stability testing. The team began with a commercial grade of Eastar Copolyester EB062, producing the first prototypes, eventually moving to the medical-grade MB002.

“We were very happy with the prototypes,” says Potter. “We only had to tweak them from that point.”

Maintaining barrier was also a priority. “We had to prove that the microbial barrier of MB002 when used for the tube capped with the urea closure was maintained for three years,” adds Potter.

While MB002’s gas and moisture barrier was “not the same as that of glass, it was sufficient for the application,” reports Ken Breeding, technology platform manager for Eastman. He adds that MB002 withstands accidental droppage, given its impact strength.

The new plastic tube’s flat side prevents it from rolling, and its wider-diameter neck eases practitioner access. A peel-away, heat-shrink tamper evident seal was added. Each 21-in. tube is embossed with the Artegraft name on the outside.

Secondary packaging costs may be decreased, because eliminating glass also eliminated much of the cushioning need for transport and warehousing. It is lighter than glass, adds Breeding, so shipping weight will not be an issue.

“The redesign is a more functional, cost-effective package,” says Potter. “Glass molding is more of an art, whereas plastic blow molding is known for its manufacturing capabilities and efficiencies.”

Eastman’s Breeding reports that the medical-grade Eastar Copolyester MB002 is a resin specifically developed for extrusion blow molding containers in medical applications where aesthetics such as high clarity and gloss, coupled with high toughness and chemical resistance are desirable. The resin is compatible with the same sterility and validation processes used for Artegraft’s existing glass tubes.

Eastman’s medical market segment team provided expert consultation about Eastar, and just-in-time delivery of resin to the blow-molder to meet production deadlines.

Meredith Springfield, a plastic molder, ran the first commercial production order. National Novelty supplied the 28mm Urea Closures.

Artegraft was among the first vascular grafts approved by FDA. It has been in continuous clinical use since 1970 and has been successfully implanted in more than 100,000 patients in the United States.


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