Nondestructive Package Tests Lure Device Manufacturers

Originally Published MDDI September 2002

NEWS & ANALYSIS

Erik Swain

Packaging engineers have been intrigued for years by the idea of a nondestructive test for porous medical packages. Until recently, the only way to test the integrity of a porous package without destroying it was by visual inspection. A technology that could do the same thing might allow for integrity inspection of an entire packaging run—at least for lower-volume, higher-cost devices—with better detection than what the human eye can provide. It could also prove to be a useful package development tool.

That interest has not yet turned into a great number of sales, however, as device manufacturers have balked at paying for such technology—the prices of which run from approximately $15,000 to $100,000.

"The whole issue of nondestructive testing is not receiving the kind of acceptance that you might otherwise think," says consultant Donald Barcan, president and chief executive officer of Donbar Industries Inc. (DBI; Long Valley, NJ). "Most nondestructive tests require capital-intensive equipment and the testing process can take longer to run. Also, some of the newer nondestructive test equipment cannot pinpoint the precise location of leaks."

Manufacturers of these systems, however, are hoping that interest will increase once the American Society for Testing and Materials (ASTM; West Conshohocken, PA) approves test methods for some of the technologies. Some approvals from ASTM's F02 committee on flexible barrier materials, which includes the F02.60 subcommittee on medical packaging, could come as early as this fall. FDA recognizes most F02.60 documents as consensus standards, and showing that an ASTM standard is being met may make things easier for a device manufacturer come inspection time.

At least three suppliers are offering systems that can perform nondestructive tests on medical packages with paper or Tyvek.

Mocon Inc. (Minneapolis) has a technology that identifies defects in trays with paper or Tyvek lids by masking the porous part of the package (which creates two chambers), introducing a CO₂ trace gas, and evacuating the bottom chamber. If an infrared sensor detects the gas in the bottom chamber, an alarm sounds.

ASTM round-robin tests for the method have been completed and a proposed standard has passed the F02.60 subcommittee, says Ron Pilchik, business manager for Mocon's medical packaging integrity group. A ballot is now before the full committee, and approval could come in October, he says.

"Some potential customers have said they do not want to move on [purchasing the technology] until ASTM covers the CO₂ detection method," Pilchik says. That designation, he says, should make device manufacturers more at ease with how the technology will be accepted by FDA, though he notes that he has met with FDA several times and the agency "well understands how it works."

Sonoscan Inc. (Elk Grove Village, IL), has a system that uses acoustic micro imaging to inspect the bond between Tyvek and a film. A high-frequency ultrasound is pulsed into the seal and collects echoes from it, resulting in an image that shows any defects within the seal.

Sonoscan, however, sees more potential in markets such as pharmaceutical packaging and microelectronics. For porous medical packaging, "it's a tangential test methodology," says Jack Richtsmeier, Sonoscan's business development manager. "It tells you a lot about your sealing and your process parameters, but it can't check for a [pinhole] leak." Therefore, he says, despite a number of successful test runs, device firms have not shown much interest in paying for the technology for that application.

As a result, Sonoscan is not pursuing an ASTM designation for use with porous medical packaging. "Ultrasonic imaging is a technology that has ASTM approval, just not in that specific area," Richtsmeier says. "People are using it anyway."

Packaging Technologies and Inspection LLC (PTI; Tuckahoe, NY) is more optimistic, as it is pursuing ASTM designations for its vacuum leak technology and its airborne ultrasonic imaging technology, both of which can be used for nondestructive testing of porous medical packages.

With the vacuum technology, which can be used with trays with porous lidding or with pouches with porous overwraps, "all you need is 110 volts," says Tony Stauffer, PTI's president. He explains that it has an algorithm that automatically sets the reject, pressure, and testing criteria from the initial test samples, making it easy to operate.

The airborne ultrasonic imaging technology does not come into contact with the package, instead passing it through ultrasonic transmitters and receivers and providing an image of the level of attenuation of ultrasonic waves on the seal perimeter. "You get a visual image, like a photograph, of the heat seal, which may not be something that can be seen by the eye," Stauffer says. "And it gives you validatable, quantifiable data."

The vacuum technology is currently in ASTM round-robin testing, and work on a standard for the imaging technology could begin soon, he says.

Copyright ©2002 Medical Device & Diagnostic Industry