Sealing the Deal for Quantitative, Nondestructive Testing of Medical Packaging

Without a package, you don’t have a product, says Oliver Stauffer, COO, Packaging Technology Inspection (PTI). What’s worse in the medical space, without a sterile package, you have a liability, he adds. His company, which develops package inspection systems, offers technologies to ensure the integrity of sterile barrier systems by verifying seal integrity through nondestructive, quantitative testing methods.

 Norbert Sparrow

The medical device industry has long relied on manual visual inspection to ferret out defective packaging. That technique "is cheap and easy, and used to be just fine," says Stauffer. "But today, good-enough testing capability just isn’t good enough. There is a greater reliance on quantitative testing methodologies, which allow you to really evaluate package quality according to relevant standards. They draw a line in the sand -- there is no gray area, no emotion. Given the requirements of the FDA and other regulatory bodies, quantitative data is king. Without it, your process validation is on thin ice," says Stauffer. The airborne ultrasound and vacuum decay tests, developed by PTI, generate quantitative data on package integrity and leakage that is beyond the reach of conventional technology, he adds. Moreover, the tests are nondestructive.

Nondestructive testing is especially critical if you are manufacturing implantable or injectable products, says Stauffer. “You can test all of your products, not just a sampling. If you are doing a test on one out of 100 packages, what is the risk that five of those packages have defective seals?” he asks. “When developing a risk assessment of failure, the frequency of testing and the method used weighs heavily on the manufacturer.”

PTI’s VeriPac test system is based on the vacuum decay test method (ASTM F2338-09) and uses an absolute or differential pressure transducer leak test system. The system is suited for filled and sealed rigid, semi-rigid, and flexible packaging made of porous or nonporous materials.

The company’s noncontact ultrasound inspection method is suited for detecting delaminations, folds, inclusions, and gaps between layers of pouch materials. To use this effectively, it must be possible to place the seal in a direct line between a pair of transducers and move the seal (or the transducers) the length of the seal, which can be done at speeds of up to 20cm per second. The technology is suitable for the inspection of flexible packaging systems.

Both inspection methods can be used with a variety of sterile barrier systems composed of various materials, including Tyvek and paper.

“We look at physical, not just visual, properties,” says Stauffer, which is an important distinction as “not all of the defects you can see are physical, and not all physical defects are visually apparent.” For example, a seal may look fine because the sealing process has left a visual imprint on the material. If the process temperature is off, however, the inner layers of a material may not have sealed properly. “That can result in a gross defect and the product may actually make it to market, because it looks sealed. Those are the types of process related defects that often cause critical recalls.” When you are testing for physical defects, he adds, that won’t happen.

“Manual inspection has 80 percent reliability, at best, at detecting defective seals,” says Stauffer. That’s just not good enough today, he adds. And as quantitative testing methods improve and costs associated with various methods are reconciled, we will see greater movement to these newer more reliable test methods, he predicts.

Focused on medical packaging design and technology?

Norbert Sparrow, Editor in Chief, UBM Canon


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