Medical Device Link.

Originally Published PMPN July 2003

Package Testing

by Erik Swain

An overwhelming number of technologies are available for testing medical device and pharmaceutical packages. Firms can devise their own tests or adhere to standardized methods. But whichever path they choose, they must ensure that the test is performed the same way every time.

The need for consistency is often used as an argument for following a standardized method. As long as the method is followed and the instrumentation is maintained exactly as prescribed in the standard, repeatability should not be a problem.
“More technologies are coming in, which means more for industry to learn,” says Perry Hock, technical director for GH Testing (Cincinnati). “We are getting more and more calls from companies that want us to run standardized tests in lieu of them running their own.” 

Eric Joneson, general manager, technical services, Lansmont Corp. (Monterey, CA), says “firms are getting the message that package testing produces a result that is an optimized package, not just a package that will work.”

STANDARDS

As part of the standards drive, ASTM International’s (West Conshohocken, PA) subcommittee F02.60 on medical packaging has been active in establishing new test methods for medical package testing. The subcommittee had many of its older methods accepted by FDA as consensus standards and is now devoting much time to certifying new methods.

One area where much work has taken place is nondestructive tests. Last year, the subcommittee approved a method developed by Mocon Inc. (Minneapolis) that detects leaks in a porous barrier material by carbon dioxide tracer gas. It is being published as ASTM F2228-02. This year, the subcommittee has been considering a vacuum-decay method developed by Packaging Technologies & Inspection LLC (PTI; Tuckahoe, NY). 
The vacuum-decay method can be used with a flexible package or a tray with a porous barrier material. The package or tray is placed in the test chamber. With a flexible package, the porous barrier is masked off by a flexible barrier. With a tray, the opening is closed off with the bladder. A vacuum is drawn on the chamber, which is isolated from the vacuum source. A pressure transducer monitors the vacuum over the test time. Any leak results in a rapid change in pressure. 

At the subcommittee’s meeting on April 9, 2003, in Kansas City, MO, consultant Dana Guazzo and PTI’s Heinz Wolf presented results of a round-robin study for the method. The study found the method could detect tray defects as small as 15 cm3/min, and lidded package defects as small as 30 cm3/min, as well as flag incomplete seal bonding. It is now up to the subcommittee to evaluate the data and the proposed instructions for using the method. 

The ASTM subcommittee is not only working on new standards, but it is also looking to strengthen old ones. 

Most notably, the subcommittee is preparing a new round-robin study for one of its oldest standards, F88-00. That method measures seal strength of flexible packaging materials. In the new study, at least 16 laboratories will perform the method in hopes of producing data showing its consistency. It will be conducted jointly with subcommittee F02.30 on food and consumer packaging.

“The method has been updated a couple of times, but the precision and bias statements and the round-robin have never been updated,” says Marie Tkacik, who chairs F02.60. “We want to take the control of the tail angle of the peel into consideration. That’s a very important technical issue that has not previously been addressed. We will also be looking at the speed of the test, the direction of the peel, and the effect of peeling materials of different thickness but the same sealant layer,” says Tkacik, who is also engineering manager for Tolas Healthcare Packaging (Feasterville, PA).
Some firms, however, might prefer to use F1140-00, which pressurizes the package internally until it fails.

“Burst testing, as opposed to a standard tensile test, tests the entire seal versus a one-inch test strip,” says Jim Zynda, sales manager, Test-A-Pack Products, Carleton Technologies Inc. (Orchard Park, NY). “It duplicates what the package might see in the rigors of the field.”

Another test approved last year—the ASTM F2096-02 bubble leak test—has already paid dividends for some device firms, says Patrick Nolan, technical director of DDL Inc. (Eden Prairie, MN). “A few of our clients have had FDA ask them for a validated method that tested the whole package,” he says. “It’s extremely rare that you get pinholes in Tyvek, but FDA wanted to see a whole-package test, not just one that tested the poly layer. And 2096 basically covers that. You can set up the pressure so that you can see where the hole is exactly.”

ASTM is not the only source of package-testing standards. ISTA, the association for transport packaging (East Lansing, MI), has several standards that are being used increasingly by the medical device and pharmaceutical industries.

While strength and integrity tests are the primary concerns of device companies, “there is a gravitation towards doing more temperature-extreme conditioning,” says Nolan. “Some customers have even had FDA ask them why they are not testing for temperature extremes. The ISTA 2A test has conditioning cycles that device companies seem to be picking up such as they need to. It allows you to pick and choose about nine different conditions to satisfy the extremes.”

CONSISTENCY

The pharmaceutical industry tends to have more customized testing and inspection procedures than the medical device industry. Firms that operate this way must find their own ways to ensure the test will be performed the same way every time.

Many vendors who serve the testing and inspection market offer products and services that help ensure repeatability. Safeline Inc. (Tampa, FL), which makes metal detectors and creates test samples, is such a company.

“We create plastic tablets with very small pieces of metal in them according to the parameters that the customer requests,” says George Louli, Safeline’s director of marketing. “The metal pieces are incredibly hard for the human eye to see. Running the plastic tablet through the equipment is part of the validation process. If 100 are sent through, 100 have to be rejected. We can also create different test samples that emulate a particular end-use product. We can even produce a test tablet in the shape of a capsule that can be thrown into the production stream, because in the real world, it wouldn’t fly through by itself.”

Other vendors encourage their customers to work with them during product development, before all the characteristics of the packaged product are known. That way, consistent testing and inspection methods that are tailored specifically to the product can be more easily devised.

Micron Pharmaworks (Tampa, FL) has a product that detects pinholes in blister packages, says Peter Buczynsky, president. The firm works with customers early on to help them figure out how small a hole they need to be able to detect.

“For years, 100 microns was the industry standard to detect the smallest hole. We started supplying equipment that could detect 50 microns and lower,” he says. “In actuality, you can get false rejections if you set up a test that’s too sensitive. Some customers ended up going back and asking for 100 microns again. The best way to handle it is for them to send us their packaged products, and we will drill laser holes in them for their permeability and longevity studies. During that process they can get a sense of what size hole is acceptable and what is not.”

In some cases, pharmaceutical companies perform testing processes on packaging components that have not yet been filled. In other cases, they demand that their suppliers do such tests.

“There is now a different level of screening that pharmaceutical companies are demanding of their suppliers,” Louli says. “Some of that stemmed from one incident where a lot of bottles were being rejected for metal contamination. It was found that even the empty bottles were rejecting. It turned out that metal contamination entered into the bottle at the preform stage. So, some are demanding that their suppliers prescreen their products prior to shipping them. This is a proactive approach that will be good for industry.”

CONVERGENCE

The medical device and pharmaceutical industries share many of the same goals when it comes to testing and inspecting packages. The need for consistency and repeatability is a significant similarity. However, each has evolved its own practices, and the technologies and methods used can be quite different. 

“Most pharmaceutical products are using nonporous material packages, while a large segment of the medical market uses porous Tyvek or paper for sterilization purposes. However, many medical manufacturers are using foils and films for packaging, which brings in the convergence of technologies,” says Stephen Franks, executive vice president of TM Electronics Inc. (Boylston, MA). “Nondestructive package test methods are more easily applied to nonporous material packages and are more available.”

Yet, with the increasing popularity of combination products, there may be opportunities to draw on each other’s practices.

“Medical device packaging and sterile pharmaceutical packaging have a lot of similarities, but those involved use a different thought process,” Tkacik says. “Both have needs for strength and integrity testing, but the requirements for particulate control vary within physical, visual, and environmental testing. We can learn from each other and get more involved in developing industry standards together.” 

Copyright ©2003 Pharmaceutical & Medical Packaging News