Sterile Barrier Systems: Five Pitfalls for Medical Device Manufacturers
It is crucial that medical devices maintain sterility until they arrive at the end user location. If sterility is lost, there may be serious consequences for the manufacturer: the return of the non-sterile product or, in the worst case, the negative impact on a patient's health leading to the device's approval being withdrawn. Therefore, medical technology companies make great efforts to ensure the correct packaging, testing and validation so the sterile barrier system remains intact. The burden on the packaging during its transition from the MDM to the patient is enormous and the risks to the integrity of the sterile barrier are numerous: The production method in the factory, the packing process, vibration during transport in trucks or aircraft, and careless packing workers are all potential sources of danger because hairline cracks or damage may be sufficient to affect the integrity of the medical product packaging, which may in turn effect the package's sterility. We spoke with industry experts and asked them to list from their perspective in the development and validation of medical packaging what are the most common errors. Transport Probably the biggest threat to the sterile barrier is during transport. The manufacturer has the responsibility to ensure the product arrives without damage to the customer. MDMs must be able to validate their packaging is capable of providing reasonable protection against transport risks. Most companies therefore conduct thorough testing that simulates the transport of their products. In many cases, however, this testing does not reflect the conditions under which the products are actually shipped. "Some (MDMs) take an easy or simplified test path. They do not select the actual worst-case scenario which can lead to overlooked, subsequent problems." says Nicole Kaller, Packaging Engineer at DuPont. It is crucial to know all the routes of distribution so the packaging can undergo a complete transport chain risk analysis and all possible threats to the package's sterility can be considered. It can for example yet have an impact on the sterile barrier if the truck carrying the packaging crosses a high mountain and the pressure condition therefore change. "Persons responsible for packaging solutions sometimes lack imagination. But it is essential to imagine the 'dangers' facing a package between completion of sterile packaging and the time-of-arrival to the customer," said Eric Schmohl, Customer Support Manager at DuPont. Cost Cost always plays a major role in packaging. Even if the price differences from one material to another are only fractions of a cent, when used in large numbers, the impact is noticeable on the profit margin. For this reason, manufacturers often opt for the cheapest version of a material, but that can turn into an expensive choice fast. For example, film combinations are often chosen because they are quite cheap, but the choice does not really fit the needs of the packaging.

"If the film is not chosen properly, the packaging process can lead to problems such as punctures or microinjuries in the film by sharp-edged products," says Daniel Ziebarth of the Südpack GmbH. "Sometimes there are products that have sharp or square edges that can damage the lower film if the wrong material was used." Ziebarth notes that companies have been reluctant to change their packaging to newer and better materials because they were afraid the re-qualification and validation effort. Development The development of new medical device products often takes several years to complete. Some companies make the mistake of not including in their early design process the aspects of packaging, sterilization, transportation, and storage. "If the product is developed without thinking about the packaging, there is already a failure," says Eric Schmohl. "If the product is made and I choose a sterilization method that is not compatible with the packaging or even the product, I create a lot of problems." The company now has to retrace its steps back to the product development process or redesign a product with a new packaging concept before it can be put on the market. Both possibilities can cost the company dearly. So MDMs should make sure to consider packaging early if they develop a new product. The Packaging System "From the sterile barrier to the packing box, the entire packaging system must be suitable for the product remains sterile," says Beate Klumpp, Director of Testing Services at mdt medical device testing GmbH. Klumpp says it is a common mistake that MDMs choose a package which is not adapted to the product. For example, lightweight packaging would be used for heavy products such as metal implants for cost reasons, but the product would then pierce the packaging during transportation. Frequently, a single sterile barrier system for multiple medical devices will be used. This may mean that the products are either too closely packed and strongly press against the seal or have too much space, so both the product and the packaging may be damaged. Testing Testing should not only serve to meet the demands of regulatory authorities. Testing provides important insights into which packing methods are suitable for a particular product. Therefore, the company should ensure the methods actually used in the test are appropriate for what is being tested. "You have to not only measure to produce numbers. The measurement must also be reasonable and what is measured must also be right," says Thierry Wagner, Regulatory Affairs Director at DuPont. He recommends a validation of test methods, which is also a regulatory requirement. The manufacturer must check whether it gets the same results when the test was performed on a different day, by another employee or in another laboratory. Only when the two criteria "repeatability" and "reproducibility" are given, it can be assumed that the methods have been applied correctly. Wagner explains that a test method validation in the pharmaceutical industry that is standard may not meet the same standard in medical technology. From: Thomas Klein