By Sean Fenske, Editor-in-Chief

The product development lifecycle for medical devices is substantial. As such, if optimization can be accomplished during any part of the journey to speed time to market, it is a welcome opportunity. Not only does it help get the product to the healthcare sector faster, but it can also reduce costs for the manufacturer.

Prior to embarking on this type of best practice, the manufacturer needs to ensure there is no reduction in the comprehensiveness of the testing. Similarly, patient safety must remain paramount and not be sacrificed in favor of moving the product through the process faster. As such, it’s typical for medtech OEMs to partner with experts who maintain procedures to safeguard against any omission or oversight during testing of packaging, cleaning, and sterilization procedures.

To share insights on how his company helps organizations enhance these aspects of product development, Brian Nissen, Director of Engineering at Cretex Medical | QTS, responded to several questions. In the following Q&A, Nissen speaks to speeding up the validation of packaging, cleaning, and sterilization through the use of product families.

Sean Fenske: Since today’s discussion centers around product families, can you please explain what these are and provide examples?

Brian Nissen: Product families are groups of devices that share common characteristics such as materials, geometry, and manufacturing process, so they can be validated as a group rather than individually. In orthopedics, for example, a line of bone screws that differ only in length or diameter and share a common manufacturing process could be considered one family. By treating them as a family, manufacturers can streamline testing, reduce redundancy, and still demonstrate safety and effectiveness across the group. Depending on the type of testing, a product line might have different family groupings for package validation, sterilization validation, and cleaning validation. At QTS, our experts work with customers to help them analyze their products, organize families to reduce costs, and maximize speed to market.

Fenske: What attributes within a product family need to be shared (or similar) to realize benefits for testing and validations?

Nissen: To gain efficiencies with a product family approach, devices should share key attributes such as material composition, surface finish, and general design features that affect how the device interacts with the packaging system and the cleaning and sterilization processes. The process by which the devices are manufactured, including what materials those devices come into contact with, can also be important when constructing families. When the proper attributes align, you can often use representative testing to demonstrate functionality and homogeneousness across the group. The more consistent the family is, the easier it is to justify that the validation data applies to all members.

Fenske: How do you select the best representative samples from the product family for testing? How do you ensure all aspects of the product family are covered?

Nissen: When selecting representative samples, we typically look for the devices with characteristics that would be most challenging to the process being validated. For example, in a family of cannulated instruments, the longest or narrowest lumen may be chosen as the test article for cleaning and sterilization because of the difficulty in removing manufacturing residues or bacteria. If validating the same family for package validation, we may select the heaviest or sharpest instrument because that is the instrument most likely to damage the packaging system. By validating the most difficult member of the family, we can be confident the other designs will also meet requirements.

Fenske: What must be kept top of mind for packaging validations when using product families? Does the packaging need to be similar for the entire family?

Nissen: Yes, packaging similarity is important. Packaging validation is comprised of stability testing, focused on the shelf life of the sterile barrier system (i.e., pouch and tray), and performance testing (focused on how the entire packaging system behaves under handling, distribution, and storage).

Family groupings for performance testing generally share a common protective packaging and sterile barrier system design due to the nature of the test, which is focused on how the package system protects the sterile barrier during distribution and handling. The test article selected should be the most challenging content of the packaging system (e.g., size, surface finish, sharp edges, potential for movement within the package). That way, you can be confident the packaging system will stand up for all members of the family.

For stability testing, because it is focused on the sterile barrier system itself, we can create larger families since not all members of that family will adversely interact with the sterile barrier. When contents do not interact with the sterile barrier system, these families can be created on the basis of common sterile barrier materials, sterilization methods, and sealed package specifications.

Fenske: With cleaning validations, can the same cleaning process be used for different product families?

Nissen: Yes. Ideally, the same cleaning process would be used for all of the customer’s families. A common process usually makes the most sense operationally, saving time, minimizing validation complexity, and reducing processing costs. Arriving at a common cleaning process, however, can be complicated. Device families, which are formed on the basis of product design similarity and potential contaminants, can represent unique challenges. A family of devices with very complex geometry may make it difficult to clean each surface. A family of additive-manufactured devices can be challenging because of contaminants collecting in porous surfaces. You could also have a family whose manufacturing process exposes them to a unique contaminant that requires a special detergent.

At QTS, our experts have years of experience finding the right solutions that serve the needs of a wide variety of devices. We work with customers to design families and test strategies that make cleaning as efficient as possible.

Fenske: In terms of sterilization validation, what considerations go into radiation sterilization versus ethylene oxide (EO) sterilization?

Nissen: Radiation sterilization validation is primarily microbially based. Families are organized around product design and potential for biological contamination through handling. Generally, components from the same manufacturer created using the same process and handled in the same manner can all be treated as a single product group. Packaged materials outside the sterile barrier are less of a consideration when validating the sterility of a radiation-sterilized product.

EO sterilization involves processes that are based on the transfer of heat, gases, and humidity. Thus, the entirety of the package and product design needs to be accounted for. Dense products with restrictive openings are more difficult to sterilize than products that are thinner or more diffuse and have many porous surfaces.

With EO sterilization, biological contamination is less of a concern because the overkill method is employed, combined with using specially designed process challenge devices with a test product inoculated with difficult-to-kill indicator organisms. QTS experts will help you determine the sterilization modality that is the best fit for your product’s needs.

Fenske: Does the use of product families present particular concerns for FDA or international regulations?

Nissen: Product families are readily allowed in the U.S. and ISO standards. The key is to ensure there is a sound, scientific justification for the product family, and the representative product tested presents the most challenging case from the family. At QTS, our experts have years of experience in designing families that meet compliance requirements. We’re here to help you navigate sterilization, cleaning, and packaging rules.

Fenske: Do you have any additional comments you’d like to share based on any of the topics we discussed or something you’d like to tell orthopedic device manufacturers?

Nissen: We encourage customers to work with QTS early in the product design process so we can help them minimize challenges related to cleaning, sterilization, and packaging. There may be ways to simplify the supply chain or identify product families early, which could help them realize cost savings by reducing the amount of testing required.

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