ANSI/AAMI ST72:2019 update & key learnings on BET

ANSI/AAMI ST72:2019 provides guidance for BET/LAL of implantable medical devices.


A new resource clarifying FDA guidelines for 510(k) submission was released at the end of November. This standard provides guidance for bacterial endotoxin testing (BET) – also known as limulus amebocyte lysate (LAL) testing – an added requirement for many implantable devices as of a 2016 update to FDA regulations.


ANSI/AAMI ST72:2019 applies to sterile implantable devices that make contact with non-intact tissue, now including many orthopedic implants, which were previously exempted. This includes both new products for 510(k) submission and new batches of existing products.


The 2016 FDA update was a significant change, and the industry was in need of a standard to accompany the requirement.


Standard updates

The American National Standards Institute (ANSI) and the Association for the Advancement of Medical Instrumentation (AAMI) updated ST72 – originally issued in 2011 – to consolidate guidance released since the original publication date and the 2016 FDA regulation, and to expand guidelines on how to justify the use of alternatives to batch release testing within the parameters of the regulation.


The primary change is the expanded scope of products that fall under the latest FDA regulation. The addition of a BET requirement left many manufacturers with little to no experience with the process or best practices, so clear guidelines were needed to explain which products require testing and how to conduct that testing correctly.


The second major change is additional guidelines around alternatives to batch testing. Such alternatives include reducing the number of samples tested, reducing the frequency of testing, testing representatives from product families or using alternatives to a finished product (i.e., surrogate product). This can help conserve time, resources and products for marketing use, but it requires a scientifically sound rationale based on a thorough risk assessment, focused on the overall risk to the patient. The risk assessment can help determine whether an alternative to batch testing would be appropriate.


If you decide to pursue an alternative and have developed a course of action, you can work with your testing partner and follow the specific guidance in ST72:2019 to develop test instruction and perform testing against your alternative process. Be sure to keep this transition well-documented in case of an FDA audit.


Manufacturer’s responsibility

If the BET requirement applies to your device, each lot or batch you plan to release should be tested for bacterial endotoxins before entering the market. If testing discovers endotoxin levels above the specification within the standard, you may need to document that and conduct a gap analysis to assess where endotoxins are coming from. This means reviewing your process, supplies, water quality, etc., to determine the source. You may then need to determine how to reduce or remove endotoxins to mitigate risk.


Failure to meet requirements before going to market could lead to FDA warning letters, audits, recalls, fines or even legal action from consumers or the FDA. Worst of all, you could put patients at risk and tarnish your reputation, which can irreparably damage your product and company.


The best way to ensure your testing is compliant is to find a testing partner with deep BET experience. Whether you are new to BET or lack confidence in your current processes, finding the right testing partner adds the expertise you need to confidently assess your product’s compliance.


Choosing your testing partner

Vetting a testing partner for the right skill and commitment to quality is the key to success. Once you find a potential partner, you’ll want to ensure their testing is done correctly, that they work well with your team, and that they offer strong client support. Further, knowing more about their testing experience can offer insight into their exposure to and ability to adjust for different testing considerations. Finally, ask about their success with on-time delivery.


Having a strong partner in your corner offers peace of mind that each step of the BET/LAL process is done correctly. WuXi AppTec’s experts are available to guide you through the new standard. Reach out to WuXi AppTec for more information.


WuXi Medical Device Testing offers testing services in St. Paul, Minn., Atlanta, Ga., and Suzhou, China.