Medical Device Testing…Smartly
Lisa Olson, VP of testing and service development at WuXi AppTec, was a part of the staff written article, “It Begins and Ends with Testing.” She took time to present a full array of responses that were not able to be included in the article, so they are presented here.
Q: What’s the most common error OEMs make when it comes to establishing a testing regimen for a device?
Olson: Many OEMs have significant budget constraints and design their testing programs to meet the budget rather than to answer all of the pertinent safety questions. Many studies can be designed to be cost effective and answer safety questions. For example, extractable/leachable programs for medical devices can be designed in a variety of ways. Study costs can range from a few thousand to nearly a million dollars depending on the study design. Because the guidelines are not proscriptive, designing a study that meets the intent of the guidelines and regulatory expectations can be difficult. In some cases, such as when evaluating known materials, extensive studies may not be needed. Conversely, limited evaluations on new materials are not appropriate.
Q: How does device testing in the design phase alleviate problems discovered further into development or manufacturing?
Olson: Testing early in the design phase can help identify materials that may have some unexpected risk factors or that lose key materials properties when used. Identifying potential problems early can mean that time and effort is not wasted on a material that has to be redesigned and then retested. Further, some choices in materials and additives will impact the amount of testing that has to be done in the future. Colorants are a prime example. Not all colorants have been tested for specific medical device applications, though they may be on the GRAS list (Generally Recognized as Safe). What seems a simple design choice in the beginning could possibly have significant implications at the point of regulatory review.
Q: How can device manufacturers realize cost savings through efficient testing?
Olson: There are a variety of ways to maximize the data coming from test programs without compromising the quality of the information. The approach must start at the beginning of the design process with smart material choices and early characterization programs. By starting materials characterization tests early in development, later studies for biocompatibility, extractable/leachables and preclinical safety can be designed to specifically target any potential risks suggested by the early characterization data. This allows programs to be efficiently designed rather than casting broad nets. Additionally, many studies can be designed so that multiple endpoints can be collected at once rather than creating separate studies for individual endpoints.
Q: How do you respond to the questions over the safety of medical devices and the lack of testing of them?
Olson: I believe that most medical device manufacturers do have patient safety foremost in their minds when developing testing programs. Millions of dollars are spent every year to characterize and demonstrate the safety of medical devices and materials. Unfortunately, even with extensive test programs and sophisticated modeling, not every safety question can be addressed before the device is used clinically. Manufacturers, test laboratories and regulatory agencies must continue to partner with each other to improve the quality of testing and program reviews. It cannot become a situation where good enough is considered acceptable. All the major stakeholders must continue to think critically about designing test programs based on risk factors and asking the right questions to improve patient safety.