Opening the doors to perception

Although there is no crystal ball to predict the cohesiveness of a medical device’s design, materials and production process, there are two doors development teams can unlock to open up their probability for a successful scale-up. Del R. Lawson, PhD, R&D manager in 3M’s Medical Solutions Division, provides the keys to those doors.

The medical device design process is bound to have challenges as it progresses into the production stage. Catching all of them can be tricky, but the good news is that many are preventable. Although there is no crystal ball to predict the cohesiveness of a medical device’s design, materials and production process, there are two doors development teams can unlock to open up their probability for a successful scale-up. Both rely on proper planning and, when done correctly, can test for potential setbacks before challenges evolve into more significant issues during full-scale production. 

Engineers looking to advance or refresh their design mindset with a more holistic approach should question two factors in the early stages of the development process: the production and material effects on device performance. 

Key #1: Managing process effects for success 

Development teams who challenge their assumptions and processes may uncover obstacles they may not have otherwise caught presented by the speed, friction and pressure during scale-up. To improve medical device developers’ overall design, walking through the below questions can be an excellent place to start this effort.

How have you factored in friction?

As production rates and machinery increase to meet the advancing needs of a project, the impacts of friction on certain materials and designs often follow suit. It can be difficult to predict where friction might manifest production issues; one area particularly subject to such stress, however, is the adhesive liner. 

The adhesive release liner supports a major aspect of a medical device’s designed functionality, and ensuring it is applied properly protects the product’s usability. Adhesive liners must be applied with balanced tension to reduce the impacts of manufacturing. Too tight, and the liner can wrinkle or inhibit the run speed. Yet when liner release values are too loose (low adhesive holding force between the liner and adhesive layer), they could fall off prematurely on the converting equipment. If a team plans to remove and reuse liners, look for any scratches or damage that could affect the final product. 

How might heat or other curing procedures affect adhesives?

If the answer to this question is unclear, stability and aging studies can forecast how adhesives may react to heat-based production steps. If the selected bonding agent is heat activated, the production process may need to be adjusted to avoid exposing the device prematurely. The same may be true for exposure to UV wavelengths and other common ‘cure’ conditions.

Will cleaning and maintenance influence design?

The cleaning and maintenance of manufacturing equipment are a given part of any medical device’s production. Yet what manufacturers use to clean and maintain equipment is not often thought of as an influential factor in design. Certain cleaning products or methods could be incompatible with the product’s materials or construction. Conversely, ineffective cleaning could gum up or contaminate equipment, especially when running different materials on the same line. 

Thoroughly evaluating cleaning agents, methods and preventative maintenance can reduce unexpected stops to production or impact to the final device performance. 

Understanding how the production process can influence the final device does not have to take a ‘wait and see’ approach. Rather, teams that use the questions above from the start of a project can stay ahead of potential issues and adjust accordingly. 

Key #2: Managing material effects for success 

Material compatibility is paramount to achieve optimal product performance and functioning components. When every material is thoughtfully selected, manufacturers can reduce the odds of premature failures, and in many cases, they can improve overall device performance. By leveraging the questions below, companies can stay ahead in ensuring material compatibility. 

How will the device materials hold up over time?

The test of time can reveal many insights about a device’s materials. Teams must prioritize their device’s essential properties and be mindful of potential contamination points, including naturally occurring sources and those triggered during manufacturing or sterilization. 

Two ways to do so are through ageing and sterilization studies. They help evaluate material compatibility and identify potential stressors by manipulating temperature and time to show where the development process should focus before progressing further. Early sterilization studies can help with selecting the best method for the finish device. These two studies can help companies to identify sources of concern and problem-solve before they scale up. 

Will the product need to adhere to the skin? 

Selecting an adhesive can often occur as an afterthought during medical device development. Selecting an adhesive can often occur as an afterthought during medical device development. If teams factored this into the design earlier, picking the right adhesive could drastically contribute to performance and overall efficacy. Companies that leverage the full potential of an adhesive can add to a device’s functionality significantly.  

Have material and manufacturing compatibility been thoroughly vetted?

Testing the final version of a product with the given manufacturing process is fundamental to ensuring material compatibility. In addition, evaluating more than one lot of production equivalent materials can act as an approach to proactively assure critical material compatibility in terms of regulatory, safety, efficacy and appearance performance. 

Asking questions to improve outcomes 

Development teams can execute a more seamless scale-up by managing how the selected components and assembly process will affect their device design. Although some are already asking several or all of these important questions, they must remember to bring this curiosity into the conversation early in the process. Doing so helps mitigate potential escalating issues.