Technological watch

Manufacturing effects on materials have become a significant area of focus for medical device manufacturers in recent times. “Materials are the major or possible cause of 30 to 40% of FDA recalls for medical devices," according to Jeffrey Ellis. 1 And according to a McKinsey report, product “quality events” (including recalls, warning letters, consent decrees, warranties, and lawsuits) cost the medical device industry between $2.5 and $5 billion annually.” 2

Pushing the Limits & Developing New Materials

As technologists continue to progress our reality into that of a sci-fi movie, they are pushing the limits of materials causing molecular-level variation to affect the quality of products. Additionally, scientists are breaking ground formulating new materials through the insertion of dissimilar substances. Some examples of cutting-edge materials are the following:

• Bioabsorbable metals that allow for future MRIs after elimination3
• Wound assisting materials that form part of the new growth tissue4
• “Artificial ovaries made from a biological hydrogel”5
• “Patient-specific vascular stents made from a citric acid-based polymer”5
• Injectable gels that carry biochemical signals3

Manufacturing Causes

When pushing materials to their limits, their properties become more susceptible to minor manufacturing changes or variation that would otherwise be trivial. Additionally, new formulations of materials are susceptible to manufacturing-based failures due to lacking historical knowledge of variation. Some well-established effects on product performance are processing time, temperature, and pressure along with material storage conditions such as humidity, UV radiation, and temperature. However, other lesser known manufacturing factors are impacting more recent products in the field such as:

• Moisture in material, weak welding, or in-mold stress resulting in weakened products with shortened lives6
• Improperly prepared resins leading to unexpected failures2
• Contamination with particulates or other materials during formulation changing material performance2
• PVC Plasticizer leaching into a hydrogel causing crystals blocking an electrical signal1

Conclusion

Being a part of the 30% - 40% of companies with materials-related recalls can be a detriment to your business. Consider incorporating materials science into your development capabilities and reach out to experts to understand what manufacturing variation could cause material property changes. Assess materials in your risk analysis and especially test for potential variation factors having a direct or confounding effect on your product’s performance.

Editor's Note: Stacie Depner will be moderating "Tech Talk Panel: Criteria for Choosing the Right Material for Your Device," during the MD&M West 2020 conference on Wednesday, February 12, at 8:30 AM - 9:30 AM in Room 210C. She will be joined by panelists Ekaterina Tkatchouk, principal engineer, research & development, Surgical Structural Heart at Edwards Lifesciences; Gilles Robert, CEO at Ceramaret; Tim Conrad, principal implant design and materials engineer - research and technology at Advanced Bionics; and Jay Jayashankar, materials & process development engineer at Cardiovascular Systems Inc.

References

Sparrow, Norbert, "Material failure is root cause of many medical device recalls,"  Plastics Today, March 2017.

Heintz, Amy, "Mitigating Risks of Materials Failures in Medical Devices,"  MD+DI, June 2015

"Materials Science in Medical Device Manufacturing," Proven Process Medical Devices Web site.

Mir, M., Ali, M.N., Barakullah, A. et al. "Synthetic polymeric biomaterials for wound healing: a review," Progressive Biomaterials 7, 1–21 (2018). https://doi.org/10.1007/s40204-018-0083-4

Barbella, Michael, "Practical Matters: A Look at Medical Device Materials," Medical Product Outsourcing, March 2018.

"Causes of Plastic Failure," Thomas Net.