FDA Proposes Re – Classification of Silver Wound Dressings

Silver-based wound dressings have long been a key tool in the management of chronic wounds, due to silver’s multi-modal antimicrobial action and thus efficacy against bacteria and fungi, including resistant strains like MRSA^1-3. It was thought that silver’s multi-modal action would infer low bacterial resistance development compared to traditional antibiotics; however, recent research has started to challenge this assumption and has indicated the emergence of “clinically significant silver-resistant” bacteria due to the widespread use of silver products^4-6.

In light of this changing scientific understanding of bacterial resistance to silver, the U.S. FDA is proposing a rule to reclassify silver wound dressings (21 CFR Part 878 [Docket No. FDA-2023-N-3275], 30^th November 2023). This potential shift in the regulatory landscape aligns with the FDA’s integral role to promote the responsible use of antimicrobials and facilitate efficient product development as part of the National Strategy for Combating Antibiotic-Resistant Bacteria (CARB)^7,11.

The FDA’s proposal introduces a new classification scheme for antimicrobial wound dressings, categorising them into Class III or Class II medical devices based on the antimicrobial resistance (AMR) concern associated with their antimicrobial ingredients. The FDA is proposing to classify them as such:

• High level of AMR concern antimicrobials named as polymyxin B, silver sulfadiazine & bacitracin, which would be classified as Class III devices^7,8.
• Medium level of AMR concern antimicrobials include silver, zinc, chlorhexidine & Benzalkonium Chloride, which would be classified as Class II Medical devices.
• Low level of AMR concern antimicrobials include peroxides (the antimicrobial present in Matoke’s Reactive Oxygen® technology)⁸.

The reclassification would subject Class III devices to the rigorous and costly Premarket Approval (PMA) application process. In some cases, this would require new clinical studies to be performed, which for class III medical devices are estimated at >$30 million⁹. Those reclassified as Class II products would be subject to certain special controls in addition to general controls. The potential financial and operational burden of this reclassification could lead to some manufacturers withdrawing products from the market, as well as making it more difficult to gain market clearance for traditional antimicrobials such as silver. This could reduce the diversity of products available on the market. As a result, healthcare providers and industry stakeholders have raised concerns that this could limit patient access to vital wound care products, which in turn could result in higher morbidity and treatment times¹⁰.

This all highlights the increasing importance of developing alternative antimicrobial technologies.

Matoke Reactive Oxygen® species (RO) has been specifically designed to tackle the growing threat of antimicrobial resistance and is a major breakthrough in chronic wound management. Matoke RO generates hydrogen peroxide, an antimicrobial with multiple modes of action. Pathogenic species are overwhelmed by its multiple modes of action and thus cannot find a pathway to antimicrobial resistance. It is being developed in several different formats to offer new solutions to the market, patients and clinicians.

References

1. Kędziora, A., et al. (2023) ‘Silver Nanoparticles in Wound Healing: A Review’, Materials (Basel), 16(2), p. 744. https://pmc.ncbi.nlm.nih.gov/articles/PMC9864212/
2. Vizient Inc. (2025) Reviewing the efficacy, advantages and considerations of silver dressings in wound management. https://www.vizientinc.com/newsroom/blogs/2025/reviewing-the-efficacy-advantages-and-considerations-of-silver-dressings-in-wound-management (Accessed: 19 June 2025).
3. S. Food and Drug Administration (2005) 510(k) Summary for Milliken Silver Wound Dressings. https://www.accessdata.fda.gov/cdrh_docs/pdf5/K051445.pdf
4. S. Food and Drug Administration (2016) Silver – FDA. https://www.fda.gov/media/100644/download (Accessed: 19 June 2025).
5. Wounds International (2012) APPROPRIATE USE OF SILVER DRESSINGS IN WOUNDS. Available at: https://woundsinternational.com/wp-content/uploads/2023/02/26953778fdfb53b9c87f7c6f05dd07eb.pdf (Accessed: 19 June 2025).
6. Li H, Xu H. Mechanisms of bacterial resistance to environmental silver and antimicrobial strategies for silver: A review. Environ Res. 2024 May 1;248:118313. doi: 10.1016/j.envres.2024.118313. Epub 2024 Jan 26. PMID: 38280527.
7. S. Food and Drug Administration (2023) Medical Devices; General and Plastic Surgery Devices; Classification of Certain Solid Wound Dressings; Wound Dressings Formulated as a Gel, Creams, or Ointment; and Liquid Wound Washes. https://www.federalregister.gov/documents/2023/11/30/2023-26209/medical-devices-general-and-plastic-surgery-devices-classification-of-certain-solid-wound-dressings (Accessed: 19 June 2025).
8. King & Spalding (2024) FDA Issues Proposed Rule Classifying Certain Wound Dressings and Liquid Wound Washes For the First Time. https://www.kslaw.com/news-and-insights/fda-issues-proposed-rule-classifying-certain-wound-dressings-and-liquid-wound-washes-for-the-first-time (Accessed: 19 June 2025).
9. Sertkaya A, DeVries R, Jessup A, Beleche T. Estimated Cost of Developing a Therapeutic Complex Medical Device in the US. JAMA Netw Open. 2022 Sep 1;5(9):e2231609. doi: 10.1001/jamanetworkopen.2022.31609. PMID: 36103178; PMCID: PMC9475382.
10. Alliance of Wound Care Stakeholders (2025) Letter to FDA & OMB Urging Withdrawal of Proposed Reclassification of Antimicrobial Wound Dressings. https://www.woundcarestakeholders.org/advocacy/submitted-comments/letter-to-fda-urging-withdrawal-of-proposed-reclassification-of-certain-antimicrobial-wound-dressings (Accessed: 19 June 2025).
11. S. Food and Drug Administration (2024) Antimicrobial Resistance. Available at: https://www.fda.gov/emergency-preparedness-and-response/mcm-issues/antimicrobial-resistance (Accessed: 19 June 2025).