Number of lots required for stability testing of a Class II device in the 510(k)


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I have question about the number of lots required for stability testing of a Class II device in the 510(k). We have a request from the reviewer of our last submission for 3 lots used in testing shelf life. I cannot find anything to support his request other than the Drug guideline. Has anyone ever had a question about in relation to the number of lots needed for stability report in a 510(k)?

as you correctly pointed out, lot-based shelf life testing is a typical concept of pharmaceutical products. Is your product a combination device or a degradable device? Has the reviewer given you any indication why potential lot-based variances should be tested?

Until now, I have not heard of FDA/ODE reviewers are suggesting that shelf life (stability) testing should be performed on multiple lots. I have seen some FDA guidance documents that suggest testing multiple lots for characteristics such as coating particulates, corrosion and a few other characteristics, but not in the context of shelf life testing.

Some "seemingly dated" FDA medical device guidance documents mention testing multiple lots for shelf life testing. For example:

FDA 1991 Guidance: Shelf Life of Medical Devices (attached)
- This is the only FDA device shelf life guidance that broadly covers all types of devices
- It refers to 1985 and 1989 FDA guidance documents for contact lenses that mention testing 3 lots, and 2 to 3 lots, respectively

More recent FDA device guidance documents I checked that discuss shelf life testing but do not mention how many lots to test:
- 2019 PTCA Catheters Guidance
- 2010 Non-Clinical Engineering Tests and Recommended Labeling for Intravascular Stents and Associated Delivery Systems Guidance
- 2018 Coronary, Peripheral, and Neurovascular Guidewires – Performance Tests and Recommended Labeling DRAFT Guidance
- 2018 Peripheral Vascular Atherectomy Devices - Premarket Notification [510(k)] Submissions DRAFT Guidance

The FDA-recognized pharma guideline for testing 3 lots/batches is mentioned in ICH Q1A
Data from formal stability studies should be provided on at least three primary batches of the drug substance.

Other documents I checked that do not mention testing multiple lots/batches:
- ASTM F2914 2012 SG for Identification of Shelf-life Test Attributes for Endovascular Devices (interesting since it provides examples of attributes typically not impacted by aging (e.g.. stent/hard plastic dimensions, MR compatibility, marker radiopacity, corrosion resistance)
- EN ISO 11607-1 2017 Packaging for terminally sterilized medical devices-Part 1-Requirements for materials, sterile barrier systems and packaging systems (ISO 11607-1 2006+A1 2014)

Note: "Stability" is a term that is mostly used in the pharma industry, whereas "shelf life" is the term I have seen primarily used for medical devices. However, 11607-1 does use the term "stability" and does not use "shelf life".



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Hi Sam and Plan B,

My medical device is not a combination product nor is made of degradable materials. My team is baffled on the requirement for 3 lots for stability/shelf life.
Thanks for the inputs!

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