Many are Armoloy-coated. Although single-use devices will only be utilized once, doctors, dentists, and the patients who rely on them need the item’s performance to be maximized. For many types of medical instruments, that means applying a biocompatible chromium coating.
ISO 10993-10
ISO 10993-10
Intracutaneous Testing
Intracutaneous Testing Shows No Irritation from ME-92® Coating
summary
What is Intracutaneous Irritation?
Intracutaneous (or intradermal) irritation testing is used to assess whether a material or its extract causes localized skin irritation when injected just beneath the skin. This test is especially important for evaluating implantable or blood-contacting medical devices, where even trace chemical irritants leaching from a material could cause inflammation, redness, or swelling.
According to ISO 10993-10, any adverse skin reaction such as erythema (redness) or edema (swelling) is monitored over 72 hours. The lower the irritation score, the safer and more biocompatible the material is deemed.
What is an Intracutaneous Irritation Test?
This test involves injecting both test extracts and control substances into rabbits and observing the skin’s reaction at the injection sites. For this study:
- ME-92 was extracted using saline (0.9% NaCl) and sesame oil, following ISO 10993-10 extraction guidelines.
- Extracts were injected into five sites on the right side of each rabbit.
- Corresponding control vehicles (saline or sesame oil) were injected on the left side.
- Sites were observed at 24, 48, and 72 hours for signs of erythema and edema.
A difference in mean irritation score of 1.0 or less between test and control groups is considered non-irritant.
ME-92 Intracutaneous Test Summary
ME-92’s coating was applied to 304 stainless steel (Lot #38408) and tested at NAMSA, an ISO-accredited lab. The key findings:
- Saline Extract Irritation Score (Test – Control): 0.0
- Sesame Oil Extract Irritation Score (Test – Control): 0.0
- Erythema/Edema Observed: None beyond slight, isolated redness (Grade 1), consistent with normal injection response
- Conclusion: ME-92 coating caused no irritation in this vivo model
All animals remained healthy, and controls behaved as expected, validating the study.
Why Intracutaneous Testing Matters
Biocompatibility is not just about what a coating does—it’s about what it doesn’t do. ME-92 showed no signs of irritation in tissue-contact testing, reinforcing its safety for use in implants, surgical devices, and blood-contact medical tools. Low irritation scores help prevent post-op complications and ensure faster healing.
Other Biocompatibility Standards
Explore more compatibility standards we certify to.
Frequently Asked Questions
Yes, as long as the weld is machined and blended. This is a positive application to consider since a welded area is very susceptible to corrosion during autoclave.
Biocompatible coatings enhance the durability, safety, and performance of surgical instruments by preventing corrosion and wear while ensuring they remain safe for use in the body. To learn more about the key benefits and differences between coating types like BIO-TDC and ME-92, read our full blog here.
A disposable medical instrument must perform as well as a reusable device and even disposable instruments require autoclave prior to use. Disposable instruments experience galling and dulling of edges during their short usage, but still must perform to a high level. The ME-92® biocompatible coating reduces these undesirable occurrences.
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