ISO 10993-23 Update: New In Vitro Skin Irritation Models Offer Regulatory and Cost Advantages
Advancing In Vitro Skin Irritation Testing for Global Submissions
The latest update to ISO 10993-23 introduces two newly validated reconstructed human epidermis (RhE) models for in vitro skin irritation testing: LabCyte EPI-MODEL24 and KeraSkin™. These additions mark a significant advancement for medical device manufacturers seeking global market approvals, especially in regions such as the EU, Japan, and South Korea.
What's New?
The standard now officially recognises:
- KeraSkin™ – Developed in South Korea, tailored for Asian skin profiles
- LabCyte EPI-MODEL24 – Developed in Japan, suited for high-throughput testing
Both models are compliant with OECD Test Guideline 439 and serve as robust, animal-free alternatives for skin irritation testing.
Type:
Author:
Elena Henderson, BSc | MBSI | MRSB | MBTS
Elena is Principal Consultant at Cormica and a specialist in biological evaluations for medical devices under ISO 18562 & ISO 10993. With 8 years at Cormica MET as a Biocompatibility Assessor, she has contributed to successful UK, EU, and US regulatory submissions.
Why Does This Matter?
- Global Market Access With a Single Test
For manufacturers marketing in both Europe and Asia, these models streamline regulatory submissions. LabCyte EPI-MODEL24 offers strong predictive performance and is widely accepted by Japanese authorities, while KeraSkin™ is particularly relevant for Korean submissions and Asian population studies. Together, they offer a dual-compliant pathway that reduces duplication of effort. - Validated and Reliable Results
KeraSkin™ offers strong histological fidelity and reproducibility, using keratinocytes derived from Asian donors. LabCyte EPI-MODEL24 boasts high specificity and sensitivity, correlating closely with human skin barrier properties. Both utilise the MTT assay for determining tissue viability, a well-established endpoint for irritation testing. - Lower Test Costs
These methods reduce the required extract volume by approximately one-third compared to standard protocols. This means lower consumable costs and more efficient lab resource usage.
Technical Enhancements in the Standard
- Flexible Plate Configuration: New plate layouts (Tables C.7 and C.8) accommodate both models with defined positions for controls, test items, and tissue samples.
- Expanded Aliquot Tolerances: Guidelines now support wider options for transfer volumes, enabling greater flexibility in test execution.
- Alternative Readout Wavelength: For LabCyte EPI-MODEL24, absorbance may be measured at 650 nm, increasing compatibility with certain lab equipment.
- Modified MTT Protocols: Especially for KeraSkin™, the update allows reduced MTT solution volumes, simplifying workflow.
Practical Considerations
While these new methods present clear advantages, Cormica is currently evaluating the performance and stability of both models in-house. As with any newly adopted model, reliability and reproducibility are key to ensuring valid, reportable data.
Our expert teams are also liaising with external partners to confirm readiness for implementation, particularly with regard to tissue supply and test scheduling.
Conclusion
The ISO 10993-23 update represents a meaningful step forward in harmonising global regulatory expectations for in vitro irritation testing. The addition of KeraSkin™ and LabCyte EPI-MODEL24 not only enhances scientific validity but also provides practical benefits in cost, flexibility and market access.
Cormica will continue to support clients through these updates, offering guidance on regulatory applicability and executing validated test plans tailored to your product and regional strategy.