What does ISO 10993-23 irritation testing mean in practice?
ISO 10993-23 assesses the irritant potential of a medical device and is therefore a key component of biosafety. Modern irritation tests utilize reconstructed human epidermal models (RhE) that realistically replicate the physiological barrier function and deliver robust, regulatory-accepted results. The aim is to identify early on whether a product or its extracts can cause local irritation of the skin or mucous membranes.
The testing is performed exclusively using extraction methods according to ISO 10993-12. Soluble and mobile substances are captured using suitable extracts. This allows for the simulation of relevant exposure scenarios for the respective medical device. The selection of extraction conditions depends on the material, application, and type of contact, within the normative specifications.
Typical endpoints include the viability of the RhE tissue. In combination with positive and negative controls, this results in a scientifically sound assessment that ensures both sensitivity and specificity. The robust methodology allows for clear conclusions even with complex matrices or borderline viabilities.
The results are directly incorporated into the biological evaluation according to ISO 10993-1. Normal results indicate a low risk of irritation, while abnormal findings require further toxicological analysis or may necessitate design and material adjustments.
Norm criteria – at a glance
| Norm criterion | Requirement / content | Note |
|---|---|---|
| Model | RhE (reconstructed human epidermis) | Physiological barrier |
| Exposure | ISO 10993-12 extract or direct surface contact | Use scenario |
| Endpoints | Viability + model-specific markers | Robust conclusion |
| Controls | Positive/negative controls | Standard-compliant |
| Use of data | Input for ISO 10993-1 | Risk management/technical file |
How we test your medical device – step by step
- Request a quote by phone or online. Key inputs: device, materials/components, contact type and exposure duration, and the device condition (e.g., sterilized/reprocessed).
- Send your device after accepting the quote. Please provide the sample in the marketed/used state where possible (including reprocessed state if applicable).
- Upon receipt, we start testing and document sample logistics and - where relevant - ISO 10993-12 aligned preparation/extraction parameters.
- We perform ISO 10993-23 irritation testing - preferably using validated RhE models and relevant endpoints (e.g., viability, markers), aligned with contact site and duration.
- You receive a digital, QES-signed report with professional interpretation. Upon request, we coordinate next steps through external toxicology (ISO 10993-17) and the ISO 10993-1 Biological Evaluation.
Why HygCen?
- DAkkS accredited testing laboratory (DIN EN ISO/IEC 17025) with GLP-compliant processes.
- Risk-based study design aligned with intended contact type, duration and use.
- Testing in the original state, including relevant processing/sterilization/reprocessing influences.
- Digital, QES-signed report with expert interpretation for MDR technical documentation.
- One-stop coordination: we manage interfaces to independent toxicologists for ISO 10993-17 and the ISO 10993-1 Biological Evaluation when needed.
ISO 10993‑23 irritation testing commonly uses validated reconstructed human epidermis models such as EpiDerm™ or SkinEthic™. These models reproduce key aspects of the human skin barrier and provide realistic, regulator‑accepted irritation data. Model selection depends on material properties, device category and intended use.
Direct surface‑contact testing is relevant when a device is applied directly to skin or mucosa, or when extractable testing does not realistically represent clinical exposure. This applies particularly to coated materials or devices with low substance mobility. Direct contact simulates real‑world application conditions with high fidelity.
Typical endpoints include RhE tissue viability as a key assessment parameter. In addition, nonspecific inflammation- or stress-related tissue responses can be used to detect early stimulatory effects. These additional endpoints can contribute to a better classification, particularly with complex materials or borderline viability values. Some models also allow for the consideration of further histological or morphological parameters, which support the overall assessment.
Extracts are selected using a risk‑based ISO 10993‑12 approach, employing polar and non‑polar media to represent realistic worst‑case release conditions. Time and temperature parameters simulate clinical exposure, ensuring soluble and mobile constituents are adequately captured for assessment.
Validated RhE models, strict positive and negative controls and clearly defined acceptance criteria ensure highly reproducible, regulator‑ready irritation results. These data are then integrated into the ISO 10993‑1 Biological Evaluation together with other toxicological and biological endpoints.
Related links
ISO 10993-12 – Sample preparation & reference materials, ISO 10993-18 – Chemical characterization, ISO 10993-10 – Skin sensitization, ISO 10993-5 – Cytotoxicity, ISO 10993-3 – Genotoxicity, ISO 10993-4 – Hemocompatibility, Pyrogenicity & endotoxin – incl. ISO 10993-11 coordination, ISO 10993-1 – Biological Evaluation