Testing the multi-sterilization compatibility of materials requires cyclic sterilization tests, performance comparison tests, and verification of certification documents, with a focus on evaluating their physical, chemical, and biological stability after gamma ray, ethylene oxide (EO), and high-temperature, high-pressure steam sterilization. The following are the specific testing methods:
1. Multi-Sterilization Compatibility Test Procedure
|
Steps |
Test Content |
Purpose |
|
Pretreatment |
Place the material sample at 120°C for 4–6 hours to remove moisture |
Prevent moisture from causing hydrolysis or degradation during sterilization. |
|
Cyclic Sterilization |
Perform 3–5 rounds of alternating sterilization according to the actual usage sequence (e.g., Gamma → EO → Steam) |
Simulate real-world multi-scenario usage conditions to expose cumulative damage. |
|
Performance Testing |
After each round of sterilization, test appearance, mechanical strength, transmittance, color difference, etc |
Identify performance degradation trends and determine if standards are exceeded. |
Recommended Dosage/Conditions:
Gamma Rays: 25–50 kGy (Pharmaceutical Grade Standard)
EO Sterilization: 450–600 mg/L, 37–55°C, 1–6 hours
Steam Sterilization: 121°C, 15 psi, 30 minutes
2. Key Performance Evaluation Indicators
|
Indicator |
Acceptance Standard |
Test Method |
|
Appearance Changes |
No obvious discoloration (ΔE < 3), no fogging, no cracks |
Visual inspection + colorimeter measurement. |
|
Mechanical Properties |
Tensile strength and impact strength decrease < 15% |
Universal testing machine test. |
|
Transparency Retention |
Light transmittance > 85% (applicable to visible parts) |
Spectrophotometer measurement. |
|
Chemical Safety |
No bisphenol A precipitation, ethylene oxide residue < 10 ppm |
HPLC and GC-MS detection. |
Biocompatibility: Meets ISO 10993 requirements after sterilization. Cytotoxicity and sensitization tests.
Important Note: Some materials show no abnormalities after a single sterilization cycle, but their performance drops sharply after multiple cycles; therefore, multiple rounds of testing are necessary.
3. Certification and Document Verification
ISO 11137: Verify the suitability of gamma ray sterilization.
ISO 11135: Confirm compliance of the EO sterilization process.
ISO 10993: Ensure that biosafety is not compromised by sterilization.
COA (Certificate of Analysis): Request performance comparison data before and after irradiation from the supplier to ensure traceability.
