灭菌相容性研究要测哪些性能

结论：灭菌相容性不只看产品能不能用，还要看变了多少

灭菌相容性研究要回答的是：产品和包装经过灭菌过程之后，是否仍然满足所有要求。

注意是「所有要求」，不只是「还能用」。 力学性能下降但仍在规格内、外观变色但功能正常、包装密封强度下降但仍能密封——这些情况下产品「还能用」，但性能已经改变，而改变的幅度关系到货架期内的表现。

所以相容性研究不只做合格与否的判断，还要测出变化的幅度。 变化幅度大的项目，在货架期内可能进一步劣化到不合格。

研究的范围

相容性研究要覆盖几个方面：

产品的材料性能。 力学、物理、化学性能。

产品的功能。 各项功能是否正常。

产品的外观。 变色、变形、表面变化。

包装的性能。 密封、阻隔、强度。

化学变化。 是否产生新的物质。

生物学影响。 灭菌引入的物质对生物相容性的影响。

灭菌效果本身。 属于灭菌确认，但与相容性研究相关。

「化学变化」和「生物学影响」在轻量的相容性研究中常被省略，但它们是生物学评价的输入，不能因为产品「看起来没问题」就跳过。

材料性能的测试

「断裂伸长率」对辐照灭菌的材料特别敏感。 拉伸强度可能变化不大，但断裂伸长率明显下降，说明材料在变脆。只测强度不测伸长率，可能漏掉这个变化。

「压缩永久变形」对含密封件的产品重要，因为密封件性能下降会影响产品的密封功能。

功能验证

材料性能之外，产品功能也要验证：

活动部件。 转动、滑动、开合是否顺畅。

密封功能。 产品自身的密封。

电气功能。 含电气部分的产品。

配合尺寸。 装配部位的配合是否改变。

使用中的操作。 按实际使用方式操作一遍。

功能验证应当按实际使用方式做，而不只是静态检查。某些变化只在动态使用中才表现出来——比如塑料件变形后活动部件卡滞、密封件硬化后密封力不足。

包装性能的测试

密封强度。 剥离力、爆破强度。

密封完整性。 有无通道。

材料强度。 包装材料本身的强度。

阻隔性能。 阻菌、透气、水汽透过。

外观。 变色、脆化、分层。

易开性。 无尘开启是否仍然可行。

「易开性」在辐照后可能改变。 材料脆化后，原本能剥离的密封可能变成撕裂，开启时产生碎屑造成污染。这一项应当验证而不只是假定不变。

多次灭菌的处理

有些情况下产品会经历多次灭菌：

返工。 首次灭菌后发现问题，返工后重新灭菌。

剂量不足补照。 辐照剂量不足时补充照射。

可重复使用产品。 使用后再次灭菌。

处理原则是： 明确规定是否允许多次灭菌、允许几次；对允许的次数做相容性验证；在产品上或资料中标识。

「返工重新灭菌」是实务中最常遇到的情形，而企业往往没有规定次数上限，也没做相应验证。建议明确规定并验证，因为累积的灭菌剂量或热历程对材料的影响可能超过单次。

结果的解读

拿到数据之后：

与未灭菌样品对比。 看变化幅度。

与规格限值对比。 看是否仍在规格内。

评估趋势。 变化幅度大的项目要关注货架期内的进一步变化。

识别敏感项目。 哪些性能对灭菌最敏感，这些是后续监控的重点。

判断余量。 灭菌后距规格限值还有多少余量。

「余量」是实用的判断依据。 灭菌后性能刚好在规格内，说明余量已经用完，批次差异或货架期内的进一步劣化很可能导致不合格。这种情况下应当改进材料或工艺，而不是接受。

与其他验证的衔接

与灭菌确认。 相容性用的灭菌参数应当是确认过的参数，并按上限做。

与稳定性研究。 相容性研究的样品可以进入稳定性研究，看后续变化。

与生物学评价。 化学表征应当用灭菌后的样品。

与包装验证。 包装的完整性验证应当在灭菌后做。

与运输验证。 运输验证的样品应当是灭菌后的。

这几项衔接好，可以共用样品，减少重复。 建议在规划阶段就把各项验证的样品需求统一考虑。

样品的准备

相容性研究的样品准备影响结论的可靠性：

最终状态。 经过全部加工、装配、包装。

量产工艺。 试制样品的工艺可能与量产不同。

足够数量。 覆盖各测试项目，含破坏性试验。

对照样品。 未灭菌的同批样品作为对照。

批次覆盖。 必要时覆盖多个批次，反映批间差异。

记录完整。 批号、生产日期、工艺参数。

「对照样品」是必需的。 没有未灭菌的对照，就无法判断变化是灭菌造成的还是材料本身的特性。

数据的用途

相容性研究的数据有几个去向：

技术文件。 作为产品符合性的证据。

稳定性研究的起点。 灭菌后的性能是货架期变化的起点。

生物学评价的输入。 化学表征的结果。

工艺参数的依据。 材料耐受范围决定了灭菌参数的上限。

变更评估的基线。 将来变更时的对比基准。

建议把数据整理成便于查阅的形式，因为它在后续多个环节会被反复用到。

我们的做法

做灭菌相容性研究时，我们建议按确认参数的上限处理样品，因为生产中会有波动，按名义值验证留的余量可能不够。

测试项目上，对于辐照产品我们会建议加测断裂伸长率——这一项比拉伸强度更能反映材料的脆化程度，而脆化是辐照的典型影响。

另外，我们建议相容性研究的样品保留一部分进入储存观察，因为某些变化在灭菌后会继续发展，只看处理后立即的数据可能偏乐观。

如果你在规划灭菌相容性研究，可以把材料信息、灭菌参数和产品结构发过来一起讨论，或者直接联系：132 4819 8029。能力范围见服务介绍，送检要求见送检要求，其他问题见常见问题。

English version

Conclusion. A sterilisation compatibility study answers whether product and packaging still meet all requirements after the sterilisation process. Note all requirements rather than merely still usable. Mechanical performance reduced but within specification, discolouration with function intact, seal strength reduced but still sealing: in each case the product still works while its performance has changed, and the extent of that change bears on behaviour across shelf life. A compatibility study therefore does not only judge pass or fail but measures the extent of change, because properties that shift substantially may degrade further within shelf life to the point of failure.

Scope of the study. Product material properties, covering mechanical, physical and chemical characteristics. Product function, covering whether each function operates. Product appearance, covering discolouration, distortion and surface change. Packaging performance, covering sealing, barrier and strength. Chemical change, covering whether new substances appear. Biological effects, covering the impact of sterilisation-introduced substances on biocompatibility. And sterilisation effectiveness itself, which belongs to sterilisation validation while relating to compatibility. Chemical change and biological effects are often omitted from lightweight compatibility studies, yet they are inputs to biological evaluation and cannot be skipped because the product looks fine.

Testing material properties. Mechanical testing covers tensile strength, elongation at break, impact strength and flexure. Physical testing covers hardness, density, dimensions and melting or softening point. Surface testing covers roughness, coefficient of friction and coating adhesion. Optical testing covers transparency, haze and colour. Elastomer testing covers compression set, recovery and sealing force. And bonding covers bond strength and peel. Elongation at break is particularly sensitive for irradiated materials: tensile strength may change little while elongation falls markedly, indicating embrittlement, so measuring strength without elongation can miss the change. Compression set matters for products containing seals, since declining seal performance affects the product's sealing function.

Functional verification. Beyond material properties, function requires verification. Moving parts must rotate, slide and open smoothly. The product's own sealing function must work. Electrical functions must operate where electrical parts are present. Assembly fits must not have changed. And operation must be exercised as in actual use. Verify function as the product is actually used rather than by static inspection, since some changes appear only dynamically, such as a distorted plastic part binding a moving assembly or a hardened seal providing insufficient sealing force.

Testing packaging performance. Seal strength covers peel force and burst strength. Seal integrity covers the presence of channels. Material strength covers the packaging material itself. Barrier performance covers microbial barrier, permeability and water vapour transmission. Appearance covers discolouration, embrittlement and delamination. And openability covers whether aseptic opening remains possible. Openability can change after irradiation: once the material embrittles, a seal that peeled may tear instead, generating particles and causing contamination. Verify it rather than assuming it unchanged.

Repeated sterilisation. Products sometimes undergo sterilisation more than once: through rework after a problem is found; through additional irradiation where the dose was insufficient; and in reusable products sterilised after each use. The principles are to state explicitly whether repeat sterilisation is permitted and how many times, to verify compatibility for the permitted number, and to mark it on the product or in the documentation. Rework is the case most often encountered, and manufacturers frequently neither limit the number nor verify it. Set a limit and verify it, because accumulated dose or thermal history can affect materials more than a single cycle.

Interpreting results. Compare against unsterilised samples to see the extent of change. Compare against specification limits to see whether the product still conforms. Assess trends, attending to properties that changed substantially and may change further within shelf life. Identify sensitive properties, which become the focus of later monitoring. And judge the margin remaining to the specification limit. Margin is the practical criterion: performance just within specification after sterilisation means the margin is exhausted, and batch variation or further degradation across shelf life will probably produce failures. Improve the material or process rather than accepting that situation.

Connections to other validation. To sterilisation validation, since compatibility should use validated parameters and be performed at their upper limit. To stability studies, since compatibility samples can enter stability testing to observe subsequent change. To biological evaluation, since chemical characterisation must use sterilised samples. To packaging validation, since integrity should be assessed after sterilisation. And to transport validation, whose samples should be sterilised. Coordinating these allows samples to be shared and duplication reduced; consider the sample requirements of all validations together at the planning stage.

How we handle it. For compatibility studies we suggest processing samples at the upper limit of validated parameters, since production varies and verification at nominal values may leave insufficient margin. On test items we suggest adding elongation at break for irradiated products, since it reflects embrittlement better than tensile strength and embrittlement is the characteristic effect of irradiation. We also suggest retaining some compatibility samples for storage observation, since some changes continue developing after sterilisation and data measured immediately afterwards can read optimistically.

Send us the material information, sterilisation parameters and product construction and we will work through the study. Phone or WeChat: +86 132 4819 8029.