Understanding and applying the ISO 10993-19 standard: Physico-chemical, morphological and topographical characterisation of materials

What is ISO 10993-19?

ISO 10993-19 defines the methods and criteria for analysing the physico-chemical characteristics of materials intended to come into contact with the human body. 

It complements the other standards in the ISO 10993 series by proposing a material profile that describes its physical, chemical, morphological and topographical properties. These characteristics directly influence the biological response and must be known before any toxicological assessment.

Why is it important to comply with ISO 10993-19?

• Regulatory requirements

International regulations (Regulation (EU) 2017/745, FDA 21 CFR, etc.) require scientific justification of biocompatibility. This justification must be provided not only by literature data, but also, and more often than not, by device-specific test results. 

• Risk control

Precise knowledge of the nature and structure of the material enables us to anticipate interaction reactions with tissues, body fluids or cells.

What are the key parameters to characterize?

The standard classifies characteristics into three main categories:

Physico-chemical characteristics

• Chemical composition: constituent elements of the material (metals, polymers, ceramics, etc.).
• Degree of crystallinity, molecular weight, polydispersity for polymers.
• Solubility, density, conductivity, thermal properties (Tg, Tm).

Morphological characteristics

• Material shape and structure (granulometry, porosity, molecular orientation).
• Homogeneity of material at micro- or nano-scale.
• Dispersed phase / continuous phase (for composite or multiphase materials).

Topographical characteristics

• Surface roughness (Ra, Rq), relief, surface patterns.
• Topography at different scales: nano, micro and macroscopic.
• Use of techniques such as electron microscopy (SEM) or 3D profilometry.

Which analytical methods to use?

Depending on the nature of the material and the targeted parameters, different techniques are recommended:

When should ISO 10993-19 be applied?

Conclusion

ISO 10993-19 is not just a technical exercise: it is a strategic tool for ensuring safety, reducing development costs, and meeting the expectations of regulatory authorities.

By integrating this standard from the earliest stages of a medical device's life cycle, manufacturers have a solid basis for demonstrating the biocompatibility of their products in a scientifically rigorous way that complies with international requirements.