About FDA´s Technical Considerations for Additive Manufactured Medical Devices

This page highlights key takeaways from FDA’s guidance document: Technical Considerations for Additive Manufactured Medical Devices.

Main FDA message: final device performance is determined by the full manufacturing system (material + machine + printing parameters + post-processing). For additively manufactured devices, robust validation and process control must be aligned with the risk profile of the finished device.

Key FDA statements and practical implications

1) Device performance depends on material, machine and post-processing (page 3–4)

• FDA emphasizes that the interaction between the material and the machine matters and that the full workflow needs a robust process validation and acceptance protocol.
• Printing and process parameters should be captured and validated, which can include individual machine validations.

2) Design controls and process controls apply (page 6)

• For Class II and Class III devices (and select Class I devices), FDA references 21 CFR 820.30 (Design Controls).
• Manufacturers must also establish procedures for monitoring and control of process parameters for validated processes to ensure requirements continue to be met.

3) Build placement, orientation and packing density matter (page 12)

• Placement, orientation and packing density within the build volume can be integral to device/component quality.
• Build orientation can affect functional performance through anisotropic properties.
• Many machines have regions where they print optimally and regions where they do not (e.g., near edges vs center).
• The affected region may differ for every machine, even between machines of the same model.

4) Build path, calibration and maintenance influence performance (page 14)

• The build path (energy/material delivery path) can impact quality; consistency of build path is important between identical parts.
• Some machines allow changes in energy delivery/build path that do not change geometry but may still influence final performance.
• Proper calibration and preventative maintenance are identified as key factors to achieve low rejection rates.
• Optimal settings can vary across devices/components and can also vary between machines of the same model, even for the same part.

5) FDA treats photopolymer resins as starting raw materials (page 15)

• FDA describes that the starting material may undergo significant physical and/or chemical changes during manufacturing.
• Therefore, the starting material can significantly affect build success and the properties of the final device.

6) Incoming material specifications and change control (page 16)

• Material specifications for incoming materials (e.g., powders, liquid monomer/polymer systems) may differ from the properties of the finished device.
• When any material specification is changed, the impact on the build process and the final device should be understood and documented.

7) Post-processing must be documented and its effects understood (page 17)

• Final device performance and material properties can be affected by post-processing steps (e.g., residue removal, heat treatment/stress relief, machining).
• All post-processing steps should be documented, including discussion of their effects on materials and final device performance.
• Process parameter monitoring and control remain required for validated processes.

8) Validation responsibility lies with the device manufacturer (page 18)

• FDA states that validation of medical devices and their manufacturing process must be performed by medical device manufacturers.

9) Orientation and location can change mechanical properties (page 23)

• Mechanical properties may be impacted by build orientation and build location.
• Production processes should be properly developed, controlled and monitored so parts are not adversely affected by fabrication orientation.

10) Polymer crosslinking systems: evaluate degree of cure (page 25)

• For AM processes that use polymer crosslinking, FDA indicates that percent crosslinking and degree of curing should be evaluated to ensure the material is fully cured and within specification.

11) Residual manufacturing materials must be controlled and removed (page 26)

• FDA defines “manufacturing material” as materials used in or produced during manufacturing that may remain as residue/impurity on the final device (not by design).
• FDA highlights increased risk of residual starting material or support material remaining on the finished device.
• The removal process should be described and should ensure residues are removed or limited to levels that do not affect safety, effectiveness or quality.
• Only sufficiently cleaned devices should be provided to the end user.

Conclusions

• FDA clears or approves finished medical devices, not specific materials (nor raw materials) for general use in medical device manufacturing.
• Materials used to formulate or construct medical products are evaluated within the context of FDA’s review of safety and effectiveness for the intended use of the finished product.
• Devices made using 3D printing technology are subject to applicable regulatory requirements.
• Quality System (QS) requirements depend on device classification and the regulation(s) to which the device is subject.
• Medical devices are classified into Class I, II and III, with regulatory control generally increasing from Class I to Class III. The classification regulation defines regulatory requirements for a general device type.

Need support to build a controlled workflow?

If you need help aligning materials, printer selection, printing parameters and post-processing controls for regulated or safety-critical applications, contact us by email: info@3dresyns.com.