Another guest post today, this one by Reed Smith’s Matt Jacobson on the draft guidance document released earlier this week by the FDA.With the 3D printing of medical devices at the forefront of the burgeoning additive manufacturing revolution − and inevitably to become the target, eventually, of product liability litigation – anything the FDA does to move the ball forward (or not) is of great interest.

As always, our guest blogger deserves all the credit (and any blame) for what follows.Take it away Matt.

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The blog is not a stranger to 3D printing, the cooler and slang term for the additive manufacturing process.See here, here, here, and here.

The U.S. Food and Drug Administration (FDA) is not a stranger to 3D printing either.It has already approved more than 80 medical devices and one prescription drug that are produced by 3D printing techniques.It also held a public workshop to obtain information and input about 3D printing issues on October 8 and 9, 2014.FDA brought together technical 3D printing expertise from various industries and sectors to help the agency develop an evaluation process for future submissions of medical devices resulting from additive manufacturing techniques.After the workshop, FDA was silent on 3D printing, well that is, until last Tuesday, when it released a draft guidance for Technical Considerations for Additive Manufactured Devices.

Although the FDA workshop was almost a year-and-a-half ago, it was not for nothing, as the draft guidance is based on the feedback from the workshop.According to FDA, the draft guidance is a “leap-frog” guidance to share FDA’s “initial thoughts regarding technologies that are likely to be of public health importance early in product development.”While the draft guidance is not meant to be a comprehensive document to address all regulatory requirements, it highlights the technical considerations and recommendations for design, manufacturing, and testing of medical devices that include at least one fabrication step using additive manufacturing.

FDA is careful to warn that the guidance does not apply to any devices that use bioprinting − incorporating biological, cellular, or tissue-based products into the additive manufacturing process.

FDA also provides that point-of-care manufacturing (that is, on-site 3D printing of devices in hospitals and doctor's offices) “may” raise additional technical considerations.Despite the mounting desire to migrate personalized, 3D device manufacturing from central processing hubs to point-of-care manufacturing in a health care setting, we understand why FDA avoided detailed discussion and guidance regarding point-of-care manufacturing.Not only does point-of-care manufacturing involve additional technical considerations, but it also raises not insignificant regulatory and legal complications (such as whether each “point of care” is a “manufacturer” under the statute) – all of which remain unresolved.

The guidance is split up into two categories of considerations: 1) design and manufacturing and 2) device testing.Both sections overlap in substance, and the device testing section in particular provides strong, detailed recommendations for what a device manufacturer should include in a premarket submission for a device that uses additive manufacturing. This will likely have an effect on how 3D printing device companies design, manufacture, and test their devices, especially those who manufacture patient-matched devices (devices that are “customized” for a specific patient’s anatomy, usually based on medical imaging data), to which the FDA draft guidance pays particular attention.

FDA’s recommendations for design and manufacturing considerations, are not as useful, as many of the sound platitudinous. These include:

  • That manufacturing and dimensional specifications be carefully considered and documented.
  • For patient-matched devices, understanding the image quality and the role deformation may play.Also ensuring that the label expiration date account “for time-dependent changes to the patient anatomy before the device is used.”
  • Any software used to make patient-matched modifications to a device’s design should include “internal checks to prevent the user from exceeding the pre-established device specifications documented in the device master record.”
  • All software file conversation steps should be tested in “worst-case scenarios.”
  • Before a device is additively manufactured, considerations should be made forbuild volume placements, use of support material, layer thickness, build paths, machine parameters, and environmental considerations.
  • Understanding the chemical properties of the material being used and how the additive manufacturing process may affect those properties.
  • Process validation and consistency of quality are key.In other words, “knowledge of how the variability of each input parameter and processing step affects the final finished device or component is critical to ensuring party quality.”

For device testing considerations, FDA recommends that the following (if applicable for the particular device) be included in a premarket submission for a medical device using 3D printing:

  • Range of dimensions for the device (small, medium, large) and any dimensions that may be altered to match a patient’s anatomy.
  • Performance testing results.While these are generally the same for any device, whether 3D printed or traditionally manufactured, for 3D printed devices build direction orientation should be considered when testing is performed.
  • Dimensional tolerances and measurements should be specified.
  • All materials involved in the manufacturing of the medical device should be clearly identified.
  • Material polymers may need to be tested to ensure that they will not unintentionally form chemical properties through the additive manufacturing process, which may pose a risk to patient health.
  • Interlayer bonding materials should be characterized.
  • Any cleaning and sterilization process for a final product should be validated and should consider the complex geometry of the final product.Only additive manufactured devices that were cleaned of manufacturing materials should be provided to the end user.
  • The biocompatibility of the final device should be evaluated.
  • Additional labeling considerations for patient-matched devices is recommended to include the patient identifier, identifying use, file design iteration, and that the patient be surveyed for potential anatomical changes (between the time of imaging and surgery).

As stated in the guidance, FDA is aware that 3D printing “is a rapidly growing technology,” which has numerous advantages for medical devices, but at the same time “pose[s] challenges in determining optimal characterization and assessment methods for the final finished device, as well as optimal process validation and acceptance methods for these devices.”The FDA’s guidance is long overdue, but the agency has evidently thought about the unique considerations involved in 3D printing of medical devices.

Interested parties should note that FDA is accepting comments on the draft guidance now and hopefully the final guidance will come soon (at least quicker than the draft guidance). To ensure FDA considers your comments before it begins work on the final version of the guidance, submit either electronic or written comments on the draft guidance within 90 days [Docket No. FDA-2016-D-1210]. Who knows maybe by the time the final guidance comes out, we may be 3D printing a version for our book shelf, or even of our book shelf.