Medical device manufacturers need to control and minimised the concentration of leachables and extractables by eliminating and extracting them before use, as well as control and maximise polymer conversion of their medical devices produced in their facilities to ensure maximum conversion from monomer to polymer, to say conversion from a photoreactive liquid 3D resin into a fully cured and "safe" biomedical device. Ensuring that medical devices are traded without any trapped unreacted monomers and any other sort of leachables and extractables is responsibility of medical device manufacturers since legally are and will always be responsible of the quality of their traded products.
Both, biocompatible 3D resins and medical devices need to be properly designed in tune with reliable printing setups and workflows to fully comply with the Quality requirements for the manufacturing of medical devices (Class I, IIa, IIb and III) or food packaging products. Not all the printers, post processing setups, and controls meet the required minimum specifications for printing medical devices, or food/pharma packaging, for passing certification standards.
Acknowledge that biocompatible 3D resin manufacturers supply photoreactive photopolymer 3D resins, not finished biomedical devices, consequently their certification as suppliers of medical devices is not legally valid as replacement of the certification required for medical device manufacturers.
This document published by the FDA: Technical Considerations for Additive Manufactured Medical Devices clearly highlights that:
Removing Manufacturing Material Residues and Sterilization AM facilitates the creation of devices with complex geometries... additively manufactured devices are expected to increase the difficulty in removing manufacturing material residues (cleaning) and in sterilization...validation of the reduction of the manufacturing material residue to levels that do not adversely affect the device’s quality and sterilization process validation should account for the complex geometry of your device under worst-case conditions (e.g., greatest amount of residual manufacturing materials...Manufacturing material means any material or substance used in or used to facilitate the manufacturing process, a concomitant constituent, or a byproduct constituent produced during the manufacturing process, which is present in or on the final finished device as a residue or impurity not by design or intent of the manufacturer...There is also an increased risk of residual manufacturing material, such as excess starting material or support material, remaining on the final finished device. Since residual manufacturing material may negatively affect the performance of the device, you should describe the process used to ensure removal of residual manufacturing materials to a level where they do not affect the safety and effectiveness of the device...When a manufacturing material could reasonably be expected to have an adverse effect on device quality, the manufacturer must establish and maintain procedures for the use and removal of such residual manufacturing material to ensure that it is removed or limited to an amount that does not adversely affect the device's quality..It is important to note that many end user facilities may not have routine access to the equipment or materials needed to implement cleaning procedures that are designed to remove residual manufacturing materials and that personnel are likely not adequately trained to perform such cleaning procedures. Therefore, only devices that are sufficiently cleaned of residual manufacturing materials should be provided to the end user... Therefore, we also recommend that you include an overview or summary of manufacturing residue removal process...demonstrate that your device is cleaned of manufacturing residues before being provided to the end user. The extent to which manufacturing material residue must be reduced is determined on case-by-case basis considering characteristics such as: manufacturing processes, intended use, materials, type and duration of exposure, intended anatomical location, and type of device. In addition, we recommend using final finished devices after they have undergone all other processing for assessment of manufacturing material removal and validation of the sterilization process... We recommend that you evaluate the biocompatibility of the final finished device as described in the guidance “Use of International Standard ISO-10993, "Biological Evaluation of Medical Devices Part 1: Evaluation and Testing within a Risk Management Process...If chemical additives with known toxicities are used (e.g., certain additives, catalysts, binding and curing agents, uncured monomers, plasticizers), additional information, as outlined in the guidance may be necessary.
3D resins need to be compliant (not certified) and designed in accordance to the quality requirements relevant to the biomedical application for which were designed.
Their certification is not legally valid nor relevant, nor can be used by medical manufacturers as replacement of their own certifications, in accordance to the specific certification requirements by the regulatory authority of each country where their products will be traded.
Unfortunately, the use of non relevant certifications of raw materials suppliers is a common, confusing and perplexing misleading practice by some resin suppliers with the aim of gaining sales by promoting the validity of their certifications, as replacement of the legal responsibility of medical device manufacturers of having their own certifications, which legally are (and should always be) responsible for certifying their products, production processes, facilities and companies.