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Medical textiles: value and limitations

Features | September 9, 2019 | By:

How Medical Device Master Files can support a productive business partnership.

by Elaine Duncan

Medical Device Master Files, known as a MAF, have value for textile contract manufacturers and the medical device developer in many ways. Most medical device manufacturers who incorporate a medical textile into their product will seek a knowledgeable textile contractor who can address the quality system needs of medical products. Some textile medical devices are even built from the ground up by the textile contractor, so device producers are looking for a knowledgeable partner. When a textile contractor commits to a U.S. Food and Drug Administration (FDA) MAF, the medical device producer can anticipate a facilitated medical device premarket application.

Textile contractors and the FDA

From its inception, the FDA guidance document for the Device Master File submission said that the MAF would “not be accepted if it was not substantive in nature and does not contain information that may be reasonably regarded as trade secret or confidential.”  Originally thought to be of value only for a Premarket Approval (PMA) or Investigational Device Exemption (IDE), a Master File now has broader utility due to the more in-depth reviews for 510(k) -Premarket NOTIFICATION or a deNOVO application.

Regardless of the type of premarket submission the medical device producer may require, allowing the FDA to have access to proprietary information from the component supplier can enhance the quality of the overall review process for the FDA.  

The textile contract manufacturer has a great deal of intrinsic proprietary information to protect, yet the textile chemicals and mechanical processes can impact the safety of a medical device. Some contractors have been in business for many decades and even the machines in use are considered trade secret and proprietary.

The sources of raw materials, how they are prepared for the textile operation, the mechanics and parameters of the processing, scouring parameters and cleaning are all typical types of proprietary “know-how” that support or detract from the quality of the textile component. Properties such as tensile strength, stretch and flexibility and of course, biocompatibility, can be directly traced to the textile contractor’s proprietary know-how. It is not at all uncommon for FDA to consider that these processes can contribute risk to the quality of the final device and thus it will desire to understand more about the overall risk mitigations in place for the textile when reviewing the final medical device application.

If every time an FDA application is filed the entire playbook of the textile contractor were to be made available, the potential for the contractor’s proprietary information to become inadvertently disclosed increases. Despite the good intentions of regulatory departments to safeguard submission files, there are simply many opportunities for disclosures. Freedom of Information requests, although usually redacted, represent another potential risk for disclosure of proprietary processes.

The device producer

Of course, the medical device producer is responsible for the premarket application content for the finished device, but a textile component may play a prominent role in the performance and safety of the final product. Medical device producers who file the FDA applications are responsible for mitigating the risks associated with the product, and therefore typically make contract agreements to procure components that meet their quality specifications.

Other than quality audits and in-process inspections, the medical device producer must put faith in the textile contractor to perform per the agreement. It is unlikely the medical device producer can be knowledgeable of every aspect of production of the textile component and thus the producer must have confidence that the contractor has quality controls in all aspects of the production.

A Master File does not remove the obligation from the device producer to assure the safety of the final product, but when FDA is able to review the quality of production of the textile, and the contractor understands and mitigates the process risks, there is another layer of confidence in the overall safety and performance of the device.

Addressing limitations

Master Files have limitations. The textile contractor is not responsible for assuring that the textile component described in the Master File is safe for all potential medical applications, particularly because the producer will usually have their own proprietary processes and trade secrets that go into making the final device.

Testing for a textile used for a bandage can be very different from a similar textile used as an implant. For example, the textile manufacturer might not even know the method of sterilization of the final device, or be aware of any other manufacturing aids, such as adhesives, which could be used on the textile in the final device. But when the Master File holder has conducted basic biocompatibility safety testing on the textile component, the device producer can focus on final device performance and testing for their own intended use.

The FDA guidance “Use of International Standard ISO 10993-1, “Biological evaluation of medical devices – Part 1: Evaluation and testing within a risk management process” Annex B describes recommended content for a Device Master File to support biocompatibility evaluations. When the Master File demonstrates the quality control of the processing and procurement of raw materials, the sourcing of any manufacturing additives and the preliminary biocompatibility of the basic textile, the FDA can see the supply chain is stable.

Increasingly, FDA expects medical device manufacturers to assess the chemical risks associated with the final device, yet such assays cannot be conducted perpetually on every batch of textiles. Therefore, the full picture of biomaterial safety cannot depend solely on the so-called “endpoint” testing, or even exotic chemical extractions, but rather it is an amalgam of the commitment that the textile component contractor will reproducibly supply a textile with stable chemical composition and physical features and the proper incorporation of that textile into the finished device.

The Master File is not intended to take the place of the biocompatibility assurance by the final device manufacturer, but it can demonstrate for the FDA reviewer that the textile component comes from a contractor who is dedicated to producing a medical device-quality textile.

Making adjustments

A Device Master File requires “care and feeding,” but need not be a burden to the textile contractor. When initially filed, the scope of the information may not be sufficient for a specific FDA reviewer or for a particular medical product under review. The reviewer may have additional questions for the medical producer applicant, which were not addressed in the MAF. Either from such questions or as the textile contractor begins to incorporate more quality systems information relevant to medical devices, there may be a desire to add to the Device Master File.

Sometimes contents simply get out of date and need revision. The MAF can be amended at any time. Putting in a bit of time when establishing the Master File to organize the structure of the table of contents to facilitate future updates can be very valuable. Master Files can be modified by edits, new inclusions can be added or changes in chapter content may be made. Ideally the structure can be maintained so that existing access letters are not made obsolete with the change.


There is no fee to the FDA to submit a Device Master File, although it must meet the FDA’s guidelines for document type and quality. It is not required that the submitter is a registered contract manufacturer to submit the Master File, although in certain circumstance, such as when the textile company serves as a Contract Manufacturer, registration with FDA may be required.

Setting a periodic review period to ensure the information is current is critical to its value. And each time the contractor enables access to the Master File by a client’s FDA reviewer, assuring the contents are appropriate to this new accession is very important.

Clients (the medical device producer) will need to know the general content of the information in the Master File in order to properly make reference to its contents in their FDA application. A well-constructed Table of Contents can help to direct the client to content without revealing the proprietary information inside.

The Master File holder (the textile contractor) will provide a letter of access addressed to the FDA which is included in the client’s submission. This letter should identify the MAF number and if appropriate, which sections of the Master File are to be accessed by the FDA reviewer for the particular submission at hand. It is important that the Master File access letter names the client’s device to be reviewed, so that the MAF holder only provides access for each particular product and not a blanket access letter for all potential and future FDA submissions.

Some suppliers have sought a fee from the device producers for access to the Master File. It would seem that this practice may have lost its luster. It could be difficult to perceive value of the contents of the Master File when it is sequestered at the FDA. If the Master File is intended to be a sales incentive to attract potential medical device producers as clients, it can be awkward to charge for an item that may or may not prove to be of direct value to the submission success. Instead we more often see the MAF to be a starting point where the medical device producer is attracted to the potential supplier because of their commitment to quality and cooperation with the FDA.

Device Master Files (MAF) facilitate reviews of premarket submissions, help to support a productive business partnership and show FDA that the dedicated medical textile contractor has established quality systems to help assure safe medical devices.

Elaine Duncan, MSME, RAC, AIMBE is president of Paladin Medical Inc. She consults with medical device manufacturers to plan and assist in the development of new medical devices and the regulatory submissions for premarket notification and approval. More about Device Master Files is available at

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