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The value and limitations of medical device master files

Advanced Textiles, Markets | November 1, 2019 | By:

by Elaine Duncan

Medical device master files, known as MAFs, have value for textile contract manufacturers and the medical device developer in many ways, but there are some practical limitations. Most medical device manufacturers that incorporate a medical textile into their products will seek a knowledgeable textile contractor who can address the quality system needs of medical products. But some textile medical devices are 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. This is the application that provides scientific, regulatory documentation to the FDA to demonstrate the safety and effectiveness of a new device.

Textile suppliers 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 application (PMA) or investigational device exemption (IDE) application, a master file now has broader utility. 

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.  

FDA-designated Celliant® has miniaturized minerals that absorb heat and give off infrared light to improve local circulation. The minerals can be added to polyester or nylon and then blended with materials such as wool, cotton, Lycra®, Tencel™ and others. Photo: Hologenix LLC.

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

It is not at all uncommon for the FDA to consider a full range of processes that may contribute risk to the quality of the final device and, thus, it will want 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, it would increase the potential for the contractor’s proprietary information to become inadvertently disclosed. Despite the good intentions of regulatory departments to safeguard submission files, there are simply many opportunities for disclosures. 

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 that 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. 

It is unlikely the medical device producer can be knowledgeable about 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 the 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 its 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, that could be used on the textile in the final device. 

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 its own intended use. 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.

Making adjustments

A device master file requires “care and feeding,” but need not be a burden to the textile contractor. When it is 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 that 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 can facilitate future updates, and thus be very valuable. Master files can be modified by edits, new inclusions can be added, or changes in chapter content may be made. 


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 the FDA may be required. 

Clients (medical device producers) will need to know the general contents of the information in the master file in order to properly refer to its contents in their FDA applications. A well-constructed table of contents can help direct clients 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. Some suppliers have sought a fee from the device producers for access to the master file, but 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 its commitment to quality and cooperation with the FDA. 

Elaine Duncan, MSME, RAC, AIMBE is president of Paladin Medical® Inc. She spoke at the Advanced Textiles Conference in October 2019 at IFAI Expo. 

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