What Is a Drug Master File?
A Drug Master File (DMF) is a submission to the FDA that may be used to provide confidential detailed information about facilities, processes, or articles used in the manufacturing, processing, packaging, and storing of one or more human drugs.
DMFs are not approved or disapproved by the FDA — they are simply held on file. A DMF's value lies in its ability to allow manufacturers to reference it in drug applications (NDAs, ANDAs, INDs) without the applicant needing to disclose confidential supplier information directly in their own submissions.
The Five Types of DMFs
Type I — Manufacturing Site, Facilities, Operating Procedures, and Personnel
This type is rarely used in practice. Type I DMFs are voluntarily filed to describe manufacturing facilities and operating procedures. Most of this information is better included directly in the drug application.
Type II — Drug Substance, Drug Substance Intermediate, and Material Used in Their Preparation
The most commonly filed DMF type. Used by API manufacturers to protect their proprietary synthesis routes and manufacturing processes while allowing drug product manufacturers to reference their materials in NDA/ANDA submissions.
Type III — Packaging Material
Filed by manufacturers of primary packaging components (bottles, closures, foil, blister packs) to describe container/closure systems without revealing proprietary manufacturing details to drug product manufacturers.
Type IV — Excipient, Colorant, Flavor, Essence, or Material Used in Their Preparation
Filed by excipient manufacturers to support drug product applications. Increasingly important as regulators scrutinize excipient quality more closely.
Type V — FDA-Accepted Reference Information
A miscellaneous category for information that does not fit into Types I–IV. Rarely used in practice.
When Do You Need to File a DMF?
Filing a DMF is generally optional — you are not required to have one. However, a DMF becomes necessary when:
- A drug product manufacturer wants to use your API or excipient in their NDA/ANDA and needs to reference your confidential data
- Your customer (the drug product manufacturer) requires it as a condition of doing business
- You want to protect your proprietary manufacturing process while still enabling regulatory review
Common Scenario
An API manufacturer in India wants to supply an active ingredient to a U.S. generics company. The generics company files an ANDA with the FDA and needs to reference the API's specifications and manufacturing process. Instead of revealing their proprietary synthesis route to the generics company (and thus to the public record), the API manufacturer files a Type II DMF and grants the generics company a Letter of Authorization (LOA) to cross-reference it.
How to Submit a DMF
- 1Prepare the DMF content A DMF must contain: an administrative section, a summary of the DMF content, and an applicant's section (which may be disclosed) and a restricted section (confidential). The restricted section is not disclosed to anyone who does not have an LOA.
- 2Submit electronically via ESG DMFs must be submitted electronically to the FDA's Electronic Submissions Gateway using eCTD (electronic Common Technical Document) format.
- 3Receive your DMF number Upon submission, FDA assigns a DMF number (e.g., DMF 12345). This number is what your customers will reference in their drug applications.
- 4Issue Letters of Authorization (LOAs) For each customer you wish to allow to reference your DMF, issue a formal LOA addressed to the FDA. The LOA authorizes the specific applicant to reference specific sections of your DMF.
Annual Update Requirements
DMF holders must submit an Annual Report to the FDA within 60 days before each anniversary date of the original DMF submission. The annual report must certify that the DMF is current and accurate, and report any changes made since the last update.