What Is a Drug Master File at COFEPRIS?

How the Expediente Maestro del Fármaco works in Mexico’s regulatory framework — and what it means for foreign API manufacturers.

What is a Drug Master File?

A Drug Master File (DMF) is a confidential submission to a regulatory authority that contains detailed information about a pharmaceutical ingredient — its composition, manufacturing process, facilities, and quality controls. It allows an API manufacturer to share proprietary technical data with a finished product manufacturer, who then references it in their own registration dossier without disclosing the information publicly.

How does COFEPRIS define and use the DMF?

In Mexico, the equivalent document is the Expediente Maestro del Fármaco (EMF). COFEPRIS uses it as part of the pharmaceutical ingredient quality documentation within a product registration dossier. Mexico does not operate a formalized, standalone DMF submission procedure equivalent to other regulatory systems. The EMF exists within the registration process — referenced by the finished product manufacturer as part of the registration dossier, not filed independently by the API manufacturer.

When is it required?

The EMF is required when a foreign API manufacturer supplies the active ingredient used in a finished product seeking sanitary registration at COFEPRIS. It forms part of the quality module of the registration dossier and must be available at the time of submission. It is not a pre-submission filing — its existence and completeness are evaluated as part of the overall dossier review.

What does it cover?

The EMF is expected to contain the information that supports the quality, identity, and consistency of the API: manufacturing process description, site information, specifications, analytical methods, validation data, and stability information. The structure and depth of the EMF are evaluated under COFEPRIS’s own technical criteria — which are defined within Mexico’s regulatory framework.

What should a foreign manufacturer know?

Two aspects of the EMF in Mexico deserve particular attention. First, there is no formal notification pathway for API-level changes. If a manufacturer modifies a process, specification, or validation, there is no established COFEPRIS procedure to notify those changes at the ingredient level. The responsibility for requesting any modification to the registration conditions falls on the finished product manufacturer — not the API manufacturer. Second, the absence of a formal EMF framework means there is no official reference document that specifies exactly what the EMF must contain or how it should be structured. Manufacturers adapting existing documentation packages for Mexico do so without a published checklist to validate against.

Understanding these conditions early in the planning process helps teams identify where their existing documentation aligns with COFEPRIS’s framework — and where it may need to be adapted.

If your team is preparing an API registration dossier for Mexico and wants to assess how your current documentation aligns with COFEPRIS’s framework, explore our API Registration services for Mexico or speak with Freyr’s regulatory team.