Marco Theobold

Director of Medical Device and Drug Services

Submitting ASMFs to the UK Medicines and Healthcare Products Regulatory Agency

Oct 17, 2023

Do you need to submit a Master File to the UK’s Medicines and Healthcare Products Regulatory Agency (MHRA) for your active substance?  

Similar to Europe Medicines Agency (EMA), the MHRA only accepts one type of Master File: Active Substance Master Files (ASMFs). The ASMF’s main objective is to protect active substance manufacturers’ (ASM) valuable confidential intellectual property or ‘know-how’. It also allows the Applicant or Marketing Authorization (MA) holder to take full responsibility for the medicinal product and active substance quality control.  

With the submission of an ASMF, MHRA has access to all the information necessary for evaluating the suitability of any active substance use in the medicinal product. 

UK Master File Requirements 

After the United Kingdom formally left the European Union on January 31, 2020, the UK halted participation in ASMF work sharing procedures with EU Member States. As a result, Master Files for the UK must now be submitted to MHRA by registering an MHRA account instead of through the Common European Submission Portal. Submissions to the MRHA are considered nationally authorized products and are only assessed on a national basis. 

Like EMA Master Files, ASMFs must be submitted to MHRA in eCTD format. The quality sections of the Active Substance Master Files are structured in the same way as EMA Master Files with Applicant and Restricted Parts. The Applicant Part (AP) should be submitted with the Marketing Authorization dossier along with a letter of access. Only the Restricted Part (RP) of the Master File is considered to be confidential.  

The relevant documentation should also be timed to arrive at approximately the same time as the Marketing Authorization dossier: no more than one month before and not after the intended Marketing Authorization dossier submission date. It’s important to communicate with the MA holder ahead of time to coordinate your ASMF and MA dossier submission dates.  

Annual reports are not a requirement for ASMFs submitted to the MHRA. Instead, you will be expected to keep Master Files up to date with amendments as needed. 

MHRA ASMF Submission Is Challenging

Submitting your MHRA ASMFs properly can be complicated and time consuming, which is why working with Master File Specialists can make all the difference. At Registrar Corp, our DMF Specialists work to assure that your ASMFs are filed correctly and on time while also keeping your confidential intellectual property safe. Learn more about how Registrar Corp can help you submit your ASMFs to MHRA today. 



Marco Theobold

Director of Medical Device and Drug Services

A highly regarded expert in medical device and drug regulations by the U.S. Food & Drug Administration (FDA), Marco brings a unique perspective for medical device and drug companies seeking to distribute products in the United States. He proudly provides guidance on FDA regulations for pharmaceutical, medical device, and radiation emitting device (RED) companies.

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