An Active Substance Master File (ASMF) is a confidential regulatory document used in the European Union (EU) and several other regions to provide detailed information on the manufacture and quality control of an active pharmaceutical ingredient (API). Its purpose is to protect the intellectual property of the API manufacturer while allowing regulatory authorities to verify that the active substance used in a medicinal product consistently meets the required quality standards.
The ASMF consists of two main parts:
- The Applicant’s Part (Open Part): Contains information that can be shared with the Marketing Authorization Holder (MAH), including general details on manufacturing, quality specifications, and analytical controls.
- The Restricted Part (Closed Part): Contains proprietary or confidential data, such as detailed process descriptions, controls of intermediates, and in-process testing. This section is submitted only to the competent authorities.
Regulatory agencies assess the ASMF as part of the marketing authorization application for a finished medicinal product. Unlike the Certificate of Suitability (CEP), which certifies compliance with a European Pharmacopoeia monograph, the ASMF allows flexibility for non-pharmacopoeial substances or complex manufacturing processes.
The ASMF system promotes transparency, confidentiality, and harmonization within the EU regulatory framework. It enables multiple applicants to use the same active substance from one manufacturer without disclosing the manufacturer’s confidential know-how, ensuring both product quality assurance and intellectual property protection.
