With the amendment of the Pharmaceutical Affairs Law enforced in April 2005, approvals for drug substances that had been necessary in the past were no longer required and instead the information of quality and manufacturing method of drug substance are required to be included in the application document of finished product. The master file (MF) system aims at protecting intellectual property of relevant information at the time of license application and facilitating review work by allowing a registrant (master file registrant) of drug substances to separately submit information on quality and the manufacturing method of drug substances to be used in drug products (Notifications No. 1117-(3) of the Evaluation and Licensing Division of PFSB and No. 1117-(1) of the Director of Medical Devices Evaluation, Evaluation and Licensing Division of PFSB dated November 17, 2014). MF registration is optional.
Items that may be registered through the MF system are drug substances, intermediates, and additives, nevertheless raw materials of regenerative medicine products (e.g.,cells, media, medium additives or processing materials of cells) may also be registered through the system. When an overseas drug substance manufacturer submits an MF registration application, it is necessary to appoint an in-country caretaker to handle the activities of the MF registrant in Japan. When the registered contents of the MF are changed, an application to change the MF or a minor MF modification notification must be submitted.