Role of US Drug Master File (US DMF)US Drug master file (US DMF) submission to US FDA of all information required for an NDA is the responsibility of the drug manufacturer; however, in many cases, information on materials used in the production or packaging of the drug product, such as the formulation of a packaging material, is considered by the supplier to be confidential trade secret information. Consequently, the US Drug Master File (US DMF) system was developed to permit suppliers to make those information of their products directly available to US FDA for its review of drug company applications that involve the use of the supplier's material. The technical contents of a US Drug master file (US DMF) are reviewed in connection with the review of relevant NDA (New Drug Application) submission.