A Type IV DMF is a file within the FDA which can be used by excipient manufacturers to submit confidential formulation, safety and manufacturing information about the excipient that may be needed by the agency in reviewing a new drug application (NDA) for a drug product containing that excipient. These files are only referenced by FDA as part of a specific NDA review and are not authorized or approved by FDA.
Users of the excipient are required to submit a DMF reference letter from the excipient manufacturer to the FDA as part of their NDA to allow FDA authority to access the DMF for their application. An FDA guidance document exists which describes what types of information are required in a Type IV DMF and the format which should be used. Not a lot of detailed information is required. Mostly, it is up to the excipient manufacturer to determine what types of information they want to include in the DMF. Further, there is no requirement that an excipient have a DMF. This determination is entirely up to the manufacturer of the excipient, depending on the nature of any confidential information which may exist.