1. How to prepare a pre-request for designation (pre-RFD) Publication: [Silver Spring, Maryland] : Office of Combination Products, Office of the Commissioner, February 2018 Subject(s): Equipment and Supplies -- classificationDrugs, Investigational -- classificationInvestigational New Drug ApplicationPharmaceutical Preparations -- classificationHumansUnited StatesUnited States. Department of Health and Human Services.United States. Food and Drug Administration.