42 CFR §441.25

1. (a)FFP is not available in expenditures for the purchase or administration of any drug product that meets all of the following conditions:
   1. (1)The drug product was approved by the Food and Drug Administration (FDA) before October 10, 1962.
   2. (2)The drug product is available only through prescription.
   3. (3)The drug product is the subject of a notice of opportunity for hearing issued under section 505(e) of the Federal Food, Drug, and Cosmetic Act and published in the Federal Register on a proposed order of FDA to withdraw its approval for the drug product because it has determined that the product is less than effective for all its labeled indications.
   4. (4)The drug product is presently not subject to a determination by FDA, made under its efficacy review program (see 21 CFR 310.6 for an explanation of this program), that there is a compelling justification of the drug product's medical need.
2. (b)FFP is not available in expenditures for the purchase or administration of any drug product that is identical, related, or similar, as defined in 21 CFR 310.6, to a drug product that meets the conditions of paragraph (a) of this section.