CERTIORARI TO THE UNITED STATES COURT OF APPEALS FOR THE ELEVENTH CIRCUIT.
Stevens, J., delivered the opinion for a unanimous Court.
JUSTICE STEVENS delivered the opinion of the Court.
The question presented is whether the statutory prohibition against the marketing of a "new drug" without the prior approval of the Food and Drug Administration (FDA) requires respondent Generix Drug Corp. to have approved new drug applications (NDA's) before it may market its generic drug products. In statutory terms, we are required to determine whether the term "drug" as used in the relevant sections of the Federal Food, Drug, and Cosmetic Act (Act), as amended, 21 U. S. C. § 301 et seq. (1976 ed. and Supp V), refers only to the active ingredient in a drug product or to the entire product. We hold that Congress intended the word to have the broader meaning.
The active ingredients in most prescription drugs constitute less than 10% of the product; inactive "excipients" (such as coatings, binders, and capsules) constitute the rest. The term "generic drug" is used to describe a product that contains the same active ingredients but not necessarily the same excipients as a so-called "pioneer drug" that is marketed
under a brand name.*fn1 Respondent Generix is a distributor of generic drugs manufactured by other firms.
The Government initiated this action to enjoin Generix from distributing in interstate commerce a number of generic drug products that contain eight specified active ingredients.*fn2 It alleged that the FDA had never approved new drug applications with respect to any of those products.*fn3
The District Court held that a generic drug product containing the same active ingredients as a previously approved pioneer drug is a "new drug," requiring an NDA, only if there is a reasonable possibility that the differences in excipients between the generic product and the pioneer will make the generic product less safe and effective. 498 F.Supp. 288, 292. The court found clear evidence in support of the general proposition that differences in excipients may affect the safety and effectiveness of drug products. Excipients may affect the rate at which the active ingredient is delivered to a diseased organ. If delivery is too fast, the patient may be harmed just as if he received an overdose; if delivery is too slow, the treatment of the disease may be ineffective. Id., at 291.
In this case, the District Court found that the Government had established a reasonable possibility that the safety and effectiveness of six of respondent's generic drug products might be affected by differences between their excipients and those found in approved products.*fn4 Accordingly, it enjoined the defendants from further distribution of products containing the designated active ingredients.
The Court of Appeals for the Fifth Circuit, now the Eleventh Circuit, vacated the District Court's injunction and remanded with instructions to dismiss the complaint. 654 F.2d 1114. It held that the statutory prohibition against the sale of a "new drug" without prior approval does not apply to a drug product having the same active ingredients as a previously approved drug product, regardless of any differences in excipients. It based that conclusion on its view that the statutory requirement of evaluating the safety and effectiveness of new drugs must normally relate to active ingredients, because the precise technique of formulating the finished drug is not part of the information generally known to the medical or scientific community. Moreover, it believed that the legislative history suggested that Congress had not intended ...