What is the difference between New Molecular Entity and New Active Ingredient?

An New Molecular Entity (NME) is an active ingredient that contains no active moiety that has been previously approved by the Agency in an application or has been previously marketed as a drug in the United States. A pure enantiomer or a racemic mixture is an NME only when neither has been previously approved or marketed.

A New Active Ingredient (NMI) includes those products whose active moiety has been previously approved or marketed in the United States, but whose particular ester, salt, or noncovalent derivative of the unmodified parent molecule has not been approved by the Agency or marketed in the United States, either alone, or as part of a combination product.

The terms New Molecular Entity (NME) and New Chemical Entity (NCE) are sometimes used interchangeably; however, they are distinct. An NCE is defined in 21 CFR 314.108(a) as “a drug that contains no active moiety that has been approved by the FDA in any other application submitted under 505(b) of the Act.” The term NME is not defined in the statute or regulations. An NME is an active ingredient that contains no active moiety that has been previously approved by the Agency in an application submitted under section 505 of the Act or has been previously marketed as a drug in the United States.