Under the "Second Generation Medicated Feeds" final rule published in the Federal Register of May 3, 1986, new terminology, definitions, and requirements for the need of approved medicated feed applications were established. The term "drug" is interpreted as referring only to type A medicated articles since these articles are regulated as drugs. Type A products are intended solely for use in the manufacture of type A, B, or C products. Type B products are regulated as feeds, not as drugs. Type B products are intended solely for the manufacture of other medicated feeds. Both type A medicated articles and type B medicated feeds may be used in the manufacture of other type B or type C medicated feeds. Type C products are medicated feeds fed directly to animals, as finished, complete feeds. Category II type A medicated articles have a higher potential of causing significant residues in human food derived from animals than Category I type A medicated articles. Drugs in Category I have no withdrawal periods at the lowest use level in each species for which they are approved. Drugs in Category II have withdrawal periods at the lowest use level, or are regulated on a "no residue" basis, or with a "zero" tolerance because of carcinogenic concerns (21 CFR 558.3). Only the use of Category II type A medicated articles in the manufacture of medicated feeds require approved medicated feed applications.
The final rule also establishes two separate CGMP regulations applicable to medicated feed manufacturers. CGMP regulations in 21 CFR 225.10 through 225.115 apply only to facilities manufacturing one or more medicated feeds for which an approved medicated feed application is required. Therefore, these CGMP regulations, which include the daily inventory requirements of 21 CFR 225.42, apply only to those facilities using a Category II type A medicated article to manufacture a medicated feed.
Manufacturers using solely Category I type A medicated articles and/or type B medicated feeds to manufacture medicated feeds are exempt from the need of approved medicated feed applications. Manufacturers that use only these medicated products are required to be in compliance with a separate set of less restrictive CGMP regulations 21 CFR 225.120 through 225.202. There has been confusion concerning the daily inventory requirements of the CGMP regulations (21 CFR 225.42) which are applicable to the use of Category II type A medicated articles. This CPG clarifies the requirements of this CGMP section.
The daily inventory requirements of 21 CFR 225.42 are applicable to Category II type A medicated articles used in the manufacture of medicated feeds. The term "daily" means each day a Category II type A medicated article is in use. Daily inventory records should show when and which Category II type A medicated article was used, how much was used, and how much remains after each use.
When a feed manufacturer uses both Category I type A medicated articles and Category II type A medicated articles, the daily inventory requirements of 21 CFR 225.42 will apply to the use of all type A medicated articles. The 21 CFR 225.42 daily inventory requirements do not apply to type B medicated feeds used in the manufacture of other medicated feeds.