21 CFR 520.1720 : Food And Drugs (§ 1.1 To Parts 1403-1499) — (Subpart A To Parts 590-599) — Food And Drug Administration, Department Of Health And Human Services (Continued) (Subpart A To Parts 590-599) — Animal Drugs, Feeds, And Related Products (Subpart A To Parts 590-599) — Oral Dosage Form New Animal Drugs (§ 520.23 To § 520.2645) — Phenylbutazone oral dosage forms.