---
kind: "section"
citation: "21 C.F.R. § 558.633"
title: "21"
number: "558.633"
heading: "Tylvalosin."
url: "https://uscodex.org/cfr/21/558.633"
---

# §558.633. Tylvalosin.

- (a) **Specifications.** Type A medicated articles containing 77.12 grams tylvalosin per pound as tylvalosin tartrate.
- (b) **Sponsor.** See No. 066916 in [§ 510.600(c)](/cfr/21/510.600.md?p=c) of this chapter.
- (c) **Related tolerances.** See [§ 556.748](/cfr/21/556.748.md) of this chapter.
- (d) **Special considerations.**
  - (1) Federal law restricts medicated feed containing this veterinary feed directive (VFD) drug to use by or on the order of a licensed veterinarian. See [§ 558.6](/cfr/21/558.6.md) for additional requirements.
  - (2) VFDs for tylvalosin shall not be refilled.
  - (3) Crumbled Type C medicated feeds must bear an expiration date of 7 days after the date of manufacture.
- (e) **Conditions of use.**

## Notes

### Amendments

[81 FR 36790, June 8, 2016, as amended at 81 FR 67153, Sept. 30, 2016; 84 FR 12504, Apr. 2, 2019; 87 FR 17948, Mar. 29, 2022; 87 FR 58968, Sept. 29, 2022]

### Authority

Authority: 21 U.S.C. 354, 360b, 360ccc, 360ccc-1, 371.

### Source

Source: 40 FR 13959, Mar. 27, 1975, unless otherwise noted.

### Amendments

[81 FR 36790, June 8, 2016, as amended at 81 FR 67153, Sept. 30, 2016; 84 FR 12504, Apr. 2, 2019; 87 FR 17948, Mar. 29, 2022; 87 FR 58968, Sept. 29, 2022]