21 CFR § 520.1044c - Gentamicin sulfate powder.

---
identifier: "/us/cfr/t21/s520.1044c"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 520.1044c - Gentamicin sulfate powder."
title_number: 21
title_name: "Food and Drugs"
section_number: "520.1044c"
section_name: "Gentamicin sulfate powder."
chapter_name: "FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES"
subchapter_number: "E"
subchapter_name: "ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS"
part_number: "520"
part_name: "ORAL DOSAGE FORM NEW ANIMAL DRUGS"
positive_law: false
currency: "2026-04-05"
last_updated: "2026-04-05"
format_version: "1.1.0"
generator: "[email protected]"
authority: "21 U.S.C. 360b."
regulatory_source: "40 FR 13838, Mar. 27, 1975, unless otherwise noted."
cfr_part: "520"
---


# 520.1044c Gentamicin sulfate powder.

(a) *Specifications.* Each gram of powder contains gentamicin sulfate equivalent to:

(1) 16.7, 66.7, or 333.3 milligrams (mg) gentamicin.

(2) 333.3 mg gentamicin.

(b) *Sponsors.* See sponsors in § 510.600(c) of this chapter for use as in paragraph (d) of this section as follows:

(1) No. 000061 for products described in paragraph (a)(1) of this section.

(2) Nos. 016592 and 061133 for product described in paragraph (a)(2) of this section.

(c) *Related tolerances.* See § 556.300 of this chapter.

(d) *Conditions of use in swine*—(1) *Amount.* Administer in drinking water for 3 consecutive days as follows:

(i) For colibacillosis: Gentamicin sulfate equivalent to 25 mg of gentamicin per gallon of drinking water to provide 0.5 mg per pound of body weight per day;

(ii) For swine dysentery: Gentamicin sulfate equivalent to 50 mg of gentamicin per gallon of drinking water to provide 1 mg per pound of body weight per day. Treatment may be repeated if dysentery recurs.

(2) *Indications for use.* For control and treatment of colibacillosis in weanling swine caused by strains of *Escherichia coli* sensitive to gentamicin, and for control and treatment of swine dysentery associated with *Brachyspira hyodysenteriae.*

(3) *Limitations.* Withdrawal period: 10 days. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

[77 FR 4226, Jan. 27, 2012, as amended at 81 FR 94989, Dec. 27, 2016; 83 FR 48945, Sept. 28, 2018; 84 FR 8972, Mar. 13, 2019; 87 FR 10968, Feb. 28, 2022]