21 CFR § 526.1130 - Hetacillin.

---
identifier: "/us/cfr/t21/s526.1130"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 526.1130 - Hetacillin."
title_number: 21
title_name: "Food and Drugs"
section_number: "526.1130"
section_name: "Hetacillin."
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: "526"
part_name: "INTRAMAMMARY 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."
cfr_part: "526"
---


# 526.1130 Hetacillin.

(a) *Specifications.* Each single-dose, 10-milliliter syringe contains hetacillin potassium equivalent of 62.5 milligrams (mg) ampicillin.

(b) *Sponsor.* See No. 000010 in § 510.600(c) of this chapter.

(c) *Related tolerances.* See § 556.316 of this chapter.

(d) *Conditions of use in lactating cows*—(1) *Amount*. Infuse the contents of one syringe (equivalent to 62.5 mg ampicillin) into each infected quarter. Repeat at 24-hour intervals for a maximum of 3 treatments.

(2) *Indications for use.* For the treatment of acute, chronic, or subclinical mastitis in lactating cows caused by susceptible strains of *Streptococcus agalactiae, Streptococcus dysgalactiae, Staphylococcus aureus,* and *Escherichia coli*.

(3) *Limitations.* Milk that has been taken from animals during treatment and for 72 hours (6 milkings) after the latest treatment must not be used for food. Treated animals must not be slaughtered for food until 10 days after the latest treatment. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

[57 FR 37335, Aug. 18, 1992, as amended at 75 FR 10168, Mar. 5, 2010; 84 FR 53311, Oct. 7, 2019; 86 FR 13186, Mar. 8, 2021]