21 CFR § 526.464 - Cloxacillin benzathine.

---
identifier: "/us/cfr/t21/s526.464"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 526.464 - Cloxacillin benzathine."
title_number: 21
title_name: "Food and Drugs"
section_number: "526.464"
section_name: "Cloxacillin benzathine."
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"
---


# 526.464 Cloxacillin benzathine.

(a) *Specifications.* Each single-dose, 7.5- or 10-milliliter syringe contains cloxacillin benzathine equivalent to 500 milligrams (mg) cloxacillin.

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

(c) *Related tolerances.* See § 556.165 of this chapter.

(d) *Conditions of use in dry cows*—(1) *Amount*. Infuse the contents of one syringe (equivalent to 500 mg cloxacillin) into each quarter immediately after last milking, but no later than 30 days before calving.

(2) *Indications for use.* For the treatment of mastitis caused by *Staphylococcus aureus* and *Streptococcus agalactiae* including penicillin resistant strains in dairy cows during the dry period.

(3) *Limitations.* Animals infused with this product must not be slaughtered for food until 30 days after the latest infusion. Federal law restricts this drug to use by or on the order of a licensed veterinarian.

[86 FR 13186, Mar. 8, 2021]