21 CFR § 524.838 - Esafoxolaner, eprinomectin, and praziquantel.

---
identifier: "/us/cfr/t21/s524.838"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 524.838 - Esafoxolaner, eprinomectin, and praziquantel."
title_number: 21
title_name: "Food and Drugs"
section_number: "524.838"
section_name: "Esafoxolaner, eprinomectin, and praziquantel."
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: "524"
part_name: "OPHTHALMIC AND TOPICAL 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 13873, Mar. 27, 1975, unless otherwise noted."
cfr_part: "524"
---


# 524.838 Esafoxolaner, eprinomectin, and praziquantel.

(a) *Specifications.* Each milliliter (mL) of topical solution contains 12 milligrams (mg) esafoxolaner, 4 mg eprinomectin, and 83 mg praziquantel.

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

(c) *Conditions of use*—(1) *Amount.* Administer the entire contents of a provided unit applicator topically once a month at a minimum dose of 0.055 mL/lb (0.12 mL/kg), which delivers a minimum dose of 0.66 mg/lb (1.45 mg/kg) esafoxolaner, 0.23 mg/lb (0.51 mg/kg) eprinomectin, and 4.55 mg/lb (10.0 mg/kg) praziquantel.

(2) *Indications for use.* For the prevention of heartworm disease caused by *Dirofilaria immitis.* Kills adult fleas (*Ctenocephalides felis*) and is indicated for the treatment and prevention of flea infestations, the treatment and control of *Ixodes scapularis* (black-legged tick) and *Amblyomma americanum* (lone star tick) infestations, and the treatment and control of roundworms (fourth-stage larval and adult *Toxocara cati*), hookworms (fourth-stage larval and adult *Ancylostoma tubaeforme;* adult *Ancylostoma braziliense*), and tapeworms (*Dipylidium caninum*) in cats and kittens 8 weeks of age and older, and weighing 1.8 lbs or greater.

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

[88 FR 55566, Aug. 16, 2023]