GroundRules
21 CFR 520.2520d: d Trichlorfon, phenothiazine, and piperazine.
Where this section sits in the code
- Title 21—Food and Drugs
- CHAPTER I—FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES
- SUBCHAPTER E—ANIMAL DRUGS, FEEDS, AND RELATED PRODUCTS
- PART 520—ORAL DOSAGE FORM NEW ANIMAL DRUGS
(a) Specifications. Each 54.10 grams (1.91 ounces) of water dispersible powder contains 9.10 grams of trichlorfon, 6.25 grams of phenothiazine, and the equivalent of 20.0 grams of piperazine base (as piperazine dihydrochloride).
(b) Sponsor. See No. 054771 in § 510.600(c) of this chapter.
(c) Conditions of use in horses—(1) Amount. 18.2 milligrams (mg) of trichlorfon, 12.5 mg of phenothiazine, and 40 mg of piperazine base per pound of body weight.
(2) Indications for use. For removal of bots (Gastrophilus nasalis, Gastrophilus intestinalis), large strongyles (Strongylus vulgaris), small strongyles, large roundworms (ascarids, Parascaris equorum), and pinworms (Oxyuris equi).
(3) Limitations. Do not use in horses intended for human consumption. Federal law restricts this drug to use by or on the order of a licensed veterinarian.
Collected 2026-08-27T02:24:47Z. Source file · JSON