21 CFR § 520.1802c - Piperazine-carbon disulfide complex with phenothiazine suspension.

---
identifier: "/us/cfr/t21/s520.1802c"
source: "ecfr"
legal_status: "authoritative_unofficial"
title: "21 CFR § 520.1802c - Piperazine-carbon disulfide complex with phenothiazine suspension."
title_number: 21
title_name: "Food and Drugs"
section_number: "520.1802c"
section_name: "Piperazine-carbon disulfide complex with phenothiazine suspension."
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"
---


# 520.1802c Piperazine-carbon disulfide complex with phenothiazine suspension.

(a) *Specifications.* Each fluid ounce contains 5 grams of piperazine-carbon disulfide complex and 0.83 gram of phenothiazine.

(b) *Sponsor.* See No. 054771 in § 510.600(c) of this chapter.

(c) *Conditions of use in horses and ponies*—(1) *Amount.* Administer 1 fluid ounce per 100 pounds of body weight by stomach tube or dose syringe after withholding feed overnight or for 8 to 10 hours.

(2) *Indications for use.* For removing ascarids (large roundworms, *Parascaris equorum*), bots (*Gastrophilus* spp.), small strongyles, and large strongyles (*Strongylus* spp.).

(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.

[45 FR 52782, Aug. 8, 1980, as amended at 78 FR 28826, May 20, 2014]