[Federal Register Volume 60, Number 150 (Friday, August 4, 1995)]
[Rules and Regulations]
[Pages 39847-39848]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 95-19281]



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DEPARTMENT OF HEALTH AND HUMAN SERVICES
21 CFR Part 558


New Animal Drugs for Use in Animal Feeds; Ivermectin

AGENCY: Food and Drug Administration, HHS.

ACTION: Final rule.

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SUMMARY: The Food and Drug Administration (FDA) is amending the animal 
drug regulations to reflect approval of a supplemental new animal drug 
application (NADA) filed by Merck Research Laboratories, Division of 
Merck & Co., Inc. The original NADA provides for the use of a Type A 
medicated article containing ivermectin in manufacturing Type C 
medicated feed for production swine. The supplemental NADA expands use 
of the feed to breeding swine. The feed is intended for treatment and 
control of certain endo- and ectoparasites.

EFFECTIVE DATE: August 4, 1995.

FOR FURTHER INFORMATION CONTACT: Melanie R. Berson, Center for 
Veterinary Medicine (HFV-135), Food and Drug Administration, 7500 
Standish Pl., Rockville, MD 20855, 301-594-1643.

SUPPLEMENTARY INFORMATION: Merck Research Laboratories, Division of 
Merck & Co., Inc., P.O. Box 2000, Rahway, NJ 07065, is the sponsor of 
approved NADA 140-974, which provides for the use of a Type A medicated 
article containing 0.6 percent ivermectin (2.72 grams per pound (g/lb)) 
in manufacturing Type C medicated feed containing 1.8 g of ivermectin 
per ton (t). The feed is indicated for the treatment and control of 
certain gastrointestinal roundworm, lungworm, kidney worm, lice, and 
mite infestations of growing swine (up to 220 lb in body weight) as in 
Sec. 558.300 (21 CFR 558.300). The feed is administered so as to 
provide 0.1 milligram of ivermectin per kilogram (mg/kg) of body weight 
per animal per day. Merck has filed a supplemental NADA expanding use 
of the ivermectin-containing feed to include breeding swine. To achieve 
the same dosage level (i.e., 0.1 mg of ivermectin per kg of body 
weight) in the larger animals, the supplemental NADA provides for an 
ivermectin concentration up to 11.8 g/t of Type C medicated feed.
    The supplemental NADA is approved as of August 4, 1995, and the 
regulations are amended in Sec. 558.300 to reflect the approval. The 
basis of approval is discussed in the freedom of information summary.
    Additionally, approval of the supplemental NADA increases the 
highest concentration of ivermectin permitted in Type C medicated feed 
from 1.8 to 11.8 g/t. The feed can be manufactured from either a Type A 
medicated article or a Type B medicated feed. Currently, the Category 
II table in Sec. 558.4 (21 CFR 558.4) specifies that the maximum 
concentration of ivermectin permitted in a Type B feed is 182 g/t 
(i.e., 100 x the 1.8 g/t now approved for Type C feed). However, 
because the supplemental NADA increases the highest drug concentration 
permitted in the Type C feed to 11.8 g/t, this justifies a 
corresponding increase in the maximum ivermectin concentration in the 
Type B feed to 1,180 g/t (i.e., 100 x the 11.8 g/t). Accordingly, FDA 
is also amending the Category II table in Sec. 558.4 to reflect this 
increase.
    In accordance with the freedom of information provisions of part 20 
(21 CFR part 20) and Sec. 514.11 (e)(2)(ii) (21 CFR 514.11(e)(2)(ii)), 
a summary of safety and effectiveness data and information submitted to 
support 

[[Page 39848]]
approval of this application may be seen in the Dockets Management 
Branch (HFA-305), Food and Drug Administration, rm. 1-23, 12420 
Parklawn Dr., Rockville, MD 20857, between 9 a.m. and 4 p.m., Monday 
through Friday.
    Under section 512(c)(2)(F)(iii) of the Federal Food, Drug, and 
Cosmetic Act (21 U.S.C. 360b(c)(2)(F)(iii)), this approval for food-
producing animals qualifies for 3 years of marketing exclusivity 
beginning August 4, 1995, because the supplemental NADA contains 
reports of new clinical or field investigations (other than 
bioequivalence or residue studies) essential to the approval and 
conducted or sponsored by the applicant. The 3 years of marketing 
exclusivity applies only to the use for which the supplemental NADA is 
approved.
    The agency has carefully considered the potential environmental 
effects of this action. FDA has concluded that the action will not have 
a significant impact on the human environment, and that an 
environmental impact statement is not required. The agency's finding of 
no significant impact and the evidence supporting that finding, 
contained in an environmental assessment, may be seen in the Dockets 
Management Branch (address above) between 9 a.m. and 4 p.m., Monday 
through Friday.

List of Subjects in 21 CFR Part 558

    Animal drugs, Animal feeds.
    Therefore, under the Federal Food, Drug, and Cosmetic Act and under 
authority delegated to the Commissioner and redelegated to the Center 
for Veterinary Medicine, 21 CFR part 558 is amended as follows:

PART 558--NEW ANIMAL DRUGS FOR USE IN ANIMAL FEEDS

    1. The authority citation for 21 CFR part 558 continues to read as 
follows:

    Authority: Secs. 512, 701 of the Federal Food, Drug, and 
Cosmetic Act ( 21 U.S.C. 360b, 371).

Sec. 558.4  [Amended]

    2. Section 558.4 Medicated feed applications is amended in 
paragraph (d) in the ``Category II'' table in the entry for 
``Ivermectin'' under the third column by removing ``182 g/ton (0.02%)'' 
and adding in its place ``1,180 g/ton (0.13%)''.
    3. Section 558.300 is amended by revising paragraphs (c)(1)(i) and 
(iii) to read as follows:


Sec. 558.300  Ivermectin.

* * * * *
    (c) * * *
    (1) * * *
    (i) Amount. For growing-finishing swine feed 1.8 grams of 
ivermectin per ton (to provide 0.1 milligram per kilogram of body 
weight per day). For mature and breeding swine feed 1.8 to 11.8 grams 
of ivermectin per ton (to provide 0.1 milligram per kilogram of body 
weight per day).
* * * * *
    (iii) Limitations. Feed as the only feed for 7 consecutive days. 
For use in swine only. Withdraw 5 days before slaughter.
* * * * *

    Dated: July 26, 1995.
Robert C. Livingston,
Director, Office of New Animal Drug Evaluation, Center for Veterinary 
Medicine.
[FR Doc. 95-19281 Filed 8-3-95; 8:45 am]
BILLING CODE 4160-01-F