Skip to Content

We invite you to try out our new beta eCFR site at We’ve made big changes to make the eCFR easier to use. Be sure to leave feedback using the 'Feedback' button on the bottom right of each page!


Oral Dosage Form New Animal Drugs; Spinosad and Milbemycin Oxime

Document Details

Information about this document as published in the Federal Register.

Document Statistics
Document page views are updated periodically throughout the day and are cumulative counts for this document. Counts are subject to sampling, reprocessing and revision (up or down) throughout the day.
Published Document

This document has been published in the Federal Register. Use the PDF linked in the document sidebar for the official electronic format.

Start Preamble


Food and Drug Administration, HHS.


Final rule.


The Food and Drug Administration (FDA) is amending the animal drug regulations to reflect approval of a new animal drug application (NADA) filed by Elanco Animal Health. The NADA provides for veterinary prescription use of chewable tablets containing spinosad and milbemycin oxime in dogs for the treatment and prevention of flea infestations and for the prevention and control of various internal parasites.


This rule is effective March 8, 2011.

Start Further Info


Angela Clarke, Center for Veterinary Medicine (HFV-112), Food and Drug Administration, 7500 Standish Pl., Rockville, MD 20855, 240-276-8318, e-mail:

End Further Info End Preamble Start Supplemental Information


Elanco Animal Health, A Division of Eli Lilly & Co., Lilly Corporate Center, Indianapolis, IN 46285, filed NADA 141-321 that provides for veterinary prescription use of TRIFEXIS (spinosad and milbemycin oxime) Chewable Tablets in dogs for the treatment and prevention of flea infestations and for the prevention and control of various internal parasites. The NADA is approved as of January 4, 2011, and the regulations in part 520 (21 CFR part 520) are amended by adding § 520.2134 to reflect the approval.

In accordance with the freedom of information provisions of 21 CFR part 20 and 21 CFR 514.11(e)(2)(ii), a summary of safety and effectiveness data and information submitted to support approval of this application may be seen in the Division of Dockets Management (HFA-305), Food and Drug Administration, 5630 Fishers Lane, rm. 1061, Rockville, MD 20852, between 9 a.m. and 4 p.m., Monday through Friday.

Under section 512(c)(2)(F)(ii) of the Federal Food, Drug, and Cosmetic Act (21 U.S.C. 360b(c)(2)(F)(ii)), this approval qualifies for 3 years of marketing exclusivity beginning on the date of approval.

FDA has determined under 21 CFR 25.33 that this action is of a type that does not individually or cumulatively have a significant effect on the human environment. Therefore, neither an environmental assessment nor an environmental impact statement is required.

This rule does not meet the definition of “rule” in 5 U.S.C. 804(3)(A) because it is a rule of “particular applicability.” Therefore, it is not subject to the congressional review requirements in 5 U.S.C. 801-808.

Start List of Subjects

List of Subjects in 21 CFR Part 520

End List of Subjects

Therefore, under the Federal Food, Drug, and Cosmetic Act and under the authority delegated to the Commissioner of Food and Drugs and redelegated to the Center for Veterinary Medicine, 21 CFR part 520 is amended as follows:

Start Part


End Part Start Amendment Part

1. The authority citation for

End Amendment Part Start Authority

Authority: 21 U.S.C. 360b.

End Authority Start Amendment Part

2. Add § 520.2134 to read as follows:

End Amendment Part
Spinosad and milbemycin.

(a) Specifications. Each chewable tablet contains 140 milligrams (mg) spinosad and 2.3 mg milbemycin oxime, 270 mg spinosad and 4.5 mg milbemycin oxime, 560 mg spinosad and 9.3 mg milbemycin oxime, 810 mg spinosad and 13.5 mg milbemycin oxime, or 1,620 mg spinosad and 27 mg milbemycin oxime.

(b) Sponsor. See No. 000986 in § 510.600 of this chapter.

(c) Conditions of use in dogs—(1) Amount. Administer once a month at a Start Printed Page 12564minimum dosage of 13.5 mg/pound (lb) (30 mg/kilogram (kg)) of body weight spinosad and 0.2 mg/lb (0.5 mg/kg) of body weight milbemycin oxime.

(2) Indications for use. To kill fleas; for the prevention and treatment of flea infestations (Ctenocephalides felis); for the prevention of heartworm disease (Dirofilaria immitis); and for the treatment and control of adult hookworm (Ancylostoma caninum), adult roundworm (Toxocara canis and Toxascaris leonina), and adult whipworm (Trichuris vulpis) infections in dogs and puppies 8 weeks of age or older and 5 lbs of body weight or greater.

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

Start Signature

Dated: March 2, 2011.

Leslie Kux,

Acting Assistant Commissioner for Policy.

End Signature End Supplemental Information

[FR Doc. 2011-5144 Filed 3-7-11; 8:45 am]