Animal & Veterinary

NADA 006-707 Sulquin 6-50 Concentrate - supplemental approval (June 2, 1997)

Approval Date: June 2, 1997

Freedom of Information Summary
NADA 006-707





Solvay Animal Health, Inc.
Mendota Heights, MN 55120

Generic Name:

sodium sulfaquinoxaline liquid

Trade Name:

Sulquin 6-50 Concentrate

Marketing Status:

Over the Counter (OTC)

Effect of Supplement:

DESI finalization recognizing that Sulquin 6-50 Concentrate is, when used as directed, safe and effective for the labeled indications.


See below


A. Dosage Form: Liquid

B. Route of Administration: Oral

C. Recommended Dosage: Chickens & turkeys-0.04% & 0.025%

D. Indications of Use: For control of coccidiosis in chickens and turkeys. For the control of acute fowl cholera and fowl typhoid in chickens and turkeys.


NADA 6-707 was originally approved as safe for use as labeled on February 14, 1949. The drug was the subject of National Academy of Science/National Research Council (NAS/NRC) reports which were published in the FEDERAL REGISTER of July 9, 1970 (FR 70-8718). The Academy evaluated the product as (1) probably effective as an aid in prevention and control of outbreaks of coccidiosis in chickens, turkeys, pheasants (and other game birds), cattle and sheep (provided the species of coccidia for the respective hosts are shown); (2) effective as an aid in the prevention and control of coccidiosis (Eimeria stiedae) in rabbits; and (3) probably effective as an aid in the control, and treatment of bacterial infections in cattle, lambs, and swine when such infections are caused by pathogens sensitive to sulfaquinoxaline. The Academy stated that:

  1. For systemic use the recommended dosage levels should be documented with regard to whether such dosage levels produce effective blood levels and tissue concentrations.
  2. Each disease claim should be properly qualified as "appropriate for use in (name of disease) caused by pathogens sensitive to (name of drug)" and if the disease cannot be so qualified the claim must be dropped.
  3. The labels should carry a warning that treated animals under the conditions that prevail must actually consume sufficient medicated water to provide a therapeutic dose under the conditions that prevail. As a precaution the labels should state what the desired oral dose is in terms of animal weight per day for each species to serve as a guide to effective use of the preparations in water.
  4. The label claims "for prevention of" or, "to prevent" should be replaced with "as an aid in the control of" or, "to aid in the control of."
  5. The label caution statements need to be revised to "incorporate current toxicological information."

The Food and Drug Administration concurred with the Academy's findings, interpreting the phrase "...cannot be so qualified..." in paragraph (2) to mean " not supported by adequate data..." (See Fed. Reg. vol. 35, NO. 132-Thursday, July 9, 1970). FDA then proceeded to review all available data relating to the effectiveness of products subject to NADA 6-707 to determine which label claims were supported by the requisite proof of effectiveness. That review resulted in a letter to the firm dated July 6, 1992, in which the agency stated that it had concluded that such data supported effectiveness for the control and treatment of coccidial diseases in chickens and turkeys. Thereafter, the sponsor complied with the evaluation of NAS/NRC and FDA's conclusions by submitting a supplemental application which revised the labeling of its sodium sulfaquinoxaline liquid product in the following manner: Appropriate oral doses for all the allowable species and claims based on milliliters per gallons of water or milligrams per pound body weight are on the current labels.

  1. Each disease claim on the label has been properly qualified with the appropriate genus and species of bacteria susceptible to sulfaquinoxaline. Disease claims which were not so qualified have been deleted.
  2. The manufacturer's label carries the warning statement that treated animals must have the medicated water adjusted to compensate for variation in age and the weight of animals, the nature and severity of disease signs, and environmental temperature and humidity, each of which affects water consumption.
  3. Claims made for prevention have been revised to read "Control of.." where appropriate.
  4. The label carries all the current toxicological statements concerning the use of sulfaquinoxaline under the heading "Caution".


NADA 6-707 was originally approved as safe on February 14, 1949. No further safety data are required.


The NAS/NRC evaluation of the drug is concerned only with the effectiveness and safety of the drug for the treated animal. FDA's approval of the supplemental application did not involve reevaluation or reaffirmation of the human food safety data in the parent application.

At the time sulfaquinoxaline was approved a negligible tolerance of 0.1 ppm in all edible tissues was applied to animal drug residues based on subchronic (90-day) toxicology studies. This "negligible tolerance" concept is based on two precepts:

  1. the residue present is at a level of insignificance and
  2. the safety of the residue is supported by limited toxicology data. The toxicology data available for sulfaquinoxaline, i.e., a 90-day dog study, permits a tolerance for sulfaquinoxaline residues in edible tissues of 0.1 ppm.


The DESI finalization supplemental NADA satisfies the requirements of section 512 of the Act and demonstrates that Sulquin 6-50 Concentrate (sulfaquinoxaline liquid) when used under its proposed conditions of use, is safe and effective for the labeled indications. The approval provides for use of sulfaquinoxaline for the control and treatment of specific diseases in chickens and turkeys.

The "probably effective" finding of the NAS/NRC regarding sulfaquinoxaline which was published in the FEDERAL REGISTER of July 9, 1970, was subsequently reviewed by FDA, resulting in the upgrade to "effective" status with respect to the claims noted in the paragraph above. The firm submitted revised labeling to conform and, therefore, this supplemental NADA complies with the NAS/NRC evaluation and FDA's conclusions.

Other sulfaquinoxaline liquid products for use in food-producing animals are currently on the market as over-the-counter products. When the NADA was reviewed under NAS/NRC/DESI program, it was an over-the-counter product and this marketing status remains unchanged. Therefore, the Center for Veterinary Medicine has concluded that this product should retain over-the-counter marketing status.

Under the Center's supplemental approval policy (21 CFR 514.106(b)(2)), this is a Category ll change. The approval of this change is not expected to have any adverse effect on the safety or effectiveness of this new animal drug and, therefore, did not require a reevaluation of the human food or target animal safety data in the parent application.


  1. Sulquin 6-50 Concentrate 6 fl. oz
  2. Sulquin 6-50 Concentrate gallon size

Copies of applicable labels may be obtained by writing to the:

Food and Drug Administration
Freedom of Information Staff (HFI-35)
5600 Fishers Lane
Rockville, MD 20857

Or requests may be sent via fax to: (301) 443-1726. If there are problems sending a fax, call (301) 443-2414.

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