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U.S. Department of Health and Human Services

Animal & Veterinary

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NADA 140-859 BIO-COX® + AUREOMYCIN® - original approval

Approval Date: June 13, 1989

I. GENERAL INFORMATION:

NADA 140-859
Sponsor: American Cyanamid Company
PO Box 400
Princeton, NJ 08540
Generic Name: salinomycin sodium + chlortetracycline
Trade Name: BIO-COX® + AUREOMYCIN®
Marketing Status:  

 

II. INDICATIONS FOR USE

For the prevention of coccidiosis in broiler chickens caused by Eimeria acervulina, E. tenella, E. maxima, E. necatrix and E. mivati and as an aid in the reduction of mortality due to E. coli infections susceptible to such treatment.

III. DOSAGE

A. DOSAGE FORM

Finished feeds manufactured from:

BIO-COX
Supplied as a medicated premix in 50 pound bags. Each pound of premix contains 30 mg of salinomycin sodium activity.

AUREOMYCIN 50, 70, and 100 Granular Type A medicated articles
Contains chlortetracycline calcium complex equivalent to 50, 70, and 100 grams of chlortetracycline HCl per pound of premix.

B. ROUTE OF ADMINISTRATION Oral administration via the feed.
C. RECOMMENDED DOSAGES: Salinomycin sodium (from BIO-COX) at concentrations ranging from 0.0044% to 0.0066% (40 to 60 g/ton) in finished feed. Chlortetracycline (from AUREOMYCIN) at a concentration of 0.055% (500 g/ton) in finished feed.

 

IV. Effectiveness

The approved original NADA 128-686 for BIO-COX (salinomycin sodium) contained adequate data to establish that salinomycin sodium at a range of 0.0044% to 0.0066% (40 to 60 g/ton) in finished feed is safe and effective for the prevention of coccidiosis caused by Eimeria acervulina, E. tenella, E. brunetti, E. maxima, E. necatrix and E. mivati .

The approved original NADA 48-761 for AUREOMYCIN chlortetracycline (32 FR 14155; 10/12/67) contained adequate data to establish that, at concentrations of 500 g/ton of feed, the drug is safe and effective as an aid in the reduction of mortality due to E. coli infections susceptible to such treatment.

Data supplied in this submission demonstrate that the combination of salinomycin sodium at concentrations of 0.0044% to 0.0083% (40 to 75 g/ton) + at a concentration of 0.055% (500 g/ton) is effective for the prevention of coccidiosis in broiler chickens caused by E. necatrix, E. acervulina, E. tenella, E. maxima, E. brunetti and E. mivati , and as an aid in the reduction of mortality due to E. coli infections susceptible to such treatment.

A. Non Interference in Battery Studies

Experiment A-86-21 E. coli Challenge Study

Four hundred Hubbard X Hubbard broiler chickens at nine days of age were used in an adequate, well-controlled battery study. The study was conducted in a uniform environment with a 12 hour light-dark cycle to test for noninterference of BIO-COX salinomycin with the antibacterial efficacy of AUREOMYCIN chlortetracycline.

This study was conducted by using the recommended use level of chlortetracycline (500 g/ton). The experimental treatment groups were as follows: uninfected nonmedicated control, infected nonmedicated control, infected chlortetracycline at 500 g/ton (550 ppm), infected salinomycin at 75g/ton (82.5 ppm) and infected chlortetracycline at 500 g/ton (550 ppm) with salinomycin 75g/ton (82.5 ppm).

There were four replicate pens per treatment and each pen contained five males and five females. At 3 hours post-treatment initiation the nine-day-old-birds were challenged by injection in the right thoracic air-sac with a culture containing approximately 1.4 X 10-4 cfu per dose of chlortetracycline sensitive E. coli . Noninfected control birds were injected similarly with sterile phosphate buffered saline. The birds were medicated for 5 days and a 7-day withdrawal period ensued. Feed consumption and mortality were recorded daily for each pen. Birds were weighed at 5 and 12 days post challenge. Results are in Table 1. Survivors were sacrificed 12 and 13 days post challenge. At necropsy, all birds were assigned air sac lesion scores. Air sac swabs were cultured in attempts to recover the challenge E. coli.

The results presented in Table 2 show that chlortetracycline incorporated in the diet at 550 ppm (500 g/ton) prevented development of E. coli induced air sac infection in chickens challenged with E. coli . BIO-COX salinomycin in combination with chlortetracycline did not interfere with the antibacterial efficacy of chlortetracycline in broilers.

The investigators involved in the above study were:

J.D. Kobland, R.L. Lubas, J.L. Samuel
American Cyanamid Company
Agricultural Research Div.
PO Box 400
Princeton, NJ 08540

(Eds. note: The following table consists of 6 columns.)

Table 1 Experiment A-86-21 Summary of Daily Gain/Chick

Drug E.coli Daily Gain/ Daily Gain/ Trt Level Challenge Chick (g) Chick (g) Grp. Treatment (ppm) 0-5 days* 0-12 Days A Non-Medicated 0 No 31.6 39.0 C Non-Medicated 0 Yes 23.7 32.5 D Chlortetracycline 550 Yes 30.6 37.6 E Salinomycin 82.5 Yes 22.2 30.1 F Salinomycin + 82.5 Chlortetracycline 550 Yes 27.4 36.0 * Treatment period (Eds. note: The following table consists of 8 columns.)

Table 2 Experiment A-86-21 Summary of Mortality, Average Air Sac Lesion Scores, E. coli Recovery Scores and Incidence of Chickens Positive for E. coli

                                                                         Av.       No. Chickens
Trt.    Treatment       Drug        E. coli      No.        Av.         E. coli      Positive
Grp.                    Level      Challenge    Dead/     Lesion       Recovery    For E. coli/
                        (ppm)                   Total*    Score**       Score       Total ***
                                                                       
A       Non-Medicated         0              No         0/40        0.05           0.00            0/40
C       Non-Medicated         0             Yes         9/40        1.80           1.19           17/40 
D       Chlortetracycline   550             Yes         1/38        0.60           0.07            2/38 
E       Salinomycin          82.5           Yes         6/39        1.70           0.67            8/39 
F       Salinomycin +        82.5           Yes         0/40        1.12           0.15            4/40 
        Chlortetracycline   550

* Number of chicks which died due to induced E. coli infection per total chicks (chicks which died at challenge or accidently were excluded from these data).
** Mean scores were computed from pen averages.
*** Excluding birds which died at challenge.

B. Coccidial Challenge Studies

Two week old Hubbard X Hubbard broiler chickens were used in adequate, well-controlled battery studies. The studies were conducted in a uniform environment with continuous artificial illumination to test for noninterference of AUREOMYCIN chlortetracycline with the anticoccidial effectiveness of BIO-COX salinomycin. Recent field strain isolates collected from various broiler producing regions of the United States were used. For each study, combinations of E. acervulina/E. mivati, E. necatrix and E. brunetti or E. acervulina, E. maxima and E. tenella were used. Combinations of three challenge species in each study were used to differentiate areas of the intestines infected by the parasite.

These studies were conducted by using the lowest recommended use level of salinomycin (40 g/ton). The experimental treatment groups were as follows: Group I - noninfected, nonmedicated control; Group II - infected, nonmedicated control; Group III - infected, salinomycin 40 g/ton; Group IV) infected, chlortetracycline 500 g/ton; Group V - infected, salinomycin 40 g/ton + chlortetracycline 500 g/ton.

In each of these studies all pens were preselected, birds were randomized by weight and assigned to cages with 10 birds/cage, and 4 replicates were used per treatment group. Groups were medicated 2 days before infection was administered. Evaluations were by lesion scores, (analysis was performed on preselected birds from each pen), dropping scores, weight gains and feed conversions.

Salinomycin at 40 g/ton in combination with AUREOMYCIN chlortetracycline at 500 g/ton provided better anticoccidial activity than that obtained with either chlortetracycline alone or unmedicated controls.

The investigators involved in the above studies were as follows:

S.E. Cheng, D.V.M., Ph.D.
Michael D. Sims, B.S.
Kent L. Puffenbarger, B.S., M.S.
Patricia C. Gerber, A.A.S.
A. H. Robins, Company
Research And Development Division
1211 Sherwood Avenue
Richmond, VA 23220

(Eds. note: The following table consists of 11 columns.)

Table 3 Anticoccidial Activity of Salinomycin in Combination with Chlortetracycline Against a Mixed Eimeria Infection* In Two Week Old Chicks (Study 85-217)

                                                 Average
Treat-                        Coccidiosis        Dropping
ment         Medication         Induced          Scores**           ----Weight Gain (average/pen)----         Feed Conversion          Total 
Group        Infection         Mortality        D-4 - D-8          Day 5     Day 6     Day 7     Day 14      Day 7     Day 14     Lesion Scores***
I              None                   0/40                 0.0              1823.2      2234.7     2558.7      6359.7        1.59         1.65              0.0 
               Uninfected       
II             None                   5/40                 2.7              1053.4      1022.5     1318.3      4745.1        2.21         2.08              5.7 
               Mixed 
         
III            Salinomycin            0/40                 1.4              1431.4      1623.1     1963.8      5369.7        1.82         1.88              4.1 
               40 g/ton Mixed 
IV             Chlortetracycline      0/40                 2.1              1033.8      1481.1     1914.9      5221.4        1.79         1.83              3.2 
               500 g/ton Mixed 
V              Salinomycin            0/40                 0.4              1606.8      2019.3     2408.8      5854.4        1.63         1.72              2.1 
               40 g/ton + 
               Chlortetracycline 
               500 g/ton Mixed

Note: Treatment V provided superior (P 0.05) lesion scores over both Treatment IV and Treatment II.
*E. acervulina/mivati, Log No. 984b, Cullman, AL, 100,000 sporulated oocysts; E. necatrix, Log No. 325A-73, Green Co., GA, 20,000 sporulated oocysts; E. brunetti, Log No. 237A-51, Madison, WI, 40,000 sporulated oocysts.
** Pen dropping scores assigned using a scale of 0 to 4 (Moorehouse and Baron,1970).
*** Lesion scores of 0 to 4 were determined for three areas of the small intestine plus ceca with maximum possible lesion score of 16. (Johnson and Reid, 1970).

(Eds. note: The following table consists of 11 columns.)

Table 4 Anticoccidial Activity of Salinomycin in Combination with Chlortetracycline Against a Mixed Eimeria Infection* In Two Week Old Chicks (Study 85-218)

                                                 Average
Treat-                        Coccidiosis        Dropping
ment         Medication         Induced          Scores**           ----Weight Gain (average/pen)----         Feed Conversion          Total 
Group        Infection         Mortality        D-4 - D-8          Day 5     Day 6     Day 7     Day 14      Day 7     Day 14     Lesion Scores***
I              None                   0/40                 0.0              1772.2      2086.0     2436.0      5618.6        1.48         1.56              0.0
               Uninfected 
II             None                   3/40                 2.05              929.8       672.3      858.6      3183.3        2.46         2.63              4.7
               Mixed 
III            40 g/ton Mixed         0/40                 0.7              1845.7      2270.0     2443.7      5266.4        1.57         1.66              0.7
               Salinomycin 
IV             500 g/ton              0/40                 0.9              1246.5      1625.2     1958.7      4320.5        1.62         1.98              3.3
               Chlortetracycline 
               Mixed    
V              40 g/ton               0/40                 0.5              1782.5      2202.7     2464.2      5297.9        1.54         1.65              1.2
               Salinomycin +   
               500 g/ton
               Chlortetracycline
               Mixed

Note: Treatment V provided superior (P 0.05) lesion scores over both Treatment IV and Treatment II.
* E. acervulina/mivati, Log No. 984B, Cullman, AL, 100,000
sporulated oocysts; E. necatrix, Log No. 325A, Green Co., GA, 20,000
sporulated oocysts; E. brunetti, Log No. 237A-51, Madison, WI, 40,000
sporulated oocysts.
** Pen dropping scores assigned using a scale of 0 to 4 (Moorehouse and Baron, 1970).
*** Lesion scores 0 to 4 were determined for three areas of the small intestine plus ceca with maximum possible total lesion score of 16. (Johnson and Reid, 1970).

 

V. ANIMAL SAFETY

The original approved NADAs for salinomycin (NADA 128-686) and for chlortetracycline (NADA 48-761) contained adequate data to establish the safety of each drug for broiler chickens.

The safety of the 2 drugs when used in combination was demonstrated in the noninterference battery and coccidial challenge studies described in this document. In each of the several studies there was no evidence that drug was the cause of any mortality or toxicity.

Based on the data in the parent NADAs and from the noninterference battery and anticoccidial challenge studies, the combination is safe to be fed to broiler chickens as indicated on the label.

The data show that the combination of BIO-COX salinomycin at 40 - 60 g/ton plus AUREOMYCIN chlortetracycline at 500 g/ton in the feed of broiler chickens fulfills all the requirements for a combination drug for animals as follows:

A. Each drug component makes a contribution to the claimed effects;

B. The dosages of each drug component are such that the combination is safe and effective; and

C. The label claims are not antagonistic.

 

VI. HUMAN SAFETY

A. Data to Support Human Safety

The safety of the approved products, salinomycin sodium (BIO-COX) and chlortetracycline (AUREOMYCIN) has been established by data submitted in their respective original NADAs, NADA 128-686 and NADA 48-761.

The tolerance for residues of chlortetracycline in edible tissue of chicken is established at 4.0 ppm in kidney and 1.0 ppm in muscle, liver, fat and skin (21 CFR 556.150). Safe concentrations of total residues of salinomycin in the edible tissues of chickens are 0.6 ppm for muscle, 1.8 ppm for liver and 1.2 ppm for skin/fat. (Safe concentrations refer to the concentrations of total residues considered safe in edible tissues.) Total residues are highest in liver tissue. Parent drug salinomycin in skin/fat was established as the marker substance for total residues in liver. An upper limit of 200 ppb (0.2 ppm) for residues of parent salinomycin in skin/fat is established for uses of salinomycin with a zero day withdrawal.

B. Residue Depletion/Non Interference Studies

Residue data supporting the approved individual uses of salinomycin and chlortetracycline and their withdrawal times of 0 and 1 day, respectively, were submitted in their respective original applications (see Part A above).

Drug residue elimination and assay noninterference studies were conducted to establish that each drug in the presence of the other does not exceed its established safe concentration of tolerance, as applicable, at the proposed withdrawal time and that neither drug interferes in each other's tissue residue assay.

Control chicken muscle, liver, skin/fat were fortified to contain 2.0 ppm salinomycin, 2.0 ppm roxarsone and/or 0.50 ppm chlortetracycline. The analyses of these samples by the chlortetracycline microbioassay procedure showed quantitative recovery of chlortetracycline either in the presence or absence of salinomycin plus roxarsone.

Control skin/fat tissue homogenate were spiked with combinations of salinomcyin (0.7 ppm) and chlortetracycline (1.0 ppm). Chlortetracycline did not interfere with the tissue residue assay procedure (HPLC) for salinomycin.

A tissue depletion study was conducted by A.H. Robins Company under protocol 86-0595 at the A.H. Robins Farm in Ashland, VA. Tissues were obtained from broiler chickens fed one of the following: 1) unmedicated control diet for 42 days; 2) a diet containing the drug combination of 75 g/ton salinomycin plus 45 g/ton roxarsone plus 200 g/ton chlortetracycline for the first 37 days, then a diet containing the drug combination of 75 g/ton of salinomycin plus 45 g/ton of roxarsone plus 500 g/ton chlortetracycline from Day 37 to 42. The medicated group was switched on the morning of Day 42 to unmedicated control diet, and birds were sacrificed following drug withdrawal periods of 0 to 7 days. Tissues were collected, and tissue levels of drug residue determined for the respective drug as follows: salinomycin at Day 0 post withdrawal, chlortetracycline on days 0, 3, 5 and 7 days post withdrawal, and roxarsone at days 0, 3 and 7 post withdrawal. Tissues from chickens receiving unmedicated feed during the entire study served as controls with tissues being collected on day 42 of the study.

The target tissue for residue elimination studies for salinomycin is skin/fat. Salinomycin assayed at <.1 ppm in skin/fat, which is below the upper limit of (0.2 ppm) for the marker residue.

At withdrawal days of 0, 3, 5, and 7 all samples assayed for chlortetracycline residues were well below 1 ppm, the established tolerance. Kidney tissue was not assayed, as chicken kidney is no longer considered to be an edible tissue.

The results of the residue depletion study (Table 5) support the 24 hour withdrawal for this salinomycin - chlortetracycline combination .

(Eds. note: The following table consists of 6 columns.)

Table 5 Residue Depletion - Assay Results (ppm) 

                                       ----------------Tissue---------------- 
                       Withdrawal
Parameter              Day Assay       Skin w/Fat    Muscle    Liver    Fatpad 
Salinomycin 
Established Safe  
Concentration                                   0.2 
(as determined by marker 
residue) 
Salinomycin Assay              0                0.1 
(highest residue found  
in any broiler) 
Chlortetracycline 
Established  
Tolerance                                       1.0           1.0         1.0        1.0 
Chlortetracycline Assay 
(highest residue               0                0.415         0.292       0.520      0.048 
found in any broiler)          3                0.039         0.029       0.047      0.025 
                               5                0.054         0.070       0.053      0.025 
                               7                0.033         0.028       0.033      0.025

Sensitivity of the Method:

  • salinomycin - 0.10 ppm
  • chlortetracycline - 0.025 ppm.

A regulatory analytical method for salinomycin is not required. A practical analytical method for the determination of tissue residues of chlortetracycline is available in the Food Additives Analytical Manual on display in FDAs Freedom of Information Room (Room 12A-30, 5600 Fishers Lane, Rockville, MD 20857).

 

VII. AGENCY CONCLUSIONS

The data submitted in support of this NADA satisfy the requirements of Section 512 of the Act and demonstrate that the combination of salinomycin sodium at concentrations of 40 to 60 g/ton (0.0044 to 0.0066%) + chlortetracycline at 500 g/ton (0.055%) in finished feed for broilers is safe and effective for the indications stated on the product labeling.

The tolerances for residue of chlortetracycline in edible tissue of chicken are established at 4.0 ppm in kidney and 1 ppm in uncooked muscle, liver, fat and skin (21 CFR 556.150). Safe concentrations of total residue of salinomcyin in edible tissues of chickens are 0.6 ppm for muscle, 1.8 ppm for liver and 1.2 ppm for skin/fat. The data submitted in support of the NADA indicated that the residues of chlortetracycline were below the established tolerance in edible tissue and the residues of salinomycin were below the safe concentration in the edible tissues.

The 24 hours withdrawal time before slaughter is satisfactory.

Adequate directions for use of the proposed drug combination in broiler chickens have been written for the requested claims of this NADA. Products containing salinomycin and chlortetracycline alone are currently available over-the-counter.

The Agency has concluded that approval of the combination (salinomycin + chlortetracycline) will not significantly increase human exposure to residue in edible tissues.

 

VIII. LABELING (Attached)

  1. Blue Bird Type C Medicated Broiler Feed package label

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

Freedom of Information Office
Center for Veterinary Medicine, FDA
7500 Standish Place
Rockville, MD 20855