• Decrease font size
  • Return font size to normal
  • Increase font size
U.S. Department of Health and Human Services

Animal & Veterinary

  • Print
  • Share
  • E-mail

NADA 141-018 SaraFlox® Injection - original approval

Approval Date: March 28, 1996

I. GENERAL INFORMATION

NADA141-018
Sponsor:Abbott Laboratories
1401 Sheridan Road
North Chicago, IL 60064
Generic Name:sarafloxacin hydrochloride
Trade Name:SaraFlox® Injection
Marketing Status:A prescription (Rx) product which carries the following caution statement "Federal (USA) law restricts this drug to use by or on the order of a licensed veterinarian."
Diagnosis:Diagnosis of an E. coli infection in the day-old broiler is based on the presumptive identification of the organism in the day-old broiler as a part of chick quality monitoring program. This presumptive identification may be based on such considerations as breeder flock history, physical examination, necropsy and yolk sac culture.

 

II. INDICATIONS FOR USE

SARAFLOX® INJECTION is indicated for control of early mortality associated with Escherichia coli (colibacillosis) susceptible to sarafloxacin in day-old broiler chickens.

 

III. DOSAGE

A.DOSAGE FORM:SARAFLOX® INJECTION is available as an 80 mL sterile-solution-fill in a 100 mL glass bottle at a concentration of 50 mg sarafloxacin base per mL.
B.ROUTE OF ADMINISTRATION:SARAFLOX® INJECTION is to be mixed with sterile physiological saline and should be administered as a single injection subcutaneously in the back of the neck to day-old broiler chickens.
C.RECOMMENDED DOSAGES:Chicks should be injected at a concentration of 0.1 mg per chick in a volume of 0.2 mL. The contents of one bottle will be sufficient to inject 40,000 broiler chickens.

 

IV. EFFECTIVENESS

Six studies were reported demonstrating the effectiveness of sarafloxacin in controlling mortality associated with E. coli infections in day-old chicks. Dose range-finding and dose confirmation studies, in which day-old chicks were challenged with an intramuscular injection of E. coli, indicated that sarafloxacin was highly effective in reducing total mortality and E. coli positive mortalities. The dose of 0.1 mg was as effective as higher doses in reducing mortality during 14-day study periods.

Three field dose confirmation studies were conducted to confirm the effectiveness of this antibacterial in a large number of chicks infected by natural means (through egg contact or at the hatchery). Both total and E. coli-associated mortality (positive culture and lesion score greater than 1) were significantly reduced by 0.1 and 0.2 mg sarafloxacin injected subcutaneously. The two levels of sarafloxacin were similarly effective in each study.

A. Pivotal Studies

  1. Dose Range-Finding Study
    1. Type of Study: This was a dose range-finding study of sarafloxacin injection administered to broiler chickens artificially infected with E. coli by injection.
    2. Investigator:

      Jeffrey Davidson, D.V.M., M.P.V.M.
      Health Management Services
      Tulare, California 93275

    3. General Design

      1. Purpose: The purpose of this study was to determine an effective dose of a single injection of sarafloxacin for the control of colibacillosis in day-old broiler chicks with artificially induced disease.
      2. Animals: Day-old Arbor Acre x Arbor Acre chicks; 240 males, 240 females, were used in this study. For each of 8 treatments, there were 3 pens of 20 chicks each (10 males, 10 females).
      3. Controls: One group was uninfected and untreated; another was infected and untreated.
      4. Challenge: Diluted inoculum (0.1 mL) containing 8 x 10(4) colony forming units (CFU) E. coli per chick: serotype 01 was injected into the breast muscle.
      5. Diagnosis: E. coli presence was determined by culture of necropsy swabs from air sacs and pericardia.
      6. Dosage Form: A solution containing 96.1 mg sarafloxacin free-base per milliliter was used.
      7. Route of Administration: The drug was administered by subcutaneous injection.
      8. Dose: The doses tested were a single 0.2 mL injection containing 0 mg, 0.025 mg, 0.05 mg, 0.1 mg, 0.2 mg, 0.3 mg, or 0.4 mg sarafloxacin per chick.
      9. Test Duration: The test spanned 14 days.
      10. Pertinent Variables Measured: The principal criteria of efficacy were total mortality and mortality attributable to E. coli infection. Supportive data recorded were morbidity observations, feed consumption, and body weight by sex within pen.
    4. Results:

      Table 4.1. Total and E. coli Positive Mortality in Induced Infections Treated with Sarafloxacin

      Treatment GroupMortalities
      Sarafloxacin (mg)TotalE. coli Positive
      0*1/60 (1.7%)1/1 (100%)
      030/60 (50%)27/30 (90%)
      0.02517/60 (28.3%)17/17 (100%)
      0.058/60 (13.3%)8/8 (100%)
      0.14/60 (6.7%)4/4 (100%)
      0.26/60 (10%)5/6 (83%)
      0.31/60 (1.7%)1/1 (100%)
      0.41/60 (1.7%)1/1 (100%)
      Totals68/480 (14.2%)64/68 (94%)
      *uninfected
    5. Statistical Analysis: The study used a randomized complete block design with eight treatments in three blocks. A survival model and weighted least squares analysis were used to examine total and E. coli mortalities. Tests of significance were made at the P< or =.05 level. Stepwise nonorthogonal contrasts were examined for the main effect of treatment.
    6. Conclusion: Subcutaneous injection of sarafloxacin in dosages greater than 0.025 mg was effective in controlling mortality due to E. coli infection in young broilers.
    7. Adverse Reactions: No adverse reactions were observed.
  2. Dose Confirmation Study

    1. Type of Study: A dose confirmation study was conducted using sarafloxacin injection in broiler chickens artificially infected with E. coli by injection.
    2. Investigator:

      Jeffrey Davidson, D.V.M., M.P.V.M.
      Health Management Services
      Tulare, California 93275

    3. General Design:

      1. Purpose: The purpose of this study was to further determine the dose of a single injection of sarafloxacin for the control of colibacillosis in broiler chicks with artificially induced disease.
      2. Animals: Day-old Arbor Acre x Peterson chicks; 360 males, 360 females were used in this study. For each of 4 treatments there were 6 pens of 30 chicks each (15 males, 15 females).
      3. Controls: One group was uninfected and untreated; another was infected and untreated.
      4. Challenge: Diluted inoculum (0.1 mL) containing 7 x 10(5) colony forming units (CFU) E. coli per chick: serotype 02 was injected into the breast muscle.
      5. Diagnosis: E. coli presence was determined by culture of necropsy swabs from air sacs and pericardia.
      6. Dosage Form: A solution containing 102.2 mg sarafloxacin free-base per milliliter was used.
      7. Route of Administration: A subcutaneous injection was administered.
      8. Dose: A single 0.2 mL injection of 0 mg, 0.05 mg, or 0.1 mg sarafloxacin per chick was administered.
      9. Test Duration: The test spanned 14 days.
      10. Pertinent Variables Measured: Principal criteria of efficacy were total mortality and mortality attributable to E. coli infection. Other supportive data recorded were morbidity observations, feed consumption, and body weight by pen.
    4. Results:

      Table 4.2. Total and E. coli Positive Mortality in Induced Infections Treated with Sarafloxacin

      Treatment GroupMortalities
      Sarafloxacin (mg)TotalE. coli Positive
      0*2/180 (1.1%)2/2 (100%)
      0102/181 ** (56.4%)99/102 (97%)
      0.0531/180 (17.2%)31/31 (100%)
      0.110/180 (5.6%)8/10 (80%)
      Totals145/721 (20.1%)140/145 (97%)
      * uninfected
      ** One extra chick placed at initiation
    5. Statistical Analysis: The study used a randomized complete block design with four treatments in six blocks. A survival model and weighted least squares analysis were used to examine total and E. coli mortalities. Tests of significance were made at the P< or =.05 level. Orthogonal contrasts were used to measure treatment differences.
    6. Conclusion: Based on reduction of mortality, subcutaneous injection of 0.1 mg sarafloxacin was determined more effective than 0.05 mg in controlling E. coli infection in young broilers.
    7. Adverse Reactions: No adverse reactions were observed.
  3. Dose Confirmation Study

    1. Type of Study: A dose confirmation study was conducted using sarafloxacin injection in broiler chickens artificially infected with E. coli by injection.
    2. Investigator:

      Carey L. Quarles, Ph.D.
      Colorado Quality Research, Inc.
      Fort Collins, Colorado 80524

    3. General Design:

      1. Purpose: The purpose of this study was to confirm the efficacy of a single injection of 0.1 mg sarafloxacin for the control of mortality due to colibacillosis in broiler chicks with artificially induced disease.
      2. Animals: Day-old Arbor Acre x Arbor Acre broiler chicks; 270 males, 270 females were used in this study. For each of 3 treatments, there were 6 pens of 30 chicks each (15 males, 15 females).
      3. Controls: One group was uninfected and untreated; another was infected and untreated.
      4. Challenge: Diluted inoculum (0.1 mL) containing 1 x 10(4) colony forming units (CFU) E. coli per chick: serotype 01 was injected into the breast muscle.
      5. Diagnosis: E. coli presence was determined by culture of necropsy swabs from air sacs and pericardia.
      6. Dosage Form: A solution containing 100 mg sarafloxacin free-base per milliliter was used.
      7. Route of Administration: A subcutaneous injection was administered.
      8. Dose: A single 0.2 mL injection containing 0 mg or 0.1 mg sarafloxacin per chick was administered.
      9. Test Duration: The test spanned 14 days.
      10. Pertinent Variables Measured: Principal criteria of efficacy were total mortality and mortality attributable to E. coli infection. Other supportive data recorded were morbidity observations, feed consumption, and body weight by pen.
    4. Results:

      Table 4.3 Total and E. coli Positive Mortality in Induced Infections Treated with Sarafloxacin

      Treatment GroupMortalities
      Sarafloxacin (mg)TotalE. coli Positive
      0*3/180 (1.7%)0/3 (0%)
      0**101/180 (56.1%)100/101 (99%)
      0.137/180 (20.6%)37/37 (100%)
      Totals141/540 (26.1%)137/141 (97.2%)
      * Uninfected vs. infected (P<.01).
      ** Infected, untreated vs. sarafloxacin (P<.01)
    5. Statistical Analysis: The study used a randomized complete block design with three treatments in six blocks. A survival model and weighted least squares analysis were used to examine total and E. coli mortalities. Tests of significance were made at the P< or =.05 level. Treatment effects were measured by orthogonal contrasts.
    6. Conclusion: Based on reduction of mortality, subcutaneous injection of 0.1 mg sarafloxacin was confirmed effective in controlling E. coli infection in young broilers.
    7. Adverse Reactions: No adverse reactions were observed.
  4. Field Dose Confirmation Study

    1. Type of Study: A dose confirmation study was conducted using sarafloxacin injection in broiler chickens in which E. coli infection occurred naturally.
    2. Investigator:

      James McNaughton, Ph.D.
      PARC Institute, Inc.
      Easton, Maryland 21601

    3. General Design

      1. Purpose: To determine the effective dose of a single injection of sarafloxacin for the control of colibacillosis in broiler chicks with naturally occurring disease.
      2. Animals: 3360 Day-old broiler chicks were used in this study. For each of 3 treatments there were 16 pens of 70 chicks each. Males and females were included in each pen.
      3. Controls: One group was not treated.
      4. Diagnosis: E. coli presence determined by culture of necropsy swabs from air sacs and pericardia.
      5. Dosage Form: A solution containing 50.5 mg sarafloxacin free-base per milliliter was used. This dosage form is the marketed form of SARAFLOX® INJECTION.
      6. Route of Administration: A subcutaneous injection was administered.
      7. Dose: A single 0.2 mL injection containing 0 mg, 0.1 mg, or 0.2 mg sarafloxacin per chick was administered.
      8. Test Duration: The test spanned 14 days.
      9. Pertinent Variables Measured: The principal criteria of efficacy were total mortality and mortality attributable to E. coli infection. Other supportive data recorded were morbidity observations, feed consumption, and body weight by pen.
    4. Results:

      Table 4.4. Total and E. coli Positive Mortality in Natural Infection Treated with Sarafloxacin

      Treatment GroupMortalities
      Sarafloxacin (mg)Total*E. coli Positive*
      085/1120 (7.6%)60/1120 (5.4%)
      0.153/1119** (4.7%)9/1119 (0.8%)
      0.251/1120 (4.6%)4/1120 (.4%)
      Totals189/3359 (5.6%)73/3359 (2.2%)
      * Control vs. sarafloxacin (P<.05)
      ** One chick was unaccounted for.
    5. Statistical Analysis: The study used a randomized complete block design with 3 treatments in 16 blocks. A survival model and weighted least squares analysis were used to examine total and E. coli mortalities. Tests of significance were made at the P< or =.05 level. Orthogonal contrasts were used to measure treatment differences.
    6. Conclusion: Based on reduction of mortality, and with an insignificant statistical difference between the two doses, subcutaneous injection of 0.1 mg sarafloxacin was as effective as 0.2 mg in controlling E. coli infection in young broilers.
    7. Adverse Reactions: No adverse reactions were observed.
  5. Field Dose Confirmation Study

    1. Type of Study: A dose confirmation study was conducted using sarafloxacin injection in broiler chickens in which E. coli infection occurred naturally.
    2. Investigator:

      Carey L. Quarles, Ph.D.
      Colorado Quality Research, Inc.,
      Fort Collins, Colorado 80524

    3. General Design:

      1. Purpose: The purpose of this study was to further determine the dose of a single injection of sarafloxacin for the control of colibacillosis in broiler chicks with naturally occurring disease.
      2. Animals: 2400 Day-old broiler chicks were used in this study. For each of 3 treatments there were 16 pens of 50 chicks each. Males and females were included in each pen.
      3. Controls: One group was not treated.
      4. Diagnosis: E. coli presence determined by culture of necropsy swabs from air sacs and pericardia.
      5. Dosage Form: A solution containing 52.4 mg sarafloxacin free-base per milliliter was used. This dosage form is the marketed form of SARAFLOX® INJECTION.
      6. Route of Administration: A subcutaneous injection was administered.
      7. Dose: A single 0.2 mL injection containing 0 mg, 0.1 mg, or 0.2 mg sarafloxacin per chick was administered.
      8. Test Duration: The test spanned 14 days.
      9. Pertinent Variables Measured: The principal criteria of efficacy were total mortality and mortality attributable to E. coli infection. Other supportive data recorded included lesion scoring, morbidity observations, feed consumption, and body weight by pen.
    4. Results:

      Table 4.5. Total and E. coli Positive Mortality in Natural Infection Treated with Sarafloxacin

      Treatment GroupMortalities
      Sarafloxacin (mg)Total*E. coli Positive*
      0174/800 (22%)110/800 (14%)
      0.170/800 (8.8%)20/800 (2.5%)
      0.254/798** (6.8%)10/798 (1.2%)
      Totals298/2398 (12%)40/2398 (5.8%)
      *Control vs. sarafloxacin (P<.05)
      ** Miscount of 2 chicks at initiation.
    5. Statistical Analysis: The study used a randomized complete block design with 3 treatments in 16 blocks. A survival model and weighted least squares analysis were used to examine total and E. coli mortalities. Tests of significance were made at the P< or =.05 level. Orthogonal contrasts were used to measure treatment differences.
    6. Conclusion: Based on reduction of mortality, and with an insignificant statistical difference between the two doses, subcutaneous injection of 0.1 mg sarafloxacin was as effective as 0.2 mg in controlling E. coli infection in young broilers.
    7. Adverse Reactions: No adverse reactions were observed.
  6. Field Dose Confirmation Study

    1. Type of Study: A dose confirmation study was conducted using sarafloxacin injection in broiler chickens in which E. coli infection occurred naturally.
    2. Investigator:

      Michael D. Sims, B.S.
      Virginia Scientific Research, Inc.
      Harrisonburg, Virginia 22601

    3. General Design:

      1. Purpose: The purpose of this study was to confirm the dose of a single injection of sarafloxacin for the control of colibacillosis in broiler chicks with naturally occurring disease.
      2. Animals: 2400 Day-old broiler chicks were used in this study. For each of 3 treatments there were 16 pens of 50 chicks each. Males and females were included in each pen.
      3. Controls: One group was not treated.
      4. Diagnosis: E. coli presence was determined by culture of necropsy swabs from air sacs, livers, and pericardia.
      5. Dosage Form: A solution containing 50 mg sarafloxacin free-base per milliliter was used. This dosage form is the marketed form of SARAFLOX® INJECTION.
      6. Route of Administration: A subcutaneous injection was administered.
      7. Dose: A single 0.2 mL injection containing 0 mg, 0.1 mg or 0.2 mg sarafloxacin per chick was administered.
      8. Test Duration: The test spanned 14 days.
      9. Pertinent Variables Measured: The principal criteria of efficacy were total mortality and mortality attributable to E. coli infection. Other supportive data recorded included lesion scoring, morbidity observations, feed consumption, and body weight by pen.
    4. Results:

      Table 4.6. Total and E. coli Positive Mortality in Natural Infection Treated with Sarafloxacin

      Treatment GroupMortalities
      Sarafloxacin (mg)Total*E. coli Positive*
      0169/800 (21%)92/800 (12%)
      0.180/800 (10%)32/800 (4.0%)
      0.263/800 (7.9%)20/800 (2.5%)
      Totals312/2400 (13%)144/2400 (6.0%)
      * Control vs. sarafloxacin (P<.05)
    5. Statistical Analysis: The study used a randomized complete block design with 3 treatments in 16 blocks. A survival model and weighted least squares analysis were used to examine total and E. coli mortalities. Tests of significance were made at the P< or =.05 level. Orthogonal contrasts were used to measure treatment differences.
    6. Conclusion: Based on reduction of mortality, and with an insignificant statistical difference between the two doses, subcutaneous injection of 0.1 mg sarafloxacin was as effective as 0.2 mg in controlling E. coli infection in young broilers.
    7. Adverse Reactions: No adverse reactions were observed.
  7. Field Dose Confirmation Studies - Combined

    1. Results:

      Table 4.7.  Total and E. coli Positive Mortality in Natural Infection Treated with Sarafloxacin

      Treatment GroupMortalities
      Sarafloxacin (mg)Total*E. coli Positive*
      0428/2720 (16%)262/2720 (9.6%)
      0.1203/2719** (7.5%)61/2719 (2.2%)
      0.2168/2718*** (6.2%)34/2718 (1.2%)
      Totals799/8157 (9.8%)357/8157 (4.4%)
      * Control vs. sarafloxacin (P<.05)
      ** One chick unaccounted for
      *** Miscount of 2 chicks at initiation
    2. Statistical Analysis: A weighted least squares analysis was used to examine total and E. coli mortalities. Both procedures used location, treatment and the interaction in the model. Tests of significance were made at the P< or =.05 level.
    3. Conclusion: Total and E. coli mortality were reduced (P<.05) by sarafloxacin. Although the difference was slight, both total and E. coli mortality were less at the 0.2 mg dose than at the 0.1 mg dose when the results of the dose confirmation studies were combined.

      It was concluded that SARAFLOX® INJECTION is effective at the 0.1 mg dose for control of early mortality associated with Escherichia coli (colibacillosis) susceptible to sarafloxacin in 1- to 3-day-old broiler chickens.

B. Corroborative Study

  1. Serum Levels of Sarafloxacin Following Administration by Subcutaneous Injection to Day-old Chicks

    1. Type of Study: This was a study to determine the serum concentration profile for sarafloxacin.
    2. Investigator:

      R.H. Rippel
      Abbott Agricultural Research Center
      Long Grove, Illinois 60047

    3. General Design:

      1. Purpose: The purpose of this study was to determine the effect of a single subcutaneous injection of either 0.1 or 0.5 mg of sarafloxacin on blood (serum) levels of the fluoroquinolone in 1- to 3-day-old broilers.
      2. Animals: Eighty-five Hubbard X Hubbard 1- to 3-day-old broiler chicks were used in this study. Birds were randomly selected from a group of 200 without regard to sex. The chicks weighed from 45 to 50 grams at the start of the trial.
      3. Route of Administration: The drug was administered by subcutaneous injection.
      4. Doses: Doses tested were 0.1 mg and 0.5 mg. Sterile water was added to the injectable solution to provide concentrations of 0.5 and 2.5 mg sarafloxacin per milliliter. Each bird was injected with 0.2 mL of the appropriate solution.
      5. Test Duration: The study spanned three days.
      6. Pertinent Parameters Measured: Blood samples were taken by cardiac puncture from five preselected birds at each time point. Samples were collected at 0.25, 0.5, 1, 2, 4, 6, 8, 24, and 48 hours post dosing. Sarafloxacin levels were measured in serum samples. The injection solutions were also analyzed to determine sarafloxacin levels.
    4. Results: The data indicate that there is a wide variation in the serum concentration of individual birds at all timepoints. Based on the small sample size per timepoint, it was determined that the most meaningful result was obtained by pooling the 0.25 hour and 0.50 hour groups to determine the mean serum concentration and standard deviation. Based on the values obtained from 9 birds, this was found to be 446.78 ± 233.78 µg/mL. This serum concentration represents sarafloxacin on a free base basis to be comparable to the units used for bacterial susceptibility determinations. Serum concentration values begin to decline following this point. No linearity was demonstrated between the serum concentrations at the 0.1 mg and those at 0.5 mg.
    5. Statistical Analysis: The data in this study were analyzed using General Linear Model (GLM) procedures.
    6. Conclusion: The average serum concentrations exceeded the current MIC90 for E. coli (0.06 µg/mL)in the first half hour post injection. The pooled data for chicks sampled at these timepoints indicate that the mean serum concentration is highest during that period and depletes over the next several hours.

 

V. ANIMAL SAFETY

A. Pivotal Studies

  1. Target Animal Safety Study: A specifically designed Target Animal Safety Study in 2-day-old chicks was conducted to address the tolerance to and safety of a single injection of sarafloxacin. Based on the results of this study, sarafloxacin is safe when administered subcutaneously to chicks at 1 to 3 days of age according to label directions.

    1. Type of Study: This was an 11-day study in broilers in which a single injection of 0, 0.1, 0.5, or 1.0 mg of sarafloxacin was administered subcutaneously at 2 days of age followed by an 11-day observation period.
    2. Study Director:

      Carey L. Quarles, Ph.D.
      Colorado Quality Research, Inc.
      Fort Collins, Colorado 80524

    3. General Design:

      1. Purpose: This study was designed to determine the toxicologic effects of sarafloxacin administered by subcutaneous injection to broilers. Potential target organs and tissues were to be identified through clinical observations, gross necropsy and histologic examination. Red blood cell counts, hemoglobin, packed cell volume, clotting time, white blood cell counts and percent differentials, body weight and feed consumption were other variables of interest.
      2. Animals: Two-day-old Peterson x Arbor Acre broilers (n = 960) were used in this study. For each of 4 treatments, there were 2 pens of 60 chicks each for each sex (480 males, 480 females). The average initial weight for females was 63.0 g; and for males was 64.1 g.
      3. Control: A subcutaneous injection of 0.2 mL of sterile water was administered.
      4. Dosage form: An aqueous formulation containing 50 mg sarafloxacin base per milliliter was used. This dosage form is the marketed form of SARAFLOX® INJECTION.
      5. Dose: The doses were 0, 0.1, 0.5, or 1.0 mg/chick in 0.2 mL sterile water.
      6. Route of Administration: The drug was administered by subcutaneous injection.
      7. Study Duration: The study spanned 11 days beginning at 2 days of age.
      8. Pertinent measurements/observations: Daily clinical observations, mortality, hematologic measurements, (Days 4 and 11), body weight (individual birds on Days 4 and 11), feed consumption (pen basis on Days 4 and 11), gross necropsy, and histopathology (Day 11) were evaluated to assess potential toxicity in broilers.
    4. Results:

      1. Clinical Observations: Vent pasting was one of the more common observations during the first seven days of the study. In the treated groups, transitory vent pasting was noted, but was not dose-related. Leg abnormalities which are also common among young birds, occurred in low incidence in all groups.
      2. Mortality: The majority (83%) of the mortalities occurred during study Days 6 through 10. Occurrences were idiosyncratic and the overall rate of 3% was considered normal. Gross necropsy findings were indicative of colibacillosis and ascites, two commonly encountered etiologies in the young chick.
      3. Body Weight: The only effect of sarafloxacin on body weight occurred at Day 4 of the study when chicks dosed at 0.1 mg were heavier (P<.05) than the 0 mg dose group, and the 1.0 mg dosed birds were heavier (P<.05) than the 0.1 mg group. Average weights at the end of the study were 341, 345, 344 and 346 g/bird, respectively, for the 0, 0.1, 0.5 and 1.0 mg doses of sarafloxacin.
      4. Feed Consumption: Sarafloxacin did not depress feed intake. Group intake averaged between 36.4 and 37.3 g/bird/day. Males consumed more than females (P<.01).
      5. Hematology: Erythrocytes, hemoglobin and packed cell volume:

        These variables were not influenced by treatment at either Day 4 or 11 when assessed in a total of 10 chicks of each sex per treatment. Sex-related differences occurred in which females had higher packed cell volumes on both Day 4 and 11 and higher hemoglobin concentrations on Day 11 (P<.01).

      6. Leukocytes: Values were within published norms for the chick. The differences noted for the comparisons of concern were primarily at Day 4 with a lower total leukocyte count, but higher eosinophil and heterophil counts in the 0.1 mg sarafloxacin group compared to that of the placebo group, but lower eosinophil counts (P<.01) for the 0.1 mg group on Day 11 compared to the placebo group. No differences occurred among levels of sarafloxacin. Other significant differences were associated with gender and the interaction of SEX X TREATMENT.
      7. Clotting time: A SEX X TREATMENT interaction occurred at Day 11 that was not dose-related. Group means varied by 1 sec at Day 4 and by 1.3 sec at Day 11.
      8. Gross and Histological Observations: Few gross lesions were found among the 10 birds of each sex per treatment group. Yolk sac abnormalities were noted grossly from two placebo birds necropsied at study end and from one in the 1.0 mg sarafloxacin group. Microscopically, each of these lesions was mildly congested. Inflammatory-type lesions were seen microscopically in the placebo and 1.0 mg dose groups in heart and bursa (1 male in each group) and liver (2 birds each group).
    5. Statistical Analysis: A randomized complete block design was used with four treatments in 4 replicate blocks (2 blocks per gender). The model included the main effects of LOCATION (i.e. column and row), SEX, TREATMENT and the SEX X TREATMENT interaction.

      The experimental unit for feed intake was the pen of animals, whereas individual birds were independent experimental units for body weight and each hematological variable.

      Single-degree-of-freedom contrasts were used to measure treatment differences. These a priori contrasts were 0 vs 0.1 mg, 0.1 mg vs. 0.5 mg, and 0.1 mg vs. 1.0 mg sarafloxacin.

    6. Conclusions: Clinical and (or) toxicity signs and mortality occurring during the study appeared to be that which would be acceptable for broiler chicks of this age. Treatment differences were not evident for these variables. Sarafloxacin did not adversely affect feed intake or weight gain.

      Clinical pathology evaluations (hematology, coagulation time, gross and microscopic pathology) revealed no biologically important treatment-related effects. Statistically significant differences in blood parameters were not clinically important, as averages for each variable were within normal ranges.

      The subcutaneous injection of sarafloxacin to 2-day-old chicks at 0.5 and 1.0 mg (five and ten times the intended field-use level of 0.1 mg) caused no adverse effects in this study. This, in conjunction with the lack of adverse effects in clinical field trials which included groups of animals receiving twice the label dose, indicates that SARAFLOX® INJECTION is safe when used in day-old chicks in accordance with label directions.

B. Corroborative Studies None.

 

VI. HUMAN SAFETY

A. Toxicity Studies

  1. A Subchronic (3-month) Oral Toxicity Study in the Mouse with A-56620 via Dietary Admixture

    1. Report Number: 90-3575
    2. Study Completion: August 23, 1991 (Start: September 6, 1990)
    3. Investigators:

      J. E. Atkinson and Ira W. Daly
      Bio/dynamics Inc.
      East Milstone, New Jersey 08575

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) was used in this study.
    5. Species and Strain of Animal: CD-1 albino mice were used.
    6. Number of Animals per Group: Animals were allocated 50/sex/group.
    7. Levels and Duration of Dosing: CD-1 mice, approximately 6 weeks of age at initiation of the study, were given doses of 0; 20,000; or 50,000 ppm of sarafloxacin HCl. Animals were randomly assigned to treatment groups and scheduled for necropsy following treatment for 3 months.
    8. Route of Administration: The drug was given orally in the diet.
    9. Parameters Studied: Clinical observations, body weight, food consumption, and macroscopic pathology were determined.
    10. Toxicities Observed: Mortality occurred at 20,000 ppm and above.
    11. No Observable Effect Level (NOEL): This was not determined.
    12. Conclusions: Doses exceeded maximum tolerated dose and drug-related mortality was observed at all dose levels. Although this study was not pivotal in the usual sense in setting the NOEL, it was critical to the regulatory decision making process.
  2. Three-Month Toxicity (with One-Month Interim Kill) Study of Abbott-56620 Administered Orally to Rats

    1. Report Number: TA84-254
    2. Study Completion: July 15, 1985 (Start: November 6, 1984)
    3. Investigators:

      J. M. Creighton and M. C. Pratt
      Abbott Laboratories
      Abbott Park, Illinois 60064

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) in liquid suspension was used in this study.
    5. Species and Strain of Animal: Sprague-Dawley rats were used.
    6. Number of Animals per Group: Animals were allocated 20/sex/group and 5/sex/group.
    7. Levels and Duration of Dosing: Sprague-Dawley rats, approximately 6 weeks of age at initiation of the study, were given doses of 0, 20, 75, 275, or 1,000 mg/kg/day of sarafloxacin suspended in 0.2 percent hydroxypropylmethyl-cellulose (HPMC). Animals were randomly assigned to treatment groups and scheduled for necropsy following treatment for 1 month (10/sex/group) and 3months (10/sex/group). Animals assigned to a 1-month recovery phase (5/sex/group) were also scheduled for necropsy.
    8. Route of Administration: Drug was given by oral gavage.
    9. Parameters Studied: Clinical observations, body weight, food consumption, ophthalmoscopic examinations, urinalysis, hematology, clinical chemistry, organ weight, and gross and microscopic pathology were studied.
    10. Toxicities Observed: Mortality was observed at 1,000 mg/kg/day.
    11. No Observable Effect Level (NOEL): 275 mg/kg/day.
    12. Conclusions: Grossly enlarged ceca in males given 75 mg/kg/day and females given 275 mg/kg/day are believed to have resulted from the pharmacologic effects of large doses of the test substance. No treatment-related microscopic alterations were detected. This study was not used for setting the NOEL due to the small number of animals, but was still used in the regulatory decision making process.
  3. Thirteen-Week Capsule Toxicity Study with Abbott-56620 in Dogs

    1. Report Number: TB90-180
    2. Study Completion: April 26, 1991 (Start: July 20, 1990)
    3. Investigators:

      A. L. Kiorpes and R. H. Weltman
      Hazleton Wisconsin
      Madison, Wisconsin

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) gelatin capsules were used in this study.
    5. Species and Strain of Animal: Juvenile Beagle dogs were used in this study.
    6. Number of Animals per Group: 6/sex/group were used in the control and high-dosage groups; 4/sex/group were used in the low-and mid-dosage groups.
    7. Levels and Duration of Dosing: 0, 10, 50, or 200 mg/kg/day of sarafloxacin in gelatin capsules were given once daily for at least 13 weeks. During the first two weeks of the study, sarafloxacin, as the hydrochloride salt, was administered on an actual weight basis without regard to its free base concentration. This resulted in actual dosages which were approximately 80 percent of the intended free base dosages. For the remainder of the study, a correction factor was used in dose calculations to adjust for the free base concentration.
    8. Route of Administration: The drug was given orally as gelatin capsules.
    9. Parameters Studied: Clinical observations, body weight, food consumption, electroretinograms, ophthalmologic examinations, electrocardiograms, urinalysis, hematology, clinical chemistry, and gross and microscopic pathology were studied.
    10. Toxicities Observed: Transient localized dermal erythema and swelling, and ocular discharge were observed.
    11. No Observable Effect Level (NOEL): 8 mg/kg/day.
    12. Conclusions: Localized erythema and/or swelling was observed in dogs given 40 or 160 mg/kg/day, which is thought to occur in response to profound vasodilation caused by high doses of sarafloxacin or other quinolones. The phenomenon was transient and species specific. Increased incidence of ocular discharge was observed in females given 160 mg/kg/day. Lowered serum globulin values observed in treated dogs were not associated with morphologic changes representative of a systemic toxicologic response.
  4. Dietary Chronic Toxicity and Carcinogenicity Study of Abbott-56620 in the Albino Rat: Chronic Toxicity Phase

    1. Report Number: 83828 (TA88-435)
    2. Study Completion: October 16, 1990 (Start: December 16, 1988)
    3. Investigator:

      S. Y. Smith
      Bio Research Laboratories, Ltd.
      Montreal, Quebec, Canada

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620).
    5. Species and Strain of Animal: Sprague-Dawley derived CD rats were used.
    6. Number of Animals per Group: Animals were allocated 20/sex/dose.
    7. Levels and Duration of Dosing: Rats, approximately 6 weeks of age at initiation, were given 0; 1,000; 10,000; or 25,000 ppm sarafloxacin hydrochloride in the diet. The approximate mean average achieved was 54, 586, and 1,541 mg/kg/day for rats given diets containing 1,000; 10,000; or 25,000 ppm sarafloxacin hydrochloride, respectively. This was a 24-month study.
    8. Route of Administration: The drug was given orally, in the diet.
    9. Parameters Studied: Clinical observations, body weight, food consumption, ophthalmoscopic examinations, urinalysis, hematology, clinical chemistry, organ weight, and gross and microscopic pathology were studied.
    10. Toxicities Observed: Nephropathy was observed.
    11. No Observable Effect Level (NOEL): 1,000 ppm (approximately 54 mg/kg/day).
    12. Conclusions: Mild renal changes were observed in the 10,000 and 25,000 ppm dose groups, believed to be a result of drug insolubility. Lowered serum total protein and globulin values for treated rats were not associated with morphologic changes representative of a systemic toxicologic response. Cecal enlargement, a common result of antibiotic reduction of enteric microbes, was observed.
  5. Dietary Carcinogenicity Study of Abbott-56620 in the Albino Mouse

    1. Report Number: 84097
    2. Study Completion: November 22, 1991 (Start: July 27, 1989)
    3. Investigators:

      B. G. Procter, R. B. Salame, and J. W. Noveroske
      Bio Research Laboratories, Ltd.
      Montreal, Quebec, Canada

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) in the diet.
    5. Species and Strain of Animal: CD-1 albino mice were used.
    6. Number of Animals per Group: Animals were allocated 70/sex/group.
    7. Levels and Duration of Dosing: Mice were treated for approximately 78 weeks with diets containing 0; 1,000; 5,000; or 20,000 ppm sarafloxacin hydrochloride. Approximate mean average achieved intake of drug was 150, 830, and 3,300 mg/kg/day for mice given diets containing 1,000; 5,000; and 20,000 ppm, respectively.
    8. Route of Administration: Drug was administered orally in the diet.
    9. Parameters Studied: Clinical signs, body weights, food consumption, hematology, gross and microscopic pathology were studied.
    10. Toxicities Observed: Increased mortality, nephropathy were observed.
    11. No Observable Effect Level: 1,000 ppm (approximately 150 mg/kg/day).
    12. Conclusions: Administration of sarafloxacin hydrochloride to CD-1 mice for approximately 78 weeks had no carcinogenic effect. Nephropathic changes were observed in mice given 5,000 or 20,000 ppm. An increased incidence in mortality was observed in the 5,000 and 20,000 ppm groups. Dilated cecum, a pharmacologic response to the bactericidal action of large doses of this antibacterial, accompanied by mechanical rotation of the intestine may have contributed to the observed increase in mortality.
  6. A Dietary Chronic Toxicity and Carcinogenicity Study of Abbott-56620 In the Albino Rat: Carcinogenicity Phase

    1. Report Number: 83828 (TA88-435)
    2. Study Completion: December 26, 1991 (Start: December 16, 1988)
    3. Investigator:

      S. Y. Smith
      Bio Research Laboratories, Ltd.
      Montreal, Quebec, Canada

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) was used.
    5. Species and Strain of Animal: Sprague-Dawley CD rats were used.
    6. Number of Animals per Group: Animals were allocated 65/sex/group.
    7. Levels and Duration of Dosing: Rats were treated for 104 weeks with 0; 1,000; 10,000; or 25,000 ppm sarafloxacin hydrochloride. (Approximate mean average achieved intake of drug was 54, 586, and 1,541 mg/kg/day.)
    8. Route of Administration: Drug was given orally in the diet.
    9. Parameters Studied: Clinical signs, body weights, food consumption, ophthalmologic examinations, hematology, clinical chemistry, urinalysis, gross and microscopic pathology, and plasma drug level were studied.
    10. Toxicities Observed: Nephropathy was observed.
    11. No Observable Effect Level (NOEL): 1,000 ppm (approximately 54 mg/kg/day)
    12. Conclusions: Based on the results of this study, no evidence of carcinogenic activity was associated with the administration of sarafloxacin hydrochloride by dietary admixture to rats for a minimum of 104 weeks. The dosages of 10,000 and 25,000 ppm produced tubular nephropathy. Cecal enlargement, a common result of antibacterial reduction of enteric microbes, was observed.
  7. Evaluation of the Effects of Orally Administered Abbott-56620 on the Embryonic and Fetal Development of the Rat

    1. Report Number: TA84-279
    2. Study Completion: August 12, 1985 (Start: December 6, 1984)
    3. Investigator:

      S. B. Lehrer
      Abbott Laboratories
      Abbott Park, Illinois 60064

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) suspended in 0.2 percent HPMC.
    5. Species and Strain of Animal: Sperm-positive, female, Sprague-Dawley derived CD rats were used.
    6. Number of Animals per Group: 20 animals were allocated to each group.
    7. Levels and Duration of Dosing: Dosing with 0, 20, 75, 275, or 1,000 mg/kg/day of sarafloxacin started on the sixth day of gestation and ended after the fifteenth day of gestation.
    8. Route of Administration: Drug was administered orally by gavage.
    9. Parameters Studied: Potential maternal toxicity, embryo lethality, and teratogenicity were studied.
    10. Toxicities Observed: There were no drug-related, toxicologically meaningful changes in the parameters studied.
    11. No Observable Effect Level (NOEL): 1,000 mg/kg/day
    12. Conclusions: The mean numbers of viable fetuses/dam and implantation sites were comparable for all treatment groups when compared to controls. Fetal body weights and sex ratios were not significantly different from controls.
  8. Three-Generation Reproduction Study of Sarafloxacin (Abbott-56620) Administered Orally in Rats

    1. Report Number: WIL-57007 (TA88-116)
    2. Study Completion: May 7, 1991 (Start: October 5, 1987)
    3. Investigator:

      M. D. Nemec
      WIL Research Laboratories, Inc.
      Ashland, Ohio

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) suspended in 0.2 percent HPMC was used.
    5. Species and Strain of Animal: The drug was administered to three generations of rats, F0, F1, and F2. Each generation was permitted to produce up to two litters.
    6. Number of Animals per Group: Three groups, each consisting of 30 males and 30 females, were used.
    7. Levels and Duration of Dosing: 75, 275, and 1,000 mg/kg/day of sarafloxacin were administered for a minimum of 70 days prior to breeding.
    8. Route of Administration: The drug was administered orally by gavage.
    9. Parameters Studied: Clinical signs, body weight, food consumption, reproductive parameters, organ weight, and gross and microscopic pathology were studied.
    10. Toxicities Observed: There were no toxicologically meaningful changes in the parameters studied. However, lower liver weight was considered an indirect adverse effect related to treatment.
    11. No Observable Effect Level (NOEL): 75 mg/kg/day
    12. Conclusions: Reduced liver weight in rats treated with 275 or 1,000 mg/kg/day was dose-related, especially in females. The effect was considered an indirect adverse effect, caused by the drug (decreased cardiac output and, therefore, liver perfusion). No macroscopic or microscopic lesions of weanlings were attributed to parental treatment with sarafloxacin hydrochloride. Pups showed no adverse treatment-related effects. Litter size, pup survivability, pup weight, sex ratio, and general physical condition were not adversely affected.
  9. Evaluation of Abbott-56620, Lot 66-298-AL in the Rat Primary Hepatocyte Unscheduled DNA Synthesis Assay

    1. Report Number: 20991 (TA84-272)
    2. Study Completion: May 16, 1985 (Start: December 11, 1984)
    3. Investigator:

      M. A. Cifone
      Litton Bionetics, Inc.
      Kensington, Maryland

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) was used.
    5. Species and Strain of Animal: Fischer 344 rats were used.
    6. Number of Animals per Group: NA.
    7. Levels and Duration of Dosing: Hepatocytes were isolated from Fischer 344 rats by collagenase perfusion and, after establishment of primary hepatocyte cultures, the cultures were treated with concentrations of 0, 1, 2.5, 5.0, 10, 25, 50, 100, 250, and 500 µg/mL sarafloxacin for 18 hours. The positive control used in the study was 2-acetyl aminofluorene (0.01 µg/mL).
    8. Route of Administration: NA.
    9. Parameters Studied: During the treatment period the cultures were provided radiolabeled (tritium) thymidine, which, if incorporated into DNA, provides an indication of DNA synthesis activity. At the end of the treatment period the cultures were prepared for autoradiography.
    10. Toxicities Observed: NA.
    11. No Observable Effect Level (NOEL): NA.
    12. Conclusions: Significant increases in unscheduled DNA synthesis were induced at concentrations of 50, 100, and 250 µg/mL; the activity was dose-related. The in vitro UDS assay showed that sarafloxacin is clearly positive in UDS inducing activity. In addition, cytotoxicity defined as reduced cell survival, was apparent at a concentration of 250 µg/mL and was only minimally toxic at 100 µg/mL.
  10. Mutagenicity Test on Abbott-56620 in an In Vitro Cytogenetic Assay Measuring Chromosomal Aberration Frequencies in Chinese Hamster Ovary (CHO) Cells

    1. Report Number: HLA10161-0-437 (TG88-133)
    2. Study Completion: December 12, 1988 (Start: April 26, 1988)
    3. Investigator:

      H. Murli
      Hazleton Laboratories
      Kensington, Maryland

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) was used.
    5. Species and Strain of Animal: Chinese hamsters were used.
    6. Number of Animals per Group: NA.
    7. Levels and Duration of Dosing: Chinese hamster ovary dividing cell cultures were treated with sarafloxacin hydrochloride dissolved in dimethyl sulfoxide at concentrations of 0, 49.8, 99.6, 149, 199, 398, 598, and 797µg/mL for assays without metabolic activation and concentrations of 120, 299, 598, 897, 1,200, and 1,590µg/mL for assays with metabolic activation. The positive control agents used in the assays were mitomycin for nonactivation studies and cyclophosphamide in the metabolic activation assay. Treatment was conducted either with or without an exogenous metabolic activation system provided by a rat liver microsomal preparation.
    8. Route of Administration: NA.
    9. Parameters Studied: Chromosomal aberration frequency was studied.
    10. Toxicities Observed: NA.
    11. No Observable Effect Level (NOEL): NA.
    12. Conclusions: Under the conditions of these assays, sarafloxacin was shown to be reproducibly clastogenic with metabolic activation, but was considered negative for inducing chromosomal aberrations under nonactivated conditions. The positive clastogenic responses were statistically significant and reproducible in the presence of the metabolic supplement.
  11. Evaluation of Abbott-56620, Lot-66-298-AL, in the Forward Mutation Assay [at the HGPRT locus of Chinese Hamster Ovary (CHO) Cells]

    1. Report Number: LB22207 (T84-273)
    2. Study Completion: February 15, 1985 (Start: January 15, 1985)
    3. Investigator:

      R R. Young
      Litton Bionetics, Inc.
      Kensington, Maryland

    4. Substance and Dosage Form: Sarafloxacin HCl (A-56620) was used.
    5. Species and Strain of Animal: Chinese hamsters were used.
    6. Number of Animals per Group: NA.
    7. Levels and Duration of Dosing: Cultures of actively growing Chinese hamster ovary cells were treated with sarafloxacin hydrochloride for four hours either in the presence or absence of rat liver microsomal metabolic activation. The concentrations of sarafloxacin were 0, 50, 100, 200, 400, 600, 800, and 1,000 µg/mL. The positive control used in the absence of metabolic activation was 5-bromo-2-deoxyuridine; the positive control used in the presence of metabolic activation was 3-methylcholanthrene.
    8. Route of Administration: NA.
    9. Parameters Studied: Mutation frequency was studied.
    10. Toxicities Observed: NA.
    11. No Observable Effect Level (NOEL): NA.
    12. Conclusions: In the presence of metabolic activation, a statistically significant increase in the number of mutations was seen at the highest dose tested, with smaller increases (2.4-, 3.6-, and 3.9-fold, relative to the concurrent negative control) at three of the remaining five lower dose levels. Based on these data, the compound is considered a suspect mutagen. The compound was negative without activation.

B. Safe Concentration of Total Residues

  1. No-Observed-Effect Level (NOEL): The safe concentration of total residue was determined from the lowest NOEL in the most sensitive species from the various toxicology studies conducted. A summary of the studies which can be used in determination of the Acceptable Daily Intake (ADI) follows:

    Table 6.1. Summary of ADI Toxicology Studies for Sarafloxacin HCl

    Study TypeSpeciesDoses mg/kg/day*NOEL mg/kg/day*
    90-day oralDog0, 10, 50, 20010
    Chronic Tox & OncogenicityRat0, 54, 586, 154154
    OncogenicityMouse0, 150, 830, 3300150
    Segment II TeratologyRat0, 20, 75, 275, 100075
    Three-generation ReproductionRat0, 75, 275, 100075
    * Doses based on sarafloxacin HCl bulk drug. The above values are uncorrected for 8 to 12% water content in the bulk drug.
    The 90-day oral dog study was selected as the most appropriate study with the lowest NOEL for determining the acceptable daily intake (ADI). The NOEL was 10 mg/kg bw/day sarafloxacin HCl bulk drug, which, when corrected for hydration, was calculated to be 8.75 mg/kg bw/day sarafloxacin HCl.
  2. Calculation of the Acceptable Daily Intake (ADI) and the Safe Concentration (SC) for Sarafloxacin HCl

    1. Acceptable Daily Intake (ADI)

      ADI = NOEL / safety factor = 8.75 mg/kg/day / 1000 = 0.00875 mg/kg/day = 8.75 µg/kg/day

    2. Safe Concentration (SC) The calculation of the safe concentration is based on the General Principles for Evaluating the Safety of Compounds used in Food-Producing Animals

      (FDA, 1986)

      (SC) = Acceptable Daily Intake (ADI) x Human Weight / Food Factor

      Where:

      Human Weight = 60 kg

      Food Factor:

      muscle = 300 g
      fat/skin = 50 g
      liver = 100g

      SC (muscle) = 8.75 µg/kg/day x 60 kg = 1.75 µg/g = 1.75 ppm / 300 g/day

      SC (fat/skin) = 8.75 µg/kg/day x 60 kg = 10.5 µg/g = 10.5 ppm / 50 g/day

      SC (liver) = 8.75 µg/kg/day x 60 kg = 5.25 µg/g = 5.25 ppm / 100 g/day

      Therefore, the safe concentration as total sarafloxacin HCl (ppm) in edible chicken tissue is:

      TissueCalculated Safe Concentration (ppm)
      Muscle1.75
      Fat/Skin10.50
      Liver5.25
  3. Threshold Assessment Sarafloxacin HCl was positive in genotoxicity assays. Sarafloxacin was not carcinogenic in mouse and rat carcinogenicity bioassays.

C. Total Residue Depletion and Metabolism Studies

Investigator:

John W. Byrd, Ph.D.
Southwest Bio-Labs, Inc.
401 N. 17th Street-#11
Las Cruces, New Mexico 88005

Animals Used: 35 male and 33 female 3-day-old broiler chicks.

Each chick received a single subcutaneous dose containing 0.094 mg (14)C-sarafloxacin HCl in 0.2 mL in the dorsal side of the neck.

Table 6.2. Total Residues (ppm) as Sarafloxacin HCl Equivalents in Pooled Edible Tissues (10 male and 9 female broiler chickens) at Various Times Post injection

GroupTermination TimeTissueMales HClFemales HCl
I1 hourLiver2.8173.618
  Breast Muscle**
  Leg Muscle0.6120.570
  Carcass1.1241.404
II14 daysLiver0.0030.001
  Breast Muscle0.0010.001
  Leg Muscle****
  Injection Site***0.0050.004
III21 daysLiver****
  Breast Muscle****
  Leg Muscle****
  Injection Site0.0050.006

* Insufficient material available for analysis
** Values < 0.001
*** Injection site included skin with adhering fat, bone and surrounding connective tissue

Metabolite characterization was carried out in the liver of broilers killed at one hour following administration of (14)C-sarafloxacin HCl. Tissues were extracted and profiled using methods similar to those in the laboratory animals. The quantitation of the radioactivity is presented in Table 6.3.

The data indicate that parent sarafloxacin comprised greater than 75% of the total radioactive residue with three to five smaller peaks each containing less than 5% of the total radioactivity injected. Approximately 10% of the radioactivity was not recovered from the column. Thus, sarafloxacin is only minimally biotransformed in the 3-day-old chicken.

Table 6.3 Quantitation of (14)C-Radioactive Components in Pooled Liver Tissue of Broilers Injected Subcutaneously with 0.094 mg (14)C-Sarafloxacin. (% TRR: Percentage of Total (14)C-radioactive Residue; ppm: µg (14)C-Sarafloxacin Hydrochloride Equivalents/g Tissue)

 MaleFemale
Radioactive Residue Peaks%TRRppm%TRRppm
Sarafloxacin HCl (Peak 4)76.102.1478.502.84
Peak 14.270.122.750.10
Peak 2ND*ND1.730.06
Peak 33.910.114.020.14
Peak 5NDND3.590.13
Peak 64.450.121.950.07
Total Recovery88.702.4992.503.34

*Peak not present

D. Comparative Metabolism

The metabolism of sarafloxacin was studied in the rat, dog, and mouse. Methods for analysis in these studies were similar to those used for the target animal species. Following administration of a 10 mg/kg single oral dose of (14)C-sarafloxacin to rats, radioactivity was excreted in the urine and feces, where it comprised 37 and 52% of the total administered drug, respectively. Of this, the majority was unchanged parent: 99 to 100% of eliminated activity in the urine and feces. Overall, parent drug in the excreta accounted for 86% of the dose. Small amounts of N-acetyl sarafloxacin and a 3'-oxo compound were also identified in the urine and feces. In the dog, a 10 mg/kg dose of (14)C-sarafloxacin was eliminated primarily in the urine (60%) with 31% of the administered radioactivity eliminated in the feces. Of this, 91 and 83% of the radioactivity in the urine and feces, respectively, was parent drug. Thus a total of 79% of the administered dose was eliminated as parent drug in the dog. No other metabolites were identified. In a separate study, 13 and 5% of a 10 mg/kg (14)C-sarafloxacin dose administered intravenously or intraduodenally to dogs, respectively, were collected in the bile within 6 hours of administration. Approximately half of the radioactivity in the bile was unchanged parent, the other half sarafloxacin glucuronide.

Mice were administered a single oral dose of 100 mg/kg (14)C-sarafloxacin. Unchanged parent in the urine comprised 11% of the administered dose, with 5% of the dose in the form of sarafloxacin glucuronide. N-acetyl sarafloxacin was also present as a minor metabolite in the mouse. Sarafloxacin was primarily excreted in the feces, where it comprised 71% of the administered radioactivity. The metabolism of a 100 mg/kg dose in mice was similar to that of a 10 mg/kg dose.

It can be seen that very little primary metabolism takes place in either target animals or laboratory animals treated with sarafloxacin. The predominant transformation of sarafloxacin is conjugation in all species tested. There are no major metabolites in the 3-day-old broiler chick.

E. Withdrawal Time

The total residue data showed that the mean concentrations of total sarafloxacin residues at 14 days after injection were well below the permitted safe concentration in the edible tissues of growing broiler chickens. Husbandry practices for broilers are such that they will only be handled at one day of age for injection with sarafloxacin HCl and not enter the human food chain until 42 or more days of age. Therefore, a withdrawal period will not be required for this use of sarafloxacin HCl in day-old broiler chickens.

F. Regulatory Method

An official regulatory method is unnecessary because a withdrawal period is not required for this use of sarafloxacin HCl in day-old broiler chickens.

G. User Safety Concerns

Sarafloxacin HCl was consistently nontoxic and nonlethal at maximally achievable concentrations following single oral or dermal exposure. Dermal exposure of 2 g/kg was shown to be noncorrosive and nonirritating to rabbit skin. Ocular exposure of 0.1 g in the rabbit eye was non-corrosive and non-irritating. Conjunctival redness completely reversed within 48 hours. Sarafloxacin HCl is not a dermal sensitization agent. In the guinea pig maximization test, the drug produced no evidence of delayed hypersensitivity.

User safety concerns associated with hypersensitivity to quinolones or photosensitization due to accidental inhalation or direct contact have been satisfactorily addressed by establishing label warnings. In addition, a toll-free telephone number will be available on the label to inform users of where they can obtain additional information concerning user safety relative to the MSDS and to report adverse effects.

 

VII. AGENCY CONCLUSIONS

The data submitted in support of this NADA satisfy the requirements of Section 512 of the Federal Food, Drug, and Cosmetic Act and 21 CFR Part 514 of the implementing regulations. The data demonstrate that sarafloxacin hydrochloride (SARAFLOX® INJECTION), a fluoroquinolone antibiotic, when administered as a single subcutaneous injection to day-old broiler chickens, is safe and effective for the control of early chick mortality caused by Escherichia coli. Based on a battery of toxicology tests, the safe concentrations for total residues of sarafloxacin HCl are 1.75 ppm in muscle, 5.25 ppm in liver, and 10.5 ppm in fat/skin. The total residue data showed that the mean concentrations of total sarafloxacin residues at 14 days after injection were well below the permitted safe concentration in the edible tissues of growing broiler chickens. Husbandry practices for broilers are such that they will only be handled at one day of age for injection with sarafloxacin HCl and not enter the human food chain until 42 or more days of age. Therefore, a withdrawal period will not be required for this use of sarafloxacin HCl in day-old broiler chickens. An official regulatory method is not required because the residue and toxicology data support a zero-day withdrawal.

Labeling restricts this drug to use by or on order of a licensed veterinarian. This decision was based on the following factors: (a) the product contains a new antimicrobial entity intended only for therapeutic purposes, (b) adequate directions cannot be written to enable lay persons to appropriately diagnose and subsequently use this product to treat colibacillosis, and (c) the rate of emergence of sarafloxacin-resistant organisms may be reduced by the involvement of veterinarians in product use.

Public health concerns associated with potential increases in antimicrobial resistance have been satisfactorily addressed by establishing conditions of use intended to minimize inappropriate use of this product, and excretion of sarafloxacin and sarafloxacin-resistant zoonotic pathogens into the environment. The sponsor has agreed to participate in a national bacterial resistance surveillance program, and has provided preapproval baseline susceptibility information on potential human pathogens known to contaminate animal carcasses.

The agency has carefully considered the potential environmental effects of this action and has concluded that the action will not have a significant impact on the human environment and that and environmental impact statement is not required. The agency's finding of no significant impact (FONSI) and the evidence supporting that finding are contained in an environmental assessment, which may be seen in the Docket Management Branch (HFV-305), Park Building (Room 1-23), 12420 Parklawn Dr., Rockville, Maryland 20855.

Under section 512(c)(2)(F)(ii) of the Federal Food, Drug, and Cosmetic Act, this approval for food producing animals qualifies for THREE years of marketing exclusivity beginning on the date of approval because the application contains reports of new clinical or field investigations and new human food safety studies essential to the approval of the application and conducted or sponsored by the applicant.

Sarafloxacin hydrochloride is under patent number U.S. 4,730,000 expiring March 18, 2005.

 

VIII. APPROVED PRODUCT LABELING

A copy of the draft facsimile labeling is attached to this document.

  1. SARAFLOX® INJECTION Master Shipper (Case) Label
  2. SARAFLOX® INJECTION Carton Label
  3. SARAFLOX® INJECTION Bottle Label
  4. SARAFLOX® INJECTION Package Insert

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