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    Toxicological evaluation of certain veterinary drug
    residues in food



    WHO FOOD ADDITIVES SERIES 39





    Prepared by:
    The forty-eighth meeting of the Joint FAO/WHO Expert
    Committee on Food Additives (JECFA)



    World Health Organization, Geneva 1997


    DANOFLOXACIN

    First draft prepared by Dr E.A.M. Good
    Veterinary Medicines Directorate
    Addlestone, United Kingdom

    1. Explanation
    2. Biological data
       2.1  Biochemical aspects
            2.1.1  Absorption, distribution, and excretion
            2.1.2  Biotransformation
       2.2  Toxicological studies
            2.2.1  Acute toxicity
            2.2.2  Short-term toxicity
            2.2.3  Long-term toxicity and carcinogenicity
            2.2.4  Genotoxicity
            2.2.5  Reproductive toxicity
                   2.2.5.1  Multigeneration reproductive toxicity
                   2.2.5.2  Developmental toxicity
            2.2.6  Special study on delayed contact hypersensitization
            2.2.7  Special studies on pharmacological activity
            2.2.8  Special studies on microbiological effects
       2.3  Observations in humans
    3. Comments
    4. Evaluation
    5. References

    1.  EXPLANATION

         Danofloxacin is a 'third-generation' fluoroquinolone antibiotic.
    It is manufactured by a stereospecific synthesis, resulting in the
    pure S (laevorotatory) form. Danofloxacin is used in veterinary
    medicine as the mesylate salt for the treatment of respiratory
    diseases in cattle, swine, and chickens.

         All of the studies of toxicity were carried out with the mesylate
    salt of dano-floxacin. The doses are expressed in terms of the active
    moiety, the zwitterion base. Desmethyldanofloxacin, which is the
    primary metabolite of danofloxacin, has similar properties. The
    toxicity and antimicrobial activity of desmethyl-danofloxacin were
    also examined, again using the mesylate salt. The structures of
    danofloxacin and desmethyldanofloxacin are shown in Figure 1.

         Danofloxacin has not previously been reviewed by the Joint
    FAO/WHO Expert Committee on Food Additives.

    FIGURE 1

    2.  BIOLOGICAL DATA

    2.1  Biochemical aspects

    2.1.1  Absorption, distribution, and excretion

         Chickens

         Groups of male 18-day-old broiler chickens were given 
    drinking-water that had been medicated to provide 5 mg/kg bw per day
    danofloxacin, for three days. Steady-state concentrations of 0.43 and
    0.21 g/ml were obtained in lung and plasma, respectively, during the
    period of administration. The half-life of danofloxacin was 4.9 h in
    plasma and 5.8 h in lung. No residues of desmethyldanofloxacin were
    detected in any of the plasma or lung samples (Lynch  et al., 1990a).

         Groups of broiler chickens were given drinking-water that had
    been medicated to provide 5 mg/kg bw per day 3H-danofloxacin for
    five days. The test substance was tritiated in the N1-cyclopropyl
    ring. The study complied with GLP guidelines. Six hours after
    withdrawal of the treated water, unchanged danofloxacin accounted for
    75% of the radiolabel in excreta, and desmethyl-danofloxacin accounted
    for 5-7% (Lynch  et al., 1990a).

         Groups of 12 male and 12 female 22-day-old broiler chickens were
    given drinking-water which had been medicated to provide 5 mg/kg bw
    per day 3H-danofloxacin, for five days. The test substance was
    tritiated in the N1-cyclo-propyl ring and had a specific activity of
    12.1 Ci/mg (expressed as base). Excreta were collected every 24 h and
    pooled by sex and day. The study complied with GLP guidelines. The
    mean level of radiolabel in excreta attained a steady state in the
    range 35-46 g/g by the first day of treatment but declined to 20 and
    6.6 g/g on the first and second days after withdrawal, respectively.
    About 85% of the radiolabel in faeces was identified as unmetabolized
    danofloxacin. There was no difference between the sexes in the pattern
    of excretion (Lynch  et al., 1988).

         Pigs

         Castrated male and female pigs (mean body weight, 40 kg) were
    given single intramuscular injections of 1.25 mg/kg bw of a prototype
    2.5% formulation of danofloxacin. Absorption was rapid, with peak
    concentrations of 0.40 g/g in plasma and 1.68 g/g in lung about 1 h
    after dosing. The half-life of plasma elimination was approximately 
    7 h (Risk  et al., 1991).

         Six castrated male and six female pigs (mean body weight, 43.3
    kg) were given five daily intramuscular injections of 1.25 mg/kg bw of
    danofloxacin tritiated in the N1-cyclopropyl ring in a 2.5% aqueous
    vehicle. The study complied with GLP guidelines. The mean radiolabel
    concentration during the two days before and the day after the last of
    the five doses was 7-8 g/g in pooled faecal homogenates and 14-18
    g/g in pooled urine samples. During this same period, the total daily
    recovery of radiolabel from urine and faeces accounted for 75-81% of
    the daily dose. The mean radiolabel concentration in bile was 1.7 g/g
    12 h after the end of treatment and had declined to 0.21 g/g by 48 h
    (Lynch  et al., 1989b).

         In pigs given a single dose of 5 mg/kg bw of danofloxacin
    intravenously, intramuscularly, or orally, detectable residues of
    danofloxacin appeared rapidly in plasma. A peak plasma concentration
    of 0.42 g/ml was attained about 3 h after oral dosing. The
    bioavailability was estimated to be 76% after intramuscular
    administration and 89% after oral administration (Mann & Frame, 1992).

         Cattle

         A group of 36 male and female calves weighing about 250 kg were
    given a single intramuscular injection of 1.25 mg/kg bw of a 2.5%
    prototype formulation of danofloxacin, and the kinetics of the
    compound were evaluated in plasma and lung tissues. The study complied
    with GLP guidelines. Absorption was rapid, with peak plasma and lung
    concentrations of 0.35 g/ml and 1.44 g/g attained 1 h after dosing.
    The half-time for plasma elimination was 3.4 h (Lynch  et al., 
    1990b).

         In a three-way cross-over design study, 12 male and female beef
    calves (mean body weight, 112 kg) were given single intravenous doses
    or five subcutaneous or intramuscular doses of 1.25 mg/kg bw per day
    of a 2.5% prototype formulation of danofloxacin. The study complied
    with GLP guidelines. Absorption was rapid: peak plasma concentrations
    of 0.37 and 0.47 g/ml were attained about 1 h after single
    subcutaneous and intramuscular doses, respectively, and the
    bioavailability was almost 100%. The values for the area under the
    concentration-time curve indicated that the levels achieved after
    intramuscular and subcutaneous administration were bioequivalent after
    one, three, and five injections (Lynch  et al., 1991a).

         The pattern of excretion of 3H-danofloxacin (tritiated in the 
    N1-cyclopropyl ring) was studied in five castrated male and four
    female calves (body weight, about 180 kg) after five daily
    intramuscular injections of 1.25 mg/kg bw (in a 2.5% aqueous vehicle).
    The study complied with GLP guidelines. The total concentration of
    danofloxacin-related material in excreta reached a plateau by the
    third day of treatment. Approximately equal amounts were excreted in
    urine and faeces. Unchanged danofloxacin accounted for about 48% of
    material excreted in faeces and 89% in urine. The desmethyl metabolite
    accounted for 12% of the material in urine samples, but the
    concentrations in faeces were too low for measurement (Lynch  et al.,
    1989a).

    2.1.2  Biotransformation

         The biotransformation of danofloxacin has been investigated in
    rats, dogs, chickens, pigs, and cattle. In all of these species, the
    main residue in the faeces was unmetabolized danofloxacin; smaller
    amounts of desmethyldanofloxacin were also found (Lynch  et al.,
    1989a,b,c, 1991a,b,c,d). The main residue in the urine of cattle,
    dogs, and rats was also danofloxacin. Desmethyldanofloxacin,
    danofloxacin- N-oxide and the -glucuronide were identified in rat,
    dog, and pig urine (Lynch  et al., 1991d).

         In the livers of most species, danofloxacin was the major
    residue, but significant residues of the metabolite
    desmethyldanofloxacin were also present (Table 1). A piperazine-ring
    degradation product constituted 43 and 27% of the radiolabel in bile
    from male and female cattle, respectively, but it was present in only
    trace amounts in bile from rats and dogs. The bile of dogs contained
    residues of danofloxacin- N-oxide, which was present in only trace
    amounts in bile from the other species (Lynch  et al., 1991d).

    2.2  Toxicological data

    2.2.1  Acute toxicity

         The results of studies of the acute toxicity of danofloxacin and
    desmethyl-danofloxacin are summarized in Table 2. All of the studies
    complied with GLP guidelines.

         In the studies by oral administration, signs of toxicity included
    exophthalmia, decreased activity, tremors, and twitching, which
    occurred within a few minutes of dosing. One of three mice given 
    2000 mg/kg bw died 29 min after dosing. Retching, clonic convulsions,
    and gasping were observed before death. After intravenous dosing, all
    three mice given 100 mg/kg bw and all three rats given 150 mg/kg bw
    died within 3 min. The signs of toxicity were similar to those
    produced after oral administration. Similar signs of toxicity were
    observed after oral and intravenous dosing with desmethyldanofloxacin.


        Table 1. Composition of residues in liver in five species given danofloxacin

                                                                                                                    

    Species     Dose regimen         Sex    Total        Danofloxacina     Desmethyldanofloxacina    Reference
                                            residue
                                                                                                                    

    Rat         5  6.25 mg/kg bw    M      2.3 ppm           67%                   18%              Lynch et al.
                per day orally       F      2.5 ppm           70%                   11%              (1991d)
    Dog         5  2.4 mg/kg bw     M      6.7 ppm           66%                   28%              Lynch et al.
                per day orally       F      5.4 ppm           58%                   37%              (1991d)
    Chicken     5  5 mg/kg bw       M      NR                78%                   16%              Lynch et al.
                per day orally       F      NR                74%                   12%              (1988)
    Pig                              M      0.95 ppm          58%                   23%              Lynch et al.
                                     F      0.96 ppm          68%                   29%              (1989c)
    Cowb        5  1.25 mg/kg bw    M      0.82 ppm          24%                   43%              Lynch et al.
                intramuscularly      F      1.1 ppm           29%                   42%              (1991d)
                                                                                                                    

    a Relative to the radiolabel recovered by high-performance liquid chromatography
    b Killed 12 h after the last dose

    Table 2. Results of studies of the acute toxicity of danofloxacin and desmethyldanofloxacin

                                                                                                              

    Species            Route           Vehicle             Sex       LD50          Reference
    (strain)                                                         (mg/kg bw)
                                                                                                              

    Danofloxacin

    Rat (Sprague-      Oral            Distilled           M & F     > 2000        Stadnicki et al. (1988a)
    Dawley)                            water
    Mouse (ICR)        Oral            Distilled water     M & F     > 2000        Stadnicki et al. (1988a)
    Rat (Sprague-      Intravenous     Sterile water       M         100-150       Stadnicki et al. (1988a)
    Dawley)
    Mouse (ICR)        Intravenous     Sterile water       M         50-100        Stadnicki et al. (1988a)
    Rabbit (New        Dermal                              M & F     > 299a        Stadnicki et al. (1988b)
    Zealand white)

    Desmethyldanofloxacin

    Rat (Sprague-      Oral            Deionized           M & F     > 2000        Stadnicki et al. (1989)
    Dawley)                            water
    Mouse (ICR)        Oral            Deionized           M         > 2000        Stadnicki et al. (1989)
                                       water
    Mouse (ICR)        Oral            Deionized           F         1500-2000     Stadnicki et al. (1989)
                                       water
    Rat (Sprague-      Intravenous     Sterile water       M         40-50         Stadnicki et al. (1989)
    Dawley)
    Mouse (ICR)        Intravenous     Sterile water       M         7.5-10        Stadnicki et al. (1989)
                                                                                                              

    a 0.5 g danofloxacin was applied to one site on intact skin and one on abraded skin of two male and one 
      female New Zealand white rabbits under an occlusive dressing for 24 h. There were no deaths or signs 
      of toxicity, except for mild erythema at all treated sites.
    
         A dose of 26 mg danofloxacin (in a volume of 0.1 ml) was
    instilled into the conjunctival sac of the left eyes of three New
    Zealand white rabbits. The eyes were not rinsed after dosing. Mild
    conjunctivitis and a colourless discharge were observed within 1 h of
    treatment. All signs had cleared within 96 h (Stadnicki  et al., 
    1988b).

    2.2.2  Short-term toxicity

         Mice

         In a study designed to identify suitable doses for a two-year
    feeding study, groups of 15 male and 15 female Crl:CD-1 (ICR)BR
    VAF/Plus mice were fed diets calculated to provide 0, 150, 300, or 600
    mg/kg bw per day of danofloxacin (74% activity) for up to 102 days.
    The study complied with GLP guidelines. One female given the high dose
    was killed in a moribund condition. Body-weight gain was reduced in
    males at the low and high doses in comparison with that of the
    controls. Decreased erythrocytic parameters were seen occasionally in
    males and females at the high dose. There were no consistent 
    dose-related changes in clinical chemistry. At termination, the
    absolute mean group weight of the kidneys of females receiving the
    high dose was significantly increased, but there were no corresponding
    pathological changes. Microscopic examination revealed caecal
    dilatation in six mice at the low dose, 23 at the intermediate dose,
    and 27 at the high dose, but not in the controls. Inflammation of the
    caecum was seen in two mice at the high dose, and Gram-positive
    bacteria, tentatively identified as  Clostridium difficile, were
    found in the inflamed caeca of both animals. Thymic lymphocytosis was
    seen in one of 15 females at the low dose, two of 15 at the
    intermediate dose, and eight of 15 at the high dose and in three of 13
    males at the intermediate dose and  six of 14 at the high dose but in
    no control. A NOEL was not identified (Stadnicki  et al., 1994a).

         Rats

         A two-week exploratory study was carried out in which groups of
    three male and three female Long-Evans rats received oral doses of 0,
    25, 50, or 100 mg/kg bw per day of danofloxacin in an aqueous vehicle.
    There were no significant effects on body-weight gain, food
    consumption, haematological, clinical chemical, or urinary parameters,
    or organ weights. At necropsy, treatment-related caecal enlargement
    was observed in treated animals (Reynolds  et al., 1987a).

         Groups of 10 male and 10 female Long-Evans rats were given doses
    of 0, 25, 75, or 150 mg/kg bw per day danofloxacin by gavage in an
    aqueous vehicle for one month. Serum chemistry and haematology were
    evaluated before treatment and on days 11-12 and 30-31. The study
    complied with GLP guidelines. There were no signs of toxicity and no
    effects on body-weight gain or food consumption. Alanine
    aminotrasferase levels were significantly increased in treated females
    receiving the high dose, and absolute liver and liver:body weight
    ratios were significantly decreased in males at this dose. No

    substance-related effects were seen in about 30 tissues from animals
    at 0 and 150 mg/kg bw and macroscopic lesions from animals in the
    other groups examined microscopically (Fisher  et al., 1988a).

         In a range-finding study designed to identify suitable doses for
    a long-term study of toxicity, groups of 10 male and 10 female Fischer
    rats were fed diets calculated to provide 0, 150, 300, 450, or 600
    mg/kg bw per day of danofloxacin for 36-39 days. Satellite groups of
    three animals of each sex were used to monitor plasma concentrations
    of the drug. Five rats given 600 mg/kg bw per day died. Body-weight
    gain and food consumption were reduced in all treated groups, and
    there was an initial dose-related decrease in food consumption.
    Changes were seen in serum chemistry, haematological parameters and
    organ weights, due to the effects of starvation and dehydration.
    Caecal dilatation was observed in all treated animals (Stadnicki 
     et al., 1994b).

         In a subsequent exploratory study in groups of 10 Long-Evans rats
    of each sex, doses intended to provide 0, 75, 150, or 300 mg/kg bw per
    day of danofloxacin were administered in the feed for seven days; the
    animals then received untreated feed for seven days and the treated
    feed for a further 12 days. Body-weight gain and food consumption were
    reduced in rats at the intermediate and high doses. Serum globulin
    levels were reduced and leukopenia was observed in all treated groups.
    Crystalluria was seen in most treated rats but in only two of 20
    controls. There was no histopathological evidence of nephropathy
    (Stadnicki  et al., 1994c).

         In a study designed to establish doses to be used in a two-year
    feeding study, groups of 15 Long-Evans rats of each sex were fed diets
    calculated to provide 0, 75, 150, or 300 mg/kg bw per day of
    danofloxacin for about three months. The study complied with GLP
    guidelines. Alopecia was seen in four females at the high dose and one
    at the intermediate dose. Discoloured urine (especially in animals at
    75 mg/kg bw) and crystalluria were observed in all treated groups, but
    there were no corresponding pathological changes in the kidneys. 
    Body-weight gain was significantly reduced in a dose-related manner.
    There were significant, dose-related increases in urinary and serum
    magnesium concentrations, which were attributed to chelation of
    magnesium ions by the test substance. Caecal dilatation was observed
    in rats at 150 and 300 mg/kg bw. A range of degenerative changes were
    observed in the testes of all males at the high dose and in one at 0,
    one at 75, and one at 150 mg/kg bw per day. Degenerating germinal
    cells were found in the epididymides of all males at the high dose and
    nine at the middle dose (Stadnicki  et al., 1994d).

         Groups of 20 male and 20 female weanling Long-Evans rats were
    selected from the F1 offspring of rats used in a multigeneration
    study which had been exposed to danofloxacin both  in utero and
    during lactation. They were then given oral doses of 25, 75, or 150
    mg/kg bw per day for up to three months, whereas 20 controls of each
    sex received deionized water. The study was conducted in accordance
    with US FDA GLP guidelines (21 CFR Part 58).

         There were no substance-related deaths and no adverse effects on
    food consumption or body-weight gain. There were no consistent 
    dose-related trends in haematological or clinical chemical values. A
    dose-related increase in proteinuria was seen in females but not
    males, which was correlated with the finding of tubular nephropathy in
    individual animals. Kidney weights were unaffected by treatment. The
    mean absolute and relative weights of the testes of rats at 75 and 150
    mg/kg bw were about 10% lower than those of controls. Lesions of the
    heart were found primarily in animals at these doses and consisted of
    either multifocal myocardial degeneration and necrosis, or multifocal
    fibrosis, or both. There was no NOEL, as renal tubular nephropathy was
    observed in all treated females (Fisher  et al., 1989a).

         The study was repeated at lower doses in order to establish a
    NOEL. Groups of 20 male and 20 female weanling Long-Evans rats were
    again selected from the F1 offspring in the multigeneration study,
    which had been exposed to danofloxacin both  in utero and during
    lactation. They were then given oral doses of 1, 2.5, or 6.25 mg/kg bw
    per day for up to three months. Twenty controls of each sex were given
    deionized water. The study was conducted in accordance with US FDA GLP
    guidelines (21 CFR Part 58).

         There were no treatment-related deaths or signs of toxicity. 
    Body-weight gain, food consumption, and haematological and clinical
    chemical parameters were unaffected by treatment. Urinalysis revealed
    a marginal increase in the incidence of haematuria in males given the
    high dose and of proteinuria in a single female at this dose. The
    absence of any corresponding pathological changes in the kidney
    indicates that the findings reflected biological variability rather
    than a substance-related effect. The NOEL was 6.25 mg/kg bw per day
    (Fisher  et al., 1990a).

         Groups of 20 male and 20 female Long-Evans rats were given oral
    doses of 1, 2.5, or 6.25 mg/kg bw per day of desmethyldanofloxacin for
    up to three months. The rats were selected from the F1 offspring in
    a multigeneration study and had been exposed to the test substance
    both  in utero and during lactation. Groups of 20 controls of each
    sex received deionized water. The study was conducted in accordance
    with US FDA GLP guidelines (21 CFR Part 58). There were no effects on
    mortality, body-weight gain, food consumption, haematological or
    clinical chemical parameters, organ weights, or gross or 
    histo-pathological findings. The NOEL was 6.25 mg/kg bw per day
    (Stadnicki  et al., 1990a).

         Rabbits

         In an exploratory study, groups of three female New Zealand white
    rabbits were given oral doses of 0, 25, 50, or 100 mg/kg bw per day of
    danofloxacin in an aqueous vehicle. Owing to significantly reduced
    feed intake and decreased body weight, treatment of rabbits at the low
    dose was stopped after 12 doses, that of animals at the intermediate
    dose after seven doses, and that of rabbits at the high dose after
    four doses. The groups were fed untreated diet for a further five to

    eight days, then killed and necropsied. Pathological examination
    revealed a dose-related incidence of enlarged caeca (Lundeen  et al.,
    1993).

         Dogs

         In an exploratory study, groups of one male and one female beagle
    dogs were given oral doses of 0, 12.5, 25, or 50 mg/kg bw per day of
    danofloxacin in gelatin capsules for two weeks. The female at the high
    dose had reduced body-weight gain and food consumption and increased
    serum blood urea nitrogen and creatinine levels. At necropsy, this dog
    had acute segmental nephrosis and renal failure. The male at the high
    dose had chronic focal necrosis without renal failure (Reynolds 
     et al., 1987b).

         In a one-month exploratory study, groups of three male and three
    female beagle dogs (10-12 months old) were given oral doses of 0, 5,
    10, or 25 mg/kg bw per day of danofloxacin in gelatin capsules. The
    study was conducted in accordance with US FDA GLP guidelines (21 CFR
    Part 58). There were no effects on behaviour, food consumption, 
    body-weight gain, blood pressure, electrocardiographic profile, or
    ophthalmic, serum chemical, or haematological parameters. At necropsy,
    a full range of tissues from all animals was examined, with particular
    attention to the weight-bearing joints. Shallow erosions were found in
    all dogs, including controls, although the grade of erosions was
    slightly higher in those at the high dose. The lesions were typical of
    those found in older dogs and did not resemble quinolone-induced
    lesions (Fisher  et al., 1988b).

         Groups of four beagle dogs of each sex aged about six months were
    given oral doses of 0, 5, 10, or 25 mg/kg bw of danofloxacin in
    gelatin capsules. The substance was administered as two equally
    divided doses per day for three months. At termination, all dogs were
    subjected to a complete pathological examination. The study was
    conducted in accordance with US FDA GLP guidelines (21 CFR Part 58).
    By day 7, reduced activity and signs of joint pain were seen in all
    eight dogs given 25 mg/kg bw and in three dogs given 10 mg/kg bw. Most
    of the affected animals showed signs of recovery by week 6, despite
    continued treatment. Body-weight gain, food consumption, heart rate,
    and respiratory rate were decreased in animals that showed clinical
    signs. There were no effects on electrocardiographic profiles, blood
    pressure, or ophthalmic, haematological, clinical chemical, or urinary
    parameters. Gross pathological changes were observed in the articular
    cartilage of the major joints of all treated animals, except for one
    female receiving the low dose. The lesions were characterized by areas
    of cartilage separation and cartilage loss (erosions). The severity of
    the lesions was dose-related. Microscopic examination revealed further
    changes, including the apparent alteration of collagen fibres when
    viewed with polarized light (Fisher  et al., 1989b).

         A second three-month study, which complied with the same GLP
    guidelines, was carried out at lower doses in order to establish a
    NOEL. Groups of four male and four female beagle dogs, aged about five
    months, were given oral doses of 0, 1, or 2.4 mg/kg bw per day of
    danofloxacin in gelatin capsules as two equally divided doses, for 91
    days. There were no signs of toxicity and no effects on body-weight
    gain, food consumption, clinical chemical or urinary parameters, or
    organ weights. There were no substance-related pathological findings.
    The NOEL was 2.4 mg/kg bw per day (Fisher  et al., 1989c).

         Groups of three male and three female beagle dogs, four to six
    months old, were given oral doses of 0, 2.5, 5, or 10 mg/kg bw per day
    desmethyldanofloxacin in gelatin capsules, administered as two equally
    divided doses, for about three months The study was conducted in
    accordance with US FDA GLP guidelines (21 CFR Part 58). There were no
    notable effects on body-weight gain, electrocardio-graphic profiles,
    serum chemical or haematological values, or organ weights. One male
    given the high dose showed signs of pain on day 65 when pressure was
    applied to the left ankle joint. One female at the low dose showed
    signs of pain on day 92 when pressure was applied to the inside of the
    left upper hind limb. At termination, histopathological changes
    typical of quinolone-induced lesions were found in the articular
    cartilage of the right femoral condyle of one male given the high dose
    (Stadnicki  et al., 1990b).

         Groups of three male and three female beagle dogs, five to six
    months old, were given oral doses of 0, 0.25 or 0.5 mg/kg bw per day
    of desmethyldanofloxacin in gelatin capsules, as two equally divided
    doses, for about three months. Further groups of dogs were given 10
    mg/kg bw per day of danofloxacin. The study was conducted in
    accordance with US FDA GLP guidelines (21 CFR Part 58).

         There were no signs of toxicity in the dogs treated with
    desmethyldano-floxacin. The dogs given danofloxacin showed signs of
    hind limb weakness, reduced activity, and stiff gait. Treatment had no
    effect on electrocardiographic profiles, serum chemical or
    haematological parameters, or organ weights. Pathological examination
    revealed typical quinolone-induced arthropathy in all dogs treated
    with danofloxacin. One male in the group given 0.5 mg/kg bw per day
    desmethyldano-floxacin was found to have a single articular erosion in
    the patellar groove of the right knee. Microscopically, the erosion
    extended into zone 2 of the articular cartilage and resembled those
    seen with other quinolones. The NOEL was 0.25 mg/kg bw per day
    (Stadnicki  et al., 1990c).

    2.2.3  Long-term toxicity and carcinogenicity

         Mice

         Groups of 50 ICR mice of each sex were fed diets containing the
    equivalent of 10, 50, or 100 mg/kg bw per day of danofloxacin for up
    to two years. Two groups of 50 controls of each sex were fed untreated
    diets. The study complied with GLP guidelines. There were no adverse

    dose-related effects on mortality rate, body weight, food consumption,
    or haematological parameters. Females receiving 100 mg/kg bw per day
    gained significantly more weight than animals in the other groups. At
    termination, less than 50% of the animals in each group, except for
    the males receiving 10 mg/kg bw per day, were still alive. The mean
    absolute kidney weight (but not the relative kidney:body weight) was
    significantly increased in females receiving 100 mg/kg bw per day,
    which probably reflected the increased body weight of these mice.
    There was no evidence of carcinogenicity (Takatsu  et al., 1995).

         Rats

         Groups of 50 male and 50 female Long-Evans rats were fed diets
    containing the equivalent of 10, 50, or 100 mg/kg bw per day of
    danofloxacin for up to two years. Two groups of 50 controls of each
    sex were fed untreated diets. The study complied with GLP guidelines.

         There were no clinical signs of toxicity, and survival was
    unaffected by treatment. At termination, however, less than 50% of
    animals in all groups were alive, except for females receiving 100
    mg/kg bw per day and one of the groups of female controls. Occasional
    statistically significant reductions in body-weight gain were seen in
    males at this dose, and females at 50 and 100 mg/kg bw per day had
    significantly increased body-weight gain between three and 16 months
    of treatment, which was correlated with increased food intake during
    this period. Overall, the body-weight changes associated with
    treatment were minimal. Ophthalmoscopic examinations during weeks 12,
    18, and 23 revealed no differences between control rats and those
    receiving 100 mg/kg bw per day. At termination, the mean leukocyte and
    neutrophil counts were significantly reduced in males receiving 100
    mg/kg bw per day; in females at this dose, the mean haemoglobin,
    haematocrit, and lymphocyte counts were reduced. Males also had
    significant increases in aspartate aminotrans-ferase and sorbitol
    dehydrogenase values, and the mean globulin value was reduced, with a
    corresponding increase in albumin:globulin ratio. The sorbitol
    dehydrogenase level was also increased in males receiving 50 mg/kg bw
    per day. The effects on clinical chemical values were not seen in
    females. There were no substance-related effects on urinary values.
    The mean testis:body weight ratio was significantly reduced in the
    group receiving 100 mg/kg bw per day. There were no significant
    effects on absolute organ weights. Gross pathological examination
    revealed an increased incidence of caecal enlargement in treated
    animals which was not correlated with any microscopic findings. (Table
    3). The histopathological findings included an increased incidence of
    renal papillary oedema, increased oligospermia, and abnormal content
    of the epididymides in rats at 100 mg/kg bw per day (Table 4).


    Table 3. Incidence of caecal enlargement in rats treated with
    danofloxacin in the diet for up to two years

                                                                    

    Sex            Dose (mg/kg       No. with caecal enlargement/
                   bw per day)       no. examined
                                                                    

    Male                0                      0/50
                        0                      0/50
                       10                      5/50
                       50                      3/50
                      100                      6/50
    Female              0                      1/50
                        0                      0/50
                       10                      1/50
                       50                      1/50
                      100                      2/50
                                                                    


        Table 4. Incidence of some non-neoplastic histopathological alterations in groups of 
             50 rats fed diets containing danofloxacin for up to two years

                                                                                              

    Sex          Dose (mg/kg     No. with papillary    No. with        No. with abnormal
                 bw per day)     oedema                oligospermia    epidydimal content
                                                                                              

    Male              0                 1                  17               25
                      0                 0                  16               32
                     10                 0                  18               28
                     50                 1                  17               29
                    100                 4                  31               36
    Female            0                 0
                      0                 2
                     10                 2
                     50                 2
                    100                 4
                                                                                              
    
         There was a significant positive trend in the incidence of
    granular-cell tumours of the uterus and vagina in treated female rats
    (Table 5); however, the trend was not significant when corrected for
    multiple comparisons. Granular-cell foci were distinguished from
    tumours by their smaller size and the absence of compressed adjacent
    tissue; nevertheless, the morphology of these lesions was essentially
    the same. When the incidences of uterine and vaginal foci and tumours
    were combined, there was no statistically significant trend in the
    combined incidence across groups. There was a significant positive
    trend in the incidence of pituitary adenomas in female rats (Table 6),
    which was not significant when corrected for multiple comparisons. In
    addition, the incidence of pituitary adenomas was within the range
    seen in controls in the five previous studies at the same laboratory:
    30/48 to 47/49 (Fisher  et al., 1996).

    2.2.4  Genotoxicity

         The results of assays for genotoxicity with danofloxacin and
    desmethyl-danofloxacin are summarized in Table 7. All of the studies
    complied with GLP guidelines.

    2.2.5  Reproductive toxicity

    2.2.5.1  Multigeneration reproductive toxicity

         Rats

         In a two-generation study of reproductive toxicity, groups of 45
    male and 45 female Long-Evans rats were given oral doses of 0, 25, 75,
    or 150 mg/kg bw per day of danofloxacin in an aqueous vehicle. The
    study was conducted in accordance with US FDA GLP guidelines (21 CFR
    Part 58). Dams at 150 mg/kg bw per day showed reduced body-weight gain
    during gestation and fewer implantation sites and produced fewer live
    pups than those at other doses. The pup weights were significantly
    reduced at birth and during lactation. Similar effects were observed
    at the first F1 mating, which were more pronounced at the second
    F1 mating, when the pregnancy rate was adversely affected in all
    treated groups. The weights of all treated F2b pups were reduced in
    a dose-related manner (Fisher  et al., 1990b).

         The F2b pups at 25 mg/kg bw per day were used in a new study
    (complying with similar GLP guidelines) when they were two months old,
    and treatment was continued. After mating to produce the F3
    generation, the pregnancy rate was only 38%, whereas that in the
    control group was 65%. Post-implantation losses were significantly
    increased and pup body weights and survival were adversely affected
    (Fisher  et al., 1990c).

    Table 5. Incidences of granular-cell proliferative lesions of the uterus 
    and vagina in female rats fed diets containing danofloxacin for up to 
    two years

                                                                          

    Lesion                              Dose (mg/kg bw per day)
                                                                          
                                0        0        10        50       100
                                                                          

    Uterus
    No. examined               48       50        50        50        50
    Granular-cell tumour        1        3         6         5         6
    Granular-cell foci          5        6         1         1         2

    Vagina                     48       49        49        49        49
    Granular-cell tumour        3        2         2         3         7
    Granular-cemm foci          0        0         1         0         0

    Uterus plus vagina
    Granular-cell tumour        4        5         8         8        13
    Granular-cell foci5         5        6         2         1         2
    Total                       9       11        10         9        15
                                                                          


        Table 6. Incidence of proliferative lesions of the pituitary gland in
    female rats fed diets containing danofloxacin for up to two years

                                                                                         

    Lesion                                         Dose  (mg/kg bw per day)
                                                                                         
                                          0         0         10        50        100
                                                                                         

    No. examined                          49        50        50        50        50
    No. with pituitary adenoma            32        32        39        39        40
    No. with pituitary hyperplasia        13        11         5         6         5
    No. of rats alive at 24 months        22        26        19        18        26
                                                                                         
    

        Table 7. Assays for genotoxicity with danofloxacin and desmethyldanofloxacin

                                                                                                             

    End-point          Test object             Concentration          S9     Results       Reference
                                                                                                             

    Danofloxacin
    In vitro
    Gene mutationa     S. typhimurium          0.01-0.2 g/platea     -      Negative      Amacher et al.
                       TA98, TA100,            0.001-0.1 g/plate     +      Negative      (1988)
                       TA1535, TA1537          0.0005-0.2 g/plate    +      Negative
    Gene mutation      L5178Y/tk+/- mouse      51-287 g/ml           -      Negative      Amacher et al.
                       lymphoma cellsc         16-215 g/ml           +      Negative      (1988)
    Gene mutation      hprt, Chinese           141-1070 g/ml         -      Negative      Guzzie et al.
                       hamster ovary           465-2500 g/ml         +      Negative      (1992)
                       cellsc
    Unscheduled        Primary rat             50-400 g/ml                  Negative      Amacher et al.
       DNA synthesis   hepatocytesc                                                        (1988)
    Cytogenetic        Human lymphocytes       25-70 g/ml            -      Positived     Amacher et al.
       alterations                             200-600 g/ml          +      Positive      (1990)

    In vivo
    Micronucleus       ICR mouse bone          1000 mg/kg bw                 Negative      Amacher et al.
       formation       marrow                  orally                                      (1990)

    Desmethyldanofloxacin
    In vitro
    Gene mutation      S. typhimurium          0.001-0.5 g/plate     +      Negative      Amacher et al.
                       TA98, TA100,            0.01-5 g/plate        -      Negative      (1991a)
                       TA1535, TA1537
    Gene mutation      L5178Y mouse            90-388 g/ml           -      Negative      Holden et al.
                       lymphoma cells          63-269 g/ml           +e     Negative      (1988)
    Unscheduled        Primary rat             2.54-102 g/ml and            Positive      Hazleton
       DNA synthesis   hepatocytes             5.02-100 g/ml                Positive      Laboratories
                                                                                           America Inc.
                                                                                           (1991a)
    Unscheduled        Primary rat             62.5-250 g/ml                Positive      Amacher et al.
       DNA synthesis   hepatocytes             62.5-500 g/mlf               Positive      (1991b)
                                                                                                             

    Table 7. (continued)

                                                                                                             

    End-point          Test object             Concentration          S9     Results       Reference
                                                                                                             

    In vivo
    Unscheduled        Fischer 344 rat         1  250-2000  mg/kg           Negative      Hazleton
       DNA synthesis   hepatocytes             bw per day  orally                          Laboratories
                                                                                           America Inc.
                                                                                           (1991b)
    Micronucleus       CD-1 mouse bone         3  250-1000                  Negative      Amacher et al.
       formation       marrow and peripheral   mg/kg bw per day                            (1991c)
                       blood                   orally
                                                                                                             

    S9, 9000  g fraction of rat liver
    a   The same bacterial strains were incubated with urine collected from mice given danofloxacin 
        intraperitoneally at 5, 50, or 100 mg/kg bw per day, with no mutagenic response.
    b   Higher concentrations toxic to tester strains
    c   Not replicated independently
    d   Significant increase in abnormal cells (chromatid breaks). To check whether the clastogenicity 
        was due to chelation, the assay was repeated without S9 but with the addition of 400 g/ml 
        magnesium sulfate; no increase in abnormal cells was observed. In the presence of S9, extra 
        washes to remove the test substance and the addition of magnesium sulfate diminished the 
        clastogenic response.
    e   From livers of uninduced rodents
    f   1.62 mmol/litre magnesium ions (as magnesium sulfate heptahydrate) added to culture medium did 
        not prevent a similar dose-related increase in unscheduled DNA synthesis.
    

         In a three-generation study of reproductive toxicity, groups of
    30 male and 30 female Long-Evans rats were given oral doses of 1, 2.5,
    6.25, or 150 mg/kg bw per day of danofloxacin. Two control groups
    received the deionized water vehicle. Treatment was begun nine weeks
    before cohabitation for males and two weeks previously for females
    (1:1 mating) and was continued throughout gestation, parturition, and
    weaning of the F1 offspring. Of these, groups of 25 of each sex were
    selected randomly, and treatment was continued during breeding of the
    F2a and F2b generations. The F2b offspring were mated in the
    same way to produce the F3 litters. Litters were culled to eight
    pups on day 4 post partum. Postnatal development of the F2b pups was
    assessed at weaning by measuring locomotor activity, auditory
    function, and ophthalmic parameters. All F0, F1, and F2 rats used
    for breeding were necropsied and the reproductive organs and main
    target organs (kidney, joints, brain, heart, and liver) were weighed
    and preserved for possible microscopic examination. The study was
    conducted in accordance with US FDA GLP guidelines (21 CFR Part 58).

         Adult animals showed no treatment-related effects on survival,
    body-weight gain, food consumption, or clinical signs. In those at 150
    mg/kg bw per day, copulatory rate and pregnancy rate were reduced and
    the length of gestation was increased. (The copulatory rate was
    defined as the percentage of those females which cohabited that had a
    vaginal flush with sperm, or an internal copulatory plug, or which
    delivered with no previous signs of mating.) Administration of 150
    mg/kg bw per day also resulted in reduced litter size and pup weight
    at birth, reduced weight gain of the neonates, and a reduction in the
    number of pups surviving to day 4 post partum. The group receiving 150
    mg/kg bw per day was terminated before the second F1 mating. The
    NOEL was 6.25 mg/kg bw per day (Stadnicki  et al., 1990d).

         In a study of exactly the same design as that described above,
    the animals received desmethyldanofloxacin instead of danofloxacin.
    There were no treatment-related effects on parental body-weight gain
    or food consumption, clinical signs, pregnancy rate, length of
    gestation, number of implantation sites, or post-implantation loss.
    Pup body-weight gain and survival were unaffected by treatment. There
    were no grossly observed abnormalities in the dams or sires (Stadnicki
     et al., 1991).

    2.2.5.2  Developmental toxicity

         Mice

         In a preliminary range-finding study, oral doses of 0, 50, 100,
    or 200 mg/kg bw per day of danofloxacin were given in an aqueous
    vehicle to groups of seven mated female ICR mice on days 6-13 of
    gestation. The study complied with GLP guidelines. The mean weights of
    the male fetuses of animals at 200 mg/kg bw per day were reduced. No
    effects were seen on dams (Kessedjian  et al., 1988a).

         In the main study, groups of 20 female Crl:COBS-CDI(ICR)BR mice
    presumed to be pregnant were given oral doses of 0, 50, 100, or 200
    mg/kg bw per day of danofloxacin in an aqueous vehicle. The dams were
    treated on days 6-13 of gestation and were killed on gestation day 18.
    A further group of 10 dams was given 200 mg/kg bw per day and used to
    monitor drug concentrations in maternal plasma and amniotic fluid. The
    study complied with GLP guidelines.

         The concentrations of danofloxacin in the amniotic fluid 5 h
    after the last of eight consecutive doses of 200 mg/kg bw per day were
    similar to those in maternal plasma, while those in fetal homogenates
    were two to three time those in maternal plasma. The incidence of 
    non-gravid females was high: the total numbers of pregnant females
    were only 13, 16, 11, and 13 in the control, low, intermediate, and
    high dose groups, respectively. One dam given 200 mg/kg bw per day
    showed piloerection and prostration on days 7-10 of gestation and was
    found to have a cutaneous abscess at necropsy. The mean body-weight
    gain of the dams at the high dose was significantly reduced during
    treatment. There were no meaningful effects on the incidences of
    resorptions or fetal deaths or on the sex ratio. The mean weights of
    both male and female fetuses were significantly reduced at the high
    dose, and the incidence of delayed ossification was increased. There
    was no evidence of teratogenicity. The NOEL was 100 mg/kg bw per day,
    on the basis of maternal and fetal toxicity (Kesseddjian  et al., 
    1989a).

         Rats

         In a preliminary range-finding study, oral doses of 0, 50, 100,
    or 200 mg/kg bw per day of danofloxacin were administered in an
    aqueous vehicle to groups of seven mated female Sprague-Dawley rats on
    days 6-15 of gestation. The study complied with GLP guidelines.
    Maternal body-weight gain was reduced in all treated groups, and the
    mean number of viable fetuses was reduced at 200 mg/kg bw per day
    (Kessedjian  et al., 1988b).

         In the main study, groups of 20 female Sprague-Dawley rats
    presumed to be pregnant were given oral doses of 0, 50, 100, or 200
    mg/kg bw per day of danofloxacin in an aqueous vehicle; 19-20 dams in
    each group were subsequently confirmed to be pregnant. The animals
    were treated on days 6-15 of gestation and were killed on gestation
    day 20. A further group of five dams was given 200 mg/kg bw per day
    and used to monitor drug concentrations in maternal plasma and
    amniotic fluid. The study complied with GLP guidelines.

         The concentrations of danofloxacin in the amniotic fluid 5 h
    after the last of eight consecutive doses of 200 mg/kg bw per day were
    similar to those in maternal plasma, while those in fetal homogenates
    were about three time those in maternal plasma. There were significant
    dose-related reductions in maternal body-weight gain in the rats at
    100 and 200 mg/kg bw per day, and mean fetal weights were also
    significantly reduced. The incidences of delayed ossification and
    dilatation of the cerebral ventricles in the fetuses were

    significantly increased at the intermediate and high doses. The NOEL
    was 50 mg/kg bw per day, on the basis of maternal and fetal toxicity
    (Kesseddjian  et al., 1989b).

         Rabbits

         In a preliminary range-finding study, groups of 11 New Zealand
    white rabbits presumed to be pregnant were given oral doses of 0, 5,
    10, or 20 mg/kg bw per day of danofloxacin on days 6-20 of gestation.
    The study complied with GLP guidelines. Inappetance was seen in all
    groups, but maternal body weight was not affected. Animals at the high
    dose had a decreased number of live fetuses and higher resorption
    rates. The mean fetal weights were reduced at the intermediate and
    high doses (Tassinari  et al., 1995a).

         In the main study, groups of 20 female New Zealand white rabbits
    presumed to be pregnant were given oral doses of 0, 2.5, 7.5, or 15
    mg/kg bw per day of danofloxacin in an aqueous vehicle. The dams were
    treated on days 6-20 of gestation and were killed on gestation day 28.
    Because of a high incidence of non-gravid females, new animals were
    randomized to the different doses so that the total numbers were 32
    controls, 29 at the low dose, 33 at the intermediate dose, and 39 at
    the high dose. The study complied with GLP guidelines.

         Eleven does at the high dose showed loss of body weight and
    reduced food consumption and then aborted their litters between days
    22 and 28 of gestation. The mean food consumption of the does with
    viable litters at 15 mg/kg bw per day was significantly reduced during
    days gestation days 13-20. There were no treament-related effects on
    litter size, sex ratio, fetal weight, or the incidences of
    malformations or variations. The NOEL was 7.5 mg/kg bw per day, on the
    basis of maternal toxicity (Tassinari  et al., 1995b).

    2.2.6  Special study on delayed contact hypersensitization

         In a study using the Buehler closed patch technique, which
    complied with GLP guidelines, danofloxacin mesylate did not cause
    delayed contact hypersensitivity in the guinea-pig. A clear positive
    result was obtained with the known sensitizer, dinitrochlorobenzene
    (Beutler  et al., 1992).

    2.2.7  Special studies on pharmacological activity

         A number of pharmacological studies of danofloxacin were
    available that were not carried out in accordance with GLP guidelines
    or with any national or international guidelines. The main features of
    these studies are summarized in Table 8.


        Table 8. Results of pharmacological assays with danofloxacin

                                                                                                                     
    Test system                 Doses                          Results                              Reference
                                                                                                                     

    Groups of six male          0, 5, 10, 20 mg/kg bw          No significant diuretic              Varner et al.
    Sprague-Dawley rats         per day orally in              activity                             (1990a)
                                distilled water

    Groups of two male          5 mg/kg bw per day             Mild transient decreases             Gromelski et al.
    and two female              intravenously                  in blood pressure, cardiac           (1990)
    beagle  dogs                                               output, left ventricular
                                                               pressure, and left ventricular
                                                               end diastolic pressure in two
                                                               dogs. No effects on electro-
                                                               cardiographic wave forms

    Groups of three male        1, 10, 100, 1000 mg/kg         No effect on central or              Varner et al.
    Sprague-Dawley rats         bw per day orally              peripheral nervous system            (1990b)
                                                               at 100 mg/kg bw per day;
                                                               salivation and tremors at
                                                               1000 mg/kg bw per day

    Groups of eight male        0, 5, 10, 20 mg/kg bw          18, 27, and 23% decreases            Varner et al.
    CD-1 mice                   per day orally in              in gastrointestinal motility in      (1990c)
                                distilled water; 4 mg/kg       comparison with vehicle
                                morphine sulfate (positive     control
                                control)

    Groups of eight             0, 5, 10, 20 mg/kg bw          Increased gastric fluid              Varner et al.
    pyloricligated male         per day intraduodenally        volume at all doses                  (1990d)
    Sprague-Dawley rats         in 0.25% methylcellulosea;     (not dose-related);
                                10 mg/kg bw per day            increased gastric acidity
                                cimetidine (positive           at all doses
                                control)
                                                                                                                     

    a  The solvent vehicle was reported to be 0.25% methylcellulose in some parts of the report and distilled water in others.
    
    2.2.8  Special studies on microbiological effects

         In a study carried out according to the methods described in
    documents M11A (1979) and M11A2 (1990) of the National Committee for
    Clinical Laboratory Standards, USA, the antibacterial activity of
    danofloxacin and desmethyldano-floxacin was determined against 64
    isolates of six genera of organisms representative of the human
    intestinal anaerobic microflora. In order to assess the
    reproducibility of the assay, four reference strains,  Bacterides 
     fragilis ATCC 25285,  Bacillus thetaiomicron ATCC 29741,
     Clostridium perfringens ATCC 13124, and  Eubacterium lentum ATCC
    43055, were added to each batch of tests. In addition, data were
    provided for the facultative anaerobes  Lactobacillus spp (14
    strains) and  Proteus spp (11 strains) isolated from faeces of
    patients in the hospital of Tourcoing, France.  Escherichia coli ATCC
    25922 and  Enterococcus faecalis ATCC 29242 were added as reference
    strains. The calculated MIC50 values are shown in Tables 9 and 10.

    2.3  Observations in humans

         No information was available. Danofloxacin is not authorized for
    human use.



        Table 9. MIC50 values for danofloxacin and desmethyldanofloxacin in vitro against some strains of 
             bacteria representative of those found in the human gut
                                                                                                        

    Species                      No. of      Inoculum                  MIC50  (g/ml)
                                 strains     density                                                    
                                             (cfu/ml)          Danofloxacin     Desmethyldanofloxacin
                                                                                                        
    Anaerobes
    Bacillus fragilis group        12        107-108               4                 128
    Fusobacterium spp.             10                              4                  16
    Clostridium spp.               10                              0.5                 0.5
    Eubacterium spp.               10                              0.5                 1
    Bifidobacterium spp.           10                              2                   8
    Peptostreptococcus spp.        12                              0.5                 2

    Facultative anaerobes
    Lactobacillus spp.             14        106                  16               > 128
    Proteus spp.                   11        106                   0.25                0.06
                                                                                                        


    Table 10. MIC50 values for danofloxacin and desmethyldanofloxacin in vitro against some strains used for quality control
                                                                                                                        

    Species                             Anaerobic incubation                        Aerobic incubation
                                                                                                                      
                                  Danofloxacin     Desmethyldanofloxacin       Danofloxacin     Desmethyldanofloxacin
                                                                                                                        
    Escherichia coli              0.06             0.06                        0.03             0.015
      ATCC 25922

    Enterococcus faecalis         1                4                           2                1
      ATCC 29242a
                                                                                                                        

    a Shown as Enterococcus faecalis ATCC 29242 on p. 5 of the report but as Enterococcus faecalis ATCC 29212 in the 
      accompanying tables (Dubreuil, 1994)
    


    3.  COMMENTS

         The Committee considered data from studies on the
    pharmacokinetics, acute, short-term, and long-term toxicity,
    carcinogenicity, reproductive toxicity, genotoxicity, and
    antimicrobial activity of danofloxacin. The results of studies on the
    acute and short-term toxicity, reproductive toxicity, genotoxicity,
    and antimicrobial activity of the metabolite desmethyldanofloxacin
    were also reviewed. Most of the studies critical for the evaluation
    were carried out in accordance with appropriate standards for study
    protocol and conduct.

         Danofloxacin was rapidly absorbed after oral administration to
    chickens and pigs and after intramuscular administration to pigs and
    cattle. Only one study was carried out in which the oral
    bioavailability of danofloxacin was calculated; in this study, the
    bioavailability after oral administration of 5 mg/kg bw to pigs was
    approximately 90%. The substance was well distributed to the tissues.
    Urine and faeces contained approximately equal amounts of danofloxacin
    and its metabolites.

         In cattle, dogs, and rats, unchanged danofloxacin was the main
    substance present in the faeces; smaller amounts of
    desmethyldanofloxacin were found. Danofloxacin was also the main
    component in urine. Desmethyldanofloxacin, danofloxacin- N-oxide, and
    the -glucuronide were also found in urine. A piperazine-ring
    degradation product was present in the bile of cattle but was found in
    only trace amounts in the bile of rats and dogs. Residues of both
    danofloxacin and desmethyldanofloxacin were found in liver samples
    from rats, dogs, and the three target species. The Committee
    considered that the metabolism of danofloxacin was very similar in
    laboratory animals and in the three target species.

         Single oral doses of both danofloxacin and desmethyldanofloxacin
    were slightly toxic to rats and mice (acute oral LD50 values in the
    range 1500 to > 2000 mg/kg bw). Signs of toxicity typical of
    stimulation of the central nervous system were observed prior to
    death.

         Several exploratory studies were carried out in rats given
    danofloxacin in the feed and by gavage and in rabbits given
    danofloxacin by gavage. Caecal dilatation was seen at doses of 25
    mg/kg bw per day and above in most of these studies. In rats,
    increased incidences of crystals in the urine were observed at doses
    of 75 mg/kg bw per day and above. There were no corresponding
    pathological changes in the kidneys. In a three-month study in which
    danofloxacin was administered to rats in the diet, degenerated
    germinal cells were found in the epididymides of all males given 300
    mg/kg bw per day and in 9 out of 15 males given 150 mg/kg bw per day.
    In view of the high doses used, the results of these studies were not
    useful in evaluating the safety of danofloxacin.

         Rats were exposed to danofloxacin  in utero and during lactation
    by administration to the dams of doses of 0, 25, 75, or 150 mg/kg bw
    per day. The rats were orally dosed at the same levels for an
    additional three months after weaning. In females, there was a 
    dose-related increase in proteinuria which correlated with the finding
    of tubular nephropathy in individual animals. In males at 75 and 150
    mg/kg bw per day, both the mean absolute and relative testicular
    weights were 10% lower than those of controls. In a follow-up 
    three-month study with lower doses, the highest dose, 6.25 mg/kg bw
    per day, was the NOEL, on the basis of renal tubular nephropathy.

         Rats were exposed to desmethyldanofloxacin  in utero and during
    lactation by administration to the dams of oral doses of 0, 1, 2.5, or
    6.25 mg/kg bw per day. The rats were treated orally at the same levels
    for an additional three months after weaning. No adverse effects were
    observed at any dose.

         Six-month-old dogs were given oral doses of 0, 5, 10, or 25 mg/kg
    bw per day of danofloxacin in gelatin capsules for three months. Those
    given the two higher doses showed signs of joint pain. Pathological
    examination revealed arthropathy characterized by areas of cartilage
    separation and erosion in all treated groups, and the severity of the
    lesions was dose-related. A second three-month study was carried out
    in immature dogs given oral doses of 0, 1, or 2.4 mg/kg bw per day
    danofloxacin in gelatin capsules. There was no evidence of arthropathy
    or any other treatment-related effect. On the basis of the results of
    the two studies, the Committee concluded that 2.4 mg/kg bw per day was
    the overall NOEL for arthropathy in dogs.

         A further three-month study was carried out in which immature
    dogs were given oral doses of 0, 2.5, 5, or 10 mg/kg bw per day
    desmethyldanofloxacin in gelatin capsules. One male of three given the
    highest dose and one female of three given the lowest dose showed
    signs of pain on examination. In the male, morphological changes were
    found in the articular cartilage of one joint. When the study was
    repeated at doses of 0, 0.25, or 0.5 mg/kg bw per day 
    desmethyldanofloxacin, one male of three given 0.5 mg/kg bw per day
    was found to have histopathological changes in the right knee typical
    of quinolone-induced arthropathy. The NOEL for desmethyldanofloxacin
    was 0.25 mg/kg bw per day, on the basis of arthropathy.

         In a 102-day range-finding study, mice were fed diets containing
    danofloxacin at concentrations equivalent to 0, 150, 300, or 600 mg/kg
    bw per day. At the highest dose, the body-weight gain of males was
    reduced, and decreased haematological parameters and increased kidney
    weights were observed in females. Caecal dilatation was observed at
    all doses, and two of 30 mice given the highest dose had inflammation
    of the caecum.

         In a two-year study of carcinogenicity, mice were fed diets
    containing doses equal to 0, 10, 50, or 100 mg/kg bw per day. Females
    at the highest dose gained more weight than the controls and showed
    increased absolute kidney weights. There were no adverse effects on
    haematological parameters, but clinical chemistry was not monitored.
    No increase in tumour incidence was observed at any dose.

         In a two-year study of carcinogenicity, rats were fed diets
    providing doses of 0, 10, 50, or 100 mg/kg bw per day danofloxacin. At
    the highest dose, mean haemoglobin, haematocrit, and lymphocyte counts
    were decreased in females, and serum aspartate aminotransferase
    activity was increased and serum globulin levels were reduced in
    males. Serum sorbitol dehydrogenase activity was increased in males
    given 50 or 100 mg/kg bw per day. The relative testicular weight was
    reduced in rats at the highest dose, and increased oligospermia and
    abnormal epididymal content were observed in this group. Caecal
    enlargement was noted in all treated groups but was not correlated
    with any microscopic findings. An increased incidence of papillary
    oedema was seen in the kidneys of rats at 100 mg/kg bw per day. There
    was a significant positive trend in the incidence of granular-cell
    tumours of the uterus and vagina in treated female rats. Tumours were
    distinguished from foci by their larger size and the compression of
    adjacent tissue, but the morphology of these lesions was similar, and
    the Committee considered that it was appropriate to combine the
    incidences of these uterine and vaginal foci and tumours. There was no
    significant trend in the combined incidence across groups. There was a
    significant positive trend in the incidence of pituitary adenomas in
    females, but the number of rats with these lesions was within the
    range in historical controls. In addition, none of the trends in
    tumour incidence was significant when corrected for multiple
    comparisons. The Committee concluded that neither the granular-cell
    lesions of the uterus and vagina nor the pituitary adenomas were
    indicative of a carcinogenic response to treatment with danofloxacin.

         The genotoxic properties of danofloxacin were investigated  in
     vitro in assays for gene mutation in bacteria and in mammalian
    cells, unscheduled DNA synthesis, and cytogenetics alterations in
    mammalian cells and for cytogenetic effects  in vivo. All of the
    tests gave negative results, except for an assay of cytogenetic
    alterations in human lymphocytes  in vitro. The clastogenicity
    observed  in vitro was reduced or abolished by addition of magnesium
    sulfate to the culture medium and/or washing the cells after treatment
    to remove danofloxacin, and appeared to be associated with the cation-
    chelating properties of danofloxacin. There was no evidence of
    clastogenicity  in vivo. Desmethyldanofloxacin induced a significant
    increase in unscheduled DNA synthesis in two independent assays in
    primary rat hepatocytes  in vitro; however, negative results were
    obtained with desmethyldanofloxacin in an assay for unscheduled DNA
    synthesis and in a test for micronucleus formation  in vivo. Thus,
    although desmethyldanofloxacin induced unscheduled DNA synthesis, this
    genotoxic potential did not appear to be expressed  in vivo.

         In a two-generation study of reproductive toxicity, rats received
    doses of 0, 25, 75, or 150 mg/kg bw per day of danofloxacin by gavage.
    In the parental generation, maternal body-weight gain was reduced at
    the highest dose and these dams had fewer implantation sites and
    produced fewer viable pups. The effects were observed at lower doses
    with subsequent matings. At the second mating of the first-generation
    animals, the pregnancy rate was adversely affected in all treated
    groups. No NOEL could be identified.

         A three-generation study of reproductive toxicity was carried out
    in which rats were given danofloxacin at doses of 0, 1, 2.5, 6.25, or
    150 mg/kg bw per day by gavage. At 150 mg/kg bw per day, the number of
    mated females and the pregnancy rate were reduced, the duration of
    gestation was increased and the litter sizes and pup weights were
    reduced; this group was terminated before the second mating of the
    first generation. In this study, in which lower doses were used than
    in the study described above, the NOEL for reproductive toxicity was
    6.25 mg/kg bw per day.

         No adverse effects were observed in a three-generation study of
    reproductive toxicity in rats with desmethyldanofloxacin in which
    doses of up to 6.25 mg/kg bw per day were administered by gavage.

         In a study of developmental toxicity in mice, there was no
    evidence of teratogenicity when danofloxacin was administered by
    gavage at doses of up to 200 mg/kg bw per day on days 6-13 of
    gestation. The dose of 200 mg/kg bw per day was toxic to the dams,
    reducing body-weight gain, and was fetotoxic, producing a reduction in
    mean fetal weight and an increased incidence of delayed ossification.
    The study was compromised by the small numbers of gravid dams in all
    groups, including the controls. The NOEL for both maternal and fetal
    toxicity was 100 mg/kg bw per day.

         Oral doses of 0, 50, 100, or 200 mg/kg bw per day were
    administered to rats on days 6-15 of gestation in a study of
    developmental toxicity. Maternal body-weight gain and food consumption
    were reduced in animals at 100 or 200 mg/kg bw per day. At these
    doses, the incidences of delayed ossification and dilatation of the
    cerebral ventricles were significantly increased. The NOEL for both
    maternal and fetal toxicity was 50 mg/kg bw per day.

         In a study of developmental toxicity, oral doses of 0, 2.5, 7.5,
    or 15 mg/kg bw per day danofloxacin were administered to rabbits on
    days 6-20 of gestation. At a dose of 15 mg/kg bw per day, maternal 
    body-weight loss, reduced food consumption, and abortion were
    observed. The NOEL for maternal toxicity was 7.5 mg/kg bw per day.

         The minimum concentration of danofloxacin resulting in 50%
    inhibition (MIC50) was determined for 64 isolates of the six
    predominant genera of human intestinal anaerobic microflora
    ( Bacteroides, Fusobacterium, Clostridium, Eubacterium, 
     Bifidobacterium, and  Peptostreptococcus). In addition, data were
    provided for the facultative anaerobes  Lactobacillus, Proteus, and

     Escherichia coli. Although  E. coli and  Proteus were the most
    sensitive organisms, the Committee agreed that they should not be
    taken into account in the calculation of the MIC50 because they are
    not predominant species in the human intestine. Instead, the Committee
    derived the mean MIC50 from the data available on 32 strains of the
    most sensitive relevant genera isolated from the human
    gastrointestinal tract, in this case  Eubacterium spp.,
     Bifidobacterium spp., and  Peptostreptococcus spp. The mean MIC50
    for these strains was 1 g/ml. This figure was used in calculating the
    upper limit of the ADI from the formula described on p. 12:


              Upper limit         1 g/ga  220 g
                             =                     
                of ADI            0.1b  1c  60 kg

                             =  37 g/kg bw

    a    Mean MIC50 for the most sensitive relevant species in the
         human intestine, in this case  Eubacterium spp.,
          Bifidobacterium spp., and  Peptostreptococcus spp.
    b    Bioavailability was determined to be about 90%, based on a 
         study in pigs given an oral dose of 5 mg/kg bw. The finding that
         danofloxacin is strongly bound to cattle faeces was considered by
         the Committee to add confidence to use of this value.
    c    A safety factor of 1 was used because sufficient relevant
         microbiological data were provided.

         The metabolite desmethyldanofloxacin was one-quarter to one-half
    as active as danofloxacin against the same isolates.

    4.  EVALUATION

         The Committee noted that danofloxacin belongs to a group of
    fluoroquinolones that is active against aerobic gram-negative bacteria
    and that the main components of the flora in the human
    gastrointestinal tract are largely unaffected by these compounds.
    Therefore, the Committee decided to base the ADI on the toxicity of
    danofloxacin and not on its effects on the intestinal flora. Moreover,
    the toxicological end-point resulted in a lower ADI.

         The Committee established an ADI of 0-20 g/kg bw per day on the
    basis of the NOEL of 2.4 mg/kg bw per day for arthropathy in a 
    three-month study in immature dogs and a safety factor of 100. The ADI
    was rounded to one significant figure, as is the standard practice
    (Annex 1, reference 91, section 2.7).

         The Committee noted that the NOEL for arthropathy in studies with
    desmethyldanofloxacin was 0.25 mg/kg bw per day. The studies of
    pharmacokinetics and metabolism showed that dogs that received oral
    doses of danofloxacin were also exposed systemically to the major
    metabolite desmethyldanofloxacin. Therefore the Committee concluded
    that it was not necessary to calculate a separate ADI for
    desmethyldanofloxacin. The Committee agreed, however, that the
    approximately 10-fold higher toxicity of the metabolite should be
    taken into account when recommending MRLs, as consumers may be
    directly exposed to desmethyldano-floxacin in liver.

    5.  REFERENCES

    Amacher, D.E., Turner, G.N., Ellis, J.H., Holden, H.E. & Kluwe, W.M.
    (1988) Danofloxacin. Genetic toxicology report. Microbial reverse
    mutation assays. Mammalian cell gene mutation assays. Unscheduled DNA
    synthesis assays. Unpublished studies Nos. 86-607-01 and 87-607-02
    from Pfizer Central Research, Groton, CT, USA. Submitted to WHO by
    Pfizer Inc., Groton, CT, USA.

    Amacher, D.E., Holden, H.E., Muehlbauer, P.A., Wahrenburg M.G. &
    Kluwe, W.M. (1990) Danofloxacin. Genetic toxicology report. Addendum.
     In vitro cytogenetics assays.  In vivo cytogenetics assays.
    Unpublished study No. 89-607-18 from Pfizer Central Research, Groton,
    CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Amacher, D.E., Ellis, J.H. & Kluwe, W.M. (1991a)
    Desmethyldanofloxacin. Genetic toxicology report. Microbial reverse
    mutation assays. Unpublished study No. 90-576-09 from Pfizer Central
    Research, Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton,
    CT, USA.

    Amacher, D.E., Holden, H. E., Muehlbauer, P.A. & Kluwe, W.M. (1991b)
    Genetic toxicology report. Unscheduled DNA synthesis assay.
    Unpublished study No. 90-576-12 from Pfizer Central Research, Groton,
    CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Amacher, D.E., Holden, H.E., Zelljadt, I. & Kluwe, W.M. (1991c)
    Desmethyldano-floxacin. Genetic toxicology report.  In vivo
    micronucleus assay. Unpublished study No. 90-576-10 from Pfizer
    Central Research, Groton, CT, USA. Submitted to WHO by Pfizer Inc.,
    Groton, CT, USA.

    Beutler, N.J., Tinkel, J.H. & Knickerbocker, M. (1992) Delayed contact
    hyper-sensitivity study in guinea pigs. Unpublished study No. 
    92-607-27 from Pfizer Central Research, Groton, CT, USA. Submitted to
    WHO by Pfizer Inc., Groton, CT, USA.

    Dubreuil, L. (1994) Antibacterial activity of a fluoroquinolone
    against bacteria isolated from human gut flora: Danofloxacin and its
    metabolite desmethyldano-floxacin (DMD). Unpublished study from
    Microbiology Department, Faculty of Pharmacy, University of Lille,
    France. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Fisher, D.O., Vernon, G.S., Mayne, J.T., Frame, G.M., Milisen, W.B.,
    Estes, P.C. & Levinsky, H.V. (1988a) A one month oral gavage study in
    Long-Evans rats. Unpublished study No. 87-607-08 from Pfizer Central
    Research, Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton,
    CT, USA.

    Fisher, D.O., Santacroce, C.E., Mayne, J.T., Frame, G.M., Saunders,
    W.J., Estes, P.C. & Levinsky, H.V. (1988b) Danofloxacin. One month
    oral capsule study in beagle dogs. Unpublished study No. 87-607-07
    from Pfizer Central Research, Groton, CT, USA. Submitted to WHO by
    Pfizer Inc., Groton, CT, USA.

    Fisher, D.O., Santacroce, C.E., Mayne, J.T., Milisen, W.B., Estes,
    P.C. & Levinsky, H.V. (1989a) Danofloxacin. Three months oral gavage
    study with  in utero exposure in Long-Evans rats. Unpublished study
    No. 88-607-12 from Pfizer Central Research, Groton, CT, USA. Submitted
    to WHO by Pfizer Inc., Groton, CT, USA.

    Fisher, D.O., Soler, G.N., Mayne, J.T., Walsh, A.H., Levinsky, H.V. &
    Estes, P.C. (1989b) Danofloxacin. Three month oral capsule study in
    beagle dogs. Unpublished study No. 88-607-14 from Pfizer Central
    Research, Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton,
    CT, USA.

    Fisher, D.O., Santacroce, C.E., Carson, D.L., Son, D.L., Walsh, A.H.,
    Levinsky, H.V. & Estes, P.C (1989c) Danofloxacin. Three month oral
    capsule study in beagle dogs. Unpublished study No. 88-607-15 from
    Pfizer Central Research, Groton, CT, USA. Submitted to WHO by Pfizer
    Inc., Groton, CT, USA.

    Fisher, D.O., Hills-Perry, P.A., Rice, J., Coleman, G.L., Estes, P.C.
    & Levinsky, H.V. (1990a) Danofloxacin. Three months oral gavage study
    with  in utero exposure in Long-Evans rats. Unpublished study No. 
    89-607-19 from Pfizer Central Research, Groton, CT, USA. Submitted to
    WHO by Pfizer Inc., Groton, CT, USA.

    Fisher, D.O., Beierschmitt, W.P., Milisen, W.B., Estes, P.C. &
    Levinsky, H.V. (1990b) A two-generation oral gavage study in 
    Long-Evans rats. Unpublished study No. 87-607-09 from Pfizer Central
    Research, Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton,
    CT, USA.

    Fisher, D.O., Powers, K.A., Beierschmitt, W.P. & Levinsky, H.V.
    (1990c) An exploratory reproductive oral gavage study in Long-Evans
    rats. Unpublished study No. 89-607-17 from Pfizer Central Research,
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Fisher, D.O., Milisen, W.B., Kluwe, W.M. & Ochoa, R. (1996) Two year
    oncogenicity study with dietary administration in Long-Evans rats.
    Unpublished study No. 93-607-31 from Pfizer Central Research, Groton,
    CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Gromelski, G.J., Panasevich, R.E. & Ciofalo, V.B. (1990) Acute
    hemodynamic effects of an intravenous infusion of CP-76,136-27 in the
    open-chest anesthetized dog. Unpublished study No. PH 247-PZ-001-90
    from Pharmakon Laboratories, Waverly, PA, USA. Submitted to WHO by
    Pfizer Inc., Groton, CT, Groton, CT, USA.

    Guzzie, P.J., Turner, G.N., Amacher, D.E. & Kluwe, W.M (1992) Genetic
    toxicology report. Antimicrobial. Unpublished study No. 92-607-26 from
    Pfizer Central Research, Groton, CT, USA. Submitted to WHO by Pfizer
    Inc., Groton, CT, USA.

    Hazleton Laboratories America Inc. (1991a) UDS assay in primary rat
    hepatocytes. Unpublished study no. 12180-0-447R. Submitted to WHO by
    Pfizer Inc., Groton, CT, USA.

    Hazleton Laboratories America Inc. (1991b)  In vivo/in vitro UDS
    assay in primary rat hepatocytes. Unpublished study no. 12180-0-494.
    Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Holden, H.E., Turner, G.N. & Ray, V.A. (1988) Genetic toxicology
    report. Nalidixic acid analog. Unpublished study No. 86-576-01 from
    Pfizer Central Research, Groton, CT, USA. Submitted to WHO by Pfizer
    Inc., Groton, CT, USA.

    Kesseddjian, M.J., Stadler, J. & Paulus, G. (1988a) Danofloxacin.
    Maternal toxicity study in mice by the oral route. Unpublished study
    No. 88028 from Pfizer Central Research, Amboise Cedex, France.
    Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Kesseddjian, M.J., Stadler, J. & Paulus, G. (1988b) Danofloxacin.
    Maternal toxicity study in rats by the oral route. Unpublished study
    No. 88059 from Pfizer Central Research, Amboise Cedex, France.
    Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Kesseddjian, M.J., Stadler, J. & Paulus, G. (1989a) Danofloxacin.
    Fetotoxicity study in mice by the oral route. Segment II. Unpublished
    studies No. 88115 and 88116 from Pfizer Central Research, Amboise
    Cedex, France. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Kesseddjian, M.J., Stadler, J. & Paulus, G. (1989b) Danofloxacin.
    Fetotoxicity study in rats by the oral route. Segment II. Unpublished
    studies No. 88093 and 88094 from Pfizer Central Research, Amboise
    Cedex, France. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Lundeen, G.R., Macaione, G.M., Santacroce, E.M. & Rice, J.R. (1993)
    Two week exploratory toleration study in New Zealand white rabbits.
    Unpublished study No. 92-607-30 from Pfizer Central Research, Terre
    Haute, IN, and Groton, CT, USA. Submitted to WHO by Pfizer Inc., USA.

    Lynch, M.J., Ronfield, R.A., Rainier, R.H., Magonigle, R.A., Frame,
    G.M., Risk, J.E., Mosher, F.R. & Harran, L.P. (1988) Danofloxacin.
    Nonclinical total residue depletion study in broiler chickens.
    Unpublished study No. 1515N-60-88-006 from Pfizer Central Research,
    Terre Haute, IN, and Groton, CT, USA. Submitted to WHO by Pfizer Inc.,
    Groton, CT, USA.

    Lynch, M.J., Ronfield, R.A., Rainier, R.H., Magonigle, R.A., Frame,
    G.M., Risk, J.E., Mosher, F.R. & Harran, L.P. (1989a) Danofloxacin.
    Nonclinical total residue excretion study in cattle. Unpublished study
    No. 1535N-60-88-008 from Pfizer Central Research, Terre Haute, IN, and
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Lynch, M.J., Ronfield, R.A., Rainier, R.H., Magonigle, R.A., Frame,
    G.M., Risk, J.E., Mosher, F.R. & Harran, L.P. (1989b) Danofloxacin. A
    nonclinical total residue excretion study in swine. Unpublished study
    No. 1525C-60-88-009 from Pfizer Central Research, Terre Haute, IN, and
    Groton, CT, CT. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Lynch, M.J., Ronfield, R.A., Rainier, R.H., Magonigle, R.A., Frame,
    G.M., Risk, J.E., Mosher, F.R. & Harran, L.P. (1989c) Danofloxacin. A
    nonclinical total residue depletion study in swine. Unpublished study
    No. 1525N-60-88-008 from Pfizer Central Research, Terre Haute, IN, and
    Groton, CT. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Lynch, M.J., Ronfield, R.A., Magonigle, R.A., Risk, J.E., Rice, J.R.,
    Millas, W.J. & Harran, L.P. (1990a) Danofloxacin. Plasma and lung
    pharmacokinetics study in broiler chickens. Unpublished Study No.
    1514C-60-90-002 from Pfizer Central Research, Terre Haute, IN, and
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Lynch, M.J., Ronfield, R.A., Magonigle, R.A., Risk, J.E., Rice, J.R.,
    Horan, M.R. & Gummerus, J.A. (1990b) Danofloxacin. Nonclinical plasma
    and lung pharmacokinetics study in cattle. Unpublished study No.
    1534N-60-89-003 from Pfizer Central Research, Terre Haute, IN, and
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Lynch, M.J., Ronfield, R.A., Magonigle, R.A., Risk, J.E., Rice, J.R. &
    Harran, L.P. (1991a) Danofloxacin. Determination of plasma
    pharmacokinetics and bioavailability in cattle. Unpublished study No.
    1532N-60-89-005 from Pfizer Central Research, Terre Haute, IN, and
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Lynch, M.J., Ronfield, R.A., Rainier, R.H., Magonigle, R.A., Frame,
    G.M., Risk, J.E., Mosher, F.R. & Harran, L.P. (1991b) Danofloxacin.
    Nonclinical total residue excretion study in broiler chickens.
    Unpublished study No. 1515N-60-88-007 from Pfizer Central Research,
    Terre Haute, IN, and Groton, CT, USA. Submitted to WHO by Pfizer Inc.,
    USA.

    Lynch, M.J., Ronfield, R.A., Magonigle, R.A., Risk, J.E., Rice, J.R.,
    Millas, W.J. & Harran, L.P. (1991c) A plasma and lung pharmacokinetics
    study in swine. Unpublished study No. 1524C-60-89-003 from Pfizer
    Central Research, Terre Haute, IN, and Groton, CT, USA. Submitted to
    WHO by Pfizer Inc., Groton, CT, USA.

    Lynch, M.J., Ericson, J., Calcagni, A., Gummerus, J. & Nowakowski,
    M.A. (1991d) The comparative metabolism of 3H-danofloxacin in
    cattle, dog and rat species. Unpublished study No. CM-90-02 from
    Pfizer Central Research, Terre Haute, IN, and Groton, CT, USA.
    Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Mann, D.D. & Frame, G.M (1992) Pharmacokinetic study of danofloxacin
    in cattle and swine. Am. J. Vet. Res., 53, 1022-1026.

    Reynolds, J.A., Saunders, W., Hatch, G.W. & Vessella, D.J. (1987a) 2
    week oral gavage toleration study in Long-Evans rats. Unpublished
    study No. 87-607-03 from Pfizer Central Research, Terre Haute, IN, and
    Groton, CT. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Reynolds, J.A., Milisen, W.B. & Frame, G.M. (1987b) Two week oral
    capsule toleration study in beagle dogs. Unpublished study No. 
    87-607-05 from Pfizer Central Research, Terre Haute, IN, and Groton,
    CT. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Risk, J.E., Ronfeld, R.A., Magonigle, R.A., Lynch, M.J., Rice, J.R.,
    Millas, W.J. & Harran, L.P. (1991) Danofloxacin. Plasma and lung
    pharmacokinetics study in swine. Unpublished study No. 1524C-60-89-003
    from Pfizer Central Research, Terre Haute, IN, and Groton, CT.
    Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Stadnicki, S.W., Stack, T.L., Knickerbocker, M. & Beutler, N.J.
    (1988a) Danofloxacin. Acute oral and intravenous toxicity studies in
    mice and rats. Unpublished study No. 87-607-10 from Pfizer Central
    Research, Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton,
    CT, USA.

    Stadnicki, S.W., Nilson, A.L. Knickerbocker, M. & Beutler, N.J.
    (1988b) Danofloxacin. Acute dermal and ocular irritation studies in
    rabbits (FHSA testing). Unpublished study No. 88-607-11 from Pfizer
    Central Research, Groton, CT, USA. Submitted to WHO by Pfizer Inc.,
    Groton, CT, USA.

    Stadnicki S.W., Rinaldi, M.T.S., Knickerbocker, M. & Beutler, N.J.
    (1989) Desmethyldanofloxacin. Acute oral and intravenous toxicity
    studies in albino mice and Sprague-Dawley rats. Unpublished study No.
    89-576-05 from Pfizer Central Research, Groton, CT, USA. Submitted to
    WHO by Pfizer Inc., Groton, CT, USA.

    Stadnicki, S.W., Cacciatore, B.A., Lundeen, G.R., Rice, J., Roesler,
    A.R., Estes, P.C. & Levinsky, H.V. (1990a) Desmethyldanofloxacin.
    Three month gavage study in Long-Evans rats with  in utero exposure.
    Unpublished study No. 89-576-06 from Pfizer Central Research, Groton,
    CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Stadnicki, S.W., Engel, S.M., Blackwell, D.K., Rice, J.R., Walsh,
    A.H., Estes, P.C. & Levinsky, H.V. (1990b) Desmethyldanofloxacin.
    Three months oral capsule study in beagle dogs. Unpublished study No.
    89-576-03 from Pfizer Central Research, Groton, CT, USA. Submitted to
    WHO by Pfizer Inc., Groton, CT, USA.

    Stadnicki, S.W., Engel, S.M., Blackwell, D.K., Rice, J.R., Estes, P.C.
    & Levinsky, H.V. (1990c) Desmethyldanofloxacin. Three months oral
    capsule study in beagle dogs. Unpublished study No. 89-576-07 from
    Pfizer Central Research, Groton, CT, USA. Submitted to WHO by Pfizer
    Inc., Groton, CT, USA.

    Stadnicki, S.W., Hallam, J.A., Ball, D.J., Pettersen, B.A., Levinsky,
    H.V., Milisen, W.B. & Estes, P.C. (1990d) Danofloxacin. A 
    three-generation oral gavage study in Long-Evans rats. Unpublished
    study No. 89-607-16 from Pfizer Central Research, Groton, CT, USA.
    Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Stadnicki, S.W., Santacroce, E.M., Lundeen, G.R., Coleman, G.L.,
    Estes, P.C. & Levinsky, H.V. (1991) Desmethyldanofloxacin. Three
    generation gavage study in Long-Evans rats. Unpublished study No. 
    89-576-04 from Pfizer Central Research, Groton, CT, USA. Submitted to
    WHO by Pfizer Inc., Groton, CT, USA.

    Stadnicki, S.W., Cacciatore, A., Rovetti, C.C., Davenport, C.J.,
    Walsh, A.H. & Rice, J.R. (1994a) Three month feeding study in CD-1
    mice. Unpublished study No. 92-607-29 from Pfizer Central Research,
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Stadnicki, S.W., Cacciatore, A., Rovetti, C.C., Davenport, C.J.,
    Chatman, L.A. & Rice, J.R. (1994b) One month feeding study in Fischer
    rats. Unpublished study No. 91-607-23 from Pfizer Pfizer Central
    Research, Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton,
    CT, USA.

    Stadnicki, S.W., Cacciatore, A., Davenport, C.J., Coleman, G.L. &
    Rice, J.R (1994c) Three week feeding study in Long-Evans rats.
    Unpublished study no. 92-607-25 from Pfizer Central Research, Groton,
    CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Stadnicki, S.W., Boldt, B.K., Rovetti, C.C., Davenport, C.J., Milisen,
    W.B. & Rice, J.R. (1994d) Three month feeding study in Long-Evans
    rats. Unpublished study No. 92-607-28 from Pfizer Central Research,
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Takatsu, S., Walsh, A.H., Shirai, N., Iidaka, T, Fukazawa, H., Iijima,
    M. & Tachibana, M. (1995) Two year oncogenicity study with dietary
    administration in ICR mice. Unpublished study No. 93-76-31 from Pfizer
    Central Research, Chita-gun, Aichi, Japan. Submitted to WHO by Pfizer
    Inc., Groton, CT, USA.

    Tassinari, M.S., Rizoli, A.M., Hills-Perry, P., Linhares, M. & Gupta,
    U. (1995a) Maternal toxicity study by oral gavage in New Zealand white
    rabbits. Unpublished study No. 93-607-33 from Pfizer Central Research,
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Tassinari, M.S., Laithwaite, H.T., Podurgiel, S.J. & Gupta, U. (1995b)
    Danofloxacin. Reproductive study III (teratology) in New Zealand white
    rabbits. Unpublished study No. 93-607-34 from Pfizer Central Research,
    Groton, CT, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Varner, L.L., Panasevich, R.E. & Ciofalo, V.B. (1990a) Diuretic assay.
    Unpublished study No. PH 209-PZ-001-90 from Pharmakon Laboratories,
    Waverly, PA, USA. Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Varner, L.L., Panasevich, R.E. & Ciofalo, V.B. (1990b)
    Neuropharmacological profile (NPP) in rats. Unpublished study No. PH
    200A-PZ-001-90 from Pharmakon Laboratories, Waverly, PA, USA.
    Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Varner, L.L., Panasevich, R.E. & Ciofalo, V.B. (1990c)
    Gastrointestinal propulsion assay in male mice. Unpublished study No.
    PH 239-PZ-001-90 from Pharmakon Laboratories, Waverly, PA, USA.
    Submitted to WHO by Pfizer Inc., Groton, CT, USA.

    Varner, L.L., Panasevich, R.E. & Ciofalo, V.B. (1990d) Secretory
    screen in pyloric ligated Shay rats. Unpublished study No. PH 
    252-PZ-001-90 from Pharmakon Laboratories, Waverly, PA, USA. Submitted
    to WHO by Pfizer Inc., Groton, CT, USA.

    


    See Also:
       Toxicological Abbreviations
       DANOFLOXACIN (JECFA Evaluation)