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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
weight of evidence
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
data from handbook or collection of data
Justification for type of information:
Data is from authoritative database.

Data source

Reference
Reference Type:
other: authoritative database
Title:
Toxicology Study of the given test chemical
Author:
NTIS
Year:
1992
Bibliographic source:
NATIONAL TOXICOLOGY PROGRAM

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
other: As mention below
Principles of method if other than guideline:
Two year repeated dose toxicity study of the given test chemical in F344 male and female rats by oral feed.
GLP compliance:
not specified
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
- Name of test material : 3-hydroxy-4-[(E)-2-(2-methoxy-5-nitrophenyl)diazen-1-yl]-N-(3-nitrophenyl)naphthalene-2-carboxamide
- Common name : 3-hydroxy-4-[(2-methoxy-5-nitrophenyl)azo]-N-(3-nitrophenyl)naphthalene-2-carboxamide, C.I. Pigment Red 23
- Molecular formula : C24H17N5O7
- Molecular weight : 487.4263 g/mol
- Smiles notation : c12c(c(c(cc1cccc2)C(=O)Nc1cc(ccc1)[N+](=O)[O-])O)/N=N/c1c(ccc(c1)[N+](=O)[O-])OC
- InChl : 1S/C24H17N5O7/c1-36-21-10-9-17(29(34)35)13-20(21)26-27-22-18-8-3-2-5-14(18)11-19(23(22)30)24(31)25-15-6-4-7-16(12-15)28(32)33/h2-13,30H,1H3,(H,25,31)/b27-26+
- Substance type : Organic
- Physical state : Solid
Specific details on test material used for the study:
Name of test material : 3-hydroxy-4-[(E)-2-(2-methoxy-5-nitrophenyl)diazen-1-yl]-N-(3-nitrophenyl)naphthalene-2-carboxamide
- Common name : 3-hydroxy-4-[(2-methoxy-5-nitrophenyl)azo]-N-(3-nitrophenyl)naphthalene-2-carboxamide, C.I. Pigment Red 23
- Molecular formula : C24H17N5O7
- Molecular weight : 487.4263 g/mol
- Smiles notation : c12c(c(c(cc1cccc2)C(=O)Nc1cc(ccc1)[N+](=O)[O-])O)/N=N/c1c(ccc(c1)[N+](=O)[O-])OC
- InChl : 1S/C24H17N5O7/c1-36-21-10-9-17(29(34)35)13-20(21)26-27-22-18-8-3-2-5-14(18)11-19(23(22)30)24(31)25-15-6-4-7-16(12-15)28(32)33/h2-13,30H,1H3,(H,25,31)/b27-26+
- Substance type : Organic
- Physical state : Solid
-Purity: >96 %

Test animals

Species:
rat
Strain:
Fischer 344
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Frederick Cancer Research Center (Frederick, MD)
- Age at study initiation: 56 days old
- Housing: rats were housed five per cage. Cages were rotated vertically once every two weeks.
- Diet (e.g. ad libitum): NIH-07 Rat, meal (Zeigler Bros., Inc., Gardners, PA), available ad libitum
- Water (e.g. ad libitum): Tap water (Birmingham Water Works) in glass water bottles with stainless steel sippers (Edstrom Automatic Watering Systems, Waterford, WI), available ad libitum
- Acclimation period: 20 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17.8° C-25.6° C
- Humidity (%): 15%-85%
- Air changes (per hr): minimum 15 changes/hour
- Photoperiod (hrs dark / hrs light): 12 hours/day

Administration / exposure

Route of administration:
oral: feed
Vehicle:
other: NIH-07 rat ration
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS: No data available

DIET PREPARATION
- Rate of preparation of diet (frequency): No data available
- Mixing appropriate amounts with (Type of food): premix of NIH-07 rat ratioon as meal, with the appropriate amount of C.I. Pigment Red 23.
- Storage temperature of food: 2 weeks for 45 °C
-Other information:The dose formulations were prepared by mixing appropriate quantities of C.1. Pigment Red 23 with feed (NIH-07 Rat Ration) to form a premix, then the remaining feed was added and mixed in a twin-shell blender equipped with an intensifier bar. Studies conducted by the analytical chemistry laboratory to determine stability and homogeneity of the dosed feed formulations indicated that the formulations were homogeneous and stable for at least 2 weeks at temperatures up to 45° C when stored in the dark. The preparations protected from light were stored at 5° C prior to use and at room temperature during use. Storage time was not more than 14 days. Periodic analyses of the dosed-feed formulations were conducted at the study laboratory and at the analytical chemistry laboratory throughout the studies. The original method used the extraction solvent nitrobenzene; the solventwas changed to a solution of 10 g potassium hydroxide in 500 mL methanol diluted to 1,000 mL with tetrahydrofuran because of inconsistent recoveries.


VEHICLE
- Justification for use and choice of vehicle (if other than water): No data
- Concentration in vehicle: 0, 10,000, 25,000, or 50,000 ppm ((500, 1250 or 2500 mg/kg))
- Amount of vehicle (if gavage): Not applicable.
- Lot/batch no. (if required): Lot UB2158
- Purity: 99.6%.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Dose levels were determined using visible spectroscopy at 478 nm. Homogeneity of the formulations was confirmed by the study laboratory. For the 2-year studies, a total of 142 samples were analyzed and five were remixed in order to be within acceptable limits.Periodically, the dose formulations were sent for referee analyses by MRI. The results from the study laboratory and from the referee analytical chemistry laboratory were generally in good agreement, with all value differences less than 13%
Duration of treatment / exposure:
2years
Frequency of treatment:
Daily
Doses / concentrations
Remarks:
0, 10,000, 25,000, or 50,000 ppm (500, 1250 or 2500 mg/kg/day)
No. of animals per sex per dose:
10 animals/dose
Control animals:
yes, concurrent vehicle
Details on study design:
Details on study design:
- Dose selection rationale: Because levels of C.I. Pigment Red 23 as high as 2500 or 50,000 mg/kg in the feed did not adversely affect survival and mean body weights in the 17-day and 13-week studies, nor cause any chemical-related lesions, doses of 0, 500, 1250, or 2500 mg/kg were selected for the 2-year studies.
Positive control:
Not specified

Examinations

Observations and examinations performed and frequency:
Observations and examinations performed & frequency
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice/day
- Cage side observations checked in table [No.?] were included. No data available

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at each weight check and at terminal sacrifice.

BODY WEIGHT: Yes
- Time schedule for examinations: once/week for 13 weeks, once/month thereafter and at sacrifice.

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): No data available
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: No data available
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No data available

FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No data available

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data available
- Time schedule for examinations: No data available

OPHTHALMOSCOPIC EXAMINATION: No data available
- Time schedule for examinations: No data available
- Dose groups that were examined: No data available

HAEMATOLOGY: Yes
- Time schedule for collection of blood: No data available
- Anaesthetic used for blood collection: No data available
- Animals fasted: No data available
- How many animals: No data available
- Parameters checked in table [No.?] were examined. No data available

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: No data available
- Animals fasted: No data available - How many animals: No data available
- Parameters checked in table [No.?] were examined. No data available

URINALYSIS: No data available
- Time schedule for collection of urine: No data available
- Metabolism cages used for collection of urine: No data available
- Animals fasted: No data available
- Parameters checked in table [No.?] were examined. No data available

NEUROBEHAVIOURAL EXAMINATION: No data available
- Time schedule for examinations: No data available
- Dose groups that were examined: No data available
- Battery of functions tested: No data available sensory activity / grip strength / motor activity / other: No data available
Sacrifice and pathology:
GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
Statistics:
Mean ± standard deviation was observed.

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Description (incidence and severity):
There were no clinical findings in rats considered to be chemically related.
Mortality:
no mortality observed
Description (incidence):
No mortality were observed at all treated group 500, 1250 or 2500 mg/kg compare to control.
Body weight and weight changes:
no effects observed
Description (incidence and severity):
Male: Mean body weights of male rats were similar to that of the controls throughout the 2-year study
Female: from week 20 to the end of the study, the mean body weights of mid- and high-dose females were consistently lower than that of the controls
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
Feed consumption by exposed male and female rats was similar to that of to the controls.
Food efficiency:
not specified
Water consumption and compound intake (if drinking water study):
not specified
Ophthalmological findings:
not specified
Haematological findings:
no effects observed
Description (incidence and severity):
In male rats, there were no biologically significant differences in hematology parameters related to chemical exposure.
In female rats, Hematocrit values, hemoglobin concentration, and erythrocyte counts interim evaluation were significantly less than those of the controls and serum total bilirubin was significantly increased in 50000 ppm female rats at the 15-month
Clinical biochemistry findings:
no effects observed
Description (incidence and severity):
In male rats, there were no biologically significant differences in clinical chemistry parameters related to chemical exposure.
Urinalysis findings:
not specified
Behaviour (functional findings):
not specified
Immunological findings:
not specified
Organ weight findings including organ / body weight ratios:
not specified
Gross pathological findings:
not specified
Neuropathological findings:
not specified
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
A slightly increased incidence of mitosis, and invasion of adjacent renal tissue by tumor cells and Kidney: nephropathy was observed.
Pituitary Gland: Adenoma or carcinoma (Combined) of the pars distalis occurred with a significant negative trend in female rats. The incidence in the high-dose group was significantly lower than in the control.
Lymphoid Tissue: Red pigment, presumably compound- related, was observed in the lymphoid tissue of the small intestine in females and in the mesenteric lymph nodes in males. There was a dose-related increase in the amount of pigment present. The pigment consisted of distinct red granules or small elongated crystals within the cytoplasm of the macrophages.
Histopathological findings: neoplastic:
not specified
Other effects:
not specified

Effect levels

Dose descriptor:
NOAEL
Effect level:
1 250 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
clinical signs
mortality
body weight and weight gain
food consumption and compound intake
haematology
clinical biochemistry
histopathology: non-neoplastic
Remarks on result:
other: No toxic effect were observed

Target system / organ toxicity

Critical effects observed:
not specified

Applicant's summary and conclusion

Conclusions:
The NOAEL value for repeated dose toxicity of the given test chemical in male and female F344 rats was considered to be 1250 mg/kg/day.
Executive summary:

Two year repeated dose toxicity study was conducted by administering the given test chemical to male and female rats at doses of 0, 500, 1250, and 2500 mg/kg in feed for 103 weeks. All animals were observed twice daily. Clinical findings for rats were noted and recorded during body weight measurements and at sacrifice. Body weights were recorded weekly for the first 13 weeks, and then every four weeks until the end of the study; body weights were also recorded at the end of the study. Feed consumption was recorded daily per cage. Complete necropsies were performed on all animals. During necropsy all organs and tissues were examined for grossly visible lesions. Tissues for microscopic examination were preserved in 10% neutral buffered formalin and routinely processed for microscopic examination (embedded in paraffin, sectioned at 4-5 microgram, and stained with hematoxylin and eosin). Complete histopathologic evaluation was performed on animals from the control and high-dose group, on selected tissues, and on target organs and gross lesions from low- and mid-dose animals. Mean ± standard deviation was observed. No mortality were observed at all treated groups 500, 1250 or 2500 mg/kg compare to control. There were no clinical findings in rats considered to be chemically related. Mean body weights of male rats were similar to that of the controls throughout the 2-year study. From week 20 to the end of the study, the mean body weights of mid- and high-dose females were consistently lower than that of the controls. Feed consumption by exposed male and female rats was similar to that of to the controls. In male rats, there were no biologically significant differences in hematology parameters related to chemical exposure. In female rats, Hematocrit values, hemoglobin concentration, and erythrocyte counts interim evaluation were significantly less than those of the controls and serum total bilirubin was significantly increased in 2500 mg/kg female rats at the 15-month. In male rats, there were no biologically significant differences in clinical chemistry parameters related to chemical exposure. A slightly increased incidence of mitosis, and invasion of adjacent renal tissue by tumor cells and Kidney: nephropathy was observed. In Pituitary Gland, adenoma or carcinoma (Combined) of the pars distalis occurred with a significant negative trend in female rats. The incidence in the high-dose group was significantly lower than in the control. In lymphoid Tissue, red pigment, presumably compound- related, was observed in the lymphoid tissue of the small intestine in females and in the mesenteric lymph nodes in males. There was a dose-related increase in the amount of pigment present. The pigment consisted of distinct red granules or small elongated crystals within the cytoplasm of the macrophages. Mononuclear cell leukemia occurred with a decreased incidence in male and female rats. Under the condition of the study, the NOAEL value for repeated dose toxicity of the given test chemical in male and female F344 rats was considered to be 1250 mg/kg/day.