4-[[4-(aminocarbonyl)phenyl]azo]-N-(2-ethoxyphenyl)-3-hydroxynaphthalene-2-carboxamide

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From03 JUN 1992 to 01 JUL 1992

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (OECD TG 407), GLP compliant

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

4-[[4-(aminocarbonyl)phenyl]azo]-N-(2-ethoxyphenyl)-3-hydroxynaphthalene-2-carboxamide

EC Number:

220-509-3

EC Name:

4-[[4-(aminocarbonyl)phenyl]azo]-N-(2-ethoxyphenyl)-3-hydroxynaphthalene-2-carboxamide

Cas Number:

2786-76-7

Molecular formula:

C26H22N4O4

IUPAC Name:

4-[(4-carbamoylphenyl)diazenyl]-N-(2-ethoxyphenyl)-3-hydroxy-2-naphthamide

Test material form:

solid: bulk

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Hoe: WISKf (SPF71)
- Source: Hoechst AG, Kastengrund, SPF breeding colony, Germany
- Age at study initiation: 6 weeks
- Housing: in groups of 5 in fully air-conditioned rooms in wire-mesh cages (type 4)
- Diet: Altromin1321 rat diet (Altromin GmbH, Lage/Lippe), ad libitum
- Water: tap water in plastic bottles, ad libitum
- Acclimation period: approx. 5 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 50 +-20
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
- dose formulations were prepared once before beginning of the study.
- 1 kg of Premix with 8-fold concentration and 7 kg of Altromin 1321 were mixed for 30 minutes using a Lödoge Plugscharmischer.

VEHICLE
-none

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

After preparation the mixture was analysed for homogenicity and compound content. (no further details provided)

Duration of treatment / exposure:

28 days

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 500, 2500, 12500 mg/kg food
Basis:
nominal in diet

No. of animals per sex per dose:

- 5 male and 5 female in each dose group

Control animals:

yes, concurrent no treatment

Details on study design:

- Dose selection rationale: Based on the results of a preliminary study (3 males/3 females, treated for 14 days with 12500 mg/kg food). Animals showed normal body weight development, no deaths or symptoms occurred, no macroscopically visible changes observed at the end of the study.

Positive control:

- none

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes,
- Time schedule: twice weekly

FOOD CONSUMPTION: yes
- Time schedule: twice weekly
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

WATER CONSUMPTION: yes
- Time schedule: once weekly over a period of 16 h

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: weeky
- Endpoint investigated: opacity of the refracting media of the eyes
- Dose groups that were examined: all

HAEMATOLOGY: Yes
- Time schedule: after 4 weeks
- Parameters checked see below in Hematology

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: after 4 weeks
- Animals fasted: No
- How many animals: all animals
- Parameters checked see below

URINALYSIS: Yes
- Time schedule for collection of urine: a few days before termination of the study
- Metabolism cages used for collection of urine: Yes
- Animals fasted: no data
- Parameters checked see below

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: weekly
- Dose groups that were examined: all
- Battery of functions tested: neurological disturbances

OTHER:
- weekly investigation of damage to the oral mucosa, impairment of dental growth

Sacrifice and pathology:

GROSS PATHOLOGY: Yes (parameters checked see below)
HISTOPATHOLOGY: Yes (parameters checked see below)

Statistics:

The following parameters were compared statistically with the control group values at the level of significance p = 0.05:
- Body weight at the designated measurement times
- Hematological data
- Clinical chemistry parameters
- Clinical chemistry parameters
- Urine data (volume, pH-value, specific weight)
- Absolute organ weights and organ to body weight ratios.

Results and discussion

Results of examinations

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

no effects observed

Ophthalmological findings:

no effects observed

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

no effects observed

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

not examined

Details on results:

CLINICAL SIGNS AND MORTALITY:
- no deaths occurred during the test
- red feces were noted in all animals treated with the test item
- red discoloured fur was observed in the animals of the high dose group
- overall no clinical observations of toxicological relevance were found

BODY WEIGHT AND WEIGHT GAIN
The body weight gains were not impaired by the administration of the test substance

FOOD AND WATER CONSUMPTION:
- The absolute and relative food consumption remained unaffected by the treatment during the whole study.
- Water consumption was comparable in all groups

CLINICAL LABORATORY INVESTIGATOIONS
- HAEMATOLOGY
- Some changes in haematological parameters were noted in male animals of the highest dosing group: Reticulocyte count was significantly decreased. However the change was only small, and remained within the range considered normal for rats of this age and strain. Furthermore there were no signs indicative for anemia. Therefore, this change is considered not to be treatment related.

- CLINICAL CHEMISTRY
Several clinical biochemistry parameters were changed at a intermediate and highest dose level. These changes were slight and were not accompanied with any alteration indicative for a toxic effect. Therefore a compound-related effect is not evident. In other cases there was no dose-dependency .

- URINANALYSIS
No treatment-related changes were detected by urine analysis. The sediments were normal.

ORGAN WEIGHTS
Some changes were noted in liver, ovary, thymus and adrenal weight of animals treated with the intermediate and highest concentration. As there was no dose-dependency these changes are considered not to be treatment-related. Regarding the increase in relative thymus weight no histpathological visible alterations were found.

GROSS PATHOLOGY
- test compound could be detected in the lumen of the alimentary tract, adherent to the surface of the mucous membrane and/or the food. The mucous membranes itself were uninjured.

Effect levels

1

Dose descriptor:

NOAEL

Effect level:

1 172 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male

Basis for effect level:

other: no clinical signs; no mortality; body weight development was not impaired; food consumption was not affected; no findings in haematology; urinalysis, gross pathology and histopathology up to highest dose tested

2

Dose descriptor:

NOAEL

Effect level:

1 193 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

female

Basis for effect level:

other: no clinical signs; no mortality; body weight development was not impaired; food consumption was not affected; no findings in haematology; urinalysis, gross pathology and histopathology up to highest dose tested

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

There were no changes in clinical appearance, functional observations, body weights, food consumption, clinical laboratory investigations, macroscopic examination, organ weights and microscopic examination that were considered to be an effect of treatment.
From the results presented in this report a definitive No Adverse Observed Effect Level (NOAEL) of 12500 mg/kg food was established, This is equivalent to a mean daily compound intake of 1172 mg/kg bw in males and 1193 mg/kg bw in females.

Executive summary:

A 28-day repeated dose toxicity study with the test item administered orally via the food to Wistar rats (SPF-bred; 5/sex/dose) was performed according to OECD TG 407. The dose levels for this study were 500, 2500 and 12500 mg/kg food. A control group was treated similarly without the test item. The dosing lasted for 28 days. The test item revealed no treatment-related findings. From the results presented in this report a definitive No Observed Adverse Effect Level (NOAEL) for the test item of 1172 mg/kg bw and day for male rats and 1193 mg/kg bw and day for female rats was established.