4'-chloro-2',5'-dimethoxyacetoacetanilide

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: well performed OECD and GLP guideline study

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'-chloro-2',5'-dimethoxyacetoacetanilide

EC Number:

224-638-6

EC Name:

4'-chloro-2',5'-dimethoxyacetoacetanilide

Cas Number:

4433-79-8

Molecular formula:

C12H14ClNO4

IUPAC Name:

N-(4-chloro-2,5-dimethoxyphenyl)-3-oxobutanamide

Details on test material:

- Name of test material (as cited in study report): Naphthol AS IRG

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

Source: Hoechst AG, Kastengrund, SPF breeding colony
Age: approx 6 weeks

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: sesame oil

Analytical verification of doses or concentrations:

not specified

Duration of treatment / exposure:

once daily, 28 applications within 29 days, 7 days/week

Frequency of treatment:

daily

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
4.0 mg / kg bw / d
Basis:
actual ingested

Doses / concentrations 2

Remarks:

Doses / Concentrations:
20.0 mg / kg bw / d
Basis:
actual ingested

Doses / concentrations 3

Remarks:

Doses / Concentrations:
100.0 mg / kg bw / d
Basis:
actual ingested

No. of animals per sex per dose:

5 female, 5 male

Control animals:

yes, concurrent vehicle

Examinations

Observations and examinations performed and frequency:

Behaviour and state of health were observed daily in all groups. Body weights and food consumption were recorded twice weekly, and water consumption once weekly.
Hematological examinations and clinical chemistry were carried out at the termination of the study. Urine analysis was also performed at the end of the study.

Sacrifice and pathology:

During necropsy the animals were examined for macroscopically visible abnormalities, the main organs weighed and the organ to body weight ratios calculated. Many organs and tissues were processed for histopathological examination and checked for microscopically visible changes.

Statistics:

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

Results and discussion

Effect levels

Dose descriptor:

NOEL

Effect level:

20 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

other: The test substance caused no detectable effects at the dose of 20mg/kg body weight per day in male and female Wistar rats when administered 28 times during 29 days.

Target system / organ toxicity

Critical effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

With regard to the present study the "no observed effect level" is 20 mg/kg body weight per day in male and female Wistar rats.

Executive summary:

Groups of 5 male and 5 female Wistar rats received Naphthol AS IRG by oral gavage at dose levels of 0, 4, 20 or 100 mg/kg body weight per day for 28 days and were necropsied at day 29.

Behaviour and state of health were observed daily in all groups. Body weights and food consumption were recorded twice weekly, and water consumption once weekly.

Hematological examinations and clinical chemistry were carried out at the termination of the study. Urine analysis was also performed at the end of the study.

During necropsy the animals were examined for macroscopically visible abnormalities, the main organs weighed and the organ to body weight ratios calculated. Many organs and tissues were processed for histopathological examination and checked for microscopically visible changes.

Body weights, hematological and clinical chemistry data, urine data (volume, pH value, specific weight), absolute and relative organ weights were analysed with the aid of a statistical program to show differences compared with the controls.

Beside unspecific symptoms males and females of the highest dose group showed impairments of motility and breathing from day 1 up to day 9 of the study. Additionally mucous feces was observed in two male animals of the highest dose group at day one of the study. Increased salivation occurred in females of the 100 mg/kg body weight per day group sporadically starting from day 23 of the study. Behaviour and general health condition of the other animals remained normal throughout the study.

Development of body weight was not impaired. Food and water consumption remained unaffected by the treatment during the whole study.

Examination of the urinary status revealed dark yellow discoloration and positive bilirubin indications in both sexes of the high dose group. No compound-related changes were observed in the other groups.

Hematological examinations showed decreases in erythrocyte counts, hemoglobin and hematocrit values in both sexes of the high dose group.

Clinical chemistry investigations showed no compound related effect.

Liver weights were increased in both sexes of the high dose group.

No compound related macroscopically visible changes were observed at necropsy.

The histopathological examinations revealed no compound-related effects.

In conclusion repeated application of 100 mg Naphthol AS IRG per kg body weight caused clinical signs of intoxication in both sexes. Additionally, signs of slight anemia and slight elevations of liver weights were observed in this group. The positive bilirubin indications in the urine could either be due to real bilirubin presence or due to interaction of the test substance or its metabolites with the test stick.

Naphthol AS IRG caused no detectable effects at the dose of 20 mg/kg body weight per day in male and female Wistar rats when administered 28 times during 29 days.

With regard to the present study the "no observed effect level" is 20 mg/kg body weight per day in males and females.