Pyrrolo[3,4-c]pyrrole-1,4-dione, 3,6-bis([1,1'-biphenyl]-4-yl)-2,5-dihydro-

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:

1992-1993

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP and OECD testing guideline compliant study with well characterized test material

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1993

Reference 2

Reference Type:

other: amendment to study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

May 12, 1981

Deviations:

yes

Remarks:

No functional observations

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Details on test material:

- Substance type: Organic
- Physical state: Solid
- Lot/batch No.: Z-2281/1,2,4,5
- Expiration date of the lot/batch: April 01, 1997
- Storage condition of test material: at room temperature in the dark

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: BRL Ltd., Basel, Switzerland
- Age at study initiation: Approximately 6 weeks
- Weight at study initiation: males (mean): 170g (males), 140g (females)
- Housing: 5 animals per cage
- Diet (e.g. ad libitum): Free access to standard pelleted laboratory animal diet
- Water (e.g. ad libitum): Free access to tap water
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 30-70
- Photoperiod (hrs dark / hrs light): 12 hours/12 hours

In-Life-phase: 1993-02-09 to 1993-04-07

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Details on oral exposure:

- PREPARATION OF DOSING SOLUTIONS: Formulations (w/w) were prepared daily within 4 hours prior to dosing, and were homogenised to visually acceptable levels.
- DOSE VOLUME: 10 ml/kg body weight. Actual dose volumes were calculated weekly according to the latest body weight.
- RECOVERY: for 14 days

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Test substance formulations in polyethylene glycol formed homogeneous suspensions. Analysis of the accuracy of dose preparations revealed values within the range of 3% to 4% of nominal, which was considered to represent an acceptable level of accuracy for formulations of this type.

Duration of treatment / exposure:

Treatment for 28 days, 7 days per week, two weeks of treatment-free recovery for satellite group.

Frequency of treatment:

Once daily (7 days per week)

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 50, 200 and 1000 mg/kg body weight/day
Basis:
actual ingested

No. of animals per sex per dose:

5 animals

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Based on the results of a 5-day range finding study, the dose levels for the 28-day toxicity study were selected to be 0, 50, 200 and 1000 mg/kg/day

Positive control:

no

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily
- Cage side observations: Mortality/Viability

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: At least once daily

BODY WEIGHT: Yes
- Time schedule for examinations: Weekly and on the day preceding termination, prior to overnight fasting.

FOOD CONSUMPTION: Yes
- Time schedule: Weekly

WATER CONSUMPTION: Yes
- Time schedule for examinations: Subjective appraisal was maintained during the study, but no quantitative investigation introduced as no effect was suspected

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: week 4; Since no treatment-related ophthalmoscopic effects were noted in week 4, no ophthalmoscopic examination was performed in week 6
- Dose groups that were examined: all groups

HAEMATOLOGY: Yes
- Time schedule for collection of blood: prior to scheduled post mortem examination
- Anaesthetic used for blood collection: Yes, ether
- Animals fasted: Yes, overnight (with a maximum of 20 hours)
- Parameters checked: Erythrocytes count, Haemoglobin, Haematocrit, Mean corpuscular volume, Mean corpuscular haemoglobin, Mean corpuscular haemoglobin concentration, Platelets count, Red cell distribution width, Total leucocytes count, Differential leucocyte count (Neutrophils, Eosinophils, Basophils, Lymphocytes, Monocytes); Prothrombin time, Partial thromboplastin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: prior to scheduled post mortem examination
- Animals fasted: Yes, overnight (with a maximum of 20 hours)
- Parameters checked: Alanine aminotransferase, Alkaline phosphatase, Aspartate aminotransferase, Gamma-glutamyl transferase, Bilirubin (total), Chloride, Cholesterol (total), Creatinine, Glucose, Phosphorus, Protein (total), Protein (albumin, globulin, Albumin Globulin ratio), Triglycerides, Urea, Calcium, Potassium, Sodium

Sacrifice and pathology:

GROSS PATHOLOGY: Yes, of - Adrenal glands, Aorta, Brain (representative regions, including cerebrum, cerebellum and pons), Caecum (Cervix), (Clitoral gland), Colon, Duodenum, Epididymides, (Eyes with optic nerve and Harderian gland), (Female mammary gland area), (Femur including joint), Heart, Ileum, Jejunum, Kidneys, (Larynx), (Lacrimal gland, exorbital), Liver, Lung (infused with formalin), Lymph nodes (mandibular, mesenteric), (Nasopharynx), Oesophagus, Ovaries, Pancreas, Peyer's patches (jejunum, ileum) if detectable, Pituitary gland, (Preputial gland), Prostate gland, Rectum, (Salivary glands - mandibular, sublingual), Sciatic nerve, (Seminal vesicles), (Skeletal muscle), (Skin), Spinal cord (cervical, midthoracic, lumbar), Spleen, Sternum with bone marrow, Stomach, Testes, Thymus, Thyroid including parathyroid, (Tongue), Trachea, Urinary bladder, Uterus, (Vagina), all gross lesions
- Organ weights: Adrenal glands, Kidneys, Ovaries, Testes, Brain, Heart, Liver, Spleen.

HISTOPATHOLOGY: Yes, Slides of adrenals, heart, kidneys, liver, spleen, stomach and testes, collected at termination from all animals of the control group and the high dose group, as well as from all gross lesions of all animals were examined by a pathologist. All abnormalities were described and included in the report.

Statistics:

The following statistical methods were used to analyse the data:
- If the variables could be assumed to follow a normal distribution, the Dunnett-test (many-to one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test (many-to-one rank test) was applied when the data could not be assumed to follow a normal distribution.
- The exact Fisher-test was applied to frequency data
All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance.

Results and discussion

Results of examinations

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortality occurred during the study period. There were no clinical signs of toxicity or behavioural changes during the study period that were considered to be related to treatment.

Red appearance of tissues and faeces was observed in all animals of the treatment groups during the 4 weeks of oral treatment. The red staining of tissues were attributed to contact with the red discoloured faeces. Among males receiving 50 mg/kg/day (Group 2), only the tail was noted to be red and among animals receiving 200 or 1000 mg/kg/day (Groups 3 and 4, respectively), the anus region or other parts of the whole body were also affected. Since the test substance is a red pigment, these findings were attributed to the physico-chemical properties of the test substance.

BODY WEIGHT AND WEIGHT GAIN
Body weights and body weight gain of treated animals were considered to have been unaffected by treatment with the test substance.

FOOD CONSUMPTION
There were no differences in food consumption before or after allowance for body weight between treated and control animals.

OPHTHALMOSCOPIC EXAMINATION
There were no ophthalmoscopic findings in week 4.

HAEMATOLOGY
Haematological parameters of treated rats were considered not to have been affected by treatment.


CLINICAL CHEMISTRY
Clinical chemistry parameters of treated rats were considered not to have been affected by treatment.

ORGAN WEIGHTS
Organ weights of animals receiving 50, 200 or 1000 mg/kg/day (Groups 2, 3 and 4) were considered to be similar as organ weights of control animals after 4 weeks of treatment and the subsequent recovery period. The statistically significant increase of the relative kidney weight (relative to the body weight) of males receiving 1000 mg/kg/day (Group 4) at week 4, when compared to the corresponding control males, was considered to have arisen by chance, as there were no corroborative findings noted in the opposite sex or in other toxicological parameters measured.

GROSS PATHOLOGY
Macroscopic observations at necropsy did not reveal any alterations that were considered to have arisen as a result of treatment.

HISTOPATHOLOGY
There were no microscopic findings recorded which could be attributed to treatment with the test substance.

Effect levels

Dose descriptor:

NOEL

Effect level:

>= 1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects observed

Target system / organ toxicity

Critical effects observed:

not specified