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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
short-term repeated dose toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2010
Report Date:
2010

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity in Rodents)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Physical state: liquid
- Purity: 100%
- Molecular Mass (g/mol): approx. 235

Test animals

Species:
rat
Strain:
Wistar
Sex:
male/female

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: Aqua dem.
Details on oral exposure:
The administration volume was 10 ml/kg body weight per day. The formulations were prepared as needed and taking into account the analytically determined stability. For the preparation of the formulations the content of test item was assumed to be nominally 100% for calculation.
The test item was administered as a solution in the vehicle. The formulations were stored at room temperature.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Before the start of treatment the stability of the formulations were analytically confirmed. For these analyses dosage forms were prepared in the same way as done in the study.
- Stability: The dosage forms prepared for analysis were analyzed shortly after preparation (2 hours) and 8 days thereafter. The analysis revealed that the test item was stable over this period within the defined limits.
- Content checks: For this purpose the test substance concentrations in formulations (including controls) given to the animals were determined two times during the study.
Duration of treatment / exposure:
29 days
Frequency of treatment:
once daily
Doses / concentrations
Remarks:
Doses / Concentrations:
100, 300, 1000 mg/kg bw
Basis:
actual ingested
No. of animals per sex per dose:
five
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale:

In a two-week pilot study five animals per sex and dose received 0, 100, 300 and 1000 mg/kg test substance. In-life data, necropsy, organ weight measurements and histopathology (stomach only) did not show any treatment-related changes up to 1000 mg/kg.

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily

DETAILED CLINICAL OBSERVATIONS: Yes (incl. Open Field Observations (OFO))
- Time schedule: once before start and once weekly thereafter

BODY WEIGHT: Yes
- Time schedule for examinations: daily

FOOD CONSUMPTION: Yes
- Time schedule for examinations: weekly

WATER CONSUMPTION: Yes
- Time schedule for examinations: weekly

HAEMATOLOGY: Yes
- Time schedule for collection of blood: once, day 28
- How many animals: all dose groups incl. controls

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: once, day 28
- How many animals: all dose groups incl. controls

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: FOB: once, day 26-27 ); MA: once, day 21-22
- Dose groups that were examined: all dose groups incl. controls
- Battery of functions tested: Functional Observational Battery (FOB); Motor Activity (MA)
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (all dose groups and controls)

ORGAN Weights:
Adrenals, brain, epididymides, heart, kidneys, Liver, Ovaries, Spleen, Testes, Thymus, uterus, prostate, seminal vesicle with coagulation glands

Fixed organs:
Adrenals, aorta, brain (cerebrum, cerebellum, ponslmedulla), epididymides, esophagus, eyes, eyelids, extraorbital lachrymal glands, femur, harderian glands, head (with nasal and paranasal cavities), heart, intestine (duodenum, jejunum, ileum, cecum, colon, rectum and remaining intestine), kidneys, larynx, liver, lymph nodes (mandibular, bronchial/hilus, and mesenteric), lung, mamma, optical nerves, ovaries, oviducts, pancreas, pharynx, pituitary, prostate, salivary glands, sciatic nerve, seminal vesicles (incl. coagulating glands), skeletal muscle (thigh), skin (mammary and muzzle), spinal cord (cervical, thoracic, lumbar), spleen, sternum, stomach (forestomach and glandular stomach), testes, thymus, thyroids (including parathyroid glands), tongue, trachea, ureter, urethra, urinary bladder, uterus with uterine cervix, vagina, Zymbal’s glands and all organs or tissues with macroscopic findings.

HISTOPATHOLOGY: Yes (high dose group and controls)
- Microscopic: Adrenals, aorta, brain (cerebrum, cerebellum, brain stem), epididymides, eyes, femur, heart, intestine (duodenum, jejunum, ileum, cecum, colon, rectum and remaining intestine), kidneys, lung, ovaries, oviducts, prostate, sciatic nerve, skeletal muscle (thigh), spinal cord (cervical, thoracic, lumbar), sternum with bone marrow, testes, seminal vesicles (incl. coagulating glands), stomach, trachea and thyroids glands, urinary bladder, uterus with uterine cervix, vagina and all organs or tissues with macroscopic findings.

HISTOPATHOLOGY: Yes (all dose groups and controls)
-Microscopic: liver, lymph nodes, spleen, thymus

Statistics:
Statistical tests on body weights and weight gain as well as on absolute organ weights were done using the Dunnett Exact Homogeneous Test. For relative organ weights the Dunnett Exact Homogeneous Test after log. Transformation was used.
If primary food and water intake data were recorded, the calculated food/water intake per animal was evaluated using adjusted Mann-Whitney U-test.
The Dunnett Exact Homogeneous or Heterogeneous Test, the Dunnett Exact Homogeneous Test after log. Transformation or the Bonferroni/Mann-Whitney U-test was used for clinical pathology parameters.
Descriptive statistics were provided per sex, dose group and time point for all parameters that were recorded with a specified unit. These included measures of general tendency (mean, median) and general variability (standard deviation, minimum, maximum) as appropriate.
For continuous variables, the statistical test procedure was based on prior knowledge of the respective variable derived from previous studies. For normally distributed variables with equal variances across treatment groups Dunnett’s tests were performed. Heteroscedastic normally distributed variables were analysed using appropriately adjusted Dunnett’s tests, using Satterthwaite adjustments for the degrees of freedom and taking the different variances within the groups into account. For log-normally distributed variables, Dunnett's tests were performed after log-transformation of the original values. If experience with historical data indicated that the assumptions for parametric analyses are violated, Bonferroni-adjusted Mann-Whitney U-tests were employed in the analyses. For small sample sizes, the exact version of this test was used. With respect to data collected in the functional observational battery categorical variables were analyzed with a repeated measures analysis of variance followed by a one-way analysis of variance using the SAS procedure PROC CATMOD.

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:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
no effects observed
Organ weight findings including organ / body weight ratios:
effects observed, treatment-related
Gross pathological findings:
effects observed, treatment-related
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Histopathological findings: neoplastic:
no effects observed
Details on results:

ORGAN WEIGHTS:

At 1000 mg/kg males exhibited higher means for liver (15-17%) and kidney (11-13%) weights (absolute and as % of terminal body weight). No other organ weight mean was remarkably or dose-dependently changed up to 1000 mg/kg.

GROSS PATHOLOGY:

Gross pathology revealed in the liver of some 1000 mg/kg males distinct lobulation, enlargement or swelling. The thymus was enlarged in one male at 300 mg/kg, which was considered as incidental.

HISTOPATHOLOGY:

In the liver minimal to slight hepatocellular cytoplasmic change/hypertrophy was seen in 1000 mg/kg males. In the absence of any other liver changes, this is not seen as an adverse effect.
In the spleen increased germinal centers were present in the white pulp follicles of 1000 mg/kg males. A treatment-relation could not be excluded for this finding.

Effect levels

open allclose all
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (actual dose received)
Sex:
female
Basis for effect level:
other: Regarding clinical examinations, clinical pathology as well as pathology the limit dose of 1000 mg/kg bw did not cause any signs of toxicity
Dose descriptor:
NOAEL
Effect level:
300 mg/kg bw/day (actual dose received)
Sex:
male
Basis for effect level:
other: microscopic changes in the spleen

Target system / organ toxicity

Critical effects observed:
not specified

Any other information on results incl. tables

ORGAN WEIGHTS:

At 1000 mg/kg males exhibited higher means for liver (15-17%) and kidney (11-13%) weights (absolute and as % of terminal body weight). No other organ weight mean was remarkably or dose-dependently changed up to 1000 mg/kg.

GROSS PATHOLOGY:

Gross pathology revealed in the liver of some 1000 mg/kg males distinct lobulation (1/5, enlargement (1/5) or swelling (1/5). The thymus was enlarged in males at 300 mg/kg bw (1/5) and 1000 mg/kg (2/5), without histopathological correlate.

HISTOPATHOLOGY:

In the liver minimal to slight hepatocellular cytoplasmic change/hypertrophy was seen in 1000 mg/kg males (4/5, grade 1; 1/5, grade 2). In the absence of any other liver changes, this is not seen as an adverse effect.

In the spleen increased germinal centers were present in the white pulp follicles of 1000 mg/kg males (1/5, grade 1; 3/5, grade 2). A treatment-relation could not be excluded for this finding.

Applicant's summary and conclusion

Executive summary:

In a repeated dose oral toxicity study in rats (Wistar, OECD TG 407), ethan-1,2 -diol, propoxylated was adimistered via gavage to 5 rats/sex/dose at 0, 100, 300, 1000 mg/kg bw for 4 weeks. Up to and including 1000 mg/kg bw no mortality occured. The behavior and clinical appearance of the rats were not influenced by the treatment up to and including 1000 mg/kg in both sexes. The body weight gain, the food and water intake were not affected up to and including 1000 mg/kg in males and females. The results from Functional Observational Battery (FOB) measurements in males and females receiving up to and including 1000 mg/kg bw did not differ from the control animals. Motor and Locomotor Activity(MA/LMA) tests did not indicate neurotoxicity up to and including 1000 mg/kg. No effects with toxiocological relevance in haematology in both sexes up to and including 1000 mg/kg bw. No remarkable changes occurred in clinical chemical parameters in the blood up to and including 1000 mg/kg in males and females. Gross pathology revealed in the liver of some 1000 mg/kg males distinct lobulation, enlargement or swelling and accordingly an increase in liver weights.

Histopathologically these findings correlated with minimal to slight hepatocellular cytoplasmic change/hypertrophy in the males of the 1000 mg/kg bw dose group. In the absence of any other liver changes, this is not seen as an adverse effect but as an adaptive response. In the spleen increased germinal centers were present in the white pulp follicles of 1000 mg/kg males. A treatment-relation could not be excluded for this finding.

Based on these results the NOAEL was considered to be 1000 mg/kg bw and day for females and 300 mg/kg bw and day for males due to the microscopic changes in the spleen