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Toxicological information

Repeated dose toxicity: oral

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Administrative data

Endpoint:
sub-chronic toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
27 Jun 1988 - 17 Jul 1989
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP - Guideline study with acceptable restriction. No ophthalmological examinations were performed prior to treatment. No information on detailed clinical examinations.
Justification for type of information:
refer to category justification provided in IUCLID section 13

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1989
Report Date:
1989

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EU Method B.26 (Sub-Chronic Oral Toxicity Test: Repeated Dose 90-Day Oral Toxicity Study in Rodents)
Deviations:
yes
Remarks:
No ophthalmological examinations were performed prior to treatment; no information on detailed clinical examinations
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
other: Sprague Dawley CD
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River, Sulzfeld; Germany
- Age at study initiation: 5-6 weeks
- Weight at study initiation: 169.6 (m) and 140.9 (f) g (control group); 157.0 (m) and 140.7 (f) g (250 mg/kg bw/d test group); 161.5 (m) and 138.4 (f) g (500 mg/kg bw/d test group); 166.5 (m) and 138.2 (f) g (1000 mg/kg bw/d test group)
- Housing: animals were housed in groups of 2-3 per sex in Makrolon type III cages with soft wood bedding (ARWI-Center, Essen, Germany)
- Diet: pelleted maintenance diet Altromin 1324 DK (Altromin GmbH, Lage, Germany), ad libitum
- Water: tap water, ad libitum
- Acclimation period: 11 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-23
- Humidity (%): 54-68
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: 27.06.1988 To: 29/30.09.1988 (main test groups) and 26.10.1988 (satellite control and test group)

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS: dosing solutions of the test substance in water were prepared daily and just prior to application.

VEHICLE
- Concentration in vehicle: 2.5, 5 and 10% w/v
- Amount of vehicle (if gavage): 10 mL/kg bw
Analytical verification of doses or concentrations:
no
Duration of treatment / exposure:
90 days
Frequency of treatment:
once daily in the morning, 5 days/week
Doses / concentrationsopen allclose all
Dose / conc.:
250 mg/kg bw/day (nominal)
Dose / conc.:
500 mg/kg bw/day (nominal)
Dose / conc.:
1 000 mg/kg bw/day (nominal)
No. of animals per sex per dose:
10 (main study), 5 (satellite control and high dose group)
Control animals:
yes, concurrent vehicle
Details on study design:
- Rationale for selecting satellite groups: satellite groups were used to assess the cumulative toxicity and reversibility of effects.
- Post-exposure recovery period in satellite groups: 27 days

Examinations

Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: animals were checked for mortality and clinical signs twice daily.

BODY WEIGHT: Yes
- Time schedule for examinations: animals were weighed at arrival, on the first day of treatment, and then weekly throughout the treatment period and before necropsy.

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Food consumption for each animal cage determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes

WATER CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule for examinations: Water consumption was calculated at weekly intervals with the exception of days where clinical examinations were performed.

OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: 1 day before necropsy
- Dose groups that were examined: control and high dose group

HAEMATOLOGY: Yes
- Time schedule for collection of blood: after 6 weeks (interim examination) and at study termination
- Anaesthetic used for blood collection: Yes (ether)
- Animals fasted: No data
- How many animals: all surviving animals
- Parameters listed in Table 1 under "Any other information on materials and methods incl. tables" were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: : after 6 weeks (interim examination) and at study termination
- Animals fasted: No data
- How many animals: all surviving animals
- Parameters listed in Table 1 under "Any other information on materials and methods incl. tables" were examined.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see Table 2 under "Any other information on materials and methods incl. tables)"

HISTOPATHOLOGY: Yes (see Table 2 under "Any other information on materials and methods incl. tables)"

ORGAN WEIGHTS: Yes (see Table 2 under "Any other information on materials and methods incl. tables)"

Necropsy included the examination of all major organs, tissues and body cavities. Histopathological examinations were performed on all the animals of the control and high dose groups. The histopathological examination of the glandular stomach was also performed in animals of the intermediate dose groups and the satellite high dose group.
Statistics:
The following statistical analyses were performed to compare mean values of control and treatment groups:
- t-test: body weights and blood parameters
- t-test followed by Dunnett’s test: biochemical parameters
- U-test: organ weights

Results and discussion

Results of examinations

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
250 mg/kg bw/d (males): slightly reduced body weights until Week 5 and in Week 7; 500 mg/kg bw/d (males): slightly reduced body weights between Weeks 1-7
Food consumption and compound intake (if feeding study):
no effects observed
Food efficiency:
not examined
Water consumption and compound intake (if drinking water study):
effects observed, treatment-related
Description (incidence and severity):
1000 mg/kg bw/d: slightly increased
Ophthalmological findings:
no effects observed
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
1000 mg/kg bw/d: edema and ulceration of the forestomach
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
500 and 1000 mg/kg bw/d: inflammatory edema of the submucosa of the forestomach as well as multiple ulcerations; acanthosis and proliferation of forestomach mucosa; 1000 mg/kg bw/d (satellite group): incomplete regeneration of forestomach mucosa
Histopathological findings: neoplastic:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY
No substance-related mortalities occurred during the study period. Due to mistakes in blood sampling, two males of the group 2 (250 mg/kg bw/d) inadvertently died. One female of group 3 (500 mg/kg bw/day) died as a result of incidental gavage errors.

BODY WEIGHT AND WEIGHT GAIN
The total body weight gain was slightly decreased during Weeks 1-7 of applications in males of groups 2 (250 mg/kg bw/d) and 3 (500 mg/kg bw/d) in comparison to control due to lower initial weight of the above test groups.

FOOD CONSUMPTION AND COMPOUND INTAKE
No substance-related effects on food consumption were observed during the study period.

WATER CONSUMPTION AND COMPOUND INTAKE
During test substance administration, the mean water intake was, probably compound related, slightly increased in test animals of the group 4 (1000 mg/kg bw/d).

OPHTHALMOSCOPIC EXAMINATION
There were no treatment-related changes at the ophthalmological examination.

HAEMATOLOGY
No substance-related effects were observed for haematological parameters at study termination. Slight changes in leukocytes, lymphocytes and thrombocytes were observed at the interim examination (after 6 weeks).

CLINICAL CHEMISTRY
No substance-related changes in clinical chemistry parameters were noted during the study.

ORGAN WEIGHTS
Although a slight reduction in the absolute organ weights of gonads, brain and thymus as well as slight increases in the relative organ weights of kidney and liver occurred in the treated groups, these effects were not considered to be treatment-related since no corresponding changes in histopathology were observed.

GROSS PATHOLOGY
Gross section revealed ulcerations and oedema restricted to forestomach in the group 4 (1000 mg/kg bw/d).

HISTOPATHOLOGY: NON-NEOPLASTIC
Histopathogical evaluation revealed inflammatory edema of the submucosa as well as multiple ulcerations associated with acanthosis and proliferation of the mucous membrane of forestomach in animals of groups 3 (500 mg/kg bw/d) and 4 (1000 mg/kg bw/d), but less distinctive in group 3. The test animals of group 2 (250 mg/kg bw/d) did not show substance-related findings in the forestomach. Animals of the 1000 mg/kg bw/d satellite group demonstrated incomplete regeneration of the forestomach mucosa after 27 treatment-free days.

Effect levels

open allclose all
Key result
Dose descriptor:
LOEL
Remarks:
local
Effect level:
500 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: inflammation and ulcerations of mucous membrane of the forestomach due to bolus administration and irritating potential of the test substance (local effect)
Key result
Dose descriptor:
NOAEL
Remarks:
systemic
Effect level:
>= 1 000 mg/kg bw/day (nominal)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: no systemic or cumulative effects

Target system / organ toxicity

Key result
Critical effects observed:
no

Applicant's summary and conclusion

Conclusions:
A 90-day repeated dose toxicity study with the test material was performed equivalent to EU Method B.26 and GLP. Administration of the test material up to and including the highest dose tested (1000 mg/kg bw/day) did not results in any substance-related adverse effects. Thus, a NOAEL ≥1000 mg/kg bw/day was derived.