2-methylenepropane-1,3-diyl diacetate

Endpoint summary

Description of key information

Repeated dose toxicity Oral: According to the results of this study, a No-Observed-Adverse-Effect Level (NOAEL) for repeated dose toxicity was estimated to be 12.5 mg/kg based on occurrence of moribundity and death, a decrease in body weight, an increase in food consumption, and injury to the liver, stomach, and duodenum at 50 or 200 (100) mg/kg.

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Initiation of the experiment (Initiation of administration): May 10, 2019
Completion of experiment (Histopathology): October 1, 2019

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

other: Crl:CD(SD)

Details on species / strain selection:

This strain is widely used in toxicity studies using rodents, there is abundant historical
data and a large number of animals are available.

Sex:

male/female

Route of administration:

oral: gavage

Vehicle:

corn oil

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Determination of the test substance concentration and homogeneity in dosing formulation
At the first preparation, 10 mL each of the analytical samples was taken from one point of each layer (upper, middle, and lower layers, n=1 in each layer) of the whole dosing formulation at each concentration. The test substance concentration in the dosing formulations was analyzed according to the method validated in analytical method validation for the determination and stability study (study No. P180490) conducted at the test facility
The relative standard deviation (RSD) of analytical values (concentration) in each layer
should not be more than 10%, and measured concentration (mean) should be within
100 ± 10% as the ratio to the nominal concentration.
Nominal concentration 20 mg/mL; measured concentration 20.11 mg/mL; RSD 1.3 %
Nominal concentration 5 mg/mL; measured concentration 5.019 mg/mL; RSD 0.6 %
Nominal concentration 1.25 mg/mL; measured concentration 1.249 mg/mL; RSD 1.1 %

Duration of treatment / exposure:

Administration period
Males
From 14 days before mating until the day before necropsy through the mating period (42 days in total).
Females
- From 14 days before mating until Day 13 of lactation (day of delivery was Day 0 of lactation) through the mating and gestation periods and delivery
- Females in the high dose group was kept dosing until Day 39 (during the gestation or lactation period).
- One non-delivered female was kept dosing until the day before necropsy.

Frequency of treatment:

Frequency of administration: Once daily, between 8:01 and 12:43 (permissible range: 8:00 to 15:00)

Dose / conc.:

12.5 mg/kg bw (total dose)

Dose / conc.:

50 mg/kg bw (total dose)

Dose / conc.:

200 mg/kg bw (total dose)

No. of animals per sex per dose:

12.5 mg/kg: 12 males 12 females
50 mg/kg: 12 males, 12 females
200 mg/kg: 7 males 12 females

Control animals:

yes, concurrent no treatment

Details on study design:

Dose level and its rationale
Dose levels were set at 12.5, 50, and 200 mg/kg.
As a result of an acute oral toxicity study [1] (two of six animals treated with 300 mg/kg died.), the dose levels were set at 10, 30, and 100 mg/kg in a dose-finding study entitled “A 14-Day Repeated Dose Oral Toxicity Study of MPDAc in Rats (Study No. P180491)” conducted at the test facility. No clear toxicological change was noted in the 100 mg/kg group. According to the results, the high dose in this study was set at 200 mg/kg, at which some toxicity effect was expected to be seen. Lower doses were set at 50 and 12.5 mg/kg. A control group (0 mg/kg group) dosed with the vehicle (corn oil) alone was also be established.
Dose volume
- 10 mL/kg
Individual volume was calculated on the basis of the most recently measured body weights.
- As for test females treated with 200 mg/kg, dose volume was reduced to 5 mL/kg on GD 20 and thereafter (June 16, 2019 and thereafter)

Statistics:

Statistical analysis was performed with a computer system (tsPharma LabSite, Fujitsu Limited). However, a statistical analysis system EXSUS Version 8.1.0 (CAC Croit Corporation, statistical analysis software: SAS 9.4 [SAS Institute Japan Inc.]) was used for the following items: urinalysis (qualitative data: results from reagent strip method and urine sediment observation) and sex ratio. In all cases, levels of p<0.01 (1%) and p<0.05 (5%) were considered to be significant and two-tailed test was used. Analysis for concentration of total T4 and TSH was conducted according to work plan.
The data of offspring were handled on a litter-basis. The body weight and food consumption of one non-pregnant female after confirmation of copulation were excluded from the evaluation. The body weight and food consumption of dead pregnant animals were analyzed until the day before necropsy.

Please see any other information on materials and methods section for further information

Description (incidence and severity):

During the dosing period, salivation was noted in 10 males and 1 satellite female treated with 200 mg/kg. This finding appeared just after dosing and disappeared by 4 hours after dosing in 1 to 9 animals per day on Days 20 to 42. Moreover, 1 male (No. 539) treated with 200 mg/kg showed a decrease in locomotor activity and soiled fur on the face on Days 19 and 20 and soiled fur on the anus on Days 19 to 22.
During the recovery period, none of the above-mentioned changes were noted in any
animal.
Other than the above, chromaturia like hematuria was noted in 1 satellite female treated with 200 mg/kg (No. 657) on Days 3 and 4 during the dosing period. This was not judged to be toxicologically significant as described above. A mass was noted in the abdomen of 1 female (No. 573) treated with 12.5 mg/kg on LD 0 and thereafter. However, it was not considered to be treatment-related because there was no dose-dependency.

Detailed clinical observations
During the dosing period, slight or moderate salivation was noted in males treated with 200 mg/kg and females treated with 200 (100) mg/kg in the hand held observation; 5 males (Nos. 537, 538, 542, 544, and 548) and 1 female (No. 591) on Day 21, 4 males (Nos. 537, 538, 542, and 548) on Day 28, 3 males (Nos. 537, 542, and 544) and 1 female (No. 594) on Day 35, and 2 males (Nos. 543 and 544) on Day 42. Moreover, soiled fur was noted on the anus of 1 male (No. 539) treated with 200 mg/kg on Day 21.
During the recovery period, none of the above-mentioned changes were noted in any animal.
Other than the above, during the dosing period, statistically significant increases in the number of rearing were noted in males treated with 12.5 mg/kg on Days 21 and 35. However, these were not considered to be treatment-related because there was no dose-dependency.
During the recovery period, a statistically increase in the number of rearing was noted in males treated with 200 mg/kg on Day 49. However, this was not considered to be treatment-related because it was slight and no consistent tendency was noted during the recovery period.

Description (incidence):

In the 50 mg/kg group, 1 female (No. 575) was euthanized moribund on LD 6. This
animal showed a decrease in body weight on LD 6 (26.0% decrease compared to the
body weight on LD 0) and a remarkable decrease in mean food consumption from LD 0
to LD 4.
In the 200 (100) mg/kg group, 5 females (Nos. 588, 592, 594, 595, and 596) died during
the gestation or lactation period. One of the animals (No. 595) was found dead on GD 2.
Three animals (Nos. 592, 594, and 596) were found dead on GD 21. One of these
animals (No. 594) showed salivation on GDs 7 to 9, and 19 and decrease in locomotor
activity on GD 20. Another animal (No. 588) showed salivation on LD 0 and was
found dead on LD 1. These animals showed a decrease in body weight at their deaths
(0.2 to 3.1% decrease compared to the body weight on the last measurement day).
Since death occurred frequently in the test females treated with 200 (100) mg/kg, it was
judged that no further administration for the surviving animals was possible and the
administration was discontinued on Day 39 (during the gestation or lactation period, see
Section 6.10.1).
Salivation was noted in 2 surviving females; on GDs 3-5 and 20 in No. 591 and GDs
19-21 in No. 598. The surviving animals showed an increase or decrease in body
weight on the day of discontinuation of administration (18.5% decrease to 8.6% increase
compared to the body weight on the last measurement day). As for animals underwent
discontinuation of administration on the delivery day, a body weight loss of 20% or more
was noted between GD 20 and LD 0, which was similar to that of the controls.
Other than the above, chromaturia like hematuria was noted in 1 female treated with
200 (100) mg/kg (No. 594) on GD 20. However, this was not judged to be
toxicologically significant because the change was noted transiently and no related
change was noted in any examination.

Description (incidence and severity):

During the dosing period, statistically significant decreases in body weights were noted
in males treated with 200 mg/kg on Days 29 to 43.
During the recovery period, no significant difference was noted between the control and
200 mg/kg groups.

Description (incidence and severity):

During the dosing period, statistically significant increases in food consumption were
noted in males treated with 200 mg/kg on Day 8 and thereafter and females treated with
200 (100) mg/kg on Day 8.
During the recovery period, no significant difference was noted between the control and
200 mg/kg groups.

Description (incidence and severity):

One female euthanized moribund treated with 50 mg/kg on LD 6 (No. 575)
No remarkable change was noted in any parameter.
Females treated with 200 (100) mg/kg
Remarkable changes were noted as follows.
No. 587: Low values of RBC count, HGB, HCT, and reticulocyte count, and high values of WBC count and lymphocyte count
No. 590: Low values of RBC count, HGB, HCT, and reticulocyte count and ratio
No. 591: Low values of reticulocyte count and ratio
No. 593: Low values of reticulocyte count and ratio and neutrophil count and ratio, and
a high value of lymphocyte ratio
No. 597: Low values of RBC count, HGB, HCT, and reticulocyte count and ratio
No. 598: Low values of RBC count, HGB, HCT, reticulocyte count and ratio, and
platelet count

Animals for scheduled euthanasia
At the end of the dosing period, a statistically significant decrease in platelet count and statistically significant increases in monocyte count and ratio were noted in males treated with 200 mg/kg.
At the end of the recovery period, none of the above-mentioned changes were noted.
Other than the above, at the end of the dosing period, statistically significant differences were noted: high values of MCV and MCH in males treated with 50 mg/kg, and a low value of neutrophil ratio and a high value of lymphocyte count in females treated with 12.5 mg/kg. However, these were not considered to be treatment-related because there was no dose-dependency.
At the end of the recovery period, statistically significant differences were noted: low values of HGB, HCT, MCV, and MCH and a high value of reticulocyte count in males treated with 200 mg/kg and a high value of RBC and a low value of reticulocyte ratio in females treated with 200 mg/kg. However, these were not judged to be treatment-related because individual values in this group were similar to those in the control group or did not deviate significantly from the range in the control group, and the
similar changes were not noted at the end of the dosing period.

Description (incidence and severity):

One female euthanized moribund treated with 50 mg/kg on LD 6 (No. 575)
No remarkable change was noted in any parameter.
Females treated with 200 (100) mg/kg
Remarkable changes were noted as follows.
No. 593: High values of glucose, Ca, and K
No. 597: Low values of total protein, albumin, and A/G ratio
No. 598: Low values of total protein, albumin, and A/G ratio, and high values of ASAT, ALAT, and γGT
Animals for scheduled euthanasia
At the end of the dosing period, statistically significant increases in ALAT, γGT, total bilirubin, and total bile acid and statistically significant decreases in albumin, glucose, and Na were noted in males treated with 200 mg/kg. Individually, remarkable high values of ASAT and ALP were noted in 3 males and 1 male compared to those of the control, respectively.
At the end of the recovery period, none of the above-mentioned changes were noted.
Other than the above, at the end of the dosing period, a statistically significant increase in Ca was noted in males treated with 200 mg/kg. However, this was not judged to be treatment-related because individual values in this group were similar to those in the control group and no related change was noted in any examination.
At the end of the recovery period, a statistically significant decrease in γGT was noted in males treated with 200 mg/kg. However, this was not judged to be treatment-related because no related change was noted in any other parameter and the change was opposite to the toxicity effect.

Description (incidence and severity):

Urinalysis in males
During the dosing period, statistically significant increases in Na and Cl were noted in males treated with 200 mg/kg.
During the recovery period, none of the above-mentioned changes was noted.
Other than the above, protein (3+) was noted in 1 male treated with 200 mg/kg. However, this was not judged to be treatment-related because the change was noted only in 1 male and no microscopic change was noted in the kidney.

Description (incidence and severity):

Functional tests
(1) Sensory reactivity to stimuli
Reactivity to stimuli was comparable in males and females at all dose levels and no abnormality was observed.
(2) Grip strength
No treatment-related change was noted.
As a change without dose-dependency and considered as not treatment-related, a statistically significant decrease in forelimb grip strength was noted in females treated with 12.5 mg/kg.

Motor activity
No treatment-related change was noted.
A statistically significant increase in motor activity was noted in males treated with
200 mg/kg between 0 and 10 minutes. However, this was not judged to be
treatment-related because their moving pattern was normal and no significant difference
was noted in total motor activity.

Description (incidence and severity):

One female euthanized moribund treated with 50 mg/kg on LD 6 (No. 575)
Low values of absolute and relative thymus weights were noted.
Females treated with 200 (100) mg/kg
Remarkable changes were noted as follows.
Nos. 587, 589, 590, 591, 593, and 597: high values of absolute and relative liver weights
No. 598: high values of absolute and relative liver and adrenals weights, and low values of absolute and relative thymus weights

Animals for scheduled euthanasia
At the end of the dosing period, statistically significant increases in absolute and relative liver weights were noted in males treated with 200 mg/kg.
At the end of the recovery period, the above-mentioned change was not noted.
Other than the above, at the end of the dosing period, a statistically significant increase in relative kidneys weight was noted in males treated with 200 mg/kg. However, this was not judged to be treatment-related because individual values in this group were similar to those in the control group and no microscopic change was noted in the kidney. Statistically significant differences were noted: high values of absolute kidney and glans penis weights in males treated with 50 mg/kg, a low value of absolute brain weight in females treated with 12.5 mg/kg, and a high value of relative liver weight in males treated with 12.5 mg/kg. However, these were not judged to be treatment-related because there was no dose-dependency.

Description (incidence and severity):

One female euthanized moribund treated with 50 mg/kg on LD 6 (No. 575)
Treatment-related changes were noted in the liver, stomach, and thymus as follows.
Liver:
- Dark reddish patch
Stomach:
- Whitish patch of the mucosa in the forestomach
Thymus:
- Small
Females treated with 200 (100) mg/kg
Dead animals (Nos. 588, 592, 594, 595, and 596)
Treatment-related changes were noted in the liver, stomach, thymus, and spleen as
follows.
Liver:
- Dark reddish patch; 1 female
- Discoloration; 1 female
- Whitish patch; 3 females
Stomach:
- Dark reddish patch of the mucosa in the glandular stomach; 1 female
Thymus:
- Small; 1 female
Spleen:
- Discoloration; 1 female
Surviving animals
Treatment-related changes were noted in the liver and thymus as follows.
Liver:
- Whitish patch; 2 females
Thymus:
- Small; 1 female
Animals for scheduled euthanasia
At the end of the dosing period
Treatment-related changes were noted in the liver, stomach, and thymus in males treated
with 200 mg/kg as follows
Liver:
- Dark reddish patch; 7 males
- Whitish patch; 5 males
Stomach:
- Whitish patch of the mucosa in the forestomach; 1 male
Thymus:
- Small; 2 males
At the end of the recovery period
None of the above-mentioned macroscopic changes were noted.
Others
- Small testis and epididymis were noted bilaterally in 1 male treated with 200 mg/kg (No. 539); however, this was not judged to be treatment-related.
- As a congenital abnormality, abnormal lobulation of the liver was noted in 2 males
(Nos. 539 and 542) and 1 satellite female (No. 656) treated with 200 mg/kg.
- As a change without dose-dependency and considered as not treatment-related, a mass was noted subcutaneously in the abdomen of 1 female treated with 12.5 mg/kg (No. 573).
Non- pregnant female treated with 200 (100) mg/kg (No. 593)
No macroscopic change was noted.
Non-delivered female in the control group (No. 554)
No macroscopic change was noted

Description (incidence and severity):

One female euthanized moribund treated with 50 mg/kg on LD 6 (No. 575)
Treatment-related changes were noted in the liver, stomach, and thymus as follows.
Liver:
- Moderate necrosis of the centrilobular hepatocytes
- Mild hemorrhage
- Mild centrilobular inflammatory cell infiltration
Stomach:
- Minimal erosion of the forestomach
- Minimal hyperkeratosis of the forestomach
- Minimal hyperplasia of the squamous cells in the forestomach
- Minimal edema of the submucosa in the forestomach
Thymus:
- Mild atrophy

Females treated with 200 (100) mg/kg
Dead animals (Nos. 588, 592, 594, 595, and 596)
Treatment-related changes were noted in the liver, stomach, and thymus as follows.
Liver:
- Moderate or marked necrosis of the centrilobular hepatocytes; 5 females
- Mild or moderate hemorrhage; 5 females
- Mild centrilobular inflammatory cell infiltration; 4 females
Stomach:
- Minimal erosion of the forestomach; 1 female
Thymus:
- Moderate atrophy; 1 female
Discoloration of the spleen was noted in 1 female at the necropsy, but microscopic examination was not conducted.

Surviving animals
Treatment-related changes were noted in the liver and thymus as follows.
Liver:
- Minimal, mild or moderate necrosis of the centrilobular hepatocytes; 4 females
- Minimal or mild hemorrhage; 2 females
- Minimal or mild centrilobular inflammatory cell infiltration; 3 females
- Minimal brown pigment deposition of the macrophage; 3 females
- Minimal regenerative hyperplasia; 1 female
Thymus:
- Minimal atrophy; 1 female

Animals for scheduled euthanasia
Treatment-related changes were noted in the liver, stomach, and duodenum.
At the end of the dosing period
Liver:
- Necrosis of the centrilobular hepatocytes in males treated with 200 mg/kg
- Hemorrhage in males treated with 200 mg/kg
- Centrilobular inflammatory cell infiltration in males treated with 200 mg/kg
- Brown pigment deposition of the macrophage in males treated with 200 mg/kg
- Regenerative hyperplasia in males treated with 200 mg/kg
Stomach:
- Hyperkeratosis of the forestomach in males treated with 200 mg/kg
- Hyperplasia of the squamous cells in the forestomach in males treated with
200 mg/kg
- Edema of the submucosa in the forestomach in males treated with 200 mg/kg
Duodenum:
- Neutrophil infiltration in the lamina propria in males treated with 200 mg/kg
Examination of spermatogenic cycle using PAS-stained specimens:
- No abnormality was noted in any animal at any stage (stages I to XIV).

At the end of the recovery period
Liver:
- Brown pigment deposition of the macrophage in males and females treated with
200 mg/kg
- Centrilobular fibrosis in a male treated with 200 mg/kg

Others
- Various histopathological changes were noted in both sexes of the control and test substance groups. However, these changes were not judged to be treatment-related as they are observed occasionally in normal rats and there was no clear dose-dependency in the incidence.
- Small testis noted in 1 male treated with 200 mg/kg (No. 539) at the necropsy was histopathological necrosis. This was not judged to be treatment-related because the change was noted only in 1 male and no effect on the testis weight was noted in any other males. In this male, macroscopic small epididymis and decrease in sperm in the lumen of epididymis were also noted; these were considered to be secondary changes associated with the testicular necrosis.
- Subcutaneous mass noted in 1 female treated with 12.5 mg/kg (No. 573) at the clinical observation and necropsy was adenocarcinoma in the histopathology and not judged to be treatment-related.

Description (incidence and severity):

Hormone concentration (total T4) analysis
One female euthanized moribund treated with 50 mg/kg on LD 6 (No. 575)
No marked change was noted in total T4 or TSH.
Females treated with 200 (100) mg/kg
No marked change was noted in total T4 or TSH.
Animals for scheduled euthanasia
At the end of the dosing period
A statistically significant decrease in total T4 was noted in males treated with 200 mg/kg.
At the end of the recovery period
The above-mentioned change was not noted.
Others
At the end of the recovery period, statistically significant differences were noted: a high value of total T4 and a low value of TSH were noted in the satellite females treated with 200 mg/kg. However, these were not judged to be treatment-related because the individual values were similar to those in the controls and no related change was noted in any examination.

Key result

Dose descriptor:

NOAEL

Effect level:

12.5 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

body weight and weight gain

food consumption and compound intake

gross pathology

mortality

Key result

Critical effects observed:

no

Conclusions:

According to the results of this study, a No-Observed-Adverse-Effect Level (NOAEL) for repeated dose toxicity was estimated to be 12.5 mg/kg based on occurrence of moribundity and death, a decrease in body weight, an increase in food consumption, and injury to the liver, stomach, and duodenum at 50 or 200 (100) mg/kg.

Executive summary:

MPDAc was repeatedly administered by oral gavage at 0 (control group), 12.5, 50, and 200 mg/kg from 14 days before mating through mating for 42 days in males, from 14 days before mating through gestation and parturition until Day 13 of lactation in females, and for 42 days without mating in satellite females to assess the repeated dose toxicity and reproductive and developmental toxicity. In addition, a 14-day recovery period was set for the control and 200 mg/kg groups and the reversibility of the toxicity effect was assessed.
Deaths occurred in 4/12 test females treated with 200 mg/kg during the gestation period. Since the remaining test females treated with 200 mg/kg were considered at risk of deaths, the dose level and volume for the test females were reduced to 100 mg/kg and from 10 mL/kg to 5 mL/kg, respectively. Thereafter, since one more test female died during the lactation period, it was judged that no further administration was possible, and the administration was discontinued. Dose level for the test females is expressed as 200 (100) mg/kg.

Repeated dose toxicity
Moribund female treated with 50 mg/kg and females treated with 200 (100) mg/kg
One female treated with 50 mg/kg was euthanized moribund and 5 females treated with 200 (100) mg/kg died during the late gestation period or early lactation period. These animals showed body weight loss. Surviving females treated with 200 (100) mg/kg showed an increase or decrease in body weight on the day of discontinuation of administration. In some of these animals, deterioration of general condition was noted. Abnormal nursing behavior was noted in 1 dam treated with 200 (100) mg/kg and no milk spot and a decreased body weight or suppressed body weight gain were noted in their offspring. These changes were limited to the moribund and dead animals; therefore, the changes were judged to be caused by deterioration of general condition.
Hepatic injury was noted in almost all females treated with 50 or 200 (100) mg/kg
described below. The cause of death/moribundity may be deterioration of general
condition due to the liver injury and overlapping effects of the test substance and
postpartum stress.
At the necropsy, dark reddish patch, discoloration, or whitish patch was noted in the liver in a few females treated with 50 or 200 (100) mg/kg and an increase in the liver weight was noted in almost all surviving females treated with 200 (100) mg/kg. Microscopically, necrosis of the centrilobular hepatocytes, hemorrhage, and centrilobular inflammatory cell infiltration, brown pigment deposition of the macrophage, and regenerative hyperplasia were noted in the liver of almost all females treated with 50 or 200 (100) mg/kg; these changes were seen similarly in males for scheduled euthanasia but more severe than those at terminal necropsy. In the hematology, decreases in RBC count, HGB, HCT, reticulocyte count and/or ratio, and platelet count, increases in WBC count and lymphocyte count or ratio, and decreases in neutrophil count and ratio were noted in females treated with 200 (100) mg/kg. In the blood chemistry, increases in ASAT, ALAT, γGT, glucose, Ca, and K and decreases in total protein, albumin, and A/G ratio were noted in females treated with 200 (100) mg/kg.
The irritating effect of test substance was noted in the stomach. In the stomach of the moribund female treated with 50 mg/kg, whitish patch of the mucosa was noted in the forestomach at the necropsy, and histopathology revealed erosion, hyperkeratosis, hyperplasia of the squamous cells, and edema of the submucosa. In the dead and surviving females treated with 200 (100) mg/kg, salivation was noted in the clinical observation and detailed clinical observations. In a dead female treated with 200 (100) mg/kg, dark reddish patch of the mucosa in the glandular stomach was noted at the necropsy and erosion of the forestomach was noted in the histopathology.
As a secondary response to the stress, small thymus, a decrease in the thymus weight, or an increase in adrenals weight was noted at the necropsy and atrophy of the thymus was noted in the histopathology in females treated with 200 (100) mg/kg.
Other than the above, discoloration of the spleen was noted in 1 dead animal; however, histopathological examination was not conducted due to autolysis. Therefore, the detail remains unclear.

Animals for scheduled euthanasia
Salivation was noted transiently in males and a satellite female treated with 200 mg/kg on Days 20 to 42. Moreover, 1 male treated with 200 mg/kg showed a decrease in locomotor activity and soiled fur on the face on Days 19 and 20 and soiled fur on the anus on Days 19 to 22.
A decrease in body weight was noted in males treated with 200 mg/kg on Days 29 to 43.
Increases in food consumption were noted in males treated with 200 mg/kg on Day 8 and thereafter and females treated with 200 (100) mg/kg on Day 8.
In the urinalysis, excretion of Na and Cl was noted in males treated with 200 mg/kg.
In the hematology, a decrease in platelet count and increases in monocyte count and ratio were noted in males treated with 200 mg/kg.
In the blood chemistry, increases in ASAT, ALAT, γGT, ALP, total bilirubin, and total bile acid and decreases in albumin, glucose, and Na were noted in males treated with 200 mg/kg.

Reproductive/Developmental toxicity
In the parental animals, no treatment-related change was noted in any examination; the estrous cycle, copulation index, fertility index, days until copulation, gestation length, number of implantations, delivery index, gestation index, or parturition/maternal behavior.
In the offspring, no treatment-related change was noted in any examination; number of newborns, number of live newborns, stillborn index, birth index, sex ratio, viability index, external examination, body weight, anogenital distance, nipple development, necropsy or plasma total T4 concentration.

NOAEL
According to the results of this study, a No-Observed-Adverse-Effect Level (NOAEL) for repeated dose toxicity was estimated to be 12.5 mg/kg based on occurrence of moribundity and death, a decrease in body weight, an increase in food consumption, and injury to the liver, stomach, and duodenum at 50 or 200 (100) mg/kg.

The NOAEL for reproductive and developmental toxicity was judged to be 200 mg/kg because no treatment-related change was noted at any dose level.

Endpoint conclusion

Endpoint conclusion:

adverse effect observed

Dose descriptor:

NOAEL

12.5 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Reliability 1.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available