Registration Dossier

Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
20 October 2017 - 13 December 2017
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Version / remarks:
22 January 2001
Deviations:
no
GLP compliance:
yes (incl. certificate)
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: breeder: Janvier, le Genest-Saint-Isle, France
- Age at the beginning of the treatment period: approximately 10-11 weeks old
- Mean body weight at the beginning of the treatment period: 295 g (range: 235 g to 358 g)
- Fasting period before study: no
- Housing: individually
- Diet: SSNIFF R/M-H pelleted diet (free access)
- Water: tap water filtered with a 0.22 µm filter (free access)
- Acclimation period: for a period of 4 or 5 days before the beginning of the treatment period.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): approximately 8 to 15 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12 h/12 h

IN-LIFE DATES: 20 November 2017 to 13 December 2017

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
other: 0.5% (w/w) methylcellulose aqueous solution
Details on exposure:
PREPARATION OF DOSING FORMULATIONS:
- Suspension in the vehicle
- Justification for use and choice of vehicle: suitable formulation in the selected vehicle
- Concentration in vehicle: 10, 30 and 100 mg/mL
- Amount of vehicle: 10 mL/kg/day
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Type of method: Ultra-Violet-Visible (UV-Vis) spectrophotometric method
Test item concentrations: were within an acceptable range of variation compared to nominal values (+/- 15%) in Weeks 1 and 4.
Homogeneity: homogenous formulations at 10 and 200 mg/mL.
Stability: not assessed, dose formulations were prepared daily.
Details on mating procedure:
- Impregnation procedure: purchased time pregnant
- Proof of pregnancy: vaginal plug (at the breeder's facility); referred to as day 0 post coitum
Duration of treatment / exposure:
Days 6 to 20 post coitum inclusive.
Frequency of treatment:
Daily.
Duration of test:
Day 21 post coitum.
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day (actual dose received)
Dose / conc.:
100 mg/kg bw/day (actual dose received)
Dose / conc.:
300 mg/kg bw/day (actual dose received)
Dose / conc.:
1 000 mg/kg bw/day (actual dose received)
No. of animals per sex per dose:
24 females
Control animals:
yes, concurrent vehicle
Details on study design:
- Rationale for dose selection:
The dose levels were selected in agreement with the Sponsor, on the basis of the results of a previous OECD 421 study (reproduction/developmental toxicity screening in rats) where female Sprague-Dawley rats received the test item in 0.5% aqueous methylcellulose by gavage at 10 mL/kg at 50, 250 or 1000 mg/kg/day prior to pairing, during pairing and throughout gestation and lactation until Day 3 post-partum. There were no toxicologically significant effects in females of this study.
Therefore, the same high-dose was used in the present study. The lower doses were selected with an approximately 3-fold interval between each dose.

- Rationale for animal assignment:computerized stratification procedure.

Examinations

Maternal examinations:
MORTALITY/MORBIDITY:
- Time schedule: each animal was checked for mortality and morbidity once a day before the treatment period and at least twice a day during the treatment period, including weekends.

CLINICAL SIGNS:
- Time schedule: from arrival, each animal was observed once a day as part of the routine examinations. From the start of the treatment period, each animal was observed once a day, at approximately the same time.

BODY WEIGHT:
- Time schedule: the body weight of each female was recorded on Days 2, 4, 6, 9, 12, 15, 18 and 21 p.c.

FOOD CONSUMPTION:
- Time schedule: the quantity of food consumed by each female was recorded for the following intervals: Days 2-4, 4-6, 6-9, 9-12, 12-15, 15-18 and 18-21 p.c.

POST-MORTEM EXAMINATION:
- Sacrifice on Day 21 post coitum
- Examined: principal thoracic and abdominal organs
Ovaries and uterine content:
The ovaries and uterine content were examined after termination, including:
- Gravid uterus weight
- Number of corpora lutea
- Number of implantation sites
- Number of early and late resorptions
- Number of dead and live fetuses
- Number of uterine scars
- Gross evaluation of placentas
Fetal examinations:
- External examinations: Yes: all fetuses per litter
- Soft tissue examinations: Yes: half fetuses per litter
- Skeletal examinations: Yes: half fetuses per litter
- Head examinations: Yes: half fetuses per litter
- Other: fetal weight, fetal sex
Statistics:
Data were compared by one-way analysis of variance and Dunnett test (mean values being considered as normally distributed and variances being considered as homogeneous) or by Fisher’s exact probability test (proportions).
Indices:
% Pre-implantation loss = 100 * (Number of corpora lutea - Number of implantation sites) / Number of corpora lutea
% Post-implantation loss = 100 * (Number of implantation sites - Number of live fetuses) / Number of implantation sites
Historical control data:
Cf attached document

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
effects observed, non-treatment-related
Description (incidence and severity):
See table 1.
There were no test item-related clinical signs. Clinical signs observed at 1000 mg/kg/day were of isolated incidence, lasted 1 or 2 days only and were of common background in laboratory rats.
Mortality:
no mortality observed
Description (incidence):
There were no unscheduled deaths.
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
See table 2.
There were no effects on mean body weight.
At 1000 mg/kg/day and when compared with controls, mean body weight change was slightly lower on Days 6 to 9 p.c. (+13 g vs. +18 g, p<0.01) with a return towards control values thereafter. Therefore, this finding was considered to be test item-related and non-adverse.
Food consumption and compound intake (if feeding study):
effects observed, non-treatment-related
Description (incidence and severity):
There were no effects on mean food consumption.
High food consumptions noted in one control female (on Days 18 to 21 p.c.) and in one female at 300 mg/kg/day (from Days 9 to 18 p.c.) were considered to be related to food spillage which is rather common in laboratory rodents.
Water consumption and compound intake (if drinking water study):
not examined
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
not examined
Gross pathological findings:
effects observed, non-treatment-related
Description (incidence and severity):
See table 4.
There were no test item-related necropsy findings (isolated incidences, no dose-relationship and/or of common background in laboratory rats).
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Other effects:
no effects observed
Description (incidence and severity):
Uterus weight, carcass weight and net body weight change from Day 6 post coitum:
See table 3.
There were no effects on mean carcass weight, mean gravid uterus weight, or mean net body weight change.

Maternal developmental toxicity

Number of abortions:
no effects observed
Pre- and post-implantation loss:
effects observed, non-treatment-related
Description (incidence and severity):
See table 5.
Number of dams with pre-implantation loss = 17, 15, 10, 16, at 0, 100, 300, 1000 mg/kg/day, respectively
Number of dams with post-implantation loss = 12, 15, 10, 13 at 0, 100, 300, 1000 mg/kg/day, respectively
Total litter losses by resorption:
no effects observed
Description (incidence and severity):
See table 5.
No dams with total resorption.
Early or late resorptions:
effects observed, non-treatment-related
Description (incidence and severity):
See table 5.
Number of dams with resorptions = 12, 15, 10, 13 at 0, 100, 300, 1000 mg/kg/day, respectively
Dead fetuses:
no effects observed
Description (incidence and severity):
See table 5.
No dead fetuses.
Changes in pregnancy duration:
not examined
Changes in number of pregnant:
effects observed, non-treatment-related
Description (incidence and severity):
At hysterectomy on Day 21 p.c., there were 24/24, 22/24, 23/24 and 24/24 pregnant dams with live fetuses in the groups treated at 0, 100, 300 or 1000 mg/kg/day, respectively.

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Remarks on result:
not determinable due to absence of adverse toxic effects

Maternal abnormalities

Abnormalities:
no effects observed

Results (fetuses)

Fetal body weight changes:
no effects observed
Description (incidence and severity):
See table 6
There were no effects on mean fetal body weight.
Mean male fetal body weight: 6.04, 6.03, 6.04, 5.93 g, at 0, 100, 300 or 1000 mg/kg/day, respectively
Mean female fetal body weight: 5.63, 5.58, 5.62, 5.63 g, at 0, 100, 300 or 1000 mg/kg/day, respectively
Reduction in number of live offspring:
no effects observed
Description (incidence and severity):
See table 5
Changes in sex ratio:
no effects observed
Description (incidence and severity):
See table 7
There were no effects on mean percentage of male fetuses (sex-ratio).
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
not examined
External malformations:
effects observed, non-treatment-related
Description (incidence and severity):
See tables 9 and 14.
External malformations observed at 100 and 300 mg/kg/day were not considered to be test item treatment related (no dose-relationship and most of them recorded at litter incidences comparable to that reported in historical control data).
Skeletal malformations:
effects observed, non-treatment-related
Description (incidence and severity):
See tables 13 and 14.
In test item-treated groups, none of the skeletal malformations were considered to be test item treatment related: they were noted at isolated incidences and there were no findings at 1000 mg/kg/day.


Visceral malformations:
effects observed, non-treatment-related
Description (incidence and severity):
See tables 11 and 14.
The malformations observed at 100 mg/kg/day were considered to be not related to the test item treatment as they were noted in only one fetus and/or found also in Historical Control Data.

Other effects:
effects observed, non-treatment-related
Description (incidence and severity):
External variations
See table 8.
All external variations were considered to be incidental as there was no dose-relationship. The incidences were comparable with controls or isolated, and/or they were of common background in laboratory rats of this strain.

Skeletal examinations
Cartilage
See table 12.
None of the cartilage findings were considered to be test item treatment-related; they were noted with no dose-relationship, at isolated or low incidences, and/or can be found in Historical Control Data.
The other cartilages were present or of normal morphology.

Variations
Fetal skeletal variations were not considered to be test item-related (including the statistically higher number of fetuses with ossification point on 14th thoracic vertebra at 100 mg/kg/day when compared with controls): they were at comparable/lower incidences to/than controls, within historical control data, not dose-related, not statistical significant and/or noted at isolated/low incidence.

Soft tissue variations
See table 10.
These visceral variations were considered to be incidental as there was no dose-relationship, the incidences were comparable with (or lower than) controls, isolated, and/or of common background in laboratory rats of this strain.

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Remarks on result:
not determinable due to absence of adverse toxic effects

Fetal abnormalities

Abnormalities:
effects observed, non-treatment-related

Overall developmental toxicity

Developmental effects observed:
no

Any other information on results incl. tables

Table 1: Clinical signs

Dose level (mg/kg/day)

0

100

300

1000

Cutaneous lesion on neck dorsal area

1

0

0

0

Piloerection

0

0

0

1

Reflux at dosing

0

0

0

1

Number of affected animals

1/24

0/24

0/24

2/24

 

Table 2: Body weight and body weight change

Dose level (mg/kg/day)

0

100

300

1000

Mean body weight

 

 

 

 

Day 6 p.c.

295

297

295

296

 

 

+1

0

0

Day 9 p.c.

312

312

310

308

 

 

0

-1

-1

Day 21 p.c.

451

447

446

446

 

 

-1

-1

-1

Mean body weight change

 

 

 

 

Days 6 - 9 p.c.

+18

+16

+15

+13**

Days 9 - 21 p.c.

+139

+135

+137

+138

Days 6 - 21 p.c.

+156

+151

+151

+151

In italic, percentage difference (%) vs. controls,

Statistically significant vs. controls:**: p<0.01.

 

Table 3: Net body weight

Dose level (mg/kg/day)

0

100

300

1000

Gravid uterus weight

102.1

99.5

101.2

97.3

Carcass weight

348.5

347.8

345.0

349.2

Net weight change from Day 6 p.c.

54.0

51.3

49.9

53.5

 

Table 4: Macroscopic post-mortem examination

Dose level (mg/kg/day)

0

100

300

1000

Lymph node(s) (bronchic): enlarged

0

0

1

0

Lungs: Irregular color (reddish)

1

0

0

1

Absence of kidney (right)

1a

0

0

0

Enlarged kidney (left)

1a

0

0

0

Segmental aplasia of uterine horn

1a

0

0

1

Enlarged placenta(s)

0

1

1

1b

Granular placenta

0

0

0

1b

No remarkable observations

22

23

22

21

a:one female ;b: same placenta of one female.

Table 5: Hysterectomy data

Dose level (mg/kg/day)

0

100

300

1000

HCD

Number of females with live fetuses at termination

24

22

23

24

388

Mean number of corpora lutea

14.6

14.9

14.6

14.8

[13.8-16.0]

Mean number of implantation sites

13.2

13.6

13.5

13.2

[12.5-14.5]

Mean pre-implantation loss (%)

9.9

8.1

8.0

10.6

[6.2-14]

Mean number of live fetuses

12.5

12.4

12.6

12.2

[11.6-13.8]

Dead fetuses (%)

0.0

0.0

0.0

0.0

[0.0-0.5]

Mean number of implantation scars

0.0

0.0

0.0

0.0

np

Mean number of early resorptions

0.7

1.1

0.9

1.0

Early+late resoprtions:[0.5-1.35]

Mean number of late resorptions

0.0

0.1

0.0

0.1

Mean post-implantation loss (%)

5.8

9.0

8.1

8.0

[3.5-11.1]

HCD: Historical Control Data (2014-2016; Sprague-Dawley rats): study mean range [min-max]; np: not presented in HCD.

 

Table 6: Fetal body weights

Dose level (mg/kg/day)

0

100

300

1000

Mean fetal body weight (g)

5.84

5.79

5.80

5.80

 

Table 7: Fetal sex

Dose level (mg/kg/day)

0

100

300

1000

Mean percentage of male fetuses (%)

53.6

47.8

49.6

52.1

 

 

Table 8: External variations

Dose level (mg/kg/day)

0

100

300

1000

HCD

Number of litters

24

22

23

24

388

Number of fetuses

300

272

289

292

5000

General

 

 

 

 

 

Local edema, F (L)

0.3 (4.2)a

0.0 (0.0)

0.0 (0.0)

0.0 (0.0)

0.8 (9.5)

Polyhydramnios, F (L)

0.0 (0.0)

0.0 (0.0)

0.0 (0.0)

0.3 (4.2)

-

Paw and digit

 

 

 

 

 

Malrotated paw, F (L)

0.3 (4.2)a

0.4 (4.5)b

0.0 (0.0)

0.0 (0.0)

0.4 (5.6)

Paw hyperflexion, F (L)

0.3 (4.2)

0.0 (0.0)

0.0 (0.0)

0.0 (0.0)

-

Litters with external variations, n (%)

2 (8.3)

1 (4.5)

0 (0.0)

1 (4.2)

6 (1.5)

Fetus with external variations, n (%)

2 (0.7)

1 (0.4)

0 (0.0)

1 (0.3)

7 (0.1)

F: fetal incidence, L: litter incidence, n: number.

a: one fetus ,b:anotherr fetus which also had bent tail (see next § Malformations).

HCD: Historical Control Data (2014-2016; Sprague-Dawley rats): fetal maximal incidences (litter maximal incidences) for the findings, -: none in HCD.

 

Table 9: External malformations

Dose level (mg/kg/day)

0

100

300

1000

HCD

Number of litters

24

22

23

24

388

Number of fetuses

300

272

289

292

5000

General

 

 

 

 

 

Anasarca, F (L)

0.0 (0.0)

0.0 (0.0)

0.3 (4.3)c

0.0 (0.0)

-

Mouth, jaw, palate

 

 

 

 

 

Cleft palate, F (L)

1.7 (4.2)

0.0 (0.0)

0.3 (4.3)c

0.0 (0.0)

0.4 (5.0)

Trunk

 

 

 

 

 

Short trunk, F (L)

0.0 (0.0)

0.4 (4.5)a

0.0 (0.0)

0.0 (0.0)

0.4 (5.0)

Anal atresia, F (L)

0.0 (0.0)

0.4 (4.5)a

0.0 (0.0)

0.0 (0.0)

0.4 (5.0)

Omphalocele, F (L)

0.0 (0.0)

0.0 (0.0)

0.3 (4.3)

0.0 (0.0)

0.4 (5.3)

Ombilical hernia, F (L)

0.0 (0.0)

0.0 (0.0)

0.3 (4.3)c

0.0 (0.0)

0.4 (4.8)

Tail

 

 

 

 

 

Bent tail, F (L)

0.0 (0.0)

0.4 (4.5)b

0.0 (0.0)

0.0 (0.0)

0.4 (5.0)

Short tail, F (L)

0.0 (0.0)

0.4 (4.5)a

0.0 (0.0)

0.0 (0.0)

1.0 (4.3)

Litters with external malformations, n (%)

1 (4.2)

1 (4.5)

2 (8.7)

0 (0.0)

11 (2.8)

Fetus with external malformations, n (%)

5 (1.7)

2 (0.7)

2 (0.7)

0 (0.0)

13 (0.3)

F: fetal incidence, L: litter incidence, n: number.

a: one fetus ,b: another fetus,c: another fetus.

HCD: Historical Control Data (2014-2016; Sprague-Dawley rats): fetal maximal incidences (litter maximal incidences) for the findings, -: none in HCD.

Table 10: Soft tissue variations

Dose level (mg/kg/day)

0

100

300

1000

HCD

Number of litters

24

22

23

24

387

Number of fetuses

145

130

138

139

2404

Kidneys

 

 

 

 

 

Dilated renal pelvis, F (L)

0.7 (4.2)

1.5 (9.1)

0.7 (4.3)

1.4 (8.3)

9.5 (28.6)

Vessels

 

 

 

 

 

Absent innominate artery, F (L)

0.7 (4.2)

0.8 (4.5)

0.0 (0.0)

0.0 (0.0)

5.1 (25.0)

Ureter

 

 

 

 

 

Dilated ureter, F (L)

5.5 (20.8)

3.1 (13.6)

1.4 (8.7)

3.6 (16.7)

7.1 (28.0)

Thymus

 

 

 

 

 

Reddish focus, F (L)

0.0 (0.0)

0.0 (0.0)

0.7 (4.3)

0.0 (0.0)

-

Litters with visceral variations, n (%)

5 (20.8)

4 (18.2)

3 (13.0)

4 (16.7)

86 (22.2)

Fetus with visceral variations, n (%)

8 (5.5)

5 (3.8)

3 (2.2)

5 (3.6)

119 (5.0)

F: fetal incidence, L: litter incidence, n: number.

HCD: Historical Control Data (2014-2016; Sprague-Dawley rats): fetal maximal incidences (litter maximal incidences) for the findings, -: none in HCD.

 

Table 11: Soft tissue malformations

Dose level (mg/kg/day)

0

100

300

1000

HCD

Number of litters

24

22

23

24

387

Number of fetuses

145

130

138

139

2404

Mouth, jaw, palate

 

 

 

 

 

Cleft palate, F (L)

2.1 (4.2)

0.0 (0.0)

0.0 (0.0)

0.0 (0.0)

-

Brain

 

 

 

 

 

Dilated 4thcerebral ventricle, F (L)

0.0 (0.0)

0.8 (4.5)

0.0 (0.0)

0.0 (0.0)

0.7 (4.2)

Gonads

 

 

 

 

 

Absent, F (L)

0.0 (0.0)

0.8 (4.5)a

0.0 (0.0)

0.0 (0.0)

-

Litterswith visceral malformations, n (%)

1 (4.2)

2 (9.1)

0 (0.0)

0 (0.0)

7 (1.8)

Fetuswith visceral malformations, n (%)

3 (2.1)

2 (1.5)

0 (0.0)

0 (0.0)

13 (0.5)

F: fetal incidence, L: litter incidence, n: number.

HCD: Historical Control Data (2014-2016; Sprague-Dawley rats), -: none in HCD.

a: one fetus with external malformations of the trunck/tail.

Table 12: Fetal skeletal examinations

Cartilage

Dose level (mg/kg/day)

0

100

300

1000

HCD

Number of litters

24

22

23

24

388

Number of fetuses

155

142

151

153

2596

Cervical vertebrae

 

 

 

 

 

Bipartite cartilage of centrum, F (L)

0.0 (0.0)

0.7 (4.5)

0.0 (0.0)

0.0 (0.0)

-

Thoracic vertebrae

 

 

 

 

 

Misshapen cartilage of centrum, F (L)

0.6 (4.2)

0.0 (0.0)

0.0 (0.0)

0.0 (0.0)

-

Bipartite cartilage of centrum, F (L)

0.0 (0.0)

0.7 (4.5)a

0.0 (0.0)

0.0 (0.0)

0.7 (4.5)

Caudal vertebrae

 

 

 

 

 

Less than 15vertebrae, F (L)

0.0 (0.0)

0.7 (4.5)

1.3 (8.7)

0.0 (0.0)

3.0 (8.0)

Misshapen cartilage, F (L)

0.0 (0.0)

0.7 (4.5)a

0.0 (0.0)

0.0 (0.0)

-

Sternebrae

 

 

 

 

 

Bipartite cartilage, F (L)

0.0 (0.0)

0.0 (0.0)

0.7 (4.3)c

0.0 (0.0)

-

Rib

 

 

 

 

 

Absent cartilage, F (L)

0.0 (0.0)

0.0 (0.0)

0.0 (0.0)

0.7 (4.2)

5.1 (21.7)

Fused cartilages, F (L)

0.0 (0.0)

0.7 (4.5)a

0.0 (0.0)

0.0 (0.0)

0.6 (4.3)

F: fetal incidence, L: litter incidence, n: number.

HCD: Historical Control Data (2014-2016; Sprague-Dawley rats): fetal maximal incidences (litter maximal incidences) for the findings, -: none in HCD.

a: one fetus with the malformation supernumerary lumbar vertebra,c: another fetus.


 

Table 13: Fetal skeletal malformations

Dose level (mg/kg/day)

0

100

300

1000

HCD

Number of litters

24

22

23

24

388

Number of fetuses

155

142

151

153

2596

Palate

 

 

 

 

 

Split, F (L)

1.3 (4.2)

0.0 (0.0)

0.0 (0.0)

0.0 (0.0)

0.7 (5.0)

Cervical vertebrae

 

 

 

 

 

Cervical rib, F (L)

0.0 (0.0)

0.0 (0.0)

0.7 (4.3)

0.0 (0.0)

-

Lumbar vertebrae

 

 

 

 

 

Supernumerary , F (L)

0.0 (0.0)

0.7 (4.5)b

0.0 (0.0)

0.0 (0.0)

-

Sternebrae

 

 

 

 

 

Fused, F (L)

0.0 (0.0)

0.0 (0.0)

0.7 (4.3)a

0.0 (0.0)

1.3 (8.7)

Litterswith skeletal malformations, n (%)

1 (4.2)

1 (4.5)

2 (8.7)

0 (0.0)

15 (3.9)

Fetuswith skeletal malformations, n (%)

2 (1.3)

1 (0.7)

2 (1.3)

0 (0.0)

18 (0.7)

F: fetal incidence, L: litter incidence, n: number.

HCD: Historical Control Data (2014-2016; Sprague-Dawley rats): fetal maximal incidences (litter maximal incidences) for the findings, -: none in HCD.

a: one fetus,b: another fetus.

 

 

Table 14: Malformed fetuses

Dose level (mg/kg/day)

0

100

300

1000

Number of litters

24

22

23

24

Number of fetuses with external examination

300

272

289

292

Number of fetuses with visceral examination

145

130

138

139

Number of fetuses with skeletal examination

155

142

151

153

 

L29393 -01, -02, -04, -10, -13: cleft/split palate

L29418-09: short trunk, anal atresia, short tail, absent gonads

L29458-05: anasarca, cleft palate, umbilical hernia, fused sternebrae

 

 

 

 

L29418-01: bent tail

 

 

 

 

 

L29431-02: dilated 4thcerebral ventricle

 

L29419-07: supernumerary lumbar vertebra

L29443-01: omphalocele

 

 

 

L29449-07: cervical rib

 

Litters with malformations, n (%)

1 (4.2)

3 (13.6)

3 (13.0)

0 (0.0)

Fetuses with malformations, n (%)

5 (1.7)

4 (2.2)

3 (1.4)

0 (0.0)

 

Applicant's summary and conclusion

Conclusions:
Under the experimental conditions and results of this study, the No Observed Adverse Effect Level (NOAEL) for maternal parameters and for embryo-fetal development was considered to be 1000 mg/kg/day in absence of adverse test item treatment effects at this dose level.
Executive summary:

The objective of this GLP study was to evaluate the potential toxic effects of the test item, on the pregnant female and on embryonic and fetal development following daily oral administration (gavage) to pregnant female rats from implantation to the day prior to the scheduled hysterectomy [Days 6 to 20 post-coitum (p.c.) inclusive].

 

Methods

Three groups of 24 time-mated Sprague-Dawley rats were administered the test item, daily by gavage from Days 6 to 20 p.c. inclusive at 100, 300 or 1000 mg/kg/day as a suspension in the vehicle [0.5% (w/w) methylcellulose aqueous solution]. A dose volume of 10 mL/kg/day was used. One additional group of 24 females received the vehicle alone under the same experimental conditions.

Test item concentration was checked two times in formulations given to the animals.

The animals were checked daily for mortality and clinical signs. Body weight and food consumption were recorded at designated intervals.

On Day 21 p.c., surviving females were euthanized and submitted to a macroscopic post-mortem examination. Hysterectomies were performed and the numbers of corpora lutea, implantations, early and late resorptions, and live and dead fetuses were recorded. The fetuses were weighed, sexed and examined for external, soft tissue and skeletal/cartilage abnormalities.

 

Results

The test item concentrations determined in Weeks 1 and 4 remained within an acceptable range of -10.5% to +0.8% when compared to the nominal values (± 15% required). No test item was observed in the control dose formulations.

 

At hysterectomy on Day 21 p.c., there were 24/24, 22/24, 23/24 and 24/24 pregnant dams with live concepti in the groups treated at 0,100, 300 or 1000 mg/kg/day, respectively.

 

There were no test item treatment-related effects in the dams in terms of mortality, clinical signs, necropsy findings, mean body weight, mean food consumption, mean carcass weight, mean gravid uterus weight, mean net body weight change from Day 6 p.c., and mean hysterectomy data. Mean body weight change was slightly lower at 1000 mg/kg/day on Days 6 to 9 p.c.(+13 g vs. +18 g in controls, p<0.01); this was considered to be test item-related and non-adverse.

 

There were no test item treatment-related effects on sex ratio or mean fetal body weight and no test item treatment-related finding at fetal examination (external, visceral and skeletal variations or malformations).

 

Conclusion

Under the experimental conditions and results of this study, the No Observed Adverse Effect Level (NOAEL) for maternal parameters and for embryo-fetal development was considered to be 1000 mg/kg/day in absence of adverse test item treatment effects at this dose level.