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Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
read-across based on grouping of substances (category approach)
Adequacy of study:
key study
Study period:
From June 19, 1979 to June 12, 1980
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
comparable to guideline study with acceptable restrictions
Justification for type of information:
Refer to the Quaternary ammonium salts (QAS) category or section 13 of IUCLID for details on the category justification. The study with the read across substance is considered sufficient to fulfil the information requirements as further explained in the provided endpoint summary.

Data source

Referenceopen allclose all

Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979
Reference Type:
study report
Title:
Unnamed
Year:
1980
Report Date:
1980

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:
yes
Remarks:
No macroscopic or microscopic examination of sacrificed dams
GLP compliance:
not specified
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Type:
Constituent
Type:
Constituent

Test animals

Species:
rabbit
Strain:
New Zealand White
Details on test animals and environmental conditions:
Animal supplier source: Accredited breeder - Oury, Domaine De la Chesnaie, 45230 Chatilloon-Coligny
Body weight: 2.7 to 2.9 kg
Sex: Female
Pre-trail period: The animal were maintained under conditions as close as possible to those of the trial for one month pre-trial and were vaccinated against myxomatosis on May 12, 1979. The male rabbits used for mating were supplied from the same breeder and placed under the same experimental conditions as the females
Housing: Animals were placed in individual caging (70×50×30 cm) with plastic perforated floor
Temperature: 21ºC ± 10ºC
Relative humidity: 50 ± 10%
Air changes: 10 times/hour
Allocation to the groups: 13 animals each were grouped to control, test group 1, test group 2 and test group 3.
Tap water: ad libitum

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Analytical verification of doses or concentrations:
not specified
Details on mating procedure:
The first mating started on September 04, 1979.
Duration of treatment / exposure:
The day of mating was considered as day 0 and the animals were dosed daily from day 6 to day 18 inclusive (for 13 consecutive days).
Frequency of treatment:
once a day
Duration of test:
28 d
Doses / concentrationsopen allclose all
Dose / conc.:
2 mg/kg bw/day
Remarks:
0.35 mg a.i./kg bw/day
Dose / conc.:
8 mg/kg bw/day
Remarks:
1.4 mg a.i./kg bw/day
Dose / conc.:
24 mg/kg bw/day
Remarks:
8.4 mg a.i./kg bw/day
No. of animals per sex per dose:
13 female rabbits per dose
Control animals:
yes
Details on study design:
Preliminary study
Animal details: 3 female New Zealand rabbits for each dose group, weighing about 3 kg
Route of administration: Oral by stomach tube
Dose levels (mg/kg bw/day): 25 mg/kg bw/day (Test group 1), 50 mg/kg bw/day (Test group 2), 100 mg/kg bw/day (Test group 3), 200 mg/kg bw/day (Test group 4), 400 mg/kg bw/day (Test group 5)
Test substance was administered as an aqueous solution at following concentration:
Test group 1: 1.25 %
Test group 2: 2.50 %
Test group 3: 5 %
Test group 4: 10 %
Test group 5: 20 %
The solution were prepared every 3rd or 4th d and stored at 4ºC. 2 mL/kg bw was administered for each group. The preliminary test results obtained indicated that the test substance was toxic at the dose levels of 100, 200 and 400 mg/kg bw/day by oral route. 50 mg/kg did seem to be the threshold of an indirect embryotoxic action.

Main study
Based on preliminary testing results, following dose levels were selected for main study:
Test group 1: 1 mg/kg bw/day
Test group 2: 5 mg/kg bw/day
Test group 3: 25 mg/kg bw/day

Examinations

Maternal examinations:
- Behaviour and clinical symptoms: daily
- Body weight: every 3 days during pregnancy
- Food consumption: daily
- Number of corpora lutea, implantations, resorptions
Ovaries and uterine content:
Staining of implantation sites with ammonium sulphide
- Number of corpora lutea
- Number of implantations
- Number of absorptions
Fetal examinations:
- Number of viable and dead foetuses
- Macroscopic external observations
- Individual weights
- Sex
- 2/3 of foetuses stained with alizarin for skeletal examination
- 1/3 of foetuses immersed on Bouin: sections cut for examination of visceral abnormalities (method adapted from Wilson technique)

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
no effects observed
Dermal irritation (if dermal study):
not examined
Mortality:
no mortality observed
Body weight and weight changes:
no effects observed
Description (incidence and severity):
No difference of growth curve of treated groups compared to controls was observed.
Food consumption and compound intake (if feeding study):
no effects observed
Description (incidence and severity):
No difference of growth curve of treated groups compared to controls was observed.
Food efficiency:
not examined
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
Gross pathological findings:
not examined
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
not examined
Histopathological findings: neoplastic:
not examined
Details on results:
No mortality, no difference of growth curve of treated groups compared to controls, no difference in food consumption.

Maternal developmental toxicity

Number of abortions:
no effects observed
Early or late resorptions:
no effects observed
Description (incidence and severity):
The rate of resorptions was considered low and comparable in all groups.
Dead fetuses:
no effects observed
Details on maternal toxic effects:
There was a higher number of non-pregnant females in group I. The rate of resorptions is considered low, and comparable in all groups. No histopathology was performed on the sacrificed dams end of term.

Effect levels (maternal animals)

Key result
Dose descriptor:
NOAEL
Effect level:
ca. 24 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
other: No effects were observed at highest test dose
Remarks on result:
other:
Remarks:
NOAEL 8.4 mg a.i./kg bw/day

Maternal abnormalities

Key result
Abnormalities:
no effects observed

Results (fetuses)

Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
External malformations:
no effects observed
Description (incidence and severity):
In the high dose group, one foetus showed a torsion of the fore limbs. No other external abnormality was observed in any of the dose groups.
Skeletal malformations:
no effects observed
Description (incidence and severity):
Incidence in treated groups were comparable to controls.
Visceral malformations:
no effects observed
Description (incidence and severity):
- Dilated and haemorrhagic cerebral ventricles in one foetus of control group
- Left hydro-ureter in one foetus of low dose group
- Retinal folds in region of optic nerve in 13 foetuses: Control: 3 (11%); low dose: 2 (9%); mid dose: 4 (14%); and high dose: 4 (16%). These were considered to be caused by fixation artefact.
Details on embryotoxic / teratogenic effects:
No foetal mortality was observed.

External abnormalities:
In the high dose group, one foetus showed a torsion of the fore limbs. No other external abnormality was observed in any of the dose groups.

Visceral abnormalities:
- dilated and haemorrhagic cerebral ventricles in one foetus of control group
- left hydro-ureter in one foetus of low dose group.
- retinal folds in region of optic nerve in 13 foetuses: Control: 3 (11%); low dose: 2 (9%); mid dose: 4 (14%); and high dose: 4 (16%). These were considered to be caused by fixation artefact.

Skeletal abnormalities: See table: Incidence in treated groups are comparable to controls.

Effect levels (fetuses)

Key result
Dose descriptor:
NOAEL
Effect level:
ca. 24 mg/kg bw/day
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: No effects were observed at highest test dose
Remarks on result:
other: NOAEL: 8.4 mg a.i./kgbw/day

Fetal abnormalities

Key result
Abnormalities:
no effects observed

Overall developmental toxicity

Key result
Developmental effects observed:
no
Lowest effective dose / conc.:
24 mg/kg bw/day
Treatment related:
no

Any other information on results incl. tables

Maternal toxic Effects

 

Preliminary study

25, 50, 100, 200, and 400 mg test material /kg bw/day using 3 animals per dose group.

 

Mortality

Dose of test substance (mg/kg bw/day)

25

50

100

200

400

mortality

1/3
(day 26)

1/3
(day 18)

2/3 (day 18,26)

3/3 (all day 10)

3/3 (all day 7)

At 50 and 100 mg groups, a clear fall in body weight was observed between days 12 and 18. At 25 mg, two of the three females showed anorexia. From first day of treatment food consumption was clearly decreased at 50 and 100 mg/kg.

 

Final study

No mortality, no difference of growth curve of treated groups compared to controls, no difference in food consumption. There was a higher number of non-pregnant females in group I. The rate of resorptions is considered low, and comparable in all groups. No histopathology was performed on the sacrificed dams end of term.

 

Teratogenic/embryotoxic effects

 

Preliminary study on 25, 50, 100, 200, and 400 mg test material/kg bw/day using 3 animals per dose group. At 50 mg, the two females showed resorption sites. The weight of foetuses of the 50 mg group were low. Macroscopic examination, number and mean weight of foetuses of the 25 mg group showed no embryotoxic effect. 50 mg/kg/day seems to be the threshold for an indirect embryotoxic action.

 

Final study

No foetal mortality was observed.

External abnormalities
In the high dose group, one foetus showed a torsion of the fore limbs. No other external abnormality was observed in any of the dose groups.

Visceral abnormalities

- Dilated and haemorrhagic cerebral ventricles in one foetus of control group

- left hydro-ureter in one foetus of low dose group.

- Retinal folds in region of optic nerve in 13 foetuses: Control: 3 (11%); low dose: 2 (9%); mid dose: 4 (14%); and high dose: 4 (16%). These were considered to be caused by fixation artefact.
Skeletal abnormalities: Incidence in treated groups are comparable to controls.

Table for Maternal effects (separate data for all dosage groups) 

Maternal effects

Parameter

control data

low dose

medium dose

high dose

dose-response
+ / -

historical

study

Number of dams examined

 

13

14

13

13

 

Clinical findings during application of test substance

 

no

no

no

no

 

Mortality of dams

state %

 

0

0

0

0

 

Abortions

 

0

0

0

0

 

Body weight (day 28) g

gain day 0-28 (end of test) g,
gain day 6-18 (treatment) g,

 

3468
541
205

3313
638
206

3450
645
246

3369
650
231

-

Food consumption (g/day/dam)
day 0-5
day 6-18 (treatment)
day 19-29

 


165
152
111


148
139
118


148
143
124


157
152
134

-

Water consumption

if test substance is applied with drinking water

 

not recorded

not recorded

not recorded

not recorded

 

Pregnancies

pregnancy rate or %

 

11
85%

8
57%

11
85%

13
100%

+/-

Necropsy findings in dams dead before end of test

 

none died

none died

none died

none died

 


 Table for developmental effects (separate data for all dosage groups)

Litter response (Caesarean section data)

Parameter

control data

low dose

medium dose

high dose

dose-response
+ / -

historical

study

Number full-term pregnant females

 

11

8

11

13

+/-

Corpora lutea

number per pregnant female

 

98
8.91

73
9.13

97
8.82

104
8.00

+/-

Implantations

number per pregnant female

 

84
7.64

71
8.87

85
7.73

98
7.54

-

Resorptions

number per pregnant female

 

1
0.09

4
0.50

2
0.18

7
0.54

-

total number of foetuses
number per pregnant female

 

83
7.55

67
8.37

83
7.55

91
7.00

+/-

pre-implantation loss

state %

 

14%

3%

12%

6%

-

post-implantation loss

state %

 

1%

6%

2%

7%

-

total number of litters

 

11

8

11

13

+/-

fetuses / litter

 

7.55

8.37

7.55

7.00

+/-

live fetuses / litter

state ratio

 

7.55

8.37

7.55

7.00

+/-

dead fetuses / litter

state ratio

 

0

0

0

0

 

fetus weight (mean)

[g]

 

33.63

31.73

34.21

35.17

+/-

placenta weight (mean)

[g]

 

not recorded

not recorded

not recorded

not recorded

 

crown-rump length (mean)

[mm]

 

not recorded

not recorded

not recorded

not recorded

 

Fetal sex ratio

[state ratio m/f]

 

40/38

26/34

39/39

48/34

+/-

 Table for developmental effects (separate data for all dosage groups)

Examination of the foetuses

Parameter

control data

low dose

medium dose

high dose

dose-response
+ / -

historical

study

External abnormalities

[%]

 

1
3.7%

0

0

0

-

Skeletal abnormal ossifications
12thpair complete [%]
13ribs left side [%]
13ribs right side [%]
13thpair complete [%]

 


47.1%
3.9%
5.9%
43.1%


8.9%


11.1%


30.9%
10.9%
10.9%
47.3%


45.0%
10.0%
6.7%
38.3%

-

incomplete ossifications sternebrae

[%]

 

32
63%

29
64%

30
55%

36
60%

-

incomplete ossifications skull

[%]

 

23
45%

9
20%

11
20%

15
25%

-

missing ossifications sternebrae

[%]

 

14
27%

11
24%

12
22%

21
35%

 

abnormal ossifications

 

1
2%

 

1
1.8%

 

-

Visceral abnormalities

[%]

 

1
3.7%

1
4.5%

0

0

-

Applicant's summary and conclusion

Conclusions:
Based on the results of the read across study, the NOAEL of test substance for maternal and embryotoxic effects/teratogenicty can be considered to be at 24 mg/kg bw/day (i.e., equivalent to 8.4 mg a.i./kg bw/day).
Executive summary:

A study was conducted to determine the teratogenicity of read across substance, C12-14 TMAC (active: 35%), according to the method comparable to OECD 414. During gestation Days 6 -18, four groups of 13 female New Zealand White rabbits were dosed by stomach tube at dose levels of 0, 2, 8 and 24 mg/kg bw/day of test substance (35% C12-14 TMAC in dobanol 45E7 (i.e., C14 -15 AE7)), in 2 mL/kg bw/day daily prepared solutions in water. Animals were sacrificed on Day 29. Examinations included daily observations of behaviour and clinical symptoms, daily food consumption, and body weight every three days. Upon sacrifice, number of corpora lutea, implantations and resorptions were examined. For foetuses, number of viable and dead, macroscopic external examinations, sex, individual weights, skeletal examinations (2/3), and visceral abnormalities (1/3) were conducted. A preliminary study was undertaken under similar conditions, applying 5 dose groups: 0, 25, 50, 100, 200 and 400 mg/kg bw/day using three animals per dose group. At 50 mg, the two females showed resorption sites. The weight of foetuses of the 50 mg group were low. Macroscopic examination, number and mean weight of foetuses of the 25 mg group showed no embryotoxic effect. 50 mg/kg/day did seem to be the threshold for an indirect embryotoxic action. In the final study, no signs of maternal toxicity was observed. Also no foetal mortality was observed. Numbers of corpora lutea and resorptions were comparable. The number of pregnancies at the low dose group did seem to be diminished, but this was considered an incidental observation. There was no change in frequency of external, visceral and skeletal observations. No maternal toxic or embryotoxic/teratogenic effects were seen up to hightest tested dose of 24 mg/kg bw/day (i.e., equivalent to 8.4 mg a.i./kg bw/day). Under the conditions of the study, the NOAEL of read across substance for maternal and embryotoxic effects/teratogenicty was at 24 mg/kg bw/day (i.e., equivalent to 8.4 mg a.i./kg bw/day) (Fave 1980). Based on the results of the read across study, similar NOAELs for maternal and development toxicity is considered for the test substance, Oleyl TMAC.