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Toxicological information

Developmental toxicity / teratogenicity

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Administrative data

Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Study period:
25th November 2015 to 18th August 2016
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2016
Report date:
2016

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Deviations:
yes
Remarks:
Animals from the first mating batch were weighed on Day 9 of gestation in error. The body weights were not used for adjustment of dosage volumes, so the error had no adverse impact on the study.
GLP compliance:
yes (incl. QA statement)

Test material

Constituent 1
Chemical structure
Reference substance name:
p-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline
EC Number:
225-716-2
EC Name:
p-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline
Cas Number:
5026-74-4
Molecular formula:
C15H19NO4
IUPAC Name:
4-[(oxiran-2-yl)methoxy]-N,N-bis[(oxiran-2-yl)methyl]aniline
Test material form:
liquid: viscous
Details on test material:
- Substance type: organic
- Physical state: liquid
- Storage condition of test material: In refrigerator (2-8°C) in the dark

Test animals

Species:
rat
Strain:
Sprague-Dawley
Details on test animals or test system and environmental conditions:
TEST ANIMALS
Source: 96 Sprague-Dawley Crl:CD (SD) IGS BR rats from Charles River (UK) Limited, Kent. Animals were delivered in two batches containing females prior to Day 3 of gestation.
Housing: individually housed in solid floor polypropylene cages with stainless steel mesh lids, furnished with softwood flakes.
Food and Water: Free access to pelleted diet (Rodent 2018C Teklad Global Certified Diet) and mains drinking water supplied from polycarbonate bottles.

ENVIRONMENT
Temperature and relative humidity were maintained at 22 ± 3 ºC and 50 ± 20% respectively. Photoperiod was controlled to give twelve hours continuous light and twelve hours darkness.

Diet, drinking water, bedding and environmental enrichment considered to not contain any contaminant at a level that might have affected the purpose of the study.

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
propylene glycol
Details on exposure:
Dose levels were selected based on available toxicity data including a preliminary study in the Rat. Results from this preliminary study were used to select a high dosage of 40mg/kg bw/day and a dosage sequence of 0 (control), 5, 15, 40 mg/ kg bw/day as follows:

Treatment Group Dose Level (mg/kg bw/ day) Treatment Volume (mL/kg) Concentration (mg/mL) Animal Numbers
Control 0 4 0 24
Low 5 4 1.25 24
Intermediate 15 4 3.75 24
High 40 4 10 24

The test item was administered daily from Day 5 to Day 19 of gestation, by gavage with propylene glycol as the vehicle. Control animals were treated in an identical manner with the vehicle alone.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Samples were taken of each test item formulation and were analyzed for concentration of p-(2,3-epoxypropoxy)-N,N-bis (2,3-epoxypropyl)aniline at Envigo Analytical Laboratory, Shardlow. The results indicate that the prepared formulations were within 101 to 109% of the nominal concentration indicating the suitability of the formulation procedure.

The test item concentration in the test samples was determined by high performance liquid chromatography with UV detection (HPLC/UV) using an external standard technique. The test item gave a chromatographic profile consisting of a single peak.
Details on mating procedure:
A total of ninety-six time-mated female Sprague-Dawley Crl:CD (SD) IGS BR strain rats were obtained from a recognised breeder. Animals were delivered in two batches containing females prior to Day 3 of gestation. The day that positive evidence of mating was observed was designated Day 0 of gestation. On the first day of treatment (Day 5 of gestation) the females weighed 214 to 310g.
Frequency of treatment:
Daily from Day 5 to Day 19 of gestation.
Duration of test:
20 days of gestation.
Doses / concentrationsopen allclose all
Dose / conc.:
0 mg/kg bw/day
Dose / conc.:
5 mg/kg bw/day
Dose / conc.:
15 mg/kg bw/day
Dose / conc.:
40 mg/kg bw/day
No. of animals per sex per dose:
Only female animals used, 24 females per treatment group.
Control animals:
yes
Details on study design:
Animals were delivered in
two batches containing females prior to Day 3 of gestation. The day that positive evidence of
mating was observed was designated Day 0 of gestation.

The animals were randomly allocated to treatment groups using a randomization procedure
based on stratified body weight to ensure similarity between the treatment groups.

Examinations

Maternal examinations:
CLINICAL OBSERVATIONS
Following arrival, all animals were examined for overt signs of toxicity, ill-health or
behavioral changes once daily during the gestation period. Additionally, during the dosing
period, observations were recorded immediately before and soon after dosing and one hour
post dosing. All observations were recorded.
Individual body weights were recorded on Day 3 (before the start of treatment) and on Days
5, 6, 7, 8, 11, 14 and 17 of gestation. Body weights were also recorded for animals at
terminal kill (Day 20).

FOOD CONSUMPTION
Food consumption was recorded for each individual animal at Day 3, 5, 8, 11, 14, 17 and 20
of gestation.
Water intake was observed daily by visual inspection of the water bottles for any overt
changes.

POST MORTEM EXAMINATION
All animals were killed by carbon dioxide asphyxiation followed by cervical dislocation on
Day 20 of gestation. All animals were subjected to a full external and internal examination
and any macroscopic abnormalities were recorded.
Ovaries and uterine content:
The ovaries and uteri of pregnant females
were removed, examined and the following data recorded:
Number of corpora lutea
Number, position and type of intrauterine implantation
Fetal sex
External fetal appearance
Fetal weight
Placental weight
Gravid uterus weight

The uteri of any apparently non-pregnant females were immersed in 0.5% ammonium
polysulphide solution to reveal evidence of implantation.
Fetal examinations:
Fetuses from each litter were divided into two groups and examined for skeletal alterations and soft tissue alterations.
Statistics:
The following parameters were analyzed statistically, where appropriate, using the test
methods outlined below:
Female body weight change, food consumption and gravid uterus weight: Shapiro Wilk
normality test and Bartlett’s test for homogeneity of variance and one way analysis of
variance, followed by Dunnett’s multiple comparison test or, if unequal variances were
observed, on alternative multiple comparison test.
All caesarean necropsy parameters and fetal parameters: Kruskal-Wallis non-parametric
analysis of variance; and a subsequent pairwise analysis of control values against treated
values using the Mann-Whitney ‘U’ test, where significance was seen.
Fetal evaluation parameters, including skeletal or visceral findings: Kruskal-Wallis nonparametric analysis of variance and Mann-Whitney ‘U’ test.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:
no effects observed
Mortality:
no mortality observed
Body weight and weight changes:
effects observed, treatment-related
Description (incidence and severity):
At 40 mg/kg bw/day, initial treatment on Day 5 of gestation was associated with slight,
statistically significant, mean body weight loss compared to control. Initial body weight loss and episodes of lower body weight gain resulted in statistically significant lower
cumulative mean body weight gain, compared to control, throughout the treatment period and
the mean overall weight gain remained statistically significantly lower than control, following
adjustment for the contribution of the gravid uterus. The lower body weight gain was
consistent with lower food intake for these animals throughout the treatment period.

At 15 mg/kg bw/day, initial treatment on Day 5 of gestation was associated with slightly
lower body weight gain, compared to control, but differences were not statistically significant
and may reflect normal biological variation. Subsequently body weight gain was similar to
control to Day 8 of gestation but statistically significant lower mean body weight gains were
apparent from Day 8 to Day 14 of gestation. Statistically significant lower mean body weight
gain, compared to control, was again apparent between Day 17 and Day 20 of gestation, but
this may have been influenced by a lower in-utero contribution from the fetuses/litters. The
episodes of lower body weight gain resulted in statistically significant lower cumulative mean
body weight gain, compared to control, from Day 11 of gestation and the mean overall weight gain remained statistically significantly lower than control.

At 5 mg/kg bw/day, there were no statistically significant differences in phased body weight
gains, compared to control, throughout gestation, although differences from control for
cumulative body weight attained statistical significance from Day 17 of gestation. These
differences were considered not to represent an adverse effect on maternal body weight gain,
as overall gain, when adjusted for the contribution of the gravid uterus, was similar to control
and showed no statistical significance.
Food consumption and compound intake (if feeding study):
effects observed, non-treatment-related
Description (incidence and severity):
At 40 mg/kg bw/day, statistically significant lower mean food consumption, compared to
control, was apparent throughout the treatment period. This lower food consumption was
consistent with lower maternal and fetal body weight observed at this dosage.

At 15 mg/kg bw/day, statistically significant lower mean food consumption, compared to
control, was apparent between Days 11 to 14 of gestation. Food consumption prior to and
after this period was considered to be similar to control.

At 5 mg/kg bw/day, food consumption was considered to be similar to control throughout
gestation.
Water consumption and compound intake (if drinking water study):
no effects observed

Effect levels (maternal animals)

Key result
Dose descriptor:
NOEL
Effect level:
15 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
body weight and weight gain

Results (fetuses)

Fetal body weight changes:
effects observed, treatment-related
Description (incidence and severity):
At 40 mg/kg bw/day, mean fetal weights, placental weight and litter weights were statistically
significantly lower than control. The lower litter weight observed was consistent with a
statistically significantly lower gravid uterus weight, compared to control, apparent at this
dosage. The lower fetal, litter and placental weights may be a consequence of reduced
nutrition in maternal animals as a result of lower food consumption at this dosage.
At 5 and 15 mg/kg bw/day, mean fetal and placental weight were similar to control and
appeared unaffected by maternal treatment. Litter weights (and gravid uterus weights) were
slightly lower than control, with differences for litter weights attaining statistical significance;
however these differences appeared to reflect the slight differences in litter size rather than
any obvious effect of maternal treatment.
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Skeletal malformations:
effects observed, non-treatment-related
Description (incidence and severity):
At 40 mg/kg bw/day, there was a higher incidence of fetuses/litters showing bipartite
ossification of the thoracic centrum, dumb-bell-shaped thoracic centrum or an ossification
centre for the rib associated with the 7th cervical vertebrae, with the litter incidence of these
findings attaining statistical significance. The skeletal effects are consistent with the low
fetal weights observed and are considered to reflect delayed fetal development as a
consequence of maternal toxicity (manifest as reduced body weight gain and, in particular,
food consumption) rather than intrinsic toxicity to the developing conceptus. Reduced
ossification of the thoracic centrum is a typical finding of reduced growth due to the
ossification of such thoracic regions last in-utero.

Neither the type, incidence nor distribution of findings apparent during detailed skeletal
examination of fetuses indicated any obvious effect of maternal treatment on fetal
development at 5, or 15 mg/kg bw/day.
Visceral malformations:
effects observed, non-treatment-related
Description (incidence and severity):
Neither the type, incidence nor distribution of findings apparent during detailed visceral
examination of fetuses indicated any obvious effect of maternal treatment on fetal
development at 5, 15 or 40 mg/kg bw/day.
At 5 mg/kg bw/day, a lower incidence of fetuses/litters showed increases in renal pelvic
cavitation compared to control with the fetal incidence attaining statistical significance.
However, this finding, in the absence of any statistical significance differences from control
at higher dosages, was considered to be incidental and unrelated to maternal treatment.

Effect levels (fetuses)

Key result
Dose descriptor:
NOEL
Effect level:
15 mg/kg bw/day
Based on:
test mat.
Basis for effect level:
fetal/pup body weight changes

Overall developmental toxicity

open allclose all
Key result
Developmental effects observed:
yes
Lowest effective dose / conc.:
15 mg/kg bw/day
Treatment related:
yes
Relation to maternal toxicity:
developmental effects in the absence of maternal toxicity effects
Key result
Developmental effects observed:
no

Applicant's summary and conclusion

Conclusions:
Within this study, treatment at 40 mg/kg bw/day was associated with initial mean body
weight loss, lower body weight gain and reduced food consumption for parental females.

Reductions in fetal, placental and litter weights and the type and incidence of fetal findings
were consistent with a delay in growth and considered to be a consequence of maternal
toxicity rather than indicating any intrinsic toxicity to the developing conceptus. The No
Observed Effect Level (NOEL) for the developing conceptus was considered to be 15 mg/kg
bw/day.
Treatment at 15 mg/kg bw/day was associated effects on body weight gain and food
consumption. This may reflect irritation of the GI tract, which is frequently observed with
test items of this nature, rather than systemic toxicity. The No Observed Effect Level
(NOEL) for the pregnant dam was 5 mg/kg bw/day.
Executive summary:

The study was performed to investigate the effects of the test item, p-(2,3-epoxypropoxy)-

N,N-bis (2,3-epoxypropyl)aniline, on embryonic and fetal development following repeated

administration by gavage to the pregnant female during gestation including the period of

organogenesis.

The study was designed to comply with the following guidelines:

 US EPA Health Effects Test Guideline OPPTS 870.3700, ‘Prenatal Developmental

Toxicity Study’ (August 1998)

 Japanese Ministry of Agriculture, Forestry and Fisheries Testing guidelines for

Toxicology studies, 12 NohSan No 8147, (24 November 2000)

 OECD Guidelines for Testing of Chemicals, No 414, ‘Prenatal Developmental

Toxicity Study’ (adopted 22 January 2001)

 Commission Regulation (EC) No 440/2008 of 30 May 2008 test methods pursuant to

Regulations (EC) No 1907/2006 of the European Parliament and of the Council on the

Registration, Evaluation, Authorisation and Restriction of Chemicals (REACH)

Methods

The test item was administered by gavage to three groups each of twenty-four time mated

Sprague-Dawley Crl:CD® (SD) IGS BR strain rats, between Days 5 and 19 of gestation

inclusive at dose levels 5, 15, and 40 mg/kg bw/day. A further group of twenty-four time

mated females was exposed to the vehicle only (Propylene glycol) to serve as a control.

Clinical signs, body weight change, food and water consumptions were monitored during the

study.

All females were terminated on Day 20 of gestation and subjected to gross necropsy

including examination of the uterine contents. The number of corpora lutea, number, position

and type of implantation, placental weights, fetal weight, sex and external and internal

macroscopic appearance were recorded. Half of each litter were examined for detailed

skeletal development and the remaining half were subjected to detailed visceral examination.

Results

Mortality

There were no unscheduled deaths.

Clinical Observations

No clinical signs were apparent throughout the study at 5, 15 or 40 mg/kg bw/day.

Body Weight

At 40 mg/kg bw/day, initial treatment on Day 5 of gestation was associated with slight, but

statistically significant, mean body weight loss compared to control. Statistically significant

lower mean body weight gains, compared to control, were apparent between Day 8 to Day 14

and Day 17 to 20 of gestation, although the latter period may have been influenced by lower

in-utero contribution from gravid uterus. Cumulative mean body weight gain was

statistically significantly lower than control throughout the treatment period and mean overall

weight gain remained statistically significantly lower than control, after adjustment for the

contribution of the gravid uterus.

At 15 mg/kg bw/day, body weight gain on Day 5 of gestation was slightly, but not

statistically significantly, lower than control. Statistically significant lower mean body

weight gains, compared to control, were apparent between Day 8 to Day 14 of gestation and

Day 17 to Day 20 of gestation, although the latter period may have been influenced by lower

in-utero contribution from gravid uterus. Cumulative mean body weight gain was

statistically significantly lower than control from Day 11 of gestation and mean overall

weight gain remained statistically significantly lower than control, after adjustment for the

contribution of the gravid uterus.

At 5 mg/kg bw/day, there were no statistically significant differences in phased body weight

gains, compared to control, throughout gestation, although differences from control for

cumulative body weight attained statistical significance from Day 17 of gestation. These

differences were considered not to represent an adverse effect on maternal body weight gain,

as overall gain, when adjusted for the contribution of the gravid uterus, was similar to control

and showed no statistical significance.

Food Consumption

At 40 mg/kg bw/day, statistically significant lower mean food consumption, compared to

control, was apparent throughout the treatment period.

At 15 mg/kg bw/day, statistically significant lower mean food consumption, compared to

control, was apparent between Days 11 to 14 of gestation.

At 5 mg/kg bw/day, food consumption was considered to be similar to control throughout

gestation.

Water Consumption

No obvious effect on water consumption was observed at 5, 15 or 40 mg/kg bw/day.

Post Mortem Studies

No macroscopic findings were apparent for adult females at 5, 15 or 40 mg/kg bw/day.

Litter Data

There was no effect of maternal treatment on numbers of implantations, in-utero offspring

survival (as assessed by the mean numbers of early or late resorptions), live litter size, sex

ratio and post-implantation losses at 5, 15 or 40 mg/kg bw/day.

Litter, Placental and Fetal Weights

At 40 mg/kg bw/day, mean fetal weights, placental weight and litter weights (and gravid

uterus weight) were statistically significantly lower than control.

At 5 and 15 mg/kg bw/day, litter weights (and gravid uterus weights) were lower than control

but only litter weights attained statistical significance. Differences appeared to reflect normal

variation in litter size as mean fetal and placental weight were similar to control.

Fetal Examination

External Examinations

At 40 mg/kg bw/day, there was an increase in the incidence of fetuses/litters with external

observations primarily due to a higher number of small fetuses.

Neither the type, incidence nor distribution of findings apparent during external examination

of fetuses on Day 20 of gestation indicated any obvious effect of maternal treatment on fetal

development at 5 or 15 mg/kg bw/day.

Visceral Examinations

Neither the type, incidence nor distribution of findings apparent during detailed visceral

examination of fetuses indicated any obvious effect of maternal treatment on fetal

development at 5, 15 or 40 mg/kg bw/day.

Skeletal Examinations

At 40 mg/kg bw/day, there was a statistically significant higher incidence of fetuses/litters

showing bipartite ossification of the thoracic centrum, dumb-bell-shaped thoracic centrum or

an ossification centre for the rib associated with the 7th cervical vertebrae. The skeletal

findings were consistent with the low fetal weights observed and were considered to reflect

delayed fetal development as a consequence of maternal toxicity, particularly lower food

consumption, rather than intrinsic toxicity to the developing conceptus.

Neither the type, incidence nor distribution of findings apparent during detailed skeletal

examination of fetuses indicated any obvious effect of maternal treatment on fetal

development at 5, or 15 mg/kg bw/day.

Conclusion

Within this study, treatment at 40 mg/kg bw/day was associated with initial mean body

weight loss, lower body weight gain and reduced food consumption for parental females.