p-(2,3-epoxypropoxy)-N,N-bis(2,3-epoxypropyl)aniline

Developmental toxicity / teratogenicity

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

Test material information

Constituent 1

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 / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day

Doses / concentrations 2

Dose / conc.:

5 mg/kg bw/day

Doses / concentrations 3

Dose / conc.:

15 mg/kg bw/day

Doses / concentrations 4

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

Description (incidence and severity):

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

Mortality:

no mortality observed

Description (incidence):

There were no unscheduled deaths.

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.

Group mean body weight and weight change results have been provided in Table 3 and 4, attached additional background information (document Study No 41502453).

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.

Group mean food consumption results have been provided in Table 6, attached additional background information (document Study No 41502453).

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

no effects observed

Description (incidence and severity):

Daily visual inspection of water bottles did not reveal any obvious intergroup differences.

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Maternal developmental toxicity

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on litter data.

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on litter data.

Early or late resorptions:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on litter data.

Dead fetuses:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on litter data.

Changes in pregnancy duration:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on litter data.

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

There was no effect of maternal treatment on litter data.

Other effects:

no effects observed

Details on maternal toxic effects:

There was no effect of maternal treatment on litter data as assessed by 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. The lack of effects on offspring numbers and survival, despite the obvious maternal findings apparent at 40 mg/kg bw/day indicates that there was no intrinsic toxicity to the developing conceptus.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOEL

Effect level:

5 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

Maternal abnormalities

Abnormalities:

no effects observed

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

Changes in postnatal survival:

no effects observed

External malformations:

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. (HOOD, R (2012): Developmental and Reproductive Toxicology)

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.

Other effects:

no effects observed

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

1

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

2

Key result

Developmental effects observed:

no

Any other information on results incl. tables

The results have been summarised in tabular format and attached in 'Additional background information' in response to decision CCH-C-2114551122-63-01/F.

References

HOOD, R (2012). Developmental and Reproductive Toxicology. A Practical Approach.

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.