2-Propenamide, 3-(1,3-benzodioxol-5-yl)-N,N-diphenyl-, (2E)-

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2016-07-29 to 2017-04-13

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

Adopted 2001-01-22

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: ICH Harmonized Tripartite Guideline, Detection of Toxicity to Reproduction for Medicinal Products. Study for Effects on Embryo-Fetal Developmental (Segment II), S5(R2), Guideline 4.1.3.Step 4 version

Version / remarks:

1993-06-24

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Version / remarks:

1998-08

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

(2E)-3-(2H-1,3-benzodioxol-5-yl)-N,N-diphenylprop-2-enamide

Cas Number:

1309389-73-8

Molecular formula:

C22H17NO3

IUPAC Name:

(2E)-3-(2H-1,3-benzodioxol-5-yl)-N,N-diphenylprop-2-enamide

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

CRL Sprague-Dawley CD® IGS rats

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Age at study initiation: 8 weeks at mating
- Weight at study initiation: The weight variation did not exceed ± 20% of the mean weight.
- Fasting period before study: No
- Housing: Individually in suspended stainless steel cages, which conform to the size recommendations in the latest Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011).
- Diet: Ad libitum (2016 Certified Envigo Teklad Global Rodent Diet®)
- Water: Ad libitum (filtered tap water)
- Acclimation period: Animals arrived on gestation day 1,2 or 3. The test started on gestation day 5.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-24
- Humidity (%): 48-70
- Air changes (per hr): Not specified
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: August 2 – September 19, 2016

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The test substance was mixed weight to volume (w/v) in corn oil. Fresh formulations containing 25, 50, 100, and 200 mg/mL of the test substance were prepared daily. The formulations were stirred at ambient temperature until a visually homogeneous mixture was achieved.

VEHICLE
- Justification for use and choice of vehicle: Solubility properties
- Concentration in vehicle: 0, 25, 50, 100 and 200 mg/mL
- Amount of vehicle: 5 mL/kg bw/day

Analytical verification of doses or concentrations:

yes

Remarks:

Homogeneity and concentration of the test substance in the vehicle, as administered to the test system, was determined as part of this study.

Details on analytical verification of doses or concentrations:

The neat test substance and selected prepared mixtures (at each concentration), were sampled in duplicate. At the initial and final preparation, a sample of the test substance (neat) was retained for stability. Prior to dosing, samples to verify the homogeneity of the test substance in the dosing mixtures were collected from the initial preparation. Samples from these preparations were collected from the top, middle, and bottom of each concentration of test substance in vehicle. The dose preparations (test and control) were sampled at the beginning as part of the homogeneity assessment, and near the end of the study for the verification of concentration.

The test substance was determined to be stable under the conditions of storage at the laboratory over the course of this study. Based on the overall neat test substance stability, and dose preparation homogeneity and concentration verification analyses, animals were considered to have received at least the target concentrations of the test.

Details on mating procedure:

- Impregnation procedure: Purchased timed pregnant (animals were received on GD1, 2, or 3, following confirmed mating by the supplier)

Duration of treatment / exposure:

9 days

Frequency of treatment:

Daily

Duration of test:

From gestation day 5 to gestation day 19

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

1 000 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

500 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

250 mg/kg bw/day (nominal)

Doses / concentrations 4

Dose / conc.:

125 mg/kg bw/day (nominal)

Doses / concentrations 5

Dose / conc.:

0 mg/kg bw/day (nominal)

Remarks:

Control (corn oil)

No. of animals per sex per dose:

20 female animals per dose and control group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Based on a developmental range-finding/toxicity study (see supporting study in IUCLID section 7.8), selected target dose levels were 125, 250, 500, and 1000 mg/kg/day. The high dose was chosen based on the absence of toxicity in the range finding study and was selected as the maximum guideline-recommended dose. A NOAEL was achieved for this study.

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: At least twice daily for viability. Cage-side observations of all animals were performed daily during the study.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Prior to the first treatment with the test substance, and approximately weekly thereafter
- Parameters examined: Potential signs noted included, but were not limited to changes in skin, fur, eyes, and mucous membranes, occurrence of secretions and excretions and autonomic activity (e.g., lacrimation, piloerection, pupil size, unusual respiratory pattern). Likewise, changes in gait, posture and response to handling as well as the presence of clonic or tonic movements, stereotypes (e.g., excessive grooming, repetitive circling), or bizarre behavior (e.g., self-mutilation, walking backwards) were also recorded.

BODY WEIGHT: Yes
- Time schedule for examinations: On gestation day 3, 5, 8, 11, 14, 17, and 20

FOOD CONSUMPTION AND COMPOUND INTAKE: Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No

WATER CONSUMPTION AND COMPOUND INTAKE: No

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: Examination of the external surface of the body, all orifices, as well as the thoracic, abdominal, and cranial cavities, and their contents. Internal examination included but was not limited to, the examination of mammary tissue. Special attention was paid to the organs of the reproductive system.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Blood sampling:

- Plasma: No
- Serum: No

Fetal examinations:

- External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]
- Head examinations: Yes: [half per litter]
- Anogenital distance of all live rodent pups: Yes
- Fetal weights: Yes
- Determination of fetal sex: Yes

Statistics:

Analytical methods for this study were based on regulatory guideline requirements. The laboratory performed statistical analysis of all quantitative data collected during the in-life phase of the study as well as post-mortem phases of the study. Inferential comparisons, between control and test groups were made with regards to homogeneity of variance, normality, and analysis of variance where appropriate. The use of the word “significant” or “significantly” indicates a statistically significant difference between control and the test groups. Significance was judged at p < 0.05. Statistical analyses were conducted using one or more of the following software applications: Provantis® version 9, Tables and Statistics, Instem LSS, Staffordshire UK; INSTAT.

Historical control data:

Not included

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

Incidental clinical signs noted in females included: slight alopecia on the abdomen, head, or right flank of 1/20 animals in the 125 mg/kg bw/day group and in 3/20 animals in the 500 mg/kg bw/day group; and a lesion on the nose/snout in 1/10 animals of the 250 mg/kg bw/day group. One 125 mg/kg bw/day group and three 1000 mg/kg bw/day group females exhibited corresponding detailed observations of hair loss; these findings were also interpreted to be incidental.

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

no effects observed

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

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Endocrine findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

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

Other effects:

not examined

Maternal developmental toxicity

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Total litter losses by resorption:

no effects observed

Early or late resorptions:

no effects observed

Dead fetuses:

no effects observed

Changes in pregnancy duration:

no effects observed

Changes in number of pregnant:

no effects observed

Other effects:

no effects observed

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Remarks on result:

not determinable due to absence of adverse toxic effects

Maternal abnormalities

Key result

Abnormalities:

no effects observed

Results (fetuses)

Fetal body weight changes:

no effects observed

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

Anogenital distance of all rodent fetuses:

not examined

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Description (incidence and severity):

Some skeletal variations occured which were non-significant and/or not dose-dependent und were thus considered to be incidental.

Visceral malformations:

no effects observed

Description (incidence and severity):

Incidental variations of the pelvis included: bilateral, moderately dilated ureters in one 125 mg/kg bw/day group and two 500 mg/kg bw/day group fetuses and left/right, moderately dilated ureters in two 125 mg/kg bw/day group and one 250 mg/kg bw/day group fetuses. There were no other visceral observations.

Other effects:

no effects observed

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Fetal abnormalities

Key result

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Applicant's summary and conclusion

Conclusions:

In a Prenatal Developmental Toxicity Study according to OECD guideline 414, the no-adverse-effect level (NOAEL) for administration of the test item by oral gavage was determined to be ≥1000 mg/kg/day under the conditions of the study and based on the maternal and fetal developmental toxicity endpoints evaluated.

Executive summary:

A prenatal developmental toxicity study according to OECD guideline 414 and GLP was conducted in timed-pregnant CRL Sprague-Dawley CD® IGS rats to determine the potential of the test item to produce pre-natal developmental toxicity, when administered orally throughout pregnancy, from implantation to one day prior to term delivery. One hundred (100) timed pregnant female rats were selected for the test and equally distributed into five groups (twenty females per group). Dose levels of 125, 250, 500, and 1000 mg/kg/day of the test item, respectively, as well as vehicle control, were selected for the test. The test substance was determined to be stable under the conditions of storage at the laboratory over the course of this study. Based on the overall neat test substance stability and dose preparation homogeneity and concentration verification analyses, animals were considered to have received at least the target concentrations of the test item. The test substance or vehicle control (corn oil) were administered daily (7 days/week) via oral intubation to each rat during gestation days (GD) 5-19 of a 21-day pregnancy. The test substance was administered as a 25 mg/mL (2.5%), 50 mg/mL (5.0%), 100 (10.0%) or 200 mg/mL (20.0%) w/v mixture in corn oil. Animals were observed daily during pregnancy for clinical signs and mortality. Individual body weights and food consumption for all pregnant females are reported on GD3, 5, 8, 11, 14, 17, and 20. Gross necropsies and caesarean sections were performed on all pregnant rats, where the pregnancy status and uterine contents were evaluated. The conceptuses were assessed for viability, external observations, and then for visceral and skeletal variations. All animals survived administration of the test item. There were no clinical signs or changes in body weight, mean body weight gain, mean food consumption and mean food efficiency considered to be attributed to the administration of the test item.There were no test substance-related changes in pregnancy rate, maternal or placental gross abnormalities, abortions, or premature deliveries. Mean number of corpora lutea, implantations and resorptions as well as pre-implantation and post-implantation loss were comparable for all females. Gravid uterine and adjusted body weights were comparable for all females. A total of 20 litters in Group 1 (240 fetuses), 20 litters in Group 2 (244 fetuses), 20 litters in Group 3 (216 fetuses), 20 litters in Group 4 (240 fetuses), and 20 litters in Group 5 (231 fetuses) were examined at caesarean section for external fetal malformations on GD20. The number of live fetuses per litter was comparable between treatment Groups for animals that survived to scheduled sacrifice and was 12.0, 12.2, 10.8, 12.0, and 11.6 respectively for Groups 1-5. Fetal sex ratios were also comparable across treatment groups. The administration of the test item resulted in no treatment-related external, visceral or skeletal teratogenic effects. Under the conditions of the study and based on the maternal and fetal developmental toxicity endpoints evaluated, the no-adverse-effect level (NOAEL) for administration of the test item by oral gavage was determined to be 1000 mg/kg/day.