Fatty acids, C9-13-neo-

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

Deviations from test guideline were not specified. Protocol and SOP deviations were reported and none of the deviations were considered to have impacted the overall integrity of the study or the interpretation of the study results.

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Neodecanoic acid

EC Number:

248-093-9

EC Name:

Neodecanoic acid

Cas Number:

26896-20-8

Molecular formula:

C10H20O2

IUPAC Name:

neodecanoic acid

Constituent 2

Reference substance name:

Neo-Decanoic Acid

IUPAC Name:

Neo-Decanoic Acid

Details on test material:

SMILES Notation: O=C(O)C(C)(CC)CC(C)CCC

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

Sprague Dawley CD (Crl:CD[SD])

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: time-mated females were received from Charles River Laboratories, Raleigh, NC
- Age at study initiation: approximately 11-12 weeks old at receipt
- Weight at study initiation: 213 g to 285 g at study randomization
- Housing: animals were co-housed (where possible) in solid-bottomed cages by dose group (no more than 2 per cage)
- Diet: basal and test diet ad libitum (Certified Rodent Diet® #5002 pelleted food, PMI® Nutrition International)
- Water: ad libitum
- Acclimation period: the rats arrived on GDs 1, 2, 3, or 4 and were acclimated prior to initiation of dosing on GD 6

ENVIRONMENTAL CONDITIONS
- Temperature: 68°F to 79°F (20°C to 26°C), During the study, the temperature was out of range (as low as 61°F). This deviation did not impact the outcome of the study because the variations from the target temperature were minimal and did not persist.
- Humidity: 30-70%
- Air changes: Ten or greater air changes per hour with fresh air (no air recirculation)
- Photoperiod: 12 hour light/12 hour dark cycle

IN-LIFE DATES: From 29 MAR 2020 to 09-APR-2020

Administration / exposure

Route of administration:

oral: feed

Vehicle:

unchanged (no vehicle)

Remarks:

basal diet

Details on exposure:

Preparation of Dietary Formulations:
The test substance was added to PMI Nutrition International, LLC LabDiet Certified Rodent Diet® 5002 on a weight/weight basis and per Testing Facility SOPs. Each lot of diet utilized was identified and recorded. Dose formulations were prepared weekly and stored at 18°C to 24°C. Diet formulations were prepared at
appropriate concentrations to meet dose level requirements.The prepared test diets were not adjusted for purity.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Dose Level (ppm) Achieved Dose Level (mg/kg/day)
0 0
2100 155.05
7000 494.42
14,000 907.38

Details on mating procedure:

Female rats were naturally bred at the supplier, by breeder male rats of the same source and strain, before shipment to the Testing Facility. The day of confirmed mating was designated gestation day 0.

Duration of treatment / exposure:

Animals were administered the test substance continuously through the diet beginning on Gestation Day 6 and continuing through the day of euthanasia GD 21.

Frequency of treatment:

Continuously through diet from GD 6 to 21.

Duration of test:

16 days

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

2 100 ppm (nominal)

Remarks:

155.05 mg/kg/day actual

Doses / concentrations 2

Dose / conc.:

7 000 ppm (nominal)

Remarks:

494.42 mg/kg/day actual

Doses / concentrations 3

Dose / conc.:

14 000 ppm (nominal)

Remarks:

907.38 mg/kg/day actual

Doses / concentrations 4

Dose / conc.:

0 ppm (nominal)

Remarks:

0 mg/kg/day actual

No. of animals per sex per dose:

25/dose

Control animals:

yes

yes, plain diet

Details on study design:

Dose levels were selected based on the results of the dose range-finding study (Charles River Study No. 00438042) which found no adverse effects up to the limit dose of 14,000 ppm (approx. 1000 mg/kg/day) in rats.

Examinations

Maternal examinations:

The animals were checked for viability at least twice daily during the study. The animals were observed for general appearance at least once during the acclimation period, daily before each dose was administered, and on the day of scheduled euthanasia. Postdose observations were recorded between 1 and 2 hours postdose. Body weights were recorded on gestation days 0 (supplier), 6, 9, 12, 15, 18, and 21. Food consumption was recorded on gestation days 6, 9, 12, 15, 18, and 21. All surviving female rats were sacrificed on gestation day 21 and blood samples were collected for hormone analysis of thyroxine T3, T4, and TSH. The thoracic, abdominal, and pelvic cavities were examined at gross necropsy. Individual thyroid weights were also recorded. Ovarian and uterine contents were examined and recorded. Thyroids and livers were examined microscopically.

Ovaries and uterine content:

On gestation day 21, all surviving females were euthanized, gravid uterine weights were recorded, and uterine contents of each female were examined (i.e., number and distribution of corpora lutea, implantation sites, placentae [size, color, or shape], live and dead fetuses, and early and late resorptions).

Fetal examinations:

Fetal body weights and sex ratios, and fetal external, visceral, coronal and skeletal morphology were evaluated. All fetuses were examined for sex and external abnormalities. Late resorptions and dead fetuses were examined for external abnormalities and sex to the extent possible. The body weight of each fetus was recorded. Approximately one-half of the fetuses in each litter were examined for visceral abnormalities by using a modification of the microdissection technique of Staples. Each fetus was fixed in Bouin's solution and the heads were subsequently examined by free-hand sectioning; head sections were stored in alcohol. The decapitated carcasses were not retained. The remaining fetuses (approximately one-half of the fetuses in each litter) were examined for skeletal abnormalities after staining with alizarin red S.

Statistics:

Any data collected during the predose period was not tabulated, summarized or statistically analyzed. All statistical tests were conducted at the 5% significance level. All pairwise comparisons were conducted using two sided tests and were reported at the 1% and 5% levels, unless otherwise noted.

Maternal body weight, body weight gains, food consumption, hormone variables, and litter observations were analysed with parametric/non-parametric analysis. Levene’s test was used to assess the homogeneity of group variances. The groups were compared using an overall one-way ANOVA F test if Levene’s test was not significant or the Kruskal-Wallis test if it was significant. If the overall F-test or Kruskal-Wallis test was found significant, then pairwise comparisons were conducted using Dunnett’s or Dunn’s test, respectively.

Ovarian/uterine parameters and fetal malformations/variations were subjected to non-parametric analysis. The groups were compared using an overall Kruskal-Wallis test. If the overall Kruskal-Wallis test was found significant, then the above pairwise comparisons were conducted using Dunn’s test.

For parental indices and mortality, a Fisher’s exact test was used to conduct pairwise group comparisons of interest.

Indices:

Pre Implantation Loss (%) = (No. of corpora lutea – no. of implants)/(No. of corpora lutea) x 100

Post Implantation Loss (%) = (No. of implants – no. of live fetuses)/(No. of implants) x 100

Historical control data:

Historical control data were attached (see attached in the information panel) including results from 82 full studies and 50 dose range studies for maternal reproductive data, 21 studies for fetal abnormalities, 31 studies for fetal soft tissue abnormalities, 76 studies for fetal skeletal abnormalities, and 69 studies for fetal skeletal ossification sites. See attachment in information panel.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related clinical signs in any group. Clinical signs included fur: erected (1 animal, 7000 ppm), wet (2 animals, 2100 ppm and 14000 ppm), stained (10 animals, 1 animal control, 3 animals 2100 ppm, 3 animals 7000 ppm, 4 animals, 14000 ppm) ; vocalization:increased (1 animal, 7000 ppm) ; skin:scab (1 animal, 2100 ppm), papule (1animal, 14000 ppm). The clinical signs observed were similar to those observed in control treated animals and/or were not observed in a dose-response manner and were unrelated to treatment.

Mortality:

no mortality observed

Description (incidence):

There were no test substance-related deaths in any group. Two females delivered their litters early and were euthanized on GD 18/19; there were no study substance-related adverse observations in these females.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

In the 14,000 ppm group, statistically significant mean body weight losses were noted after the
initiation of exposure (Gestation Days 6–8) compared to mean body weight gains in the control
group. Mean body weight gains for this group were generally comparable to the control group
throughout the remainder of the exposure period. The transient decrease resulted in a mean body
weight loss during Gestation Days 6–9 and a lower mean body weight gain when the entire
exposure period was evaluated (Gestation Days 6–21); differences were statistically significant.
Mean absolute body weights were also statistically significantly lower than the control group
during Gestation Days 8–20 (up to 6.0%). Mean corrected body weight (statistically significant)
and corrected body weight gain were also lower than the control group; mean gravid uterine
weight was comparable to the control group. Based on the low magnitude of change to mean
absolute body weight, the aforementioned effects were not considered adverse.

In the 7000 ppm group, a mean body weight loss and lower mean body weight gain were noted
following the initiation of exposure (Gestation Days 6–8) followed by a higher mean body
weight gain (Gestation Days 8–9); differences from the control group were statistically
significant. Mean body weight gains in this group were comparable to the control group
throughout the remainder of the exposure period (Gestation Days 9–21) and when the entire
exposure period (Gestation Days 6-21) was evaluated. Mean absolute body weights in the
7000 ppm group were generally comparable to the control group throughout the study, and
therefore the initial decrements in mean body weight gain were considered test substance-related
but nonadverse. Mean gravid uterine weight, corrected body weight gain, and corrected body
weight in this group were unaffected by test substance exposure.

Mean body weights, body weight gains, corrected body weight, corrected body weight gain, and
gravid uterine weight in the 2100 ppm group were unaffected by test substance exposure. Any
statistically significant differences from the control group were transient and were not considered
test substance-related.

Interval (Gestation Days) Dose in ppm (# of Dams)
0 ppm (22) 2,100 (25) 7,000 (25) 14,000 (23)
6 to 9 13.3 (4.4) 16.3 (5.1) 7.3 (7.1) -4.2 (7.0)*
9 to 12 13.7 (8.7) 11.9 (6.2) 16.8 (6.9) 16.8 (6.4)
12 to 15 18.0 (5.6) 18.7 (4.7) 17.0 (4.9) 14.2 (6.5)
15 to 21 78.9 (12.1) 81.8 (11.2) 75.8 (20.9) 77.0 (12.6)
* Kruskal-Wallis & Dunn: * = p ≤ 0.05; ** = p ≤ 0.01

Food consumption and compound intake (if feeding study):

effects observed, non-treatment-related

Description (incidence and severity):

In the 14,000 ppm group, mean food consumption, evaluated as g/animal/day, was statistically
significantly lower than the control group throughout the exposure period during Gestation
Days 6–9, 9–12, and 12–15 and when the entire exposure period (Gestation Days 6–21) was
evaluated. In addition, food utilization in this group was statistically significantly lower than the
control group during Gestation Days 6–8 and when the entire exposure period (Gestation
Days 6–21) was evaluated. The effects on mean food consumption in the 14,000 ppm group
corresponded with the mean body weight losses during the early exposure period. These effects
were considered test substance-related but nonadverse due to the transient, low magnitude of change to the
mean absolute body weights.

In the 7000 ppm group, mean food consumption was statistically significantly lower during
Gestation Days 6–9 compared to the control group and corresponded with statistically
significantly lower food utilization during Gestation Days 6–7 and the decrements in mean body
weight gain. Thereafter, mean food consumption and food utilization in this group was generally
comparable to or higher than the control group. The initial lower mean food consumption in the 7000 ppm
group was considered test substance-related, but nonadverse based on the absence of
an effect on mean absolute body weights.

Mean food consumption and food utilization in the 2100 ppm group were unaffected by test
substance exposure. Any statistically significant differences from the control group were
transient and occurred in the absence of an effect on mean body weights.



Interval (Gestation Days) Dose in ppm (# of Dams)
0 ppm (22) 2,100 (25) 7,000 (25) 14,000 (23)
6 to 9 18.76 (2.21) 19.13 (1.80) 15.80 (1.65)**10.64 (1.40)**
9 to 12 20.38 (1.89) 20.77 (1.72) 20.04 (2.28) 18.18 (2.15)**
12 to 15 20.68 (2.81) 21.65 (1.65) 21.40 (1.92) 18.86 (1.93)*
15 to 21 22.46 (2.15) 23.53 (1.73) 22.72 (1.48) 21.79 (2.27)
* Anova & Dunnett: * = p ≤ 0.05; ** = p ≤ 0.01

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:

effects observed, non-treatment-related

Description (incidence and severity):

There were lower mean total T3 thyroid hormone levels observed in the 7000 ppm and 14,000 ppm
groups compared to the control group; differences were statistically significant. However, there
were no gross or microscopic correlates in the dams observed for thyroid glands in these groups; therefore,
these low values were not considered adverse. Mean T4 and TSH levels in these groups were comparable
to the control values; statistically significant changes were not observed in a dose-response
manner.

Mean T3, T4, and TSH hormone values in the 2100 ppm group were comparable to the control group and were unrelated to treatment.


Day 21 (pg/mL)
Mean, SD Dose in ppm (# of Dams)
0 ppm (23) 2,100 (25) 7,000 (25) 14,000 (23)

Total T3 244.2 (72.56) 243.9 (62.20) 182.6 (60.52)** 135.4 (66.14)**
Total T4 13785 (4431.3) 16156 (4951.5) 17449 (4936.6)* 13180 (4788.4)
TSH 1451 (672.0) 1310 (568.7) 1772 (1174.3) 2056 (1265.3)
* = Significantly different from the control group at 0.05 using Dunnett's test
** = Significantly different from the control group at 0.01 using Dunnett's test

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, non-treatment-related

Description (incidence and severity):

In the 7000-ppm and 14,000-ppm groups, there were substance-related higher mean liver weights (15.5 g and 16.1 g compared to 13.6 g in control) which correlated to liver histopathologic changes of hepatocellular hypertrophy in 5 and 15 animals, respectively compared to 0 animals in control. However, the hepatocellular hypertrophy was minimal and characteristic of an adaptive change; and therefore, was not considered adverse. In the 2100 ppm group and all other remaining microscopic findings observed were considered incidental, of the nature commonly observed in this strain and age of rat, and/or were of similar incidence and severity in control and treated animals; and therefore, were considered unrelated to administration of NeoDecanoic Acid diet.

Dose (ppm) 0 2100 7000 14,000
No. Animals per Group 24 25 25 24
Liver
Absolute value 13.61 14.05 15.50** 16.10**
% Difference - 3.28 13.92 18.32

Gross pathological findings:

no effects observed

Description (incidence and severity):

No test substance-related gross findings were noted. The gross findings observed were
considered incidental, of the nature commonly observed in this strain and age of rat, and/or were
of similar incidence in control and treated animals and, therefore, were considered unrelated to
administration of Neo Decanoic Acid Diet.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

Minimal hepatocellular hypertrophy was noted in the 7000 and 14,000 ppm group and correlated
to the higher mean liver weights in these groups and was considered a nonadverse, adaptive
change.

All other microscopic findings observed were considered incidental, of the nature commonly
observed in this strain and age of rat, and/or were of similar incidence and severity in control and
treated animals and, therefore, were considered unrelated to administration of neo decanoic acid
diet.

Dose (ppm) 0 2100 7000 14,000
No. Animals per Group 24 25 25 24
Liver
Hypertrophy, hepatocellular 0 0 5 15**
Minimal - - 5 15**

Histopathological findings: neoplastic:

no effects observed

Maternal developmental toxicity

Number of abortions:

no effects observed

Pre- and post-implantation loss:

no effects observed

Description (incidence and severity):

There were no effects on pre- or postimplantation loss in any dose group. The changes observed were similar to concurrent controls, were not observed in a dose-response manner and were not considered test substance related.

Dose (ppm) 0 2100 7000 14,000
Preimplantation Loss (%) 13.88 (8.35) 12.69 (6.72) 17.06 (11.03) 12.86 (12.03)
Postimplantation Loss (%) 6.92 (7.25) 5.80 (8.14) 14.47 (18.46) 5.30 (7.55)

Total litter losses by resorption:

no effects observed

Description (incidence and severity):

There were no total litter losses by resorption observed in any group.

Early or late resorptions:

no effects observed

Description (incidence and severity):

There were no test substance-related increases in early or late resorptions in any group. The changes observed were similar to concurrent controls, were not observed in a dose-response manner and were not considered test substance related.

Total # Resorptions, Mean (SD)
Dose (ppm) 0 2100 7000 14,000
Early 0.9 (0.9 ) 0.8 (1.2) 1.5 (2.0) 0.7 (1.0)
Late 0 0 0 0

Dead fetuses:

no effects observed

Description (incidence and severity):

There were no dead fetuses observed in this study.

Changes in pregnancy duration:

no effects observed

Description (incidence and severity):

There were no test substance-related effects on duration of pregnancy in any dose group. The early deliveries were considered a miscalculation in timing of vaginal plug observation, which occurred in a concurrent control animal, and these deliveries were not considered test substance-related.

Observation Dose (ppm)
0 2,100 7,000 14,000
# Animals Assigned (Mated) 22 25 25 23
# Animals Pregnant
Pregnancy Rate (%) 100 100 100 100
# Nonpregnant 0 0 0 0
Maternal Wastage
# Died 0 0 0 0
# Died Pregnant 0 0 0 0
# Died Nonpregnant 0 0 0 0
# Aborted 0 0 0 0
# Premature Delivery 1 0 0 1

Total # Corpora Lutea
Corpora Lutea/Dam, Mean (SD) 15 (2.1) 15.4 (1.9) 14.7 (2.5) 15.5 (1.8)
Total # Implantations
(Implantations/Dam), Mean (SD) 12.9 (2.1) 13.4 (1.2) 12.2 (2.4) 13.4 (2.1)
Placental Exam Normal 22 25 25 23
Total # Litters 22 25 25 23
Total # Live Fetuses
(Live Fetuses/Dam), Mean (SD) 12 (2.3) 12.6 (1.4) 10.6 (3.6) 12.7 (2.3)

Changes in number of pregnant:

no effects observed

Description (incidence and severity):

There were no changes in the number of pregnant females in any group; there was 100% pregnancy rate in every dose group.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

14 000 ppm (nominal)

Based on:

test mat.

Basis for effect level:

other: there were no study substance-related adverse maternal findings at the highest dietary oral dose tested

Remarks on result:

other:

Remarks:

There were no effects that were considered adverse maternal findings at any dose tested.

Results (fetuses)

Fetal body weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

There were lower mean fetal body weights observed in the 14,000 ppm group
compared to the control group. Mean fetal weights for sexes combined, males, and females were
5.5%, 6.3%, and 5.0% lower than controls, respectively; differences were statistically significant.
However, these differences were considered test substance-related but nonadverse due to the low
magnitude of change.

Mean fetal body weights in the 2100 ppm and 7000 ppm groups and fetal anogenital
distance measurements in all dose groups were comparable to the control
group and were not considered test substance related or adverse.

Observation Dose (ppm)
0 2,100 7,000 14,000
Mean Fetal Weight (g) 5.72 (0.35) 5.8 (0.29) 5.7 (0.28) 5.4 (0.39)**
Males 5.87 (0.42) 5.92 (0.36) 5.88 (0.33) 5.5 (0.4)
Females 5.55 (0.33) 5.65 (0.26) 5.52 (0.32) 5.28 (0.43)

Reduction in number of live offspring:

no effects observed

Description (incidence and severity):

There were no test substance-related effects on the number of live offspring in any dose group. The variations in live offspring were similar to those seen in basal diet fed dams and were unrelated to treatment.


Observation Dose (ppm)
0 2,100 7,000 14,000
# Animals Assigned (Mated) 22 25 25 23

Total # Litters 22 25 25 23
Total # Live Fetuses
(Live Fetuses/Dam), Mean (SD) 12 (2.3) 12.6 (1.4) 10.6 (3.6) 12.7 (2.3)

Changes in sex ratio:

no effects observed

Description (incidence and severity):

There was no substance-related effect on fetal sex ratio in any dose group. The variations in fetal sex ratios were similar to those seen in basal diet fed dams and were unrelated to treatment.


Observation Dose (ppm)
0 2,100 7,000 14,000
# Animals Assigned (Mated) 22 25 25 23

Sex Ratio (% Male), Mean (SD) 52.26 (17.06) 51.38 (14.95) 53.10 (18.21) 55.64 (12.59)

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

There were no substance-related effects on litter size or uterine weights. The variations in litter size and weights were similar to those seen in basal diet fed dams and were unrelated to treatment.

Observation Dose (ppm)
0 2,100 7,000 14,000
# Animals Assigned (Mated) 22 25 25 23
Total # Corpora Lutea
Corpora Lutea/Dam, Mean (SD) 15 (2.1) 15.4 (1.9) 14.7 (2.5) 15.5 (1.8)
Total # Implantations
(Implantations/Dam), Mean (SD) 12.9 (2.1) 13.4 (1.2) 12.2 (2.4) 13.4 (2.1)
Gravid uterus weight (g), Mean (SD) 90.01 (15.89) 94.85 (10.61)80.65 (25.51) 90.80 (14.58)

Changes in postnatal survival:

not examined

External malformations:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related fetal external malformations or variations observed. There was a single fetus (i.e., 1 out of 266 fetuses in the 7000 ppm group) that exhibited malformations: cranial meningocele and spina bifida. There were no other fetuses with external abnormalities in this study. Since this was a single fetus and there was no dose response observed, the external malformation was not considered substance related or adverse.

There were no substance-related effects on fetal anogenital distance (AGD) in any group. The variations in AGD were similar to concurrent control and were not considered test substance related.


Observation Dose ppm (fetuses/litters)
0 ppm (132/22) 2,100 (156/25) 7,000 (130/25) 14,000 (146/23)

Mean fetus AGD all (mm) 1.98 (0.26) 1.98 (0.24) 2.01 (0.25) 2.03 (0.19)
Mean fetus AGD males (mm) 2.67 (0.13) 2.69 (0.13) 2.71 (0.16) 2.67 (0.10)
Mean fetus AGD females (mm) 1.21 (0.06) 1.22 (0.08) 1.23 (0.06) 1.23 (0.06)

Skeletal malformations:

effects observed, non-treatment-related

Description (incidence and severity):

There were no substance-related fetal skeletal malformations or variations observed. One fetus each in the control, 7000, and 14,000 ppm groups were observed with skeletal malformations. In the 14,000 group, a single fetus was observed with supernumerary
cervical vertebra. In the 7000 ppm group, there was a single fetus observed with misshapen parietal bones and splayed lumbar, sacral, and thoracic arches, which correlated with the external malformations seen in the fetus. These malformations were noted in single
fetuses; and therefore, were not considered test substance-related. In the control group, a single fetus was observed with sternoschisis.


All other variations in skeletal findings (i.e., malformations, variations, incomplete ossifications), including those in the 2100 ppm group, were similar to those seen in basal diet fed dams, were not observed in a dose-response manner, were within historical control and were considered unrelated to treatment and nonadverse.

Dose in ppm (# of Fetuses Examined/ Dams)
Observations 0 (132/22) 2,100 (159/25) 7,000 (136/25) 14,000 (147/23)

Rib
(Rib, Incomplete ossification - Variation
Litters N(%) 2(9.1) 1(4.0) 0(0.0) 0(0.0)

Rib, Wavy rib - Variation
Litters N(%) 1(4.5) 4(16.0) 1(4.0) 2(8.7)

Skull
Hyoid body, Unossified – Variation
Litters N(%) 1(4.5) 1(4.0) 2(8.0) 0(0.0)

Parietal, Misshapen – Malformation
Litters N(%) 0(0.0) 0(0.0) 1(4.0) 0(0.0)

Parietal, Small - Variation
Litters N(%) 0(0.0) 0(0.0) 1(4.0) 0(0.0)

Suture bone, Supernumerary site – Variation
Litters N(%) 0(0.0) 1(4.0) 0(0.0) 0(0.0)

Sternebra
Sternebra, Misshapen ossification site – Variation
Litters N(%) 0(0.0) 1(4.0) 0(0.0) 4(17.4)

Sternebra, Sternoschisis – Malformation
Litters N(%) 1(4.5) 0(0.0) 0(0.0) 0(0.0)

Sternebra, Unossified - Variation
Litters N(%) 2(9.1) 1(4.0) 0(0.0) 1(4.3)

Sternebra, Incomplete ossification – Variation
Litters N(%) 0(0.0) 0(0.0) 0(0.0) 1(4.3)

Sternebra, Isolatedossification site – Variation
Litters N(%) 0(0.0) 0(0.0) 0(0.0) 1(4.3)

Supernumerary rib
Cervical, Full - Variation
Litters N(%) 0(0.0) 0(0.0) 0(0.0) 1(4.3)

Cervical, Short - Variation
Litters N(%) 0(0.0) 1(4.0) 2(8.0) 0(0.0)

Thoracolumbar, Full – Variation
Litters N(%) 0(0.0) 0(0.0) 1(4.0) 0(0.0)

Thoracolumbar, Short - Variation
Litters N(%) 9(40.9) 3(12.0) 12(48.0) 7(30.4)

Vertebra
Cervical vertebra, Supernumerary – Malformation
Litters N(%) 0(0.0) 0(0.0) 0(0.0) 1(4.3)

Lumbar arch, Splayed - Malformation
Litters N(%) 0(0.0) 0(0.0) 1(4.0) 0(0.0)

Sacral arch, Splayed - Malformation
Litters N(%) 0(0.0) 0(0.0) 1(4.0) 0(0.0)

Thoracic arch, Splayed - Malformation
Litters N(%) 0(0.0) 0(0.0) 1(4.0) 0(0.0)

Thoracic centrum, Split - Variation
Litters N(%) 1(4.5) 0(0.0) 0(0.0) 0(0.0)

Thoracic centrum, Incomplete ossification - Variation
Litters N(%) 2(9.1) 1(4.0) 0(0.0) 1(4.3)

[Fetuses %] - Kruskal-Wallis & Dunn
FetusesN(%) N=Group Fetal Incidence;(%)=Mean Litter % of Fetuses with the Abnormality

Visceral malformations:

effects observed, non-treatment-related

Description (incidence and severity):

There were no test substance-related fetal visceral malformations or variations observed. The variations in visceral findings were limited to a single fetus, not observed in a dose-response manner, similar to those seen in basal diet fed dams and/or were within historical control; and therefore, were unrelated to treatment.

Observation Dose ppm (fetuses/litters)
0 ppm (132/22) 2,100 (156/25) 7,000 (130/25) 14,000 (146/23)

Situs inversus- Malformation
Fetuses N(%) 0(0.00) 0(0.00) 0(0.00) 1(0.72)
Litters N(%) 0(0.00) 0(0.00) 0(0.00) 1(4.3)

Ureter, Dilatation, Minimal – Variation
Fetuses N(%) 7(5.54) 3(1.81) 19(13.90) 11(7.81)
Litters N(%) 5(22.7) 2(8.0) 10(40.0) 8(34.8)

Ureter, Dilatation, Moderate – Variation
Fetuses N(%) 3(1.89) 3(2.17) 8(6.48) 9(6.00)
Litters N(%) 2(9.1) 2(8.0) 7(28.0) 6(26.1)

Ureter, Dilatation, Severe - Variation
Fetuses N(%) 0(0.00) 2(1.37) 1(0.57) 3(1.86)
Litters N(%) 0(0.0) 2(8.0) 1(4.0) 1(4.3)

Other effects:

not examined

Details on embryotoxic / teratogenic effects:

There were no substance-realted developmental toxicity findings at any dose.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

14 000 ppm (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: There were no test substance-related adverse embryo-fetal developmental toxicity findings in any dietary dose group. t

Fetal abnormalities

Key result

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Applicant's summary and conclusion

Conclusions:

The maternal and developmental NOAEL in rats was 14,000 ppm (i.e., 907.38 mg/kg/day), the highest dose tested, as no study substance-related adverse maternal or developmental effects were observed.

Executive summary:

The objective of this study was to determine the potential for developmental toxicity of NeoDecanoic Acid in pregnant Sprague-Dawley rats following oral (dietary) administration from Gestation Days (GD) 6 (implantation) through 21 (closure of the hard palate).

 

Timed-pregnant Crl:CD(SD) rats (GD 0 = day of confirmed mating) were provided a diet of NeoDecanoic Acid at doses of 0 (control diet), 2100, 7000, 14000 ppm (calculated equivalent (0, 155, 494, 907 mg/kg/day) once daily from Gestation Day (GD) 6 through 21 (25 rats/group). The females were sacrificed on GD 21 and the following parameters and endpoints were evaluated: viability, maternal clinical signs, maternal body weight and body weight gain, maternal food consumption, maternal thyroid hormone evaluation, gross necropsy findings, maternal thyroid weight and histopathology, organ weight, ovarian and uterine examination, fetal sex ratio, embryo/fetal viability, fetal body weight, fetal anogenital distance, and fetal abnormalities (external, visceral, and skeletal).

 

There were no test substance-related mortalities, clinical signs, placental abnormalities or gross examination findings in any dose group. Two females (1 in control and 1 in the high dose)delivered their litters early and were euthanized on GD 18/19; there were no study substance-related adverse observations in these females. These early deliveries were not considered test substance-related.

 

In the 14,000 ppm group, there was a substance-related decrease in mean maternal body weight gain that was due to a transient mean body weight loss during the first few days of dietary treatment (GD 6 to 9), but was similar to control, thereafter. The body weight loss corresponded to a decrease in mean food consumption from GD 6 to 9. Similar transient test substance related decreases in mean maternal body weight gain and food consumption were observed in the 7000 ppm group during the first two days of dietary treatment (GD 6 to 8); however, there was minimal impact on mean body weight as values in this group were ≤ 2.8% lower than control throughout the study. The variations in mean maternal body weight and food consumption in the 7000 ppm and 14,000 ppm groups were not considered adverse. There were no changes in mean maternal body weight or food consumption in the 2100 ppm group. The remaining variations in mean maternal body weight and body weight gain were similar to those seen in control fed rats and were unrelated to treatment.

In the 7000-ppm and 14,000-ppm groups, there were substance-related higher mean liver weights which correlated to liver histopathologic changes of hepatocellular hypertrophy. However, the hepatocellular hypertrophy was minimal and characteristic of an adaptive change; and therefore, was not considered adverse. In the 2100 ppm group and all other remaining microscopic findings observed were considered incidental, of the nature commonly observed in this strain and age of rat, and/or were of similar incidence and severity in control and treated animals; and therefore, were considered unrelated to administration of NeoDecanoic Acid diet.

In the 7000 ppm and 14,000 ppm groups, thyroid hormone levels (i.e., TSH and T4) were within or (T3) below the range of concurrent controls. There were no substance-related changes in thyroid hormone levels in the 2100 ppm group. There were no substance-related changes in thyroid organ weight or histopathology findings at any dose level. Since there were no other adverse thyroid findings in the dams, the effects seen on the T3 thyroid hormone levels in the 7000 ppm and 14000 ppm groups were not considered adverse.

There were no substance-related changes in developmental toxicity endpoints of embryo/fetal viability, postimplantation loss, sex ratio, or examination of fetal anogenital distance, external, visceral, or sites of incomplete ossification in any group. In the 14,000 ppm group, there was a slight decrease in mean fetal body weights were observed for males, females, and combined sexes. These differences were not considered adverse due to the low magnitude of change. Also in the 14,000 ppm group, there were 4 fetuses from 4 separate litters with the variation: misshapen ossification site of the sternebrae. Since this is a developmental variation with low incidence that would have no impact on growth and survival, it was not considered adverse.  All other embryofetal examination findings observed were similar to concurrent controls, were of singular occurrence, were not observed in a dose-response manner and/or were within historical control of the testing laboratory and were not related to NeoDecanoic Acid diet.

 

In conclusion, female (Crl:CD[SD]) rats were provided an oral NeoDecanoic Acid diet at doses of 0 (control diet),2100, 7000, 14000 ppm by fed ad libitum from GD 6 through 21. Although there were maternal effects observed, these were not considered adverse. There was no evidence of adverse developmental toxicity in any group. Therefore, the no-observed-adverse-effect level for maternal and developmental toxicity was 14,000 ppm.