1,3-Propanediol, 2,2-dimethyl-, C5-9 carboxylates

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Comparable to guideline study with acceptable restrictions; few details on test substance given, no analysis of the test compound

Data source

Reference

Reference Type:

publication

Title:

Unnamed

Year:

2004

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

few details on test substance given, no analysis of the test compound

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Details on test material:

- Name of test material (as cited in study report): Trimethylolpropane caprylate caprate
- Substance type: Polyol
- Physical state: colourless liquid
- Analytical purity: no data
- Lot/batch No.: BL 2027

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Kingston, NY
- Age at study initiation: young adult
- Weight at study initiation: Mean of the maternal body weight: 226 g (Vehicle), 225 g (200 mg/kg bw/day), 227 g (600 mg/kg bw/day), 226 g (2000 mg/kg bw/day)
- Fasting period before study: No
- Housing: Virgin females were cohabitated with singly-housed male rats, one male per female rat for a maximum of 5 days and returned to individual housing in stainless steel wire-bottomed cages after mating.
- Diet: Certified Rodent Diet No. 5002 (PMI Feeds Inc. St.Louis, MO), ad libitum
- Water: water passaged through a reverse osmosis membrane with chlorine added as a bacteriostat, ad libitum
- Acclimation period: yes, period not mentioned


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25
- Humidity (%): 30 - 70
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

dermal

Vehicle:

corn oil

Details on exposure:

TEST SITE
- Area of exposure: The back of the animals from the shoulders to the hip joints and extended ventrolaterally from the dorsal midline on each side (5x7 cm)
- % coverage: approx. 10% of the body surface
- Type of wrap if used: occlusive, gauze pad secured with Vetrap or Micropore tape
- Time intervals for shavings or clipplings: during acclimatization period


REMOVAL OF TEST SUBSTANCE
- Washing (if done): exposed area was wiped with a dermal wipe pad dampened with aqueous 1% solution of soap and then patted dry with a second clean pad
- Time after start of exposure: 6 h


TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2 mL/kg
- Concentration (if solution): 200, 600, and 2000 mg/kg/day
- Constant volume or concentration used: yes

VEHICLE
- Amount(s) applied (volume or weight with unit): 2 mL/kg
- Concentration (if solution): up to 100% (vehicle control)

USE OF RESTRAINERS FOR PREVENTING INGESTION: yes, Elizabethan collar

Analytical verification of doses or concentrations:

no

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1
- Length of cohabitation: maximum 5 days
- Further matings after two unsuccessful attempts: Not applicable
- Verification of same strain and source of both sexes: No Data
- Proof of pregnancy: Both, vaginal plug and/or sperm in vaginal smear were referred to as Day 0 of pregnancy

Duration of treatment / exposure:

Treatment on Gestation Days (GD) 6 - 15

Frequency of treatment:

Daily

Duration of test:

Termination of the study by CO2 inhalation on GD 20.

Doses / concentrations

Remarks:

Doses / Concentrations:
200, 600 and 2000 mg/kg bw/day
Basis:
nominal conc.

No. of animals per sex per dose:

25

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dose dependent occurrence of skin irritation. Higher levels than 2000 mg/kg bw/day might be expected to produce marked irritation thereby compromising the interpretaion of developmental results.
- Rationale for animal assignment (if not random): Computer-generated randomization by weight (Barlett´s test for homogeneity) such that the groups were not statistically different (5% significance level) from each other.

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Animals were checked for mortality twice daily during the treatment period and daily thereafter.


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Animals were checked for signs of reaction to treatment and/or symptoms of illness once daily before treatment, approx. 60 min after treatment during the dosing period. The dosing site was examined daily prior to substance application for signs of skin irritation according to Draize.


BODY WEIGHT: Yes
- Time schedule for examinations: Recorded on GD 0 and daily during the treatment period.


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


POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: The uterus, uterine contents, position of the fetuses in the uterus and number of corpora lutea. Number and distribution of intrauterine implantations were classified as live or death fetuses, late intrauterine deaths (resorptions) and early intrauterine resorption sites. Live fetuses were sexed and further examined (see below).

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

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 (the heads of the animals used for soft tissue examinations)

Statistics:

Clinical observations and other proportion data were analyzed using the Variance Test for Homogeneity of the Binominal Distribution. Quantitative continuous data were analyzed using Barlett´s Test for Homogeneity of Variance and the Analysis of Variance when Barlett´s Test was not significant (p>0.05). If the Analysis of Variance was significant (p>0.05), Dunnett´s Test was used to identify the statistical significance of the individual groups. If the Analysis of Variance was not appropriate, the Kruskal-Wallis Test was used when >75% ties were present. In case of significance (p>0.05), Dunn´s Method of Multiple Comparisons was used for identification of statistical significance of the individual groups.

Historical control data:

No details.
One dam having a litter consisting of seven early resorptions was pointed out as single non-dosage dependent event and to be within the ranges observed historically at the test facility.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes. Remark: local irritation

Details on maternal toxic effects:
The two highest dose levels caused some local irritation at the site of application, but no decreases in maternal weight gain or feed consumption. Two animals in the control group and one animal in the high-dose group died within 6 h after first application; these were not considered to be treatment related and the animals were replaced. One dam of the mid-dose goup (1/25) having a litter consisting of seven early resorptions was pointed out as single non-dosage dependent event and to be within the ranges observed historically at the test facility.
Necropsy findings were limited to skin flaking and scabbing first identified in life and observations related to wearing the Elizabethan collar (local alopecia, chromorhinorrhea, and neck lesions).

Effect levels (maternal animals)

1

Dose descriptor:

NOAEL

Effect level:

2 000 mg/kg bw/day (nominal)

Basis for effect level:

other: developmental toxicity

2

Dose descriptor:

NOAEL

Remarks:

local

Effect level:

200 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

3

Dose descriptor:

NOAEL

Remarks:

systemic

Effect level:

2 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
There were no significant differences from control in any of the developmental parameters measured, including embryo/fetal viability, fetal weight, malformations, or variations. The observed effects in fetuses were dose-independent and regarded to be sporadic.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Table 1: Skin reaction observations

	0 mg/kg bw/d	200 mg/kg bw/d	600 mg/kg bw/d	2000 mg/kg bw/d
Maximum possible incidences^a	375/25	375/25	375/25	375/25
Erythema
Total	0/0	2/1	22/4	91/13^b
Grade 1	0/0	2/1	10/4	81/13^b
Grade 2	0/0	0/0	4/1	10/4^b
Flaking
Total	11/3	15/2	55/6	170/17 ^b
Grade 1	11/3	9/2	27/5	61/14 ^b
Grade 2	0/0	6/1	19/4	71/14^b
Grade 3	0/0	0/0	9/1	38/7 ^b
Edema
Total	0/0	0/0	23/4	83/11^b
Grade 1	0/0	0/0	18/4	59/11^b
Grade 2	0/0	0/0	5/1	24/6^b
Scab	0/0	0/0	6/2	19/4

a:       Maximum incidence : Days x rats from first treatment on GD 6 through sacrifice on GD 20 divided by the number of rats examined per group on GD 6-20

b:        Significantly different from vehicle control group value (p≤0.01)

 

Table 2: Maternal reproductive, litter, and fetal alteration observations: Caesarian-Section results on GD 20

	0 mg/kg bw/d	200 mg/kg bw/d	600 mg/kg bw/d	2000 mg/kg bw/d
Rats pregnant and sectioned on Day 20 of gestation (n)	25	23	22^b	24
Corpora lutea/dam	16.4	16.6	16.9	16.5
Implantation sites/litter	15.0	15.4	14.9	14.2
Litter size
Live fetuses/litter	14.6	14.6	14.0	13.3
Live fetuses (n)	364	335	308	320
Dead fetuses (n)	0	0	0	0
Resorptions	0.4	0.9	0.9	0.9
Early (n)	10	20	19	21
Late (n)	1	0	0	0
Dams with any resorptions n(%)	9 (36)	11 (48)	15 (68)	11 (46)
% resorbed/litter	2.9	5.4	5.8	5.0
% male/litter	51.3	50.8	48.1	47.7
Live fetal body weight (g/litter)	3.68	3.62	3.69	3.75
Male	3.77	3.68	3.82	3.85
Female	3.58	3.56	3.58	3.65
Fetuses evaluated (n)	364	335	308	320
Litters with any alterations observed n(%)	10 (40)	8 (35)	14 (64)	7 (25)
Fetuses with any alterations observed n(%)	13 (3.5)	10 (3.0)	20 (6.5)	9 (2.0)
% fetuses/litter with any alterations observed	3.5	2.9	6.8^c	2.7

b:       Excludes values for one dam, which had a litter consisting of seven early resorptions.

c:       Significantly different from vehicle control group value (p≤0.05)

Table 3: Fetal evaluations

	0 mg/kg bw/d	200 mg/kg bw/d	600 mg/kg bw/d	2000 mg/kg bw/d
Litters evaluated	25	23	22^b	24
Fetuses evaluated	364	335	308	320
Live	364	335	308	320
Fetal gross external alterations	364	335	308	320
Tail: kinked
Litter incidence, n (%)	0(0)	1 (4.3)	0(0)	0(0)
Fetal incidence, n (%)	0(0)	1(0.3)	0(0)	0(0)
Body: hematoma
Litter incidence, n (%)	1(4.0)	0(0)	0(0)	0(0)
Fetal incidence, n (%)	1 (0.3)	0(0)	0(0)	0(0)
Fetal soft tissue alterations, evaluations	174	162	149	155
Vessels: umbilical artery descended to the left of urinary bladder
Litter incidence, n (%)	2(8.0)	3(13.0)	2(9.1)	2(8.3)
Fetal incidence, n (%)	2(1.1)	3(1.8)	3(2.0)	2(1.3)
Vessels: apparent additional umbilical artery descended left of the bladder
Litter incidence, n (%)	0(0)	0(0)	1(4.5)	0(0)
Fetal incidence, n (%)	0(0)	0(0)	1(0.7)	0(0)
Fetal skeletal alterations, evaluations	190	173	159	165
Cervical vertebrae: cervical rib present at 7th cervical vertebrae
Litter incidence, n (%)	2(8.0)	1(4.3)	1(4.8)	0(0)
Fetal incidence, n (%)	2(1.0)	2(1.2)	1(1.2)	0(0)
Thoracic vertebrae: centrum, bifid
Litter incidence, n (%)	1(4.0)	1(4.3)	5(22.7)	0(0)
Fetal incidence, n (%)	1(0.5)	1(0.6)	5(3.1)^a	0(0)
Lumbar vertebrae: centrum, bifid
Litter incidence, n (%)	0(0)	1(4.3)	0(0)	0(0)
Fetal incidence, n (%)	0(0)	1(0.6)	0(0)	0(0)
Ribs: wavy
Litter incidence, n (%)	0(0)	0(0)	2(9.1)	1(4.2)
Fetal incidence, n (%)	0(0)	0(0)	2(1.2)	1(0.5
Sternal centra: 1st, not ossified
Litter incidence, n (%)	1(4.0)	0(0)	0(0)	2(8.3)
Fetal incidence, n (%)	1(0.5)	0(0)	0(0)	2(1.3)
Sternal centra: 1st, incompletely ossified
Litter incidence, n (%)	3(12.0)	3(13.0)	2(5.1)	1(4.2)
Fetal incidence, n (%)	4(2.1)	4(2.3)	2(1.2)	1(0.6)
Pelvis: pubis, incompletely ossified
Litter incidence, n (%)	3(12.0)	0(0)	4(18.2)	3(12.5)
Fetal incidence, n (%)	3(1.6)	0(0)	5(3.1)	3(1.8)
Pelvis: ischium, incompletely ossified
Litter incidence, n (%)	0(0)	0(0)	2(9.1)	0(0)
Fetal incidence, n (%)	0(0)	0(0)	2(1.2)	0(0)

a: Significantly different from vehicle control group (p≤0.01)