Hexanedioic acid, mixed esters with decanoic acid, heptanoic acid, octanoic acid and pentaerythritol

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

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)

GLP compliance:

not specified

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Decanoic acid, ester with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol octanoate

EC Number:

234-392-1

EC Name:

Decanoic acid, ester with 2-ethyl-2-(hydroxymethyl)-1,3-propanediol octanoate

Cas Number:

11138-60-6

IUPAC Name:

2,2-bis[(octanoyloxy)methyl]butyl decanoate

Test material form:

liquid

Details on test material:

CAS Number: 11138-60-6
EC Number: 234-392-1

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: TMPCC from ExxonMobil, Lot No. 2, batch no. BL2027

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature
- Solubility and stability of the test substance in the solvent/vehicle: Suspensions in a vehicle of Mazolas corn oil (Best Foods Division, Englewood Cliffs, NJ). The formulations
were prepared daily and stirred continuously.

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc. (Kingston, NY)
- Housing: Each of the 4 treatment groups consisted of 25 presumed pregnant female rats singly housed in stainless steel wire-bottomed cages.
- Diet (ad libitum): Certified Rodent Diets no. 5002 (PMI Feeds Inc., St. Louis, MO) in individual feeders
- Water (e.g. ad libitum): local water processed by passage through a reverse osmosis (RO) membrane with chlorine added as a bacteriostat from an automatic watering system
- Acclimation period: yes

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19- 25
- Humidity (%): 30–70%
- Air changes (per hr): at least ten changes per hour
- Photoperiod (hrs dark / hrs light): 12 hr light-dark cycle

Administration / exposure

Route of administration:

dermal

Vehicle:

corn oil

Details on exposure:

TEST SITE
- Area of exposure: 5x7 cm, extended from the shoulders to the hip joints and extended ventrolaterally from the dorsal midline on each side
- % coverage: approximately 10% of body surface area
- Type of wrap if used: The skin application site was occluded during treatment with a gauze pad secured with Vetrapt or Micropores tape to prevent oral ingestion and to minimize loss of material from under the patch
- Time intervals for shavings or clipplings: The backs of the rats were clipped during the acclimation period using an Osters clipper with the appropriate blade

REMOVAL OF TEST SUBSTANCE
- Washing: the occlusive dressing was removed and the treatment area was wiped with a dermal wipe pad dampened with an aqueous 1% solution of soap and then
patted dry with a second clean pad
- Time after start of exposure: After a minimum 6-hr exposure period

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): The dosage volume of 2 mL/kg was adjusted daily on the basis of the individual body weights recorded each day before the
daily topical application.
- Concentration (if solution): four concentration levels: 0 (vehicle only), 100, 300, and 1,000mg/mL
- Constant volume or concentration used: no

VEHICLE
- Justification for use and choice of vehicle (if other than water): Mazolas corn oil, because the test material has good solubility in lipids but is sparingly soluble in water
- Lot/batch no. (if required): Mazolas corn oil (Best Foods Division, Englewood Cliffs, NJ)

Details on mating procedure:

- Impregnation procedure: virgin female rats were cohabitated with singly-housed breeder male rats, one male rat per female rat for a maximum of 5 days
- M/F ratio per cage: 1/1
- Length of cohabitation: for a maximum of 5 days
- Proof of pregnancy: female rats with spermatozoa observed in a smear of the vaginal contents or a copulatory plug in situ were considered to be at GD 0 and the female was returned to individual housing.

Duration of treatment / exposure:

on gestation days (GD) 6–15 (sperm positive day = GD 0)

Frequency of treatment:

daily with a minimum 6-hr exposure period

Duration of test:

GD 6 – GD 20

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

0 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

200 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

600 mg/kg bw/day (nominal)

Doses / concentrations 4

Dose / conc.:

2 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

25 females per group

Control animals:

yes, concurrent vehicle

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: The rats were monitored for viability at least twice daily throughout the study.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once daily before treatment, and approximately 60 min post-dosage during the dosage period and once daily during the post-dosage period.
Additionally, the dosing site was examined daily prior to application of the test material for signs of skin irritationand was graded for severity applying modifications of those described by Draize and the National Research Council (Draize et al., 1944; National Research Council, 1977). During the post-dosage period (GD 16–20), the dosing site was examined for skin irritation once daily. The application site was also examined for residue of the test material prior to the daily rinse.

BODY WEIGHT: Yes
- Time schedule for examinations: values were recorded on GD 0 and daily during the dosage and post-dosage period.

FOOD CONSUMPTION: Yes
- Food consumption: values were recorded on GD 0 and daily during the dosage and post-dosage period.

POST-MORTEM EXAMINATIONS: Yes / No / No data
- Sacrifice on gestation day 20
- Organs examined: gravid uterus was excised and weighed

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, an early resorption was defined as one in which embryonic structures were not grossly evident.
- Number of late resorptions: Yes, late resorption was defined as one in which embryonic structures were grossly evident.
- Number and distribution of live and dead fetuses were recorded for each female rat. A live fetus was defined as a term fetus that responded to stimuli. Dead fetuses
and late resorptions were differentiated by the degree of autolysis present; marked to extreme autolysis indicated a late resorption.

Fetal examinations:

- External examinations: Yes: Each fetus was examined for gross external alterations
- Soft tissue examinations: Yes: Approximately one-half of the fetuses were examined for soft tissue alterations
- Skeletal examinations: Yes: The remaining fetuses in each litter were eviscerated, cleared, stained with alizarin red S (Staples and Schnell, 1963), and examined for skeletal alterations.
- Head examinations: Yes: The heads of approximately one-half of the fetuses were fixed in Bouin solution and subsequently examined using a free-hand cross-sectioning
technique (Wilson, 1965). Gross lesions found at visceral exam were retained in neutral buffered 10% formalin for future evaluation.
- Sex determination
- Body weight determination

Statistics:

Clinical observation and other proportion data were analyzed using the Variance Test for Homogeneity of the Binomial Distribution (Snedecor and Cochran, 1967).
Quantitative continuous data (e.g., maternal body weights, body weight changes, feed consumption values, litter averages for percent male fetuses, percent resorbed conceptuses, fetal body weights, fetal anomaly data, and fetal ossification data) were analyzed using Bartlett’s Test for Homogeneity of Variance (Sokal and Rohlf, 1969) and
the Analysis of Variance (Snedecor and Cochran, 1967) when Bartlett’s Test was not significant (p>0.05). If the Analysis of Variance was significant (p<0.05), Dunnett’s
Test (Dunnett, 1955) was used to identify the statistical significance of the individual groups. If the Analysis of Variance was not appropriate, i.e., Bartlett’s Test was significant (p<=0.05), the Kruskal-Wallis Test (Sokal and Rohlf, 1969) was used when <= 75% ties were present.
In cases where the Kruskal-Wallis Test was statistically significant (p<= 0.05), Dunn’s Method of Multiple Comparisons (Dunn, 1964) was used to identify the statistical significance of the individual groups. If there were > 75% tied, Fisher’s Exact Test (Siegel, 1956) was used to analyze the data.
Count data obtained at Caesarian-sectioning of the dams were evaluated using the procedures described above for the Kruskal-Wallis Test.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

effects observed, non-treatment-related

Description (incidence and severity):

All clinical observations other than local skin irritation were considered unrelated to treatment because: (1) they were associated with wearing an Elizabethan collar; (2) the incidences were not dosage-dependent; and/or (3) the observations occurred only in one rat. Each rat in each treatment group had localized alopecia on the neck, most rats in all groups had chromorhinorrhea, and several rats in each of these groups had chromodacryorrhea (significantly fewer [p<= 0.01] in the 600- and 2,000- mg/kg/day dosage groups than vehicle only group).
These clinical observations were either associated with local irritation caused by wearing the collar or the collar preventing the rat from normal grooming.

Dermal irritation (if dermal study):

effects observed, treatment-related

Description (incidence and severity):

The only skin reaction to the vehicle (0 mg/kg/day group) was grade 1 flaking, which occurred in 3 rats beginning on GD 16 or GD 18 (during the post-dosage period) and persisting until necropsy. Dosage-dependent increases in the incidences of erythema (grades 1 and 2), flaking (grades 1, 2, and 3), edema (grades 1 and 2), and scabbing, as compared with the vehicle control values, were seen in the 600- and 2,000-mg/kg/day groups. Each of these signs of skin irritation (except scabbing) occurred in significant numbers (p<= 0.01) of the 2,000-mg/kg/day group. No hyperpigmentation or test material residues were observed on the skin surface at any time during the study. There were no significant differences in skin irritation observed between the 200- mg/kg/day dosage group and the vehicle control group.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

Three rats, two in the control group and one in the 2,000-mg/kg/day group, died within 6 hr of application of the first dosage (GD 6) and were replaced. The rats that died were examined for cause of death, gross lesions, and pregnancy status. All rats were pregnant and appeared normal at necropsy; no cause of death was identified. The deaths were not considered to be treatment related because they were not dosage-dependent.
With the exception of the three replaced rats, all rats survived until scheduled sacrifice on GD 20.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

GD 0 weights were collected and used to assign animals to treatment groups based on computer-generated (weight-ordered) randomization procedures, such that the mean body weights of each group were not statistically different at the 5% probability level using the Bartlett’s Test for homogeneity of variances.
Average body weights and body weight changes were unaffected by application dosages of the test material as high as 2,000 mg/kg/day and showed no dosage-dependent or
statistically significant differences.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Absolute (g/day) and relative (g/kg/day) maternal feed consumption values were unaffected by application dosages of the test material as high as 2,000 mg/kg/day and showed no dosage-dependent or statistically significant differences.

Ophthalmological findings:

not examined

Haematological findings:

not specified

Clinical biochemistry findings:

not specified

Urinalysis findings:

not specified

Behaviour (functional findings):

not specified

Immunological findings:

not specified

Organ weight findings including organ / body weight ratios:

not specified

Gross pathological findings:

not specified

Neuropathological findings:

not examined

Other effects:

no effects observed

Description (incidence and severity):

There were no differences from control in any of the developmental parameters measured, including embryo/fetal viability, fetal weight, malformations, or variations.

Maternal developmental toxicity

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.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

> 2 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

dermal irritation

Results (fetuses)

Fetal body weight changes:

no effects observed

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

not specified

Changes in litter size and weights:

no effects observed

Description (incidence and severity):

At termination, there were 22–25 litters per group.

Changes in postnatal survival:

not specified

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Details on embryotoxic / teratogenic effects:

The assessment of the developmental toxicity of TMPCC showed no differences across dosage groups up to 2,000 mg/kg/day for any Caesarean-sectioning or litter parameters measured. Application dosage did not cause gross external, soft tissue, or skeletal malformations or variations. The litter averages for corpora lutea, implantations, litter size, live and dead fetuses, early and late resorptions, percent resorbed conceptuses, fetal body weights (total, male and female), and percent live male fetuses were comparable among the four dosage groups and did not differ significantly. There were no dead fetuses, no dams with all conceptuses resorbed, and all placentae appeared normal.
In the 0- (vehicle), 200-, 600-, and 2,000-mg/kg/day dosage groups, litters with fetuses with any alteration numbered 10 (40.0%), 8 (34.8%), 14 (63.6%), and 7 (29.2%), respectively. The numbers of fetuses with any alteration observed were 13 (3.6%), 10 (3.0%), 20 (6.5%), and 9 (2.8%), and the percentages of fetuses per litter with any alterations were 3.5, 2.9, and 6.8% (significantly different from vehicle control group, pr0.05), and 2.7% in the 4 dosage groups, respectively. The significant difference in fetal alterations in the 600-mg/kg/day group was considered unrelated to the test material because (1) the incidences were not dosage-dependent and (2) all findings were common vessel developmental variations.
Analyses of the average numbers of fetal ossification sites per litter did not reveal biologically important or statistically significant differences among the four dosage groups. The extent of ossification of the hyoid, vertebrae, ribs, sternum, forelimbs, and hindlimbs was comparable in litters in all dosage groups.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

>= 2 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reduction in number of live offspring

fetal/pup body weight changes

changes in postnatal survival

external malformations

skeletal malformations

visceral malformations

Fetal abnormalities

Key result

Abnormalities:

no effects observed

Overall developmental toxicity

Key result

Developmental effects observed:

no

Applicant's summary and conclusion

Conclusions:

TMPCC administered dermally to Sprague-Dawley rats daily during the period of organogenesis at dosages up to 2,000 mg/kg/day produced no developmental toxicity.
The two highest dose levels caused some local irritation at the site of application, but no decreases in maternal weight gain.