Isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3-diol

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

40-51 days

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: valid without restriction; GLP guideline study conducted according to guideline OECD 422 Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1992

Report date:

1992

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Propanoic acid, 2-methyl-, monoester with 2,2,4-trimethyl-1,3-pentanediol

IUPAC Name:

Propanoic acid, 2-methyl-, monoester with 2,2,4-trimethyl-1,3-pentanediol

Constituent 2

Reference substance name:

Isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3-diol

EC Number:

246-771-9

EC Name:

Isobutyric acid, monoester with 2,2,4-trimethylpentane-1,3-diol

Cas Number:

25265-77-4

Molecular formula:

C12H24O3

IUPAC Name:

3-hydroxy-2,2,4-trimethylpentyl 2-methylpropanoate

Constituent 3

Reference substance name:

(3-hydroxy-2,2,4-trimethylpentyl) 2-methylpropanoate

IUPAC Name:

(3-hydroxy-2,2,4-trimethylpentyl) 2-methylpropanoate

Constituent 4

Reference substance name:

Texanol Ester-Alcohol; TEXANOL; 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate

IUPAC Name:

Texanol Ester-Alcohol; TEXANOL; 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate

Details on test material:

-Test article name (as reported): Propanoic Acid, 2-Methyl-, Monoester with 2,2,4-Trimethyl-1,3-Pentanediol; 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate
-Physical State and Appearance: Colorless liquid
-Date received: May 9, 1991
-Purity at start of study: 98.8%
-Purity at end of study: 98.7%
-Analytical laboratory: purity analysis was conducted by the Chemicals Quality Services Laboratory at Eastman Kodak Company
-Stability: Based on purity analysis at start and end of study, test material is considered stable.

Test animals

Species:

rat

Strain:

other: Sprague-Dawley (CD®(SD)BR/VAF Plus™)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS:
-Source: Charles River Laboratories (Kingston, NY)
-Condition at receipt: animals were isolated upon arrival and were judged healthy prior to testing
-Age at Study Initiation: 8 weeks
-Weight at Study Initiation: 270 ± 8g (males) and 199 ± 7g (females)
-Method of Animal Identification: uniquely numbered metal ear tag
-Method of Animal Distribution: animals were randomly assigned to each test group
-Housing: Starting at study initiation and continuing throughout premating, animals were housed singly in suspended, stainless-steel wire mesh cages. During the mating period, animals were housed one male with one female. Following mating, males were housed singly. On or about the 19th day of gestation, solid bottom pans containing bedding material for nesting were put in the cages of the female rats. Cages were washed once a week and absorbent paper under the cages was changed daily.
-Diet: Agway® Prolab™ Animal Diet (RMH 3200) certified ground chow was available ad libitum. Feed containers were cleaned weekly.
-Water: city water (Monroe County NY Water Authority) was supplied ad libitum through an automatic watering system during the premating, mating, gestation, and lactation periods. Females were provided with water in glass bottles while they were housed with nesting pans in their cages. Water was analyzed four times per year and analysis reports maintained on file with the testing laboratory.

ENVIRONMENTAL CONDITIONS:
-Temperature (°F): 70-76
-Relative Humidity: 44-56%
-Air changes per hour: no information
-Photoperiod (hrs dark/ hrs light): 12 hours dark/light

IN-LIFE DATES:
-Date of First Dose: May 13, 1991
-Date of Last Dose: July 2, 1991
-Duration of Dosing: Male rats were treated from the beginning of the premating period to the final treatment for the female rats and received 51 doses over 51 days. Females were dosed from the beginning of the premating period to postpartum Day 4 for a total of 40 to 51 treatments.
-Experimental Termination Date: April 27, 1992

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

unchanged (no vehicle)

Details on exposure:

All male rats were treated for 51 doses over 51 days starting on the first day of premating; all males were euthanized the following day. All female rats were treated for 40-51 doses; all female rats were euthanized on lactation Day 4. Dose levels were 0, 100, 300, or 1000 mg/kg bw/day of the test material; the test material was administered as received by oral gavage to 12 rats/sex/dose group. Animals were dosed seven days per week including holidays. Dosing volumes were calculated weekly so that animals from each dose group received volumes on a per kilogram body weight basis. Controls received a dose of distilled water equal in volume to that administered to the highest test group.

Details on mating procedure:

Females were mated 1:1 with males of the same group over a 14 day period; females not inseminated during the 1st week were placed with a proven male during the 2nd week of mating. Gestation Day 0 was defined when a copulatory plug or sperm in a vaginal smear was present. Following copulation, the males and females were housed individually until study termination. Clinical observations were performed on a daily basis.

Analytical verification of doses or concentrations:

no

Details on analytical verification of doses or concentrations:

Not applicable, the test material was administered undiluted.

Duration of treatment / exposure:

40-51 days for females; 51 days for males

Frequency of treatment:

daily

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
100 mg/kg bw/day
Basis:
actual ingested

Doses / concentrations 2

Remarks:

Doses / Concentrations:
300 mg/kg bw/day
Basis:
actual ingested

Doses / concentrations 3

Remarks:

Doses / Concentrations:
1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

12

Control animals:

other: Controls dosed with distilled water.

Details on study design:

Dose selection rationale – In a subacute oral gavage study in which the undiluted test material was administered to groups of male and female rats for 11 doses over a 15-day period at dose levels up to 1000 mg/kg bw/day, the NOAEL was 1000 mg/kg bw/day. Although slight increases in absolute and relative liver weights were seen in both sexes given 1000 mg/kg bw/day, no treatment-related lesions or changes in clinical chemistry suggestive of target organ damage were observed at necropsy.

Reproductive study - The study was conducted in 4 phases: premating (14 days); mating (1-14 days); pregnancy (21-22 days); and early lactation (4 days). Females were dosed from the beginning of the premating period to lactation Day 4 for a total of 40-51 treatments. All male rats were treated from the beginning of the premating period to the final treatment of the female rats for a total of 51 days. Dose levels were 0, 100, 300, or 1000 mg/kg bw/day; animals were dosed 7 days a week.

Examinations

Parental animals: Observations and examinations:

CLINICAL SIGNS: Clinical observations were performed on a daily basis.

BODY WEIGHT: collected on Days 0, 4, 7, 14, and 21 premating and on Days 0, 7, 14, 20 of gestation and on Days 0 and 4 post-partum for females; males were weighed on Days 0, 4, 7, 14, 21, 28, 35, 42, and 49.

FEED CONSUMPTION: determined on Days 4, 7, and 14 (premating), and on gestation Days 7, 14, and 20 for females; determined on Days 4, 7, 14, 35, 42, and 49 for males. Feed consumption was not determined during the mating period. Feed consumption for the dams was not determined on Days 0-4 postpartum.

MATING SUCCESS: Females in mated pairs were examined for up to 14 days to verify mating had occurred. The morning a vaginal plug or sperm was observed was considered Day 0 of gestation.

PARTURITION: Dams were observed for the beginning of parturition and this day was used to calculate the gestation period; the day that the dams had completely finished delivering was considered lactation Day 0.

HEMATOLOGY, CLINICAL CHEMISTRY: conducted in males only; detailed in a separate repeat-dose 51-day study report.

Oestrous cyclicity (parental animals):

Not examined

Sperm parameters (parental animals):

Not examined

Litter observations:

All pups were examined without handling as soon as possible after birth to determine the number of viable and stillborn pups. Live pups were sexed. Litters were examined for abnormalities on lactation Day 0 and 4 and live pups were weighed as a litter.

Postmortem examinations (parental animals):

GROSS PATHOLOGY: Necropsies were performed on all animals. Females that failed to deliver were euthanized on Day 23 or 24 of gestation and the uteri were examined for implantation sites. Dams that littered were examined for implantation sites and corpora lutea at the time of necropsy. The heart, liver, kidneys, adrenal glands, thymus, spleen, brain, target organs (liver and kidneys), and gross lesions were fixed in 10% buffered formalin; testes and epididymides were fixed in Bouin's fixative.

ORGAN WEIGHTS: The liver, kidneys, thymus, testes, and epididymides were weighed. Paired organs were weighed together.

HISTOPATHOLOGY: All tissues were examined microscopically from the control and high-dose males; target organs and gross lesions were examined from other groups. Ovaries from females which failed to deliver were also examined microscopically.

Statistics:

All mean data (body weight, feed consumption, organ weights, gestation period, litter size, pup body weight, litter weight, pup body weight gain, pup percent survival, hematology, and clinical chemistries) were evaluated using the Bartlett’s test (p ≤ 0.01), one-way analysis of variance (p ≤ 0.05), and Duncan’s multiple range test (p ≤ 0.05) to indicate statistical significance. Ratios (percent mortality and percent pregnancy) were compared using Chi Square Tables. Transformations (ranking) to normalize distribution of the data were performed where appropriate. A Student’s t-test was performed where the Bartlett’s test indicated statistical significance among the groups.

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Body weight and weight changes:

effects observed, treatment-related

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Other effects:

not examined

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P0)

Clinical signs/mortality: No mortality occurred except for one control female rat that showed abnormal clinical signs on gestation Day 16 and was euthanized due to poor body condition. Clinical signs for all remaining animals were limited to sialorrhea during the post-dose observation period in mid- and high-dose females and all male groups.

Body weight and body weight gain: No significant dose-related differences in body weight or body weight gain in either sex were noted during the study. The Day 0 mean body weight of the low- and high-dose group dams was significantly lower than controls; mid-dose dams were comparable to controls.

Feed consumption: Mean feed consumption for high-dose males and the female groups were significantly lower (8.4 and 11%, respectively) on Day 4 when compared to controls but from Day 7 to study termination no differences in feed consumption were noted in any group.

Organ weights: Males - all organ weights, except the kidney and liver, were comparable between the treated and control groups. Mean absolute and relative kidney weights were significantly higher in the high-dose male rats. The mean absolute liver weights in the low-dose males and mean absolute and relative liver weights in the mid- and high-dose groups were significantly higher than controls. Females - mean absolute and relative liver weights were significantly higher in high-dose females compared to controls.

Gross pathology: No treatment-related changes were observed during the macroscopic examination in any animal of either sex.

Maternal parameters: Copulation was identified in all female rats except for 1 control. Pregnancies resulted in 9 control, 7 low-dose, 10 mid-dose, and 9 high-dose animals. Mean number of dams which did or did not deliver a litter was comparable between control and treatment groups. Mean gestation length, total implants, and percent prenatal loss were comparable between control and treatment groups.

Histopathology: Centrilobular hepatocytomegaly was observed in the livers of both sexes at the mid- and high-dose levels. This was considered an adaptive response rather than a toxic response due to the absence of degenerative changes to the liver. Kidney lesions typical of α2u globulin nephropathy were observed in males.

Effect levels (P0)

Dose descriptor:

NOEL

Effect level:

1 000 other: mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: see 'Remark'

Remarks on result:

not determinable

Results: P1 (second parental generation)

Effect levels (P1)

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

clinical signs

Remarks on result:

not determinable

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

not examined

Histopathological findings:

not examined

Details on results (F1)

The low- and high-dose groups had a significantly higher mean number of live pups/litter on Day 0 compared to controls. The mean number of dead pups/litter on Day 0 was significantly lower in the low- and mid-dose groups compared to controls. The mean number of live pups/litter in the high dose group on lactation Day 4 was significantly higher than the control group. The mean number of pups/litter which died between Days 0 and 4 post-partum was significantly higher in the low-dose group when compared to the control group. The mean percent survival from Day 0 to Day 4 was comparable between control and treated groups. The mean pup body weights on lactation Day 0 and 4 were comparable between the controls and treated groups. The mean litter weights on Day 0 were comparable between control and treated groups; on Day 4 post-partum, the mean litter weights for the mid-dose group were lower than the control group. The mean number of male pups/litter on lactation Day 0 was significantly higher in all treatment groups when compared to controls. The mean number of male pups/litter on Day 4 was significantly higher in the low- and high-dose treatment groups when compared to control values. The mean number of female pups/litter on Days 0 and 4 was significantly lower in all treatment groups when compared to controls.

Effect levels (F1)

Dose descriptor:

NOEL

Generation:

F1

Effect level:

1 000 mg/kg bw/day

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: The NOEL for developmental toxicity was 1000 mg/kg bw/day. No adverse effects were observed in pups born to dams treated at that dose level.

Overall reproductive toxicity

Key result

Reproductive effects observed:

no

Any other information on results incl. tables

Table 1: Effects of Exposure to 2,2,4-trimethyl-1,3-pentanediol monoisobutyrate in Pregnant Female Rats

Parameter	2,2,4-Trimethyl-1,3-pentanediol monoisobutyrate  (mg/kg bw/day)
	0	100	300	1000
Number bred	12	12	12	12
Number pregnant	9	7	10	9
Number of dead females	0	0	0	0
Corpora Lutea of Pregnancy	19±3	18±2	17±6	18±4
Gestation Length	21.9±0.3	21.6±0.5	21.7±0.5	21.8±0.7
Percent Males on Lactation Day 0 (%)	45	53	49	50
Mean pup weights ± SD Day 0 Day 4	6.6±0.4 10.3±1.1	6.5±0.7 10.5±1.2	6.6±0.7 10.2±1.6	6.5±1.2 10.2±1.7

Applicant's summary and conclusion

Conclusions:

No neonatal or reproductive toxicity was observed following administration of Texanol® Ester-alcohol to male and female rats at dose levels of 0, 100, 300 and 1000 mg/kg bw/day for 51 days in males and 40 to 51 days in females. The NOEL for neonatal and reproductive effects was 1000 mg/kg bw/day. The NOAEL for parental toxicity was 1000 mg/kg bw/day.

In a well-conducted combined repeated dose and reproductive/developmental toxicity screening study in which groups of 12 rats/sex were administered up to 1000 mg/kg bw/day by oral gavage for 51 (males) or 40-51 (females) consecutive days of exposure during premating, mating, pregnancy and early lactation, there were no gross or microscopic effects on any reproductive organ in either sex. There were no adverse effects on any reproductive parameters and all pregnant animals delivered normally. There were no observable embryotoxic or fetotoxic effects on offspring. Based on an absence of reproductive effects in the parental generation or adverse effects on the offspring, Texanol Ester-Alcohol is not classified for “Reproductive or Developmental Toxicity” according to EU CLP.

Systemic toxicity for the male parental generation in this study is addressed in the section for Repeated-dose toxicity. Although there was an increase in absolute and relative liver weights in the high-dose female group, no treatment-related changes were observed during the macroscopic examination. Microscopically, centrilobular hepatomegaly was observed in the livers of female rats in the mid- and high-dose groups but this was considered an adaptive metabolic response rather than a toxic response due to the absence of degenerative changes to the liver. Based on this information, Texanol Ester-Alcohol is not classified for “Specific Target Organ Toxicity – Repeated Exposure” in female rats according to the GHS guidelines.

Executive summary:

In a combined repeated dose and reproductive/developmental toxicity study, undiluted Texanol Ester-alcohol was administered to 12 Sprague-Dawley rats/sex/group at dose levels of 0, 100, 300 and 1000 mg/kg bw/day for up to 51 days.  Administration of the test material did not affect the reproductive performance in this study in terms of ability to mate, mean number of live or dead pups/litter, total implants, prenatal loss, percent survival, total litter weight, mean pup weight, pup survival and postnatal growth. There were no toxicologically significant differences between the control and treated groups with respect to reproduction and development. The NOEL for reproductive and developmental toxicity was 1000 mg/kg bw/day.  Although minor effects were observed in both paternal and maternal animals, no significant toxicity was observed. The NOAEL for systemic effects in the parental generation in this study was 1000 mg/kg bw/day.