Trifluoroacetic acid

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Trifluoroacetic acid

EC Number:

200-929-3

EC Name:

Trifluoroacetic acid

Cas Number:

76-05-1

Molecular formula:

C2HF3O2

IUPAC Name:

trifluoroacetic acid

Test material form:

liquid

Details on test material:

- Supplier: Aldrich Chemical Company
- Batch: 61496MK
- Purity: 99% (assumed 100% for purposes of preparation of dose formulations)

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River (Crl:CD (SD) IGS BR)
- Age at study initiation: approximately 10 to 12 weeks of age at receipt on GD 1 to 3
- Weight at study initiation: The weight range was 245 to 299 grams at start of dosing
- Fasting period before study: No
- Diet: Certified Global 16% Protein Rodent Diet No. 2016C (pellet, Harlan), ad libitum
- Water: Water (New Jersey-American Water Company), ad libitum
- Acclimation period: The study animals arrived at the test facility on GD1-3 and were acclimated until GD6.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): Daily Average Range, 20 to 23°C
- Humidity (%): Daily Average Range, 47 to 53%
- Air changes (per hr): no information

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: A dosing volume of 5 mL/kg was applied for all animals, which was adjusted based on the latest body weight. No neutralization of the dose formalations was performed. Fresh dose formulations were prepared once daily. The pure test article has a pH of 1.1 and pKa of 0.3, and reacts strongly with water. Therefore, a PAPR with an OV/SD/HV/CL/HE organic vapour filter was used during preparation and dose administration. Due to evaporation properties of the formulations, the containers were covered with parafilm or similar covering during preparation, as well as, during dosing to ensure accurate and consistent concentration results.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses to determine homogeneity, stability, and concentration of the test and/or control materials were carried out at the testing facility.

Details on mating procedure:

The female rats were inseminated at the vendor facility. Gestation Day 0 (GD0) was the day of detection of a copulatory plug in situ and/or sperm in a vaginal smear. The weight range was 245 to 299 grams at start of dosing

Duration of treatment / exposure:

Gestation day 6 up to and including gestation day 19

Frequency of treatment:

Daily

Duration of test:

14 treatment days.

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

37.5 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

75 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

150 mg/kg bw/day (nominal)

No. of animals per sex per dose:

22 mated female rats

Control animals:

yes, concurrent vehicle

Examinations

Maternal examinations:

VIABILITY:
Animals were observed in their cages twice daily (once in the morning and once in the afternoon) for mortality, morbidity and signs of severe toxic or pharmacologic effects.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: All animals on study were examined daily from GD 4 through terminal euthanasia (GD 20). Examinations included observations of general condition, skin and fur, eyes, nose, oral cavity, abdomen and external genitalia as well as evaluations of respiration. During the stabilization period, and during the post-dosing phase, these evaluations were performed once daily. During the treatment period, these examinations were performed prior to dosing (within approximately 30 minutes) and at approximately 2 hours after dosing. Observations after dosing were limited to recording transient signs directly associated with dosing.

BODY WEIGHT: Yes
- Time schedule for examinations: Body weights were recorded for all animals on GD 4 and daily from GD 6 through 20

FOOD CONSUMPTION: Yes
- Time schedule for examinations: Feed was available without restriction 7 days/week. A weighed quantity of feed was presented to each animal daily from GD 4 to GD 18. After 2 or 3 days, any feed remaining was weighed.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 20
- Organs examined: A macroscopic post-mortem evaluation was performed on GD 20, during which corpora lutea, implantation data and uterine weights were recorded. In addition, liver and kidney weights were determined.

Ovaries and uterine content:

The ovaries and uteri were examined to determine:
- Number of corpora lutea;
- Weight of intact gravid uterus;
- Location and number of implantation sites, resorptions, fetal death, dead fetuses;
- Gross evaluation and weight of placentas.

Fetal examinations:

The fetuses were removed, weighed (live and recently dead fetuses), sexed and examined externally for defects. Approximately half of the fetuses were examined for soft tissue abnormalities. The other half was processed for staining with Alizarin Red S and examined for skeletal abnormalities and ossification state.

Statistics:

Statistical analyses were performed using the individual animal (or litter) as the basic experimental unit. For litter/fetal findings, the litter was the treated experimental unit and the basis for statistical analysis and biological significance was assessed with relevance to the severity of the anomaly and the incidence of the finding within the background control population.The following statistical methods have been used for the analysis of the results: Williams' test, Dunnett's test, Shirley's test, Steel's test, Kruskal-Wallis test, Wilcoxon rank sum tests

Indices:

Sex ratio, Pre implantation loss, Post implantation loss, Gravid uterine adjusted body weights, Mean litter placental and fetal weights

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

no effects observed

Description (incidence and severity):

There were no test article-related clinical observations

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Description (incidence):

All females survived to termination of the study

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

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:

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

Description (incidence and severity):

Test article-related organ weight increases were observed in liver and kidney (see Table below in 'any other information on results')

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

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

Description (incidence and severity):

One female each in the control and high-dose groups was not pregnant, although this was not attributed to the administration of the test article.

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

150 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: No treatment related effects on maternal toxicity at the highest dose level

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

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Effect levels (fetuses)

Dose descriptor:

NOAEL

Effect level:

150 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No treatment related effect on embryo-fetal development in rats.

Fetal abnormalities

Abnormalities:

no effects observed

Overall developmental toxicity

Developmental effects observed:

no

Any other information on results incl. tables

Analysis of initial mixes confirmed that the preparation procedure used for this study produced homogeneous mixtures and that the test material was stable in the vehicle, under refrigerated conditions, for at least seven days. The formulations were prepared daily for dosing, and no storage was required. Analyses conducted during the treatment period confirmed that dose solutions of appropriate concentration were administered.

Body weight in pregnant rats (body weight on GD20 was adjusted by subtracting weight of uterus with fetuses):

	Body weight (g)						Kidney (g)	Liver (g)
Dose (mg/kg)	GD4	GD6	GD12	GD16	GD20	GD20-adjusted
0	264	284	310	336	383	309	1.97	15.6
37.5	265	284	310	339	376	306	2.05	15.7
75	261	278	303	333	384	299	2.05	15.7
150	266	282	307	337	386	308	2.08*	17.1*

Number of live fetuses, mean number of live fetuses per litter and mean body weight of fetuse:

Dose (mg/kg)	Fetuses/Litters	Fetuses per litter	Body weight (g)
0	244/21	12	4.0
37.5	279/22	13	4.1
75	294/22	13	4.0
150	251/21	12	4.0

Applicant's summary and conclusion

Conclusions:

The No-Observed-Adverse-Effect-Level (NOAEL) of Trifluoroacetic acid for maternal and embryo-fetal development toxicity in rats was considered to be 150 mg/kg/day.

Executive summary:

A GLP compliant prenatal developmental toxicity study with Trifluoroacetic acid was conducted in rats according to OECD Guideline 414. This study was designed to assess any maternal and/or embryo-fetal toxicity of the test article, Trifluoroacetic Acid (TFA), in the rat, following daily oral (gavage) administration during the period of major organogenesis, from implantation to the day of closure of the hard palate, Gestation Days (GD) 6 to 19, with Cesarean section on GD 20. Eighty-eight time-mated female Sprague-Dawley rats were distributed into 4 groups, each containing 22 rats. The animals were administered TFA at 0 (Control Article – distilled water), 37.5, 75 and 150 mg/kg bw/day TFA at a dose volume of 5 mL/kg by oral gavage once daily from GD 6 to 19. The following parameters were evaluated for all animals: viability, detailed physical examinations (immediately prior to dosing [within approximately 30 minutes] and approximately 2 hours after dosing), body weights, including gravid uterine adjusted body weights, food consumption and organ weights. A macroscopic postmortem evaluation was performed on GD 20, during which corpora lutea, implantation data and uterine weights were recorded. The fetuses were removed, weighed (live and recently dead fetuses), sexed and examined externally for defects. Approximately half of the fetuses were examined for soft tissue abnormalities. The other half were examined for skeletal abnormalities and ossification state. Placentas were examinedand weighed.

All females survived until termination. One female each in the control and high-dose groups was not pregnant, although this was not attributed to the administration of the test article. Dosing was well-tolerated by all females, and doses up to 150 mg/kg bw/day had no adverse effect on body weight, body weight gain, food consumption, pregnancy, c-section parameters, fetal, placental, and uterine weights, organ weights, or fetal abnormalities, variations or ossification parameters. In conclusion, under the conditions of this study, the maternal and the embryo-fetal no-observed-adverse-effect-level (NOAEL) were established at 150 mg/kg bw/day TFA. Due to the non-adverse, test article-related organ weight increases, the maternal and embryo-fetal no-observed-effect-levels (NOEL) were established at 75 mg/kg bw/day (maternal) and 150 mg/kg bw/day (embryo-fetal).