Tetrahydrofurfuryl alcohol

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

not reported

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

comparable to guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

other: OECD Guideline 421 (Repeated Dose Reproduction / Developmental Toxicity Screening Test)

Deviations:

not specified

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tetrahydrofurfuryl alcohol

EC Number:

202-625-6

EC Name:

Tetrahydrofurfuryl alcohol

Cas Number:

97-99-4

Molecular formula:

C5H10O2

IUPAC Name:

tetrahydrofuran-2-ylmethanol

Test material form:

other: liquid

Details on test material:

Test substance name: Tetrahydrofurfuryl alcohol
Supplier: not reported
Lot. no.: not reported
Purity: 99.5%
Melting point: less than -80°C
Appearance and property: Colorless liquid and freely soluble in water and acetone

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Details on test animals or test system and environmental conditions:

TEST ANIMAL:
-Source: Charles River Laboratories Japan Inc. (795 Shimofurusawa, Atsugi-shi, Kanagawa)
-Age at purchase: 8 weeks old-
Age at study initiation: 10 weeks old
-Acclimation period: male/female; 13 days
-Mean body weight at study initiation: male; 393 g (364-431 g), female; 234 g (208-275 g)
-Diet: Solid feed, labo MR stock, Nosan Corporation, Lot. No.021072, 021255 ad libitum
-Water: Tap water sterilized by filtration with 1 µm diameter cartridge filter and UV radiation, ad libitum

ENVIRONMENTAL CONDITION:
-Housing: Test animals were bred in a stainless steel metal wire cage (260W x 380D x 180H mm) in animal room (No.2) with barrier system.
- Temperature: 22 ± 3°C
- Humidity: 55 ± 10%
- Air change: more than 10 times per hour
- Photoperiod: 12 hours dark / 12 hours light

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

Japanese pharmacopoeia purified water (KYOEI Pharmaceutical Industries, Ltd. Lot. No.181376)

Details on exposure:

PREPARATION OF DOSING SOLUTIONS;
The dosing formulation was prepared to be the aqueous test formulation of the pre-determined dose concentration using Japanese pharmacopoeia purified water (KYOEI Pharmaceutical Industries, Ltd., Lot No. 181376). The stability test was performed for 20% and 0.2% test substance solution, as a results, the test substance solution was stable at least for 7 days under the cold and dark conditions (4°C). Therefore, the expiration period for use of the dosing formulation was set within 7 days after preparation of dosing formulation, and each prepared formulation was subdivided by daily consumption, sealed, shaded and stored in a cold place (4°C). Moreover, nominal concentration of the test substance in the dosing formulation was confirmed by analyses using first prepared dosing formulation.
VEHICLE;The test substance is freely soluble in water. Therefore water is selected as vehicle.
TREATMENT METHODS;For administration method, the dosing formulation of 5 mL/kg body weight was treated by oral gavage using a syringe with stomach tube made by Teflon. Control group was administered with Pharmacopoeia purified water which was used as the vehicle in the same manner. Dosages were calculated based on the most recent measured body weight individually.

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

After the completion of 2-week administration before mating (in the afternoon of day 15 of administration), treated animals were paired on a 1 male: 1 female basis in each dose group and housed in the same cage up to 2 weeks until copulation was noted. During the mating period, copulation check was performed approximately on the constant time every morning (about 9:30). The copulation was confirmed by presence of a vaginal plug or presence of sperm in the vaginal smear and the day when copulation was confirmed was designated as day 0 of gestation.

Duration of treatment / exposure:

Treatment period;
Both sexes; 2 weeks of before mating period
Male; 47 days including 2 weeks before mating period
Female;Shortest 42 days – longest 52 days including 2 weeks before mating period, a cohabitation period, a gestation period and a lactation day 4 after delivery

Frequency of treatment:

Once daily in the morning

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

15 mg/kg bw/day

Doses / concentrations 2

Dose / conc.:

50 mg/kg bw/day

Doses / concentrations 3

Dose / conc.:

150 mg/kg bw/day

No. of animals per sex per dose:

12 animals per sex per dose

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale; In the single oral dose toxicity study, lethal dose level of tetrahydrofurfuryl alcohol was more than 2000 mg/kg. In the 14-day dose range-finding study in 5 weeks old rats at oral dose levels of 50, 100, 200, 500 and 1000 mg/kg/day, there were no treatment-related changes in the 50 mg/kg group. In the 100mg/kg group, an increase in motor activity was noted in only 1 female. In the 200 mg/kg group, an increase in motor activity in female and the lower value in absolute and relative weight of thymus and pituitary in female were noted. In the 500 mg/kg group, the increase and decrease in motor activity, the lower value in food consumption and enlargement of the cecum in both sexes, and piloerection in some males, a tendency to suppressed body weight gain in male, and the lower value in absolute and relative weight of thymus and pituitary in female were noted. In the 1000 mg/kg group, piloerection and the lower value in absolute and relative thymus weights in female were noted in addition to the changes noted in 500 mg/kg group.According to the above results, the maximum dose level in the present study was set at 500 mg/kg/day which is supposed to cause the toxic effect and the minimum dose level was set at 15 mg/kg/day which is supposed to cause the no toxic effect. Between these 2 doses, dose levels of 50 and 150 mg/kg/day were set (4 doses in total). Five test groups were used in the study with the composition as follows; (1) vehicle administration group (control group hereinafter), (2) 15 mg/kg/day of the test substance administration group (15 mg/kg group), (3) 50 mg/kg/day of the test substance administration group (50 mg/kg group), (4) 150 mg/kg/day of the test substance administration group (150 mg/kg group) and (5) 500 mg/kg/day of the test substance administration group (500 mg/kg group).

Examinations

Maternal examinations:

DETAILED CLINICAL OBSERVATIONS:
- All animals were observed at least twice a day, i.e., in the morning and evening, for the general appearance, behavior, morbidity and mortality. Especially, state of gestation, delivery and lactation of rats were closely observed.

BODY WEIGHT: - Males were weighed on treatment day 1 (the initiation day of the treatment) , 8, 15, 22, 29, 36, 43 and 47. Females were weighed on treatment day 1, 8 and 15, gestation day 0, 7, 14 and 20, lactation day 0 and 4.

FOOD CONSUMPTION:- For the food consumption, 24 hours intake per cage until the next day was measured on the same day of the body weight measurement. The final measurement of the food consumption was performed on the treatment day 46 for male and on the lactation day 3 for female. The measurement of the food consumption were not performed on treatment day 15 during the cohabitation period for all animals in both sexes, on treatment day 22 for males and females who’s copulation was not confirmed.

WATER CONSUMPTION: No data

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

After the completion of delivery was confirmed, each litter size (total of live and dead pups) were counted and parturition index (%) [(number of total newborn / number of implantation sites) x 100] was determined. The sex was determined individually by ano-genital distance and the sex ratio was calculated for each group. Any external abnormalities including the oral cavity in pups were observed.

General condition and mortality were examined daily and live birth index (%) [(number of live birth on checking of delivery / total number of newborns) x 100] and newborn viability index (%) [(live pups on lactation day 4 / number of live birth on checking of delivery) x 100] were determined.

Each litter was weighed per sex on days 0 and 4 of lactation and mean value was calculated per animal.

Pups were euthanized by diethyl ether anesthesia and exsanguination. The gross examinations were performed for the main organs in the thoracic and abdominal cavity of the dead animals on the day when the animal was found dead and of live pups on day 4 of lactation.

Statistics:

The obtained mean value and incidence was statistically analyzed significant difference (significance level: < 5%) between the vehicle control group and each test substance treatment group using following methods.The Bartlett’s test was performed on the parametric data (body weight, food consumption, organ weight, number of corpora lutea and implantation sites, gestation length and litter size). When homogeneous variances were found, a one-way analysis was performed, then, when significant differences were found, the comparative test between the vehicle control group and each test substance treatment group was performed using the the Scheffe’s test. When heterogeneous variances were detected, and for the nonparametric data (implantation index, birth rate, delivery index, viability index of newborn, incidence of external and visceral findings of pups), Kruskal-Wallis test was performed. As a results, when significant differences were found, the Scheffe’s type was performed. For the categorical data examination), Fisher’s exact probability test(clinical signs, incidence of the abnormal findings in necropsy and histopathological or Chi-square test (copulation index, fertility index, gestation index and sex ratio) was performed. For litter parameters, the litter mean was used as the experimental unit.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
General condition and mortality
No abnormalities were noted in the general condition of the control group, 15, and 50 mg/kg groups. In the 150 mg/kg group, slight increase in motor activity was noted after 5 - 15 minutes of administration. In the 500 mg/kg group, slight increase in motor activity and accompanied decrease in motor activity was noted in many animals through the administration period. In 2 females of the 500 mg/kg group, slight vaginal hemorrhage was noted in the latter gestation period.

Body weight: In 15 and 50 mg/kg group the body weight and body weight gain showed no significant differences compared to vehicle control group. For females in the 150 mg/kg group, the body weight on gestation day 20 showed significant lower value compared to the control group and body weight gain during the gestation period significantly decreased. In the 500 mg/kg group, for females, significant suppression of the body weight gain and significant decrease of the body weight gain during the gestation period were noted from gestation day 14.

Food consumption: In the 15 mg/kg group, no significant change was noted in food consumption during the study period. In the 150 mg/kg group, significant decrease of food consumption was noted on gestation day 14 and 20 in female. In the 500 mg/kg group, significant decrease of food consumption was noted on treatment day 1, gestation day 0, 14 and 20 in female

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

clinical signs

food consumption and compound intake

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
Viability and body weight
There was no significant difference in number of total newborn per litter, delivery index, litter size, birth rate, sex ratio, body weight on day 0 of lactation and viability index and body weight on day 4 of lactation of the 15 and 50 mg/kg group compared to the control group. No abnormality was noted in general condition of the newborn. In the 150 mg/kg group, 4 dams had live pups on checking of delivery, and the number of total newborn per litter, delivery index, litter size and birth rate significantly decreased. More than half of newborns died on day 0 of lactation. Pups survived up to day 4 of lactation were only 4 from a litter and all of them showed the lowered body weight. In the 500 mg/kg group, no female delivered and no newborn was obtained.

Morphology
The systemic edema was noted in one pup out of 28 newborns from 4 litters in 150 mg/kg group but no external and visceral abnormalities were noted in pups of any other groups. Thymic remnant in neck was noted in each group as the visceral variations. In the 50 mg/kg group, this incidence was slightly high (8.4 %) but no significant difference was noted compared to the control group (3.2 %). Additionally, persistent left umbilical artery was noted in the control group (1.2 %) and in the 50 mg/kg group (2.2 %) but no significant difference was noted between the groups.

Effect levels (fetuses)

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day

Sex:

male/female

Basis for effect level:

changes in postnatal survival

Overall developmental toxicity

Developmental effects observed:

yes

Lowest effective dose / conc.:

150 mg/kg bw/day

Treatment related:

yes

Relation to maternal toxicity:

developmental effects occurring together with maternal toxicity effects, but not as a secondary non-specific consequence of maternal toxicity effects

Dose response relationship:

yes

Relevant for humans:

yes

Applicant's summary and conclusion

Conclusions:

An oral combined repeated dose/reproductive and developmental screening test in the rat, conducted in a manner similar to the current OECD 422 guideline and in accordance with GLP, identified a maternal and developmental NOAEL of 50 mg/kg bw/day based on adverse effects on delivery indices, litter sizes, pup survival to Day 4 and other indices at 150 mg/kg/day and above.