Tricyclodecanedimethanol

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

16 May 2013 to 17 July 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study was conducted to regulatory guidelines and in compliance with GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

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:

other: JMAFF, 12 Nohsan No. 8147, Agricultural Protection Bureau, November 24 2000

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Certificate of compliance from UM GLP Monitoring Authority included in report

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

TCD Alcohol DM

IUPAC Name:

TCD Alcohol DM

Constituent 2

Reference substance name:

Tricyclodecanedimethanol

EC Number:

248-096-5

EC Name:

Tricyclodecanedimethanol

Cas Number:

26896-48-0

Molecular formula:

C12H20O2

IUPAC Name:

[3-(hydroxymethyl)tricyclo[5.2.1.0²,⁶]decan-8-yl]methanol

Test material form:

liquid: viscous

Details on test material:

- Name of test material (as cited in study report): TCD Alcohol DM
- Substance type: organic
- Physical state: clear colourless very viscous liquid
- Analytical purity: 98%
- Lot/batch No.: 50000051564
- Expiration date of the lot/batch: 15 January 2014
- Storage condition of test material: refrigerated in the dark

Test animals

Species:

rat

Strain:

other: RccHan: Wist

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: UK
- Age at study initiation: 77-86 days
- Weight at study initiation: 177 - 220
- Housing: Acclimatisation: up to four animals
During pairing: one (stock) male and one female
Gestation: one female
- Diet (e.g. ad libitum): SDS VRF1 Certified pelleted diet. The diet contained no added antibiotic or other chemotherapeutic or prophylactic agent.
- Water (e.g. ad libitum): Potable water from the public supply via polycarbonate bottles with sipper tubes. Bottles were changed at appropriate
intervals.
- Acclimation period: 5 days before commencement of pairing

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19-23 deg. C
- Humidity (%): 40-70%
- Air changes (per hr): - Filtered fresh air which was passed to atmosphere and not recirculated.
- Photoperiod (hrs dark / hrs light): 12 hrs dark/12 hrs light

IN-LIFE DATES: From: 16 May To: 11/14 June 2013

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: ethyl acetate/propylene glycol 16% w/w

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: The test substance was suspended in ethylacetate to form a homogenous suspension. Subsequently,
propylene glycol was added under constant stirring. A series of formulations at the required concentrations was prepared by dilution of individual
weighings of the test

substance as follows:

Group Treatment Dose Nominal Volume dose Concentration of
(mg/kg/day) concentration (mL/kg) ethylacetate vehicle (w/w)
(mg/mL)
1 Control 0 0 5 16 %
2 TCD Alcohol DM 250 50 5 19 %
3 TCD Alcohol DM 500 100 5 18 %
4 TCD Alcohol DM 1000 200 5 16 %
�

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Stability and homogeneity - Homogeneity and stability of the test material in the vehicle was demonstrated over a period of 24 hours at refrigerated storage (2-8°C); and for 15 days at ambient storage at concentrations of 1 mg/mL and 200 mg/mL as part of this programme of work in HLS Study
No. PJJ0003.
Achieved concentration - Samples of each formulation prepared for administration on Day 1 of treatment (Day 6 of gestation) and Day 14 of treatment
(Day 19 of gestation) were analysed for achieved concentration of the test substance.

Details on mating procedure:

- Impregnation procedure: cohoused
- M/F ratio per cage: 1:1 with identified stock males
- Length of cohabitation: as required
- Proof of pregnancy: Ejected copulation plugs in cage tray and vaginal smears were checked for the presence of sperm, referred to as day 0 of
pregnancy
- Any other deviations from standard protocol: No

Duration of treatment / exposure:

Females were treated from Day 6 to Day 19 (inclusive) after mating, once daily at approximately the same time each day.

Frequency of treatment:

once daily

Duration of test:

20 days

Doses / concentrations

Doses / concentrations 1

Remarks:

Doses / Concentrations:
0, 50, 100, 200 mg/ml at constant dose in mg/kg/day at 5 ml/kg bw
Basis:
analytical conc.

Doses / concentrations 2

Remarks:

Doses / Concentrations:
0, 250, 500, 1000 mg/kg bw/d
Basis:
analytical conc.

No. of animals per sex per dose:

20 females per dose

Control animals:

yes, concurrent vehicle

Details on study design:

The toxicity of TCD Alcohol DM was assessed during a Preliminary Toxicity and Embryo-Fetal Development Study by Oral Gavage Administration to Han Wistar Rats (Huntingdon Life Sciences Study No. PJJ0004, conducted at 600 and 1000 mg/kg/day). The doses were selected in conjunction with the Sponsor on the basis of data obtained in this preliminary study (HLS Study No. PJJ0004). Oral administration of dose levels of up to 1000 mg/kg/day (1000 mg/kg/day was selected as the limit dose for the OECD414 test guideline) to Han Wistar rats was tolerated without any significant signs of toxicity.

It was therefore considered that a high dose of 1000 mg/kg/day was appropriate for this embryo-fetal toxicity study. The low and intermediate doses selected were 250 and 500 mg/kg/day, respectively (applying a ratio of x2 between the dose levels).

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: daily
- Cage side observations checked in table [No.?] were included.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: A detailed physical examination was performed on each animal on Days 0, 5, 12, 18, and 20 after mating to monitor general health

BODY WEIGHT: Yes
- Time schedule for examinations: The weight of each adult was recorded on Days 0, 3 and 6-20 after mating

FOOD CONSUMPTION : Yes
The weight of food supplied to each adult, that remaining and an estimate of any spilled was recorded for the periods Days 0-2, 3-5, 6-9, 10-13, 14-17 and
18-19 after mating inclusive

POST-MORTEM EXAMINATIONS: Yes
- Organs examined: A complete necropsy was performed in all cases.

OTHER:
- Two females receiving 1000 mg/kg/day, 4F 61 and 4F 63, were killed for welfare reasons on Days 9 and 16 respectively, due to general
poor condition.

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
- Other: Fetuses (live and dead) Yes

Fetal examinations:

Dissected from the uterus, individually weighed and identified within the litter using a coding system based on their position in the uterus. Examined externally with abnormalities recorded, sampled as appropriate and retained in appropriate fixative. The sex of each fetus was recorded.

Fetuses eviscerated were fixed in Industrial Methylated Spirit (IMS).
Remaining fetuses were fixed whole in Bouin’s fluid and serial sections examined for visceral abnormalities.
Processing Bouin’s fixed fetuses were subject to free-hand serial sectioning.
IMS fixed fetuses were processed and stained with Alizarin Red and assessed for skeletal development and abnormalities.

Statistics:

The following data types were analysed at each timepoint separately:
Body weight, using absolute values and gains over appropriate study periods.
Gravid uterine weight and adjusted body weight
Food consumption, over appropriate study periods
Litter size and survival indices
Fetal, placental and litter weight.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
Post dose signs of salivation (with or without associated chin rubbing) were observed at all dose levels and is commonly associated with a general
distaste of formulation, but also a potential sign of reflux. Noisy breathing/rales was observed following dose administration for some individuals,
these signs are considered to be related to the oral gavage route of administration of TCD Alcohol DM, but the toxicological significance of this
finding is unclear as the signs are transient and random amongst individuals, but could be related to the route of administration of TCD Alcohol DM, rather
than direct toxicity of TCD Alcohol DM.

Treatments at 1000 mg/kg/day and to a lesser extent at 500 mg/kg/day resulted in statistically significant bodyweight loss on Days 6-7 of gestation and statistically significantly lower overall bodyweight gain, and reduced food consumption on Day 6-9 and 10-13 of gestation. The effects at 500 mg/kg/day were not considered adverse at the degree observed. The effects on bodyweight and food consumption are considered to be indicative of non-specific toxicity, with bodyweight performance showing evidence of recovery towards the end of the treatment period, and food consumption being similar to Controls towards the end of the treatment period.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOEL

Effect level:

500 mg/kg bw/day (actual dose received)

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:
Embryo-fetal survival, growth and development were not affected by treatment with TCD Alcohol DM at dose levels up to 1000 mg/kg/day.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Basis for effect level:

other:

Remarks on result:

other: There was no effect of treatment on litter data,

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Oral administration of octahydro-4,7-methano-1H-indenedimethanol (TCD Alcohol DM), an industrial chemical intermediate, to RccHan™;WIST (Han Wistar) rats during the organogenesis phase of gestation resulted in two deaths at 1000 mg/kg/day and overall low maternal bodyweight gain and a period of low food consumption at 1000 mg/kg/day. Similar effects on food and body weight were apparent at 500 mg/kg/day but were not considered adverse at the degree observed.
It was concluded from this study that the dosage of 500 mg/kg/day was the maternal no-observed- adverse-effect-level (NOAEL), based on slight but statistically significantly reduced food intake and body weight at the top dose, and 1000 mg/kg/day was the no-observed adverse-effect- level (NOAEL) for embryo-fetal survival, growth and development.

Executive summary:

The objective of this study was to assess the influence of TCD Alcohol DM (an industrial chemical intermediate) on embryo-fetal survival and development, when administered during the organogenesis and fetal growth phases of pregnancy in RccHanTM;WIST (Han Wistar) rats.

Three groups of 20 females received TCD Alcohol DM at doses of 250, 500 or1000 mg/kg/day by oral (gavage) administration, from Day 6 to 19 after mating. A similarly constituted Control group received the vehicle, ethylacetate in propylene glycol at the same volume dose. Animals were killed on Day 20 alter mating for reproductive assessment and fetal examination.

Clinical observations, body weight and food consumption were recorded. Adult females were examined macroscopically at necropsy on Day 20 alter mating and all fetuses were examined macroscopically at necropsy and subsequently by detailed internal visceral examination or skeletal examination.

Results

Two females receiving 1000 mg/kg/day were killed for welfare reasons on Days 9 and 16 of gestation, due to general poor condition. Terminal clinical signs consisted of rales, piloerection and hunched posture for both animals, additionally underactive behaviour, partially closed eyelids and abnormal gait in one animal only. The common macroscopic change was the caecum contained gas, in one animal there was also gas in the stomach, jejunum and ileum, a dark liver and the rectum had no faecal pellet formation, the other animal had minimal adipose tissue. Both females were pregnant, and all implantations appeared grossly normal.

Following administration with TCD Alcohol DM, salivation and/or chin rubbing, was observed on most days during thestudy for females receiving 250, 500 or 1000 mg/kg/day. Salivation is commonly associated with general distaste to formulation. Noisy breathing and/or rales were observed in animals at all dose levels and an isolated Control animal.

Group mean statistically significant bodyweight loss was evident between Days 6-7 of gestation for females receiving 500 or 1000 mg/kg/day and for females receiving 1000 mg/kg/day statistically significant bodyweight stasis or low gain was recorded on Days 7-8 and 17-18 of gestation respectively. Overall group mean bodyweight gain (6-20) was statistically significantly low for females receiving 500 or 1000 mg/kg/day. After the weight of the gravid uterus was excluded this difference was still apparent for adjusted bodyweight and adjusted bodyweight change (6-20) at the same dose levels, however gravid uterine weights were unaffected by treatment with TCD Alcohol.

Food consumption was slightly but statistically significantly low on Days 6-9 and 10-13 of gestation for females receiving 500 or 1000 mg/kg/day.

All females were pregnant with live young on Day 20 of gestation. There was no effect of treatment on litter data as assessed by mean numbers of corpora lutea, implantations, embryo-fetal resorptions, live young, percentage sex ratio, post-implantation loss, or placental, litter and fetal weights.

Macroscopic examination of females killed on Day 20 of gestation did not reveal any findings in females receiving TCD Alcohol DM. Embryo-fetal development was also considered to be unaffected by the test material at doses up to 1000 mg/kg/day.

Conclusion

Oral administration of TCD Alcohol DM, an industrial chemical intermediate, to RccHanTM;WIST (Han Wistar) rats during the organogenesis phase of gestation resulted in two deaths at 1000 mg/kg/day and overall low maternal bodyweight gain and a period of low food consumption at 1000 mg/kg/day. Similar effects on food and body weight were apparent at 500 mg/kg/day but were not considered adverse at the degree observed.

It was concluded from this study that the dosage of 500 mg/kg/day was the maternal no-observed- adverse-effect-level (NOAEL) and 1000 mg/kg/day was the no-observed adverse-effect- level (NOAEL) for embryo-fetal survival, growth and development.