(octahydro-4,7-methano-1H-indenyl)methyl acrylate

Endpoint summary

Description of key information

A 14 -day repeated toxicity study is available on Tricyclodecanemonomethylol acrylate. No adverse effects were observed in male and female rats treated until 1000 mg/kg bw/d.

Key value for chemical safety assessment

Toxic effect type:

dose-dependent

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

06 February 2019 - 20 March 2019

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Qualifier:

no guideline followed

Principles of method if other than guideline:

Range-finding study to the 28d repeated toxicity study

GLP compliance:

no

Remarks:

not required for a range-finding study

Limit test:

no

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: breeder: Janvier, Le Genest-Saint-Isle, France.
- Age at study initiation: on the first day of treatment, the animals were approximately 10 weeks old
- Mean body weight at study initiation: the males had a mean body weight of 430.5 g (range: 373.1 g to 461.9 g) and the females had a mean body weight of 267.5 g (range: 238.3 g to 299.4 g)
- Fasting period before study: no
- Housing: the animals were housed in twos or threes from the same sex and group in polycarbonate cages with stainless steel lids (Tecniplast 2000P, 2065 cm2) containing autoclaved sawdust (Le comptoir des sciures, Meyzieu, France).
- Diet: SSNIFF R/M-H pelleted diet (free access)
- Water: tap water filtered with a 0.22 µm filter (free access)
- Acclimation period: for a period of 8 days before the beginning of the treatment period.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): approximately 8 to 15 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12 h/12 h

IN-LIFE DATES: 06 March 2019 to 20 March 2019

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING FORMULATIONS:
- Solution in the vehicle; suitable formulation in the selected vehicle
- Concentration in vehicle: 20, 60, 200 mg/mL
- Amount of vehicle (if gavage): 5 mL/kg/day

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

2 weeks

Frequency of treatment:

daily

Dose / conc.:

0 mg/kg bw/day (nominal)

Dose / conc.:

100 mg/kg bw/day (nominal)

Dose / conc.:

300 mg/kg bw/day (nominal)

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

5 males and 5 females per dose

Control animals:

yes, concurrent vehicle

Details on study design:

Dose selection rationale:
The dose levels were selected in agreement with the Sponsor, following the results of a previous acute toxicity study performed in the same species by gavage (OECD 423). In this study, two groups of three Sprague-Dawley female rats were treated with the test item at 2000 mg/kg by the oral route. No unscheduled deaths occurred during this study and no test item-related clinical signs were observed. Based on these data, the dose of 1000 mg/kg/day was used as the maximal dose for the 14-day toxicity study.

- Rationale for animal assignment: the animals were allocated to groups (by sex) using a computerized stratification procedure so that the average body weight of each group was similar.

Observations and examinations performed and frequency:

MORBIDITY AND MORTALITY
Each animal was checked for mortality and morbidity once a day during the acclimation period and at least twice a day during the treatment period, including weekends.

CLINICAL SIGNS
Each animal was observed once a day, at approximately the same time on the days of treatment (after the dosing of the last animal of the day), for the recording of clinical signs.

BODY WEIGHT
The body weight of each animal was recorded:
- once before the beginning of the treatment period,
- on the first day of treatment,
- at least twice a week until the end of the study.

FOOD CONSUMPTION:
The quantity of food consumed by the animals in each cage was recorded twice a week during the treatment period.
Food consumption was calculated per animal and per day.

Sacrifice and pathology:

ORGAN WEIGHTS:
See Table Tissue Procedure Table
The body weight of each animal was recorded at the end of the treatment period. The organs specified in the Tissue Procedure Table were weighed wet as soon as possible after dissection.
The ratio of organ weight to body weight (recorded immediately before euthanasia) was calculated.

GROSS PATHOLOGY:
A complete macroscopic post-mortem examination was performed on all study animals.

PRESERVATION OF TISSUES
Tissues specified in the Tissue Procedure Table were preserved in 10% buffered formalin for all study animals (except for the testes which were fixed in Modified Davidson's Fixative).

HISTOPATHOLOGY:
Based on findings in stomach detected at macroscopic examination, a microscopic examination was performed on the stomach for all study animals.

Statistics:

yes

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

See Table 1.
Hypersalivation was observed in 5/5 males and 3/5 females at 300 mg/kg/day and in 5/5 males and 5/5 females at 1000 mg/kg/day, starting generally between Days 3 and 7 in both sexes.
Hypersalivation is commonly observed when a test item is administered by gavage, and it was not associated any other clinical sign; therefore it was considered to be test item-related albeit non-adverse.
The other clinical signs recorded during the treatment period (i.e. soiled urogenital region, chromodacryorrhea, scabs, alopecia and reflux at dosing), were not considered to be test item related as they were reported sporadically in only a few animals and/or seen in control animals, and/or can commonly be observed in untreated laboratory rats.

Mortality:

no mortality observed

Description (incidence):

No unscheduled death was observed during the study.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

See Table 2.
Mean body weights were not affected by the test item treatment at = 300 mg/kg/day.

A non-statistically significant and slightly lower body weight was recorded in males at 1000 mg/kg/day between Days 8 and 14 when compared to controls. Moreover, a slightly lower body weight gain was recorded in males at 1000 mg/kg/day between Days 1 and 11.
Only a non-statistically significant and slight body weight loss was recorded in females treated at 1000 mg/kg/day between Days 1 and 4. However, mean body weights of females was not affected by the test item treatment.
All these findings were considered to be test item-related albeit non-adverse.

Differences in mean body weight in males at 300 mg/kg/day were considered as mainly due to the lower body weights from two males when compared to the body weights of other males in the group during the treatment period. Moreover, no relevant changes from controls were observed in mean body weight gain. Therefore, differences in mean body weight in males at 300 mg/kg/day were not considered to be related to the test item treatment.

Other changes noted in mean body weight and mean body weight change were not attributed to the test item treatment as they were not dose related and/or of minimal magnitude and/or values remained within the range of variation commonly observed in rats of this strain and age.

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Food consumption was unaffected by the test item treatment in all study animals, except for animals treated at 1000 mg/kg/day during the first week of treatment.

At 1000 mg/kg/day, when compared to controls, slightly lower food consumption was recorded between Days 1 and 4 in males and females (-11.9 and - 6.9%, respectively), and only in males between Days 4 and 8 (-6.3%).
This effect on food consumption was transient as increasing food consumption was recorded the following days, and slightly higher food consumption was recorded between Days 11 and 14 in males and females (+8.1 and +10.5% vs. controls, respectively).

Other differences (i.e. lower mean food consumption in females treated at 300 mg/kg/day between Days 4-14 and in males treated at 100 mg/kg/day between Days 1-11 or in males treated at 300 mg/kg/day between Days 1-11) were not dose-related and/or of minimal magnitude, and therefore considered incidental.

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:

effects observed, non-treatment-related

Description (incidence and severity):

No test item-related organ weight variations were noted.

The few organs weight variations noted at the end of the treatment period were minimal to slight, often of opposing trend between sexes and groups, without dose-relationship and were consequently not considered to be related to the test item administration.

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

No test item-related macroscopic changes were noted.

All macroscopic findings noted at the end of the treatment period were of those commonly reported in the species, and none were considered to be related to the test item administration.
This included the black discoloration seen in the stomach from 1/5 males treated at 300 mg/kg/day, 1/5 females at 300 mg/kg/day and 1/5 females at 1000 mg/kg/day.
As this macroscopic change was poorly dose-related and is not uncommon in the rats kept under laboratory condition, a relationship to treatment was considered to be doubtful and therefore the decision was made to process the stomach in all study animals for microscopic examination.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, non-treatment-related

Description (incidence and severity):

No test item-related microscopic changes were noted in the stomach.

A female treated at 300 mg/kg/day presented a slight focal erosion in the glandular stomach which correlated macroscopically with black discoloration of the stomach wall.
As this microscopic change was observed in a single animal, a relationship to the test item treatment was considered to be unlikely.
Other microscopic findings noted in test item-treated animals were considered incidental changes, as they also occurred in controls, had no dose-relationship in incidence or severity, were of opposing trend between sexes and are common background findings for the species.

Histopathological findings: neoplastic:

not examined

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Critical effects observed:

no

Table 1 - Clinical signs

 

Dose (mg/kg/day)	300		1000
Sex	M	F	M	F
Number of examined animals	n=5	n=5	n=5	n=5
Hypersalivation
minimal	-	-	1	-
mild	4	2	-	1
moderate	1	1	4	3
severe	-	-	-	1

-: not applicable.

M: Males; F: Females.

Table 2 - Mean body weight change / Mean body weight (expressed in g)

Sex	Male				Female
Dose level (mg/kg/day)	0	100	300	1000	0	100	300	1000
Body weight
. Day 1 % from controls	438.4 -	432.7 (-1.3)	420.5 (-4.1)	430.6 (-1.8)	267.0 -	271.3 (+1.6)	259.1 (-3.0)	272.5 (+2.1)
. Day 4 % from controls	462.5 -	455.0 (-1.6)	437.7 (-5.4)	449.0 (-2.9)	267.6 -	269.8 (+0.8)	266.2 (-0.5)	269.1 (+0.6)
. Day 8 % from controls	481.4 -	472.0 (-1.9)	461.3 (-4.2)	462.0 (-4.0)	274.7 -	279.3 (+1.7)	268.8 (-2.2)	273.8 (-0.3)
. Day 11 % from controls	495.7 -	485.1 (-2.1)	478.0 (-3.6)	472.5 (-4.7)	279.8 -	286.9 (+2.5)	273.2 (-2.4)	284.8 (+1.8)
. Day 14 % from controls	507.9 -	495.8 (-2.4)	487.4 (-4.0)	485.5 (-4.4)	283.2 -	286.2 (+1.0)	275.9 (-2.6)	292.2 (+3.2)
Body weight change
. Days 1 to 4	+24.1	+22.3	+17.3	+18.5	+0.7	-1.4	+7.1	-3.4
. Days 4 to 8	+18.9	+17.0	+23.5	+13.0	+7.1	+9.5	+2.6	+4.7
. Days 8 to 11	+14.4	+13.1	+16.7	+10.5	+5.0	+7.6	+4.4	+11.0
. Days 11 to 14	+12.2	+10.7	+9.4	+13.0	+.35	-0.7	+2.7	+7.4
. Days 1 to 14 % from controls	+69.5 -	+63.1 (-9.3)	+66.9 (-3.7)	+54.9 (-21.1)	+16.3 -	+14.9 (-8.2)	+16.8 (+3.2)	+19.7 (+20.8)

-: not applicable; In bold: change related to the test item treatment

 

Conclusions:

Daily administration of the test item by oral gavage for 14 days in Sprague-Dawley rats at 100, 300 or 1000 mg/kg/day was clinically well tolerated. The test item treatment only induced non-adverse hypersalivation at = 300 mg/kg/day and non statistcally slight effects on food consumption and body weight at 1000 mg/kg/day in males and females.

Consequently and under the experimental conditions of the study, the No Observed Adverse Effect Level (NOAEL) was established at 1000 mg/kg/day in absence of adverse effects.

Executive summary:

The objective of this preliminary study was to evaluate the potential toxicity of the test item, following daily oral administration (gavage) in rats for 2 weeks in order to assist the selection of dose levels for a further study to be performed in this species.

 

Methods

 

Three groups of five male and five female Sprague-Dawley rats were dosed daily by the oral route (gavage), with the test item, at dose levels of 100, 300 or 1000 mg/kg/day. One control group of five males and five females received the vehicle only (corn oil) under the same experimental conditions. A constant dosage volume of 5 mL/kg/day was used.

The animals were checked daily for mortality and clinical signs were recorded daily.

Body weight was recorded once in pre-test, on the first day of treatment and then at least twice a week until the end of the study.

Food consumption was recorded twice a week during the treatment period.

On completion of the treatment period, all animals were euthanized and a full macroscopic post-mortem examination was performed. Designated organs were weighed and selected tissues were preserved. Based on findings detected at macroscopic examination, a microscopic examination was performed on the stomach for all study animals.

 

Results

 

No unscheduled death occurred during the study.

 

Minimal to severe hypersalivation was observed with a dose-related incidence at = 300 mg/kg/day. Severity grade of hypersalivation was also dose-related. This clinical sign, commonly observed when a test item is administered by gavage, was not considered as adverse.

A moderately lower body weight gain (-21.1% compared to controls) during the first week and a slightly lower body weight (approximately -4.4% compared to controls) during the second week were recorded in males at 1000 mg/kg/day. Only slight body weight loss was recorded in females between Days 1 and 4.

Food consumption was slightly reduced only in animals treated at 1000 mg/kg/day during the first week.

 

No test item-related organ weights variations or gross findings were noted. Decision was made to process the stomach in all study animals for microscopic examination as a black discoloration was seen in the stomach from 1/5 males treated at 300 mg/kg/day, 1/5 females at 300 mg/kg/day and 1/5 females at 1000 mg/kg/day but no test item-related microscopic findings were observed.

 

Conclusion

 

Daily administration of the test item by oral gavage for 14 days in Sprague Dawley rats at 100, 300 or 1000 mg/kg/day was clinically well tolerated. The test item treatment only induced non-adverse hypersalivation at = 300 mg/kg/day and non statistically slight effects on food consumption and body weight at 1000 mg/kg/day in males and females.

Consequently and under the experimental conditions of the study, the No Observed Adverse Effect Level (NOAEL) was established at 1000 mg/kg/day in absence of adverse effects.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

The 14-d study is considered to be reliable with a klimisch score of 2

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

14 -day repeated toxicity study (rat, gavage):

Three groups of five male and five female Sprague-Dawley rats were dosed daily by the oral route (gavage), with the test item, at dose levels of 100, 300 or 1000 mg/kg/day. One control group of five males and five females received the vehicle only (corn oil) under the same experimental conditions. A constant dosage volume of 5 mL/kg/day was used.

No unscheduled death occurred during the study. Minimal to severe hypersalivation was observed with a dose-related incidence at = 300 mg/kg/day. Severity grade of hypersalivation was also dose-related. This clinical sign, commonly observed when a test item is administered by gavage, was not considered as adverse. A moderately lower body weight gain (-21.1% compared to controls) during the first week and a slightly lower body weight (approximately -4.4% compared to controls) during the second week were recorded in males at 1000 mg/kg/day. Only slight body weight loss was recorded in females between Days 1 and 4. Food consumption was slightly reduced only in animals treated at 1000 mg/kg/day during the first week.

No test item-related organ weights variations or gross findings were noted. Decision was made to process the stomach in all study animals for microscopic examination as a black discoloration was seen in the stomach from 1/5 males treated at 300 mg/kg/day, 1/5 females at 300 mg/kg/day and 1/5 females at 1000 mg/kg/day but no test item-related microscopic findings were observed.

Daily administration of the test item by oral gavage for 14 days in Sprague Dawley rats at 100, 300 or 1000 mg/kg/day was clinically well tolerated. The test item treatment only induced non-adverse hypersalivation at = 300 mg/kg/day and non statistically slight effects on food consumption and body weight at 1000 mg/kg/day in males and females. Consequently and under the experimental conditions of the study, the No Observed Adverse Effect Level (NOAEL) was established at 1000 mg/kg/day in absence of adverse effects.

Justification for classification or non-classification

Based on the 14 -day repeated toxicity study, no severe organ toxicity was showed in rats treated with Tricyclodecane dimethanol diacrylate.

No classification for the repeated toxicity is required for Tricyclodecanemonomethylol acrylate, the registered substance, according to the Regulation EC n°1272/2008.