Poly[oxy(methyl-1,2-ethanediyl)], .alapha.,α'-(2,2-dimethyl-1,3-propanediyl)bis[ω-[(1-oxo-2-propenyl)oxy

Endpoint summary

Description of key information

Evaluation of the potential toxicity of the propoxylated neopentylglycol diacrylate was studied following daily oral administration (gavage) to rats for 4 weeks (OECD 407). At 1000 mg/kg/day, the test item was clinically well-tolerated and no relevant findings were noted at clinical pathology. Under the experimental conditions of the study, the No Observed Adverse Effect Level (NOAEL) was established at 1000 mg/kg/day.

Key value for chemical safety assessment

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:

key study

Study period:

10 august 2012 - 11 December 2012

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)

Version / remarks:

2008

Deviations:

no

Qualifier:

according to guideline

Guideline:

EU Method B.7 (Repeated Dose (28 Days) Toxicity (Oral))

Version / remarks:

2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

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: Charles River Laboratories France, l’Arbresle, France
- Age at study initiation: approximately 6 weeks old
- Mean body weight at study initiation: the males had a mean body weight of 194 g (range: 181 g to 207 g) and the females had a mean body weight of 170 g (range: 155 g to 185 g)
- Fasting period before study: no
- Housing: the animals were housed by five in polycarbonate cages with stainless steel lids
- Diet: SSNIFF R/M-H pelleted diet (free access)
- Water: tap water filtered with a 0.22 µm filter (free access)
- Acclimation period: 7 days before the beginning of the study.

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

IN-LIFE DATES: 30 August 2012 to 27 September 2012.

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was administered as a solution in the vehicle. It was mixed with the required quantity of vehicle. No correction factor was applied.
The frequency of dose formulation preparation was on a daily basis. The dose formulations were delivered to the study room at room temperature and protected from light.

VEHICLE
- Justification for use and choice of vehicle: test item soluble in corn oil which is commonly used on this type of study
- Concentration in vehicle: 20, 60 and 200 mg/mL
- Amount of vehicle (if gavage): 5 mL/kg/day.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Type of method: GC-FID
Test item concentrations: remained within an acceptable range of variation compared to nominal values.
Homogeneity: homogenous
Stability: not assessed, dose formulation prepared daily.

Duration of treatment / exposure:

4 weeks

Frequency of treatment:

Daily

Dose / conc.:

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

Dose / conc.:

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

Dose / conc.:

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

No. of animals per sex per dose:

5 animals per sex per dose.

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
The dose-levels were selected in agreement with the Sponsor based on the results of a previous 2 week toxicity study performed in the same species and strain. In this study, three groups of three males and three females received the test item by gavage at 100, 300 or 1000 mg/kg/day as a solution in corn oil. Another group of three males and three females received the vehicle only. There were no obvious test item-related effects in this study, except ptyalism in all animals at 300 and 1000 mg/kg/day.
Therefore, 1000 mg/kg/day was selected as the high-dose level for this 4-week study. Mid- and low-dose levels were selected in order to cover approximately three-fold intervals.

- Rationale for animal assignment: computerized stratification procedure.

Positive control:

no (not required)

Observations and examinations performed and frequency:

MORTALITY/MORBIDITY:
- Time schedule: once a day during the acclimation period and at least twice a day from the start of the treatment period including weekends.

CLINICAL SIGNS:
- Time schedule: once a day, at approximately the same time.

DETAILED CLINICAL OBSERVATIONS:
- Time schedule: once before the beginning of the treatment period and then once a week until the end of the study.

BODY WEIGHT:
- Time schedule: once before the beginning of the treatment period, on the first day of treatment and then at least once a week until the end of the study.

FOOD CONSUMPTION:
- Time schedule: once a week until the end of the study.

NEUROBEHAVIOURAL EXAMINATION:
- Time schedule: once in week 4.

HAEMATOLOGY, CLINICAL CHEMISTRY, URINALYSIS:
- Time schedule: at the end of the treatment period.

Sacrifice and pathology:

ORGAN WEIGHTS: see table below

GROSS PATHOLOGY:
Complete macroscopic post-mortem examination of all study animals

HISTOPATHOLOGY:
- on all tissues listed in the table below for the control and high dose animals (groups 1 and 4) sacrificed at the end of the treatment period,
- on liver for the low- and intermediate-dose animals (groups 2 and 3) sacrificed at the end of the treatment period,
- on all macroscopic lesions from all low- and intermediate-dose animals (groups 2 and 3) sacrificed on completion of the treatment period.

Other examinations:

no

Statistics:

Citox software (version D.6) (see § Study plan adherence) was used to perform the statistical analyses of body weight, hematology, blood biochemistry and urinalysis data. PathData software (version 6.2d2) was used to perform the statistical analysis of organ weight data (level of significance: 0.05 or 0.01).

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

At 300 and 1000 mg/kg/day, all animals except one female had ptyalism, which was considered to be test item-related but non adverse.
Incidental findings in test item-treated groups included scabs, chromorhynorrhea, nodosities and increase in size of the eye area.

Mortality:

no mortality observed

Description (incidence):

There were no unscheduled deaths during the study.

Body weight and weight changes:

no effects observed

Description (incidence and severity):

There were no effects on mean body weight and mean body weight change.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

There were no effects on mean food consumption.

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

There were no adverse effects in hematology parameters.
At 1000 mg/kg/day, two females had higher red blood cell count (8.48 and 8.62 T/L vs. control range of 7.68 to 8.43), hemoglobin concentration (15.5 and 16.3 g/dL vs. control range of 14.1 to 15.3) and hematocrit (PCV: 0.47 and 0.49 L/L vs. control range of 0.43 to 0.46) than controls and similar to or slightly higher than the upper limit of the range of historical control data. As data were available only from two females at this dose-level because the other samples were coagulated, a statistical comparison could not be performed; an effect of the treatment could not be excluded but considered to be non adverse in the absence of severe differences from controls or historical control data, and in the absence of similar findings in males.

Clinical biochemistry findings:

no effects observed

Description (incidence and severity):

The statistically significant variations from controls at 1000 mg/kg/day were considered of non toxicological significance as the differences from controls were slight and not associated with other biochemical findings, data were included in the historical control data and in the absence of similar findings in the opposite sex.

Urinalysis findings:

no effects observed

Description (incidence and severity):

There were no significant findings in urine parameters.

Behaviour (functional findings):

effects observed, non-treatment-related

Description (incidence and severity):

There were no test item-related effects at the Functional Observation Battery and motor activity.
There was a trend toward a slight decrease in mean motor activity when increasing the dose levels. However, when removing the results obtained from the outlier control animal (see below), there was no clear dose-relationship, the mean differences from controls were slight with high standard deviations and the trend was not confirmed by any clinical signs. A relationship with the test item treatment was considered to be unlikely.
One control male showed several abnormal reflex responses (righting reflex: slight difficulty in reception; touch response: bizarre response, aggressiveness, vocalization or biting; absence of papillary reflex; auditory startle reflex: violent jump; tail pinch response: hyperactivity: aggressiveness, biting) and had the higher motor activity among all males.

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

When compared with controls, the mean relative liver weight was significantly higher in males given 1000 mg/kg/day (p<0.05). This difference correlated with the hepatocellular hypertrophy seen microscopically.
Other organ weight changes were considered not to be related to the test item as they were small in amplitude, had no gross or microscopic correlates and/or were not consistent for the sexes.
The mean absolute and relative thymus weight was significantly higher in females given 1000 mg/kg/day (p<0.05 or p<0.01). In the absence of macroscopic and/or microscopic correlates, this difference was considered not to be related to the test item administration.
The mean relative kidney weight was significantly higher in males given 1000 mg/kg/day (p<0.05). In view of the minor magnitude of this difference and in the absence of macroscopic and/or microscopic correlates, this difference was considered not to be related to the test item administration.

Gross pathological findings:

effects observed, treatment-related

Description (incidence and severity):

In one female treated at 1000 mg/kg/day, the liver showed accentuated lobular pattern. This was related to the periportal vacuolation seen microscopically and related to test item administration.
A similar finding was noted in one male treated at 100 mg/kg/day. However, it was not related to any microscopic finding and consequently was unrelated to test item treatment.

The other macroscopic findings had no histological correlates or correlated with common histological findings in control rats and were considered to be incidental.
Specifically the scabs seen only in test item-treated groups are not uncommon in untreated rats of this age and strain. Consequently they were considered to be of no toxicological importance.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

effects observed, treatment-related

Description (incidence and severity):

Non adverse test item-related microscopic findings were seen in the liver.
Minimal hepatocellular hypertrophy was seen in males treated at 1000 mg/kg/day and correlated to the increased liver weights.
Minimally increased hepatocellular periportal vacuolation was seen in females treated at 100, 300 or 1000 mg/kg/day.
This could correlate to the accentuated lobular pattern seen macroscopically at 1000 mg/kg/day in one female.
There were no associated degenerative changes at any of the dose-levels.
Other microscopic findings noted in test item-treated animals were considered as incidental changes, as they also occurred in controls, were of low incidence, and/or are common background findings for the Sprague-Dawley rat.
Among these were the slight to moderate sero-cellular crusts noted in test item-treated males and females while they were not seen in controls. This lesion is frequent in untreated rats of this age and strain and was considered not as drug-related.
In females treated at 1000 mg/kg/day, there were more tubular basophilia and mononuclear inflammatory cells in the kidneys than in controls. However, the distribution, incidence and severity of these changes were considered to be within the range of normal background and consequently these findings were unrelated to test item treatment.

Histopathological findings: neoplastic:

not examined

Other effects:

no effects observed

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Remarks on result:

not determinable due to absence of adverse toxic effects

Critical effects observed:

no

Conclusions:

The test item was administered daily for 4 weeks by oral route to male and female Sprague-Dawley rats at dose levels of 100, 300 or 1000 mg/kg/day in corn oil. No adverse effects were observed in this study, the No Observed Adverse Effect Level (NOAEL) was considered to be at 1000 mg/kg/day.

Executive summary:

The objective of this study was to evaluate the potential toxicity of the test item following daily oral administration (gavage) to rats for 4 weeks,according to OECD (No. 407, 3rd October 2008) and EC (No. 440/2008, B7, 30th May 2008) guidelines.

The study was conducted in compliance with the principles of Good Laboratory Practice Regulations.

 

Methods

Three groups of five male and five female Sprague-Dawley rats received the test item by daily oral administration for 28 days at dose-levels of 100, 300 or 1000 mg/kg/day. The test item was administered as a solution in the vehicle (corn oil) at a constant dosage-volume of 5 mL/kg/day. A control group of five males and five females received the vehicle alone under the same experimental conditions.

 

Test item concentrations were checked on formulations used in weeks 1 and 4.

The animals were checked at least twice daily during the dosing period for mortality and morbidity and once daily for clinical signs. In addition, detailed clinical examinations were performed at least once weekly. Body weight was recorded once before the beginning of the treatment period, and then at least once a week during the study as food consumption. Towards the end of the dosing period, a Functional Observation Battery including motor activity measurement, and hematology, blood biochemistry and urinalysis were performed on all animals.

On completion of the treatment period, the animals were euthanized and submitted to a full macroscopic post-mortem examination. Designated organs were weighed and selected tissues were preserved. A microscopic examination was performed on selected tissues from control- and high-dose animals sacrificed at the end of the treatment period and on all macroscopic lesions.

 

Results

The test item concentrations in the administered dose formulations analyzed in weeks 1 and 4 were within the acceptance criteria (± 10% of the nominal values).

 

There were no unscheduled deaths during the study. The only test item-related clinical sign was ptyalism at 300 and 1000 mg/kg/day.There were no toxicologically relevant effectsat the Functional Observation Battery and motor activity, onmean body weight, mean body weight change and mean food consumption and on urine and blood biochemical parameters. There were no adverse effects in hematology parameters (slightly higher red blood cell parameters in females treated at 1000 mg/kg/day).

Mean liver weights were higher in males given 1000 mg/kg/day. At macroscopic examination, accentuated lobular pattern was noted in the liver from one female treated at 1000 mg/kg/day. Non adverse microscopic findings were seen in liver, i.e. minimal hepatocellular hypertrophy in four males treated at 1000 mg/kg/day and increased periportal vacuolation in females treated at 100, 300 or 1000 mg/kg/day (in three, four and four females, respectively).

Conclusion

The test item was administered daily for 4 weeks by oral route to male and female Sprague-Dawley rats at dose-levels of 100, 300 or 1000 mg/kg/day in corn oil.

Under the experimental conditions of this study, the No Observed Adverse Effect Level (NOAEL) was considered to be at 1000 mg/kg/day.

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:

This 28-day study is considered to be reliable because it was performed according to the OECD guideline (klimisch score = 1).

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

28 -day repeated toxicity study (oral route)

The objective of this study was to evaluate the potential toxicity of the propoxylated neopentylglycol diacrylate following daily oral administration (gavage) to rats for 4 weeks (OECD 407).

Three groups of five male and five female Sprague-Dawley rats received the test item by daily oral administration for 28 days at dose-levels of 100, 300 or 1000 mg/kg/day. The test item was administered as a solution in the vehicle (corn oil) at a constant dosage-volume of 5 mL/kg/day. A control group of five males and five females received the vehicle alone under the same experimental conditions.

There were no unscheduled deaths during the study. The only test item-related clinical sign was ptyalism at 300 and 1000 mg/kg/day.There were no toxicologically relevant effects at the Functional Observation Battery and motor activity, onmean body weight, mean body weight change and mean food consumption and on urine and blood biochemical parameters. There were no adverse effects in hematology parameters (slightly higher red blood cell parameters in females treated at 1000 mg/kg/day).

Mean liver weights were higher in males given 1000 mg/kg/day. At macroscopic examination, accentuated lobular pattern was noted in the liver from one female treated at 1000 mg/kg/day. Non adverse microscopic findings were seen in liver, i.e.minimal hepatocellular hypertrophy in four males treated at 1000 mg/kg/day and increased periportal vacuolation in females treated at 100, 300 or 1000 mg/kg/day (in three, four and four females, respectively).

To conclude, non adverse effects were observed in this study, the No Observed Adverse Effect Level (NOAEL) was considered to be at 1000 mg/kg/day in rats after oral exposure.

Justification for classification or non-classification

Based on the available data, no classification for the repeated toxicity is required for propoxylated neopentylglycol diacrylate according to the Regulation EC n°1272/2008.