2-Hydroxyethylmethacrylate, reaction products with proyleneoxide and Phthalic anhydride

Repeated dose toxicity: oral

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Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Type of information:

experimental study

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

The test substance in the vehicle (corn oil) was administered orally by gavage to 3 groups of 5 male and 5 female Crl:CD(SD) rats once daily for 14 consecutive days (study days 0 through 13).

GLP compliance:

no

Limit test:

yes

Test material

Test material information

Constituent 1

Test material form:

liquid

Details on test material:

- Purity: 100%

Test animals

Species:

rat

Strain:

other: Crl:CD(SD)

Details on species / strain selection:

This species and strain of animal is recognized as appropriate for reproduction studies and test facility has reproductive historical control data in the Crl:CD(SD) rat.

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Inc., Stone Ridge, New York
- Females nulliparous and non-pregnant: Yes
- Age at study initiation: 8.5 to 9 weeks old
- Weight at study initiation: 249 g to 301 g for males and 178 g to 229 g for females
- Housing: All rats were housed 2 per cage by sex in clean, solid-bottom cages with bedding material (Bed-O'Cobs®)
- Diet: ad libitum
- Water: ad libitum
- Acclimation period: 11 days

ENVIRONMENTAL CONDITIONS
- Temperature: 21.3-22.4°C
- Humidity: 44.1-53.6%
- Air changes (per hr): Minimum of 10
- Photoperiod: 12-hour light / 12-hour dark

Administration / exposure

Route of administration:

oral: gavage

Details on route of administration:

The selected route of administration for this study was oral (gavage) because this is a potential route of exposure for humans. Historically, this route has been used extensively for studies of this nature.

Vehicle:

corn oil

Details on oral exposure:

Preparation: The vehicle was dispensed daily for the first 5 days of dosing and approximately weekly thereafter for administration to the control group (Group 1) and for preparation of the test substance formulations; aliquots were prepared for daily dispensation to the control group (when prepared weekly) and stored at room temperature, protected from light. The vehicle was mixed throughout the preparation and dose administration procedures.

The test substance formulations were prepared daily for the first 5 days of dosing and approximately weekly thereafter as single formulations for each dosage level, divided into aliquots for daily dispensation (when prepared weekly), and stored at room temperature, protected from light. The test substance formulations were stirred continuously throughout the preparation and dose administration procedures. The first test substance dosing formulations were visually inspected by and were found to be visibly homogeneous and acceptable for administration.

The vehicle and test substance formulations were administered orally by gavage, once daily for 14 consecutive days (study days 0-13). The dosage volume for all groups was 10 mL/kg. Individual dosages were based on the most recently recorded body weights to provide the correct mg/kg/day dose. All animals were dosed at approximately the same time each day. The dosage levels were selected to be a limit dose because there is no previous repeated-dose data for this test substance.

Analytical verification of doses or concentrations:

no

Duration of treatment / exposure:

14 days

Frequency of treatment:

Once daily

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

100 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

500 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

5

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: Dosage levels were selected by the Sponsor Representative after consultation with the the test facility Study Director. The dosage levels were selected to be a limit dose because there is no previous repeated-dose data for this test substance.
- Animal assignment: Computerized randomization procedure

Examinations

Observations and examinations performed and frequency:

Clinical Observations and Mortality: All rats were observed twice daily, once in the morning and once in the afternoon, for moribundity and mortality. Individual clinical observations were recorded daily (prior to dose administration during the treatment period). Animals were also observed for signs of toxicity approximately 2 hours following dose administration.

Body Weights: Individual body weights were recorded on study days 0, 4, 7, 11, and 13. Group mean body weights were calculated for each of these days. Mean body weight changes were calculated for each corresponding interval and also for study days 0-13.

Food Consumption: Food consumption was recorded on study days 0, 4, 7, 11, and 13. Food intake was measured on a per cage basis and reported as g/animal/day for the corresponding body weight change intervals.

Clinical Pathology: Blood samples for clinical pathology evaluations (haematology, coagulation, and serum chemistry) were collected from all surviving animals at the scheduled necropsy (study day 14). The animals were fasted overnight prior to collection.
The following parameters were evaluated:
a) Hematology and Coagulation: WBC, RBC, haemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelet count, prothrombin time, activated partial thromboplastin time, reticulocyte count (percent and absolute), mean platelet volume, differential leukocyte count (Percent and absolute - neutrophil, lymphocyte, monocyte, eosinophil, basophil, large unstained cell), red cell distribution width, hemoglobin distribution width, platelet estimate, red cell morphology.
b) Serum Chemistry: Albumin, total protein, globulin (by calculation), albumin/globulin ratio (by calculation), total bilirubin, urea nitrogen, creatinine, ALP, ALT, AST, GGT, glucose, total cholesterol, calcium, chloride, phosphorus, potassium, sodium, triglycerides, bile acid, appearance (Includes degree of hemolysis, lipemia, and icterus).

Sacrifice and pathology:

Unscheduled Deaths: A gross necropsy was performed on all animals euthanized prior to scheduled sacrifice or that were found dead during the course of the study. The cranial, thoracic, abdominal, and pelvic cavities were opened and the contents examined. Tissues were preserved in 10% neutral-buffered fomalin only as deemed necessary by the gross findings.

Scheduled Necropsy: All surviving animals were euthanized by carbon dioxide inhalation and subjected to a gross necropsy on study day 14. The necropsy included examination of the external surface, all orifices, the cranial cavity, the external surface of the brain, and the thoracic, abdominal, and pelvic cavities, including viscera. Tissues were preserved in 10% neutral-buffered fomalin only as deemed necessary by the gross findings.

Organ Weights: Adrenals, brain, epididymides, heart, kidneys, liver, ovaries with oviducts, spleen, testes, thymus, thyroid with parathyroids were weighed from all surviving animals at the scheduled necropsy. Absolute weights, organ to final body weight, and organ to brain weight ratios were reported.

Statistics:

All statistical tests were performed using WTDMS™ unless otherwise noted. Analyses were conducted using two-tailed tests (except as noted otherwise) for minimum significance levels of 1% and 5%, comparing each test substance-treated group to the control group. Mean body weights, body weight changes, food consumption, clinical pathology parameters, and absolute and relative organ weights were subjected to a parametric one-way ANOVA to determine intergroup differences. If the ANOVA revealed significant (p<0.05) intergroup variance, Dunnett's test was used to compare the test substance-treated groups to the control group.

Results and discussion

Results of examinations

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Clinical findings for surviving animals were noted primarily in the 1000 mg/kg/day group. At the daily examinations, single occurrences of yellow material around the urogenital area and ventral trunk and a reddened left ear were noted for 2 males in the 1000 mg/kg/day group on study day 3. Approximately 2 hours following dose administration, single occurrences of clear material around the mouth was noted for 2 males and 3 females in the 1000 mg/kg/day group during study days 2-10, and a single occurrence of red material around the mouth was noted for 1 female in the 1000 mg/kg/day group on study day 3. Other clinical findings noted in the test substance-treated group males and females occurred infrequently, at similar frequencies in the control group, and/or in a manner that was not dose-related.

Mortality:

mortality observed, non-treatment-related

Description (incidence):

On study day 10, one male in the 500 mg/kg/day group was observed gasping at the daily examination and was subsequently euthanized. At necropsy, a piece of bedding material was found in the esophagus of this animal. Therefore, the death of this animal in the 500 mg/kg/day group was considered accidental and unrelated to the test substance.

Body weight and weight changes:

effects observed, non-treatment-related

Description (incidence and severity):

A slightly lower mean body weight gain was noted for males in the 1000 mg/kg/day group when the overall treatment period (study days 0-13) was evaluated compared to the control group, primarily a result of a lower mean body weight gain during study days 4-7 in this group. However, the aforementioned differences from the control group were not statistically significant and mean body weights in the 1000 mg/kg/day group were similar to the control group throughout the treatment period.

Mean body weights and body weight gains for the 100 and 500 mg/kg/day group males and 100, 500, and 1000 mg/kg/day group females were similar to the control group throughout the treatment period (study days 0-13). Differences from the control group were slight and not statistically significant.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

Mean food consumption, evaluated as g/animal/day, in the 100, 500, and 1000 mg/kg/day group males and females was similar to that in the control group throughout the treatment period (study days 0-13). Differences from the control group were slight and not statistically significant.

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

effects observed, non-treatment-related

Description (incidence and severity):

At the scheduled necropsy on study day 14, one male in the 100 mg/kg/day group had a misshapen spleen, and individual females in the 100, 500, and 1000 mg/kg/day groups were noted with dark red areas on the thymus, depressed areas on the kidneys, an accessory spleen, and/or clear fluid in the uterus. No other macroscopic findings were noted for surviving males and females at any dosage level.

Details on results:

Dosage levels of 100, 500, or 1000 mg/kg/day were well tolerated in male and female rats as there were no adverse effects on survival, body weights, food consumption, clinical pathology parameters, or organ weights. In addition, there were no noteworthy clinical or macroscopic findings at any dosage level.

Effect levels

Key result

Dose descriptor:

NOAEL

Effect level:

>= 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

male/female

Remarks on result:

other: No adverse effects observed at the highest dose tested

Applicant's summary and conclusion

Conclusions:

NOAEL (male/female): ≥1000 mg/kg

Executive summary:

The objective of this study was to determine dosage levels of the test substance to be evaluated in a potential combined repeated-dose toxicity study with the reproduction/developmental toxicity screening test (OECD 422) in rats.

The test substance, in the vehicle (corn oil) was administered orally by gavage to 3 groups of 5 male and 5 female Crl:CD(SD) rats once daily for 14 consecutive days (study days 0 through 13). Dosage levels were 100, 500, and 1000 mg/kg/day administered at a dosage volume of 10 mL/kg. A concurrent control group composed of 5 rats/sex received the vehicle on a comparable regimen. The animals were approximately 8.5 to 9 weeks of age at the initiation of dose administration. All animals were observed twice daily for mortality and moribundity. Clinical observations, body weights, and food consumption were recorded at appropriate intervals. Blood samples for clinical pathology evaluations were collected from all surviving animals prior to necropsy. A gross necropsy was conducted on all surviving rats at the scheduled euthanasia on study day 14; selected organs were weighed.

One male in the 500 mg/kg/day group was euthanized on study day 10 following clinical signs of gasping at the daily examinations. At necropsy, a piece of bedding material was found in the esophagus of this animal; therefore, the death of this animal was considered accidental and unrelated to the test substance. One male in the control group was found dead on study day 14. No remarkable clinical or macroscopic findings or noteworthy changes in body weight were noted prior to death. All other animals survived to the scheduled necropsy.

Increased incidences of yellow material around the urogenital area and ventral trunk and clear material around the mouth were noted for males and/or females in the 1000 mg/kg/day group at the daily examinations or approximately 2 hours following dose administration. No remarkable clinical findings were noted for males and females in the 100 and 500 mg/kg/day groups during the study.

A slightly lower mean body weight gain was noted for males in the 1000 mg/kg/day group when the overall treatment period (study days 0-13) was evaluated compared to the control group. The decrement in mean body weight gain at 1000 mg/kg/day was not of sufficient magnitude to affect mean body weights. Mean body weights and body weight gains in the 100 and 500 mg/kg/day group males and 100, 500, and 1000 mg/kg/day group females were similar to the control group throughout the study. In addition, mean food consumption was similar to the control group at all dosage levels throughout the treatment period.

There were no test substance-related effects on clinical pathology parameters or organ weights, and no noteworthy macroscopic findings for males or females at any dosage level.

Dosage levels of 100, 500, or 1000 mg/kg/day were well tolerated in male and female rats as there were no adverse effects on survival, body weights, food consumption, clinical pathology parameters, or organ weights. In addition, there were no noteworthy clinical or macroscopic findings at any dosage level.