(5-ethyl-1,3-dioxan-5-yl)methyl acrylate

Repeated dose toxicity: oral

Administrative data

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2013

Reference 2

Reference Type:

other: summary report

Title:

Unnamed

Year:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Version / remarks:

adopted 1996

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EPA OPPTS 870.3650, adopted July 2000

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

(5-ethyl-1,3-dioxan-5-yl)methyl acrylate

EC Number:

266-380-7

EC Name:

(5-ethyl-1,3-dioxan-5-yl)methyl acrylate

Cas Number:

66492-51-1

Molecular formula:

C10H16O4

IUPAC Name:

(5-ethyl-1,3-dioxan-5-yl)methyl acrylate

Details on test material:

- Name of test material (as cited in study report): Laromer LR 8887
- Physical state: yellowish / clear liquid
- Analytical purity: 78.1g/100g (see BASF study 11L00371)
- Purity test date: 2011-11-03
- Lot/batch No.: 110009P040
- Expiration date of the lot/batch: 2012-09-30
- Stability under test conditions: confirmed for up to 7 days (see BASF study 11L00439)
- Storage condition of test material: room temperature under light exclusion

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source:Charles River Laboratories, Research Models and Services, Germany GmbH, Sulzfeld, Germany, male and female rats were derived from different litters to rule out sibling mating
- Age at study initiation: (P) 10-11 wks;
- Weight at study initiation: (P) Males: 294-338 g; Females: 201-234 g
- Fasting period before study: no
- Housing: individually (except during overnight mating and lactation) in Makrolon type M III cages
- Diet (e.g. ad libitum): Kliba maintenance diet mouse-rat “GLP” meal, ad lib.
- Water (e.g. ad libitum): tap water ad lib.
- Acclimation period: 6 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20-24°C
- Humidity (%): 30-70%
- Air changes (per hr):15

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS:The test substance was applied as suspension, which was prepared daily. An appropriate amount of the test substance was weighed, and corn oil was added up to the desired volume. The suspension was kept homogenous during administration by stirring with a magnetic stirrer.

The administration volume was 4ml/kg b.w.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Homogeneity and concentration control analyses of the test-substance preparations were performed in all concentrations at the start of the administration period. Additionally, samples from all concentrations as reverse samples for concentration control analysis were taken at the end of the study. All concentrations were in the expected target range of 90-110% of the nominal concentration.

Duration of treatment / exposure:

31days (males), 52days (females)

Frequency of treatment:

daily

Doses / concentrations

Remarks:

Doses / Concentrations:
40, 100, 250mg/kg b.w.
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
Doses were selected based on a 14day test study in female Wistar rats. 4 rats per group were treated daily with 250, 500, and 1000 mg/kg b.w. via gavage. One animal in the high dose group was found dead on day 13, probably due to excessive irritation in the stomach and digestive system. Of the surviving three animals, one showed hyperemia in the cecum, ulceration/erosion in the glandular stomach and discoloration of the jejunum contents, two showed ulcerations / erosion in the forestomach. In the mid dose, one animal also showed erosion / ulceration in the forestomach, which were evaluated as severe enough to likely cause death throughout the much longer treatment time in the OECD422 main study. Thus the lowest dose was selected as the maximum dosage for the main study. Here, lesions in the forestomach were also observed in one animal, but severity was reduced.

Positive control:

none

Examinations

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily on workdays, daily on weekends and public holidays
- Cage side observations: check for moribund animals, pertinent behavioral changes, signs of overt toxicity, parturation, littering and lactation behavior of the dams

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: prior to the first administration, weekly thereafter
- The following parameters were examined: abnormal behavior during “handling”, fur, skin, posture, salivation, respiration, activity/arousal level, tremors, convulsions, abnormal movements, impairment of gait, lacrimation, palpebral closure, exophthalmus, feces (appearance/consistency), urine, pupil size

BODY WEIGHT: Yes
- Time schedule for examinations: day 0, weekly thereafter with the following exceptions for females: During the mating period the parental females were weighed on the day of positive evidence of sperm (GD 0) and on GD 7, 14 and 20. Females with litter were weighed on the day of parturition (PND 0) and on PND 4.

FOOD CONSUMPTION:
- Food consumption for each animal determined: Yes, except during mating

WATER CONSUMPTION: Monitored by daily visual inspection

HAEMATOLOGY: Yes
- Time schedule for collection of blood: on the day of necropsy
- Anaesthetic used for blood collection: Yes (isoflurane)
- Animals fasted: Yes (16-20h)
- How many animals: 5 per sex and group
- The following parameters were examined: Leukocyte count, Erythrocyte count, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelet count, differential blood count, reticulocytes, prothrombin time

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: on the day of necropsy
- Animals fasted: Yes (16-20h)
- How many animals: 5 per sex and group
- The following parameters were examined: ALT, AST, ALP, GGT, sodium, potassium, chlorid, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol, bile acids

URINALYSIS: Yes
- Time schedule for collection of urine: on the last day of administration, one day prior to necropsy
- Metabolism cages used for collection of urine: Yes
- Animals fasted: yes, during collection
- How many animals: 5 per sex and group
- The following parameters were examined: pH, protein, glucose, ketones, urobilinogen, bilirubin, blood, specific gravity, sediment, color, turbity, volume

NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: 3 days prior to necropsy (day 29 males, day 50 females)
- Dose groups that were examined: 5 animals per sex and group (only females with litter)
- Battery of functions tested: home cage and open field observation, motor activity, sensory motor test / reflexes (including: Reaction to an object being moved towards the face, touch sensitivity, vision (Visual placing response), pupillary reflex, pinna reflex, auditory startle response, righting response, behavior during handling, vocalization, pain perception (Tail pinch), grip strength of forelimbs and hindlimbs, landing foot-splay test)

Sacrifice and pathology:

GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
The following tissues were weighed
- in all animals: epididymides, testes
- in 5 males and females of each group: adrenal glands, brain, heart, kidneys, liver, spleen, thymus
The uteri of all cohabited female parental animals were examined for the presence and number of implantation sites. The uteri of apparently non-pregnant animals or empty uterus horns were placed in 1% ammonium sulfide solutions for about 5 minutes in order to be able to identify early resorptions or implantations.
The following tissues were examined histotechnically in at least 5 animals per sex of the control and high dose group unless noted otherwise
adrenal glands, gross lesions (all affected animals in all dosage groups), bone marrow (femur), brain, cecum, cervix, coagulation glands, colon, duodenum, epididymides, heart, ileum, jejunum, kidneys, liver, lungs, lymph nodes (auxillary and mesenteric), ovaries, oviducts, prostate gland, peyer's patches, rectum, sciatic nerve, seminal vesicles, spinal cord, spleen, stomach (also all males from the low and mid dose groups), testes, thymus, thyroid glands, trachea, urinary bladder, uterus, vagina

Other examinations:

Reproductive performance: see entry in chapter 7.8.1

Results and discussion

Results of examinations

Details on results:

CLINICAL SIGNS AND MORTALITY
No mortality was observed.
Almost all animals of the high dose group showed salivation within 2 hours after substance administration, which was most likely induced by local irritation of the digestive tract of bad taste of the substance.

BODY WEIGHT AND WEIGHT GAIN
unaffected by the test substance

HAEMATOLOGY
unaffected by the test substance

CLINICAL CHEMISTRY
unaffected by the test substance

URINALYSIS
unaffected by the test substance

NEUROBEHAVIOUR
unaffected by the test substance

ORGAN WEIGHTS
no test substance related effects.

GROSS PATHOLOGY
No test substance related effects were observed.

HISTOPATHOLOGY: NON-NEOPLASTIC
In 7 out of 10 males of the high dose group the forestomach showed minimal hyperkeratosis, which is probably due to local irritant properties of the test substance, that were already observed in the pre-study for dose selection. No further differences were observed.

Effect levels

1

Dose descriptor:

NOEL

Remarks:

systemic effects

Effect level:

>= 250 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

2

Dose descriptor:

NOAEL

Remarks:

local effects

Effect level:

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

Based on:

test mat.

Sex:

male/female

Target system / organ toxicity

Critical effects observed:

not specified