1,4-Dioxane-2,5-dione, 3,6-dimethyl-, (3R,6R)-

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2010-05-28 to 2010-09-27

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

(3R,6R)-3,6-Dimethyl-1,4-dioxane-2,5-dione

EC Number:

603-436-5

Cas Number:

13076-17-0

Molecular formula:

C6H8O4

IUPAC Name:

(3R,6R)-3,6-Dimethyl-1,4-dioxane-2,5-dione

Specific details on test material used for the study:

- Name of test material (as cited in study report): D-Lactide
- Batch: 0912000436
- Purity: 99%
- Expiration date of the lot/batch: 2010-12-04
- Stability under test conditions: stable
- Storage condition of test material: in refrigerator (2-8 °C) in the dark under nitrogen

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: approximately 8 weeks old.
- Weight at study initiation:Body weight variation did not exceed ± 20 % of the sex mean (females: 159 g).
- Fasting period before study: Animal were deprived of food overnight prior to dosing and until 3-4 hours after administration of the test substances. Water was available.
- Housing: Group housing of 3 animals per cage inlabeled Macrolon cages (MIV type; height 18 cm) containing sterilized sawdust as bedding material (Litalabo, S.P.P.S., Argenteuil, France) and paper as cage-enrichment (Enviro-dri, Wm. Lillico & Son (Wonham Mill Ltd), Surrey, United Kingdom).
- Diet (e.g. ad libitum): Free access to pelleted rodent diet (SM R/M-Z from SSNIFF@Spezialdiäten GmbH, Soest, Germany).
- Water (e.g. ad libitum): Free access to tap water.
- Acclimation period: At least 5 days before start of treatment under laboratory conditions.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0 (actual range: 19.8 - 21.5)
- Humidity (%): Relative humidity of 40-70 (actual range: 38-75)
- Air changes (per h): Approximately 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours artificial fluorescent light and 12 hours darkness per day

IN-LIFE DATES: From 04 June 2010 to: 23 June 2010

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

polyethylene glycol

Details on oral exposure:

VEHICLE
- Dose level (volume): 2000 mg/kg bw (10 mL/kg bw)
- Justification for choice of vehicle: The vehicle was selected based on trial formulations performed at NOTOX and on test substance data supplied by the sponsor.

MAXIMUM DOSE VOLUME APPLIED: 2000 mg/kg bw (10 mL/kg bw)

DOSAGE PREPARATION (if unusual): The vehicle was dehydrated before the formulations were prepared. The formulations (w/w) were prepared within 4 hours prior to dosing. Homogeneity was accomplished to a visually acceptable level. Adjustment was made for specific gravity of the vehicle. In order to obtain homogeneity, the test substance formulations were heated in a water bath with a maximum temperature of 50 °C for a maximum of 31 minutes. The test substance formulations were allowed to cool down below 40 °C prior to dosing.

CLASS METHOD (if applicable)
- Rationale for the selection of the starting dose: Not given in the report.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3 females per dose (same dose tested twice, so 6 females in total)

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Mortality/viability: Twice daily. Body weights: Days 1 (pre-administration), 8 and 15.
- Necropsy of survivors performed: yes
- Other examinations performed: Clinical signs: At periodic intervals on the day of dosing (day 1) and once daily thereafter, until day 15. The time of onset, degree and duration were recorded and the symptomgraded according to fixed scales.

Statistics:

N.A.

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Hunched posture was noted for all animals on day 1. In addition, lethargy and piloerection were noted among the majority of animals on day 1.

Body weight:

other body weight observations

Remarks:

No adverse effects observed

Gross pathology:

No abnormalities were found at macroscopic post mortem examination of the animals.

Other findings:

N.A.

Applicant's summary and conclusion

Interpretation of results:

other: CLP criteria not met

Conclusions:

Since no mortality occurred during the 14-day observation period, the LD50 of D-lactide exceeds 2000 mg/kg bw in female rats. Therefore, D-lactide is considered as not harmful upon ingestion.

Executive summary:

In an acute oral toxicity study conducted according to OECD guideline 423, group of male and female Wistar rats (n= 3/sex) were given a single oral dose of D-lactide (purity >99%) at dose level of 2000 mg/kg body weight.

No mortality or distinct clinical signs, except hunched posture, piloerection and lethargy on day 1, were observed after treatment of 6 females with the 2000 mg/kg bw dose level. Macroscopic examination of the animals at the end of the observation period did not reveal any treatment-related gross changes. Since no mortality occurred during the 14-day observation period, the oral LD50 of D-lactide is considered to exceed 2000 mg/kg bw in female rats. D-lactide is considered as not harmful upon ingestion.