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

Acute Toxicity: dermal

Administrative data

Endpoint:

acute toxicity: dermal

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 402 (Acute Dermal Toxicity)

Version / remarks:

1987

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.3 (Acute Toxicity (Dermal))

Deviations:

no

GLP compliance:

yes

Test type:

standard acute 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 no.: 0912000436
- Appearance: white flakes
- Purity: 99%
- Expiration date of the lot/batch: 2010-12-04
- Stability under storage conditions: stable
- Storage condition of test material: in refrigerator (2-8 °C) in the dark under nitrogen

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany.
- Age at study initiation: approximately 11 weeks old.
- Weight at study initiation:Body weight variation did not exceed ± 20 % of the sex mean (males: 312 g, females: 217 g).
- Fasting period before study:not applicable.
- Housing: Individually housed in labeled Macrolon cages (MIII type; height 18 cm) containing sterilised 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. During the acclimatization period the animals were group housed in Macrolon cages (MIV type).

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
- Photoperiod (hrs dark/hrs light): 12 / 12

IN-LIFE DATES: From 09 June 2010 to 23 June 2010

Administration / exposure

Type of coverage:

occlusive

Vehicle:

polyethylene glycol

Details on dermal exposure:

TEST SITE
- Area of exposure: Approximately 10% of the total body surface, i.e. approximately 25 cm² for males and 18 cm² for females.
- % coverage: Approximately 10% of the total body surface.
- Type of wrap if used:The test substance formulation was held in contact with the skin with a dressing, consisting of a surgical gauze patch (Surgy 1D, Laboratoires Stella s.a., Liege, Belgium), successively covered with aluminium foil and Coban elastic bandage (3M, St. Paul, Minnesota, U.S.A. (Coban & Micropore)).

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The skin was cleaned of residual test substance using tap water.
- Time after start of exposure: 24 hours.

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 2000 mg/kg bw (10 mL/kg bw)

VEHICLE
Polyethylene glycol 400 (Merck, Darmstadt, Germany) (specific gravity 1.125). The vehicle was dehydrated before the formulation was prepared. The formulation (w/w) was 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 formulation was heated in a water bath with a temperature of 49.3 °C for 31 minutes. The test substance formulation was allowed to cool down below 40 °C prior to dosing.

Duration of exposure:

24 hours

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

5

Control animals:

not required

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:

male/female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

test mat.

Mortality:

No mortality occurred.

Clinical signs:

other: Chromodacryorrhoea (left eye) was noted for one male on day 2. One male showed scabs on day 6 and scales on day 7 in the treated skin area.

Body weight:

other body weight observations

Remarks:

No adverse effects were observed

Gross pathology:

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

Applicant's summary and conclusion

Interpretation of results:

other: CLP criteria not met

Conclusions:

The dermal LD50 value of D-lactide in Wistar rats was established to exceed 2000 mg/kg body weight.

Executive summary:

In an acute dermal toxicity study conducted according to OECD guideline 402, a group of young adult Wistar rats (5 males and 5 females) was dermally exposed to D-lactide (purity 99%) in polyethylene glycol 400 for 24 hours to approximately 10% of body surface area at 2000 mg/kg bw. Animals were observed for 14 days. No mortality occurred. There were no treatment related necropsy findings or changes in body weight. Clinical signs as e.g. chromodacryorrhoea (left eye) was noted in one male on day 2 and one male shoed scabs on day 6 and scales on day 7 in treated skin area.

The dermal LD50 value of D-lactide in Wistar rats was established to exceed 2000 mg/kg body weight.