Dibenzyl sulphoxide

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

15.12. – 31.12.2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Council Regulation (EC) No.440/2008, published in O.J. L 142, 2008

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Dibenzyl sulphoxide

EC Number:

210-668-7

EC Name:

Dibenzyl sulphoxide

Cas Number:

621-08-9

Molecular formula:

C14H14OS

IUPAC Name:

(phenylmethanesulfinylmethyl)benzene

Test material form:

solid: particulate/powder

Details on test material:

- State of aggregation:
- Particle size distribution:
- Mass median aerodynamic diameter (MMAD):
- Geometric standard deviation (GSD):
- Shape of particles:
- Surface area of particles:
- Crystal structure:
- Coating:
- Surface properties:
- Density:
- Moisture content:
- Residual solvent:
- Activation:
- Stabilisation:
- Other:

White solid powder
Storage: The test substance was stored in dry room in dark in closed container at the room temperature.
Content of water: 0.025 % w/w (volumetric Karl Fischer titration)

Test animals

Species:

rat

Strain:

Wistar

Remarks:

Wistar Han, monitored quality

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: SPF breeding, VELAZ s.r.o., Únětice, Czech Republic, RČH CZ 21760118
- Age at study initiation: 8 - 10 weeks
- Weight at study initiation: 171 - 180 g
- Housing: animal room with monitored conditions – 3 animals of one sex in one plastic breeding cage with sterilized shavings of soft wood
- Diet (e.g. ad libitum): pelleted standard diet for experimental animals ad libitum
- Water (e.g. ad libitum): drinking tap water ad libitum (quality corresponding to Regulation No. 252/2004 Czech Coll. of Law)
- Acclimation period: 12 days

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 3°C, permanently monitored
- Humidity: 30 – 70 %, permanently monitored
- Photoperiod: 12 hour light/12 hour dark

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
Aqua pro iniectione - Lot/batch no.: 1505050287 (expiration 05/2017), producer Ardeapharma Ševětín a.s., Czech Republic

DOSING:
Test procedure with a starting dose of 300 mg/kg was selected. This level was chosen as a starting dose according the test guideline. The test substance in this dose level was administered sequentially to one group of 3 females. No death of animals was observed therefore the testing was continued with dose 2000 mg/kg (application with time distance 24 hours). Because no death of animals was observed, next step using the same dose 2000 mg/kg was performed as a confirmation.

Testing schedule: START: 300 mg/kg – 3 females (Step No.1): no deaths ► 2000 mg/kg – 3 females (Step No. 2): no deaths ► 2000 mg/kg – 3 females (Step No. 3): no deaths ► END of study

PREPARATION AND APPLICATION OF THE TEST SUBSTANCE
Immediately before application the test substance was weighed and mixed in vehicle. The test substance was administered as a suspension in water for injections.
Because of poor solubility of test substance in water, the dose level 2000 mg/kg of body weight could not be prepared. The test substance was applied divided in two applications of dose level 1000 mg/kg of body weight. There was interval 1 hour between the applications.

The test substance was administered to the stomach by tube. The single volume of administered suspension was 1 mL/100 g of animal body weight. The starting dose was 300 mg/kg of body weight.

Doses:

300 mg/kg (1st step)
2000 mg/kg (2nd step)
2000 mg/kg (3rd step)

No. of animals per sex per dose:

3 animals per dose

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: 1st day: twice (30 minutes and 3 hours after application), 2nd day: twice (in the morning and in the afternoon), thereafter days: once a day
Observations included changes in skin and fur, eyes, visible mucous membranes, behaviour of animals, somatomotor activity, reactions to stimuli, and presence of lacrimation, salivation and discharge from nostrils, function of respiratory, digestive and urogenital system.

- Necropsy of survivors performed: yes
- examinations performed:
nutritious status, body surface, body foramina, thoracic, abdominal and cranial cavity were evaluated. All gross macroscopic changes of organs and tissues were recorded on special data sheets.

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 death of animals.

Clinical signs:

Just during the first observations period (30 minutes and 3 hours p. a.) were observed these symptoms: anemic appearance of the skin and visible mucous membranes and weak porphyrin secretion from the nostrils. In some females at the dose level 2000 mg/kg the piloerection was also observed. No other clinical signs of intoxication were observed during the study.

Body weight:

Body weight was recorded and weight increments were calculated in all surviving animals at the end of study.
Weight increments were adequate to species, sex and age of animals in experiment. No reduction of body weight was observed.

Gross pathology:

No pathologic macroscopic changes were diagnosed during pathological examination.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

The test substance toxicity was evaluated on the basis of mortality, clinical signs of intoxication, body weight increments during the observation period and necropsy findings at the end of study.
The test substance administered at the dose of 2000 mg/kg caused no death of animals.
Just these symptoms shortly after application were observed: anemic appearance of the skin and visible mucous membranes and weak porphyrin secretion from the nostrils. In some females at the dose level 2000 mg/kg the piloerection was also observed. No other clinical signs of intoxication were observed during the study.
No pathologic macroscopic changes were diagnosed during pathological examination.
According to the study results the value of LD50 of the test substance, Dibenzylsulfoxide, for female rats is higher than 2000 mg/kg of body weight.

Executive summary:

The aim of the study was to investigate acute toxic effects of the test substance, Dibenzylsulfoxide, after a single oral administration to Wistar Han rats.

The testing was performed according Method B.1 tris: Acute Oral Toxicity - Acute Toxic Class Method, Council Regulation (EC) No.440/2008, published in O.J. L 142, 2008.

The test substance was administered as a suspension in water for injections, was given orally via gavage to three groups of three female Wistar CRL rats.

The dosing was performed sequentially in three groups of three females: group No. 1 - first step using the starting dose of 300 mg/kg of body weight, group No. 2 - second step using higher dose 2000 mg/kg and group No. 3 – third step using the same dose 2000 mg/kg.

The test substance administered at the dose of 2000 mg/kg caused no death of animals. No serious clinical signs of intoxication were detected during whole study. No pathologic macroscopic changes were diagnosed during pathological examination.

According to the study results the value of LD50 of the test substance, Dibenzylsulfoxide, for female rats is higher than 2000 mg/kg of body weight.