Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
12.12.2017-18.01.2018
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2018
Report date:
2018

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to guideline
Guideline:
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
Qualifier:
according to guideline
Guideline:
EU Method B.1 (Acute Toxicity (Oral))
Qualifier:
according to guideline
Guideline:
EPA OPPTS 870.1100 (Acute Oral Toxicity)
GLP compliance:
yes (incl. QA statement)
Test type:
acute toxic class method
Limit test:
no

Test material

Constituent 1
Chemical structure
Reference substance name:
Dipotassium propanedioate
EC Number:
820-064-0
Cas Number:
13095-67-5
Molecular formula:
C3H2K2O4
IUPAC Name:
Dipotassium propanedioate

Test animals

Species:
rat
Strain:
Wistar
Remarks:
controlled full-barrier maintained breeding system (SPF).
Sex:
female
Details on test animals or test system and environmental conditions:
TEST SYSTEM
- Species/strain: WISTAR rats Crl: WI(Han)
- Sex: female (non-pregnant and nulliparous)
- Number of animals: 3 per step
- Age at the beginning of the study: 8-10 weeks
- Body weight on the day of administration:
-- Step 1: 151 – 172 g
-- Step 2: 142 – 162 g
-- Step 3: 145 – 175 g

HOUSING AND FEEDING CONDITIONS
- Full barrier in an air-conditioned room
- Temperature: 22 3 °C
- Relative humidity: 55 ± 10%
- Artificial light, sequence being 12 hours light, 12 hours dark
- Air change: 10 x / hour
- Free access to Altromin 1324 maintenance diet for rats and mice
- Free access to tap water, sulphur acidified to a pH value of approximately 2.8 (drinking water, municipal residue control, microbiological controls at regular intervals)
- The animals were kept in groups in IVC cages, type III H, polysulphone cages on Altromin saw fibre bedding
- Certificates of food, water and bedding are filed for two years at BSL Munich and afterwards archived at Eurofins Munich
- Adequate acclimatisation period (at least five days) under laboratory conditions

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Details on oral exposure:
The test item was administered at a single dose by gavage using a feeding tube.
The test item was administered at a dose volume of 10 mL/kg body weight.
Doses:
Step 1: 300 mg/kg body weight. No compound-related mortality was recorded
Step 2: 2000 mg/kg body weight. No compound-related mortality was recorded
Step 3: 2000 mg/kg body weight. No compound-related mortality was recorded
No. of animals per sex per dose:
3 females per dose
Control animals:
no
Details on study design:
Preparation of the Animals:
- The animals were marked for individual identification by tail painting
- Prior to the administration a detailed clinical observation was made of all animals. Only healthy animals were used
- Prior to the administration food was withheld from the test animals for 16 to 19 hours (access to water was permitted)
- Following the period of fasting the animals were weighed and the test item was administered
- Food was provided again approximately 4 hours post dosing

Observation Period:
- All animals were observed for 14 days after dosing for general clinical signs, morbidity and mortality

Weight Assessment:
- The animals were weighed on day 1 (prior to the administration) and on days 8 and 15

Clinical Examination:
A careful clinical examination was made several times on the day of dosing (at least once during the first 30 minutes and with special attention given during the first 4 hours post-dose).
Thereafter, the animals were observed for clinical signs once daily until the end of the observation period.
Cageside observations included changes in the skin and fur, eyes and mucous membranes. Also respiratory, circulatory, autonomic and central nervous systems and somatomotor activity and behaviour pattern were examined.
Particular attention was directed to observations of tremor, convulsions, salivation, diarrhoea, lethargy, sleep and coma.

Pathology:
At the end of the observation period the animals were sacrificed with an overdosage of pentobarbital injected intraperitoneally at a dosage of 250-400 mg/kg bw.
All animals were subjected to gross necropsy and examined macroscopically for gross pathological changes.
In the absence of gross pathological changes no tissues were preserved for a possible histopathological evaluation.

Evaluation of Results:
- Results were interpreted according to OECD Guideline 423, Annex 2
- Individual reactions of each animal were recorded at each time of observation
- Toxic response data were recorded by dose level
- Nature, severity and duration of clinical observations were described
- Necropsy findings were described
With few exceptions, data were captured using a validated computerised system

Deviations:
There were no deviations from the study plan
Statistics:
not specified

Results and discussion

Preliminary study:
not applicable
Effect levels
Key result
Sex:
female
Dose descriptor:
LD50 cut-off
Effect level:
5 000 mg/kg bw
Based on:
test mat.
Mortality:
The test item showed no mortality after a single dose administration at a dosage of 2000 mg/kg body weight.
Clinical signs:
All animals dosed at 300 mg/kg bw did not show any test-item related signs of toxicity.
All animals dosed at 2000 mg/kg bw (step 2 and 3) did show signs of toxicity. The most relevant clinical findings in the animals treated with the test item at a dose of 2000 mg/kg bw were reduced spontaneous activity, piloerection, half eyelid-closure, sunken flunks, ataxia and hunched posture.
All symptoms recovered within up to 2 days post-dose.
Body weight:
None of the animals showed weight loss during the observation period
Gross pathology:
At necropsy, no macroscopic findings were observed in any animal of any step.
Other findings:
not specified

Any other information on results incl. tables

Results per Step

Step Sex / No. Starting Dose (mg/kg bw) Number of Animals Number of Intercurrent Deaths
1 Female / 1 - 3 300 3 0
2 Female / 4 - 6 2000 3 0
3 Female / 7 - 9 2000 3 0

LD50 Cut-Off

Starting Dose (mg/kg bw) Number of animals Number of intercurrent deaths LD50 Cut-Off (mg/kg bw)
300 3 0 5000
2000 6 0

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
Conclusions:
The test item showed no mortality but acute oral toxicity characteristics after a single dose administration at a dosage of 2000 mg/kg body weight.
The median lethal dose of Dipotassium malonate after a single oral administration to female rats, observed over a period of 14 days is:
LD50 cut-off (rat): 5000 mg/ kg bw
Executive summary:

The purpose of this study was to assess the toxicity of the test article when administered to rats as a single oral dose. The study was carried out in accordance with OECD TG 423 and in compliance to GLP. One group of three female WISTAR Crl: WI(Han) rats was treated with the test item by oral gavage administration at a dosage of 300 mg/kg body weight. The test item was suspended with the vehicle aqua ad injectionem (sterile water) at a concentration of 0.03 g/mL and administered at a dose volume of 10 mL/kg.

Two groups, each of three female WISTAR Crl: WI(Han) rats, were treated with the test item by oral gavage administration at a dosage of 2000 mg/kg body weight. The test item was suspended with the vehicle aqua ad injectionem (sterile water) at a concentration of 0.2 g/mL and administered at a dose volume of 10 mL/kg.

All animals used in the study after their entrance were allowed to acclimatise to the laboratory conditions for at least 5 days. The animals were observed on delivery, on inclusion in the study and before administration for mortality/morbidity and other clinical signs. All animals were examined for clinical signs several times on the day of dosing and once daily until the end of the observation period. Their body weights were recorded on day 1 (prior to the administration) and on days 8 and 15.

All animals were necropsied and examined macroscopically.

All animals of step 1 survived until the end of the study without showing any test-item related signs of toxicity. All animals of step 2 and 3 survived until the end of the study showing signs of toxicity. The most relevant clinical findings in the animals treated with the test item at a dose of 2000 mg/kg bw were reduced spontaneous activity, piloerection, half eyelid-closure, sunken flunks, ataxia and hunched posture. All symptoms recovered within up to 2 days post-dose.

Throughout the 14-day observation period, the weight gain of the animals was within the normal range of variation for this strain. At necropsy, no macroscopic findings were observed in any animal of any step.

Under the conditions of the present study, a single oral application of the test item Dipotassium malonate to rats at a dose of 300 mg/kg body weight was not associated with signs of toxicity or mortality. Under the conditions of the present study, a single oral application of the test item Dipotassium malonate to rats at a dose of 2000 mg/kg body weight was associated with slight signs of toxicity but not mortality. The median lethal dose of Dipotassium malonate after a single oral administration to female rats, observed over a period of 14 days is: LD50 cut-off (rat): 5000 mg/ kg bw