Reaction mass of 2-ethyl-4-methyl-1H-imidazole-1-propiononitrile and 2-ethyl-5-methyl-1H-imidazole-1-propiononitrile

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

28 Nov - 22 Dec 2017

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 guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

adopted 17 Dec 2001

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

1

Reference substance name:

Reaction mass of 2-ethyl-4-methyl-1H-imidazole-1-propiononitrile and 2-ethyl-5-methyl-1H-imidazole-1-propiononitrile

EC Number:

947-727-8

Cas Number:

568591-00-4

Molecular formula:

C9H13N3

IUPAC Name:

Reaction mass of 2-ethyl-4-methyl-1H-imidazole-1-propiononitrile and 2-ethyl-5-methyl-1H-imidazole-1-propiononitrile

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

(Crl:CD(SD)), SPF

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: ORIENTBIO INC., Republic of Korea
- Females nulliparous and non-pregnant: not specified
- Age at study initiation: 7-9 weeks
- Weight at study initiation: Female, 13 rats, 7 weeks old, 165.6−179.6 g;
- Weight at administration: Female, 9 rats, 8−9 weeks old, 176.6−218.0 g
- Fasting period before study: Yes, the animals were fasted overnight before dosing.
- Housing: Stainless wire mesh cage, 260W×350D×210H (mm), one animal/cage (during study)
- Diet: Pelleted rodent chow, ad libitum, (Teklad Certified Irradiated Global 18% Protein Rodent Diet 2918C), Envigo RMS, Inc., USA, Lot number: 2918C-081517MA
- Water: Public tap water in Cheongju-si was filtered and irradiated by ultraviolet light, ad libitum.
- Acclimation period: All animals were quarantined for 3 days, moved from the
quarantine room to the animal room and then, acclimated for 4 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.6−24.3
- Humidity (%): 46.9−66.8
- Air changes (per hr): 10−15 clean, fresh, filtered air changes
- Photoperiod (hrs dark / hrs light): 12/12

IN-LIFE DATES: From: Nov. 28, Dec. 1 and 5, 2017 To: Nov. 28, Dec. 15 and 19, 2017

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

for injection

Details on oral exposure:

VEHICLE
- Concentration in vehicle: at 2000 mg/kg bw dose level undiluted (used as supplied, 1.9 mL/kg), at 300 mg/kg bw dose level: 157.89 mg/mL diluted in water for injection,
- Lot/batch no.: DBA7004, JW Pharmaceutical Co., Ltd., Republic of Korea

MAXIMUM DOSE VOLUME APPLIED: 1.90 mL/kg bw

CLASS METHOD
- Rationale for the selection of the starting dose: The starting dose level was selected at 2000 mg/kg bw based on information supplied by the sponsor of the study.

Doses:

2000 mg/kg bw
300 mg/kg bw

No. of animals per sex per dose:

3 per Step / 3 steps performed

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: All animals were observed for mortality, general condition and clinical signs (type, severity, time of onset and recovery) at 30 minutes after dosing and at 1, 2, 4 and 6 hours after dosing on Day 0 and once daily thereafter for 14 days. The body weights were recorded prior to dosing on Day 0 and on Days 1, 3, 7 and on the day of necropsy (Day 14).
- Necropsy of survivors performed: yes, Furthermore, necropsy was conducted after body weight measurement on all animals found dead during the observation period.
- Other examinations performed: On Day 14, all surviving animals were anesthetized with CO2 and exsanguinated from the abdominal aorta. Complete gross postmortem examinations were performed on all animals in the study. Since no gross findings were observed at necropsy, histopathological examination was not performed.

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 300 - < 2 000 mg/kg bw

Based on:

test mat.

Effect levels 2

Key result

Sex:

female

Dose descriptor:

LD50 cut-off

Effect level:

500 mg/kg bw

Based on:

test mat.

Mortality:

Three animals were found dead at 2000 mg/kg bw on the day of dosing.
There were no deaths of animals at 300 mg/kg bw.

Clinical signs:

At 2,000 mg/kg bw, tremor was observed in all animals at 0.5 and/or 1 hours after dosing.
Then, all animals were found dead in a state of salivation, prone position and/or lying on side at 1 and/or 2 hours after dosing.
At 300 mg/kg bw, tremor was observed in one animal at 4 hours after dosing, and it disappeared at 6 hours after dosing.

Body weight:

Normal body weight gain was observed in all animals at 300 mg/kg bw throughout the study.

Gross pathology:

No grossly visible findings were observed in any animal at 300 and 2,000 mg/kg bw, respectively.

Any other information on results incl. tables

Table 1: Mortality Data

Step	Dose level mg/kg bw	sex	Number of animals		Days after dosing								Mortality
				0	1	2	3	4	5	6	7	8-14
1	2000	female	3	3*	0	0	0	0	0	0	0	0	3/3
2	300	female	3	0	0	0	0	0	0	0	0	0	0/3
3	300	female	3	0	0	0	0	0	0	0	0	0	0/3

 * all animals died 1 or 2 hours after dosing

Applicant's summary and conclusion

Interpretation of results:

other: Acute Tox. Cat. 4 according to Regulation (EC) No 1272/2008

Conclusions:

The acute oral median lethal dose (LD50) of the test substance in the female Sprague-Dawley CD strain rats was in the range of > 300 - < 2000 mg/kg bw. The LD 50 cut-off was 500 mg/kg bw.
The available data on acute oral toxicity of the test substance meet the criteria for Acute Tox. Cat 4 (H302) according to Regulation (EC) 1272/2008.