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Administrative data

acute toxicity: oral
Type of information:
experimental study
Adequacy of study:
key study
Study period:
12th June 2020 to 9th July 2020
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment

Data source

Reference Type:
study report
Report date:

Materials and methods

Test guideline
OECD Guideline 423 (Acute Oral toxicity - Acute Toxic Class Method)
GLP compliance:
The study was not within the scope of regulations governing the conduct of noncliniical laboratory studies and is not intended to comply with the regulations

Test material

Reference substance name:
Cas Number:
Test material form:
solid: particulate/powder

Test animals

Details on test animals or test system and environmental conditions:
- Age at study initiation: 8 weeks old
- Weight at study initiation: 207 to 237 g for the males and 197 to 215 g for the females
- Fasting period before study: 1 day
- Housing: Polycarbonate cages containing appropriate bedding equipped with an automatic watering valve. Animals were individually housed.
- Diet: Lab Diet Certified CR Rodent Diet 5CR4. Ad libitum, except during designated procedures
- Water: Municipal tap water, treated by reverse osmosis and ultraviolet irradiation. Freely available to each animal via an automatic watering system (except during designated procedures).
- Acclimation period: The animals were acclimated to their designated housing for at least 7 days before the first day of dosing.
- Method of randomisation in assigning animals to test and control groups: Animals were assigned to groups by a stratified randomization scheme designed to achieve similar group mean body weights. Males and females were randomized separately.

- Temperature: 68°F to 79°F (20°C to 26°C)
- Humidity: 30% to 70%
- Air changes: 10 or more per hour
- Photoperiod: 12hrs dark / 12hrs light

Administration / exposure

Route of administration:
oral: gavage
Details on oral exposure:
Reverse Osmosis Deionized (RODI) Water
- Amount of vehicle (if gavage): 10 mL/kg.

- Rationale for the selection of the starting dose: As no information about oral toxicity was known, testing was conducted at dose levels of 300 and 2000 mg/kg in 3 males and 3 females per group to provide general hazard communication information.
300 and 2000 mg/kg
No. of animals per sex per dose:
Control animals:
Details on study design:
- Duration of observation period following administration: 14 days
- Frequency of observations and weighing:
Mortality: At least twice daily (morning and afternoon) beginning upon arrival through termination
Clinical Observations: Two times on Day 0 (postdose) with the first observations within approximately 30 minutes after dosing and daily thereafter (Days 1 to 14).
Body Weights: Day -1 (prior to fasting), Day 0 (prior to dosing), and Days 7 and 14.
- Necropsy of survivors performed: yes
All results presented in the tables of the report were calculated using non-rounded values as per the raw data rounding procedure and may not be exactly reproduced from the individual data presented.
When appropriate, body weight means and standard deviations were calculated separately for males and females for each limit level administered.
When a limit test (or LD50 test reaching an upper bound) was performed, the LD50 was estimated as indicated below:
< 50% mortality: LD50 was estimated as greater than the administered dose.
= 50% mortality: LD50 was estimated as equal to administered dose.
> 50% mortality: LD50 was estimated as less than the administered dose.

Results and discussion

Effect levels
Key result
Dose descriptor:
Effect level:
> 2 000 mg/kg bw
Based on:
test mat.
Clinical signs:
other: Test article-related clinical observations included tremors, convulsions, repetitive behavior, erect fur, abnormal gait, decreased activity, partially closed eyes, constricted pupils, and prostration in 2 females administered 2000 mg/kg. Erect fur was als
Gross pathology:
A single observation of dark, discolored thymus was noted in a male administered 300 mg/kg,
but this observation was considered incidental and not test article related due to the lack of a
dose response.

Applicant's summary and conclusion

Interpretation of results:
GHS criteria not met
All animals survived until scheduled termination following administration of LSN3532787 by
oral gavage once on Day 0 in rats at levels of 300 mg/kg and 2000 mg/kg. Under the conditions
of this test, the median lethal dose of LSN3532787 is estimated to be greater than 2000 mg/kg.
Executive summary:

The objective of this study was to assess the acute toxicity of LSN3532787 when given as a single oral administration to rats. This study was intended to provide information on the potential health hazards of the test article with respect to oral exposure. Data from this study may serve as a basis for classification and/or labeling of the test article.
The study design was as follows:

Group No.Test MaterialDose Level
Adjusted Dose Level
Number of Animals

*The dose level was adjusted by a correction factor of 1.02.

The following parameters and end points were evaluated in this study: clinical signs, body weights, body weight gains, and gross pathology.
No mortality was noted during the study. Clinical observations were noted for females administered 2000 mg/kg, including tremors, convulsions, repetitive behavior, erect fur, abnormal gait, decreased activity, partially closed eyes, constricted pupils, and prostration. There were no effects noted for body weights, body weight gains, or gross pathology findings.
In conclusion, all animals survived until scheduled termination following administration of LSN3532787 by oral gavage once on Day 0 in rats at levels of 300 mg/kg and 2000 mg/kg.
Under the conditions of this test, the median lethal dose of LSN3532787 is estimated to be greater than 2000 mg/kg.