Boronic acid, [6-(benzoylmethylamino)-5-methyl-3-pyridinyl]-

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 May 2020 - 20 May 2020

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2020

Report date:

2020

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 420 (Acute Oral Toxicity - Fixed Dose Method)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Test type:

fixed dose procedure

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Boronic acid, [6-(benzoylmethylamino)-5-methyl-3-pyridinyl]-

Cas Number:

446299-81-6

Molecular formula:

C14H15BN2O3

IUPAC Name:

Boronic acid, [6-(benzoylmethylamino)-5-methyl-3-pyridinyl]-

Test material form:

solid: particulate/powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Remarks:

(SPF Caw)

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Elevage JANVIER LABS (53940 Le Genest St Isle – France)
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 8 weeks
- Weight at study initiation: 191.4 g (SD = 8.2 g)
- Fasting period before study: Food was removed on D-1 and then redistributed 4 hours after the test item administration.
- Housing: Rats were housed by group of three in solid-bottomed clear polycarbonate cages with a stainless steel mesh lid. Each cage contains sawdust bedding which was changed at least 2 times a week. Each cage was installed in conventional air conditioned animal husbandry.
- Diet (e.g. ad libitum): Ad libitum. Teklad Global 16% Protein Rodent Diet (ENVIGO 2016).
- Water (e.g. ad libitum): Ad libitum. Drinking water (tap-water from public distribution system). Microbiological and chemical analyses of the water were carried out once every six months by Bureau Veritas – Eurofins (FRANCE).
- Acclimation period: the animals were acclimatized for at least 5 days before treatment.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19ºC to 25ºC
- Humidity (%): 30 to 70%
- Air changes (per hr): ≥ 10 air changes/hour
- Photoperiod (hrs dark / hrs light): 12 hours light (07.00 to 19.00) and 12 hours dark cycle.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

DMSO

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg bw
- Justification for choice of vehicle: Dimethyl sulfoxide (DMSO) was chosen as it produced the most suitable formulation at the requested concentration.

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

DOSAGE PREPARATION (if unusual): The preparations were stirred using a vortex and by ultraturrax to obtain yellowish solutions just before the administration.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

Step 1 (2000 mg/kg bw): 1 animal
Step 2 (2000 mg/kg bw): 4 animals.

Control animals:

yes

Remarks:

(study performed on three animals receiving DMSO under requirements of OECD Guideline 423)

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: At each step, the animals were observed four times on test day 0 (day of administration), i.e. at T0+30 min, T0+1h, T0+3h and T0+4h, and once daily during days 1 to 14 post administration. The body weights were recorded on test day 0 (just before administration) then on D2, D7, and D14.
- Necropsy of survivors performed: yes.
- Clinical signs including body weight: spontaneous activity, Preyer’s reflex (noise), respiratory rate, convulsions, tremors, body temperature, muscle tone, palpebral opening, pupil appearance, salivation, lachrymation, righting reflex, back hair appearance. The body weight evolution of animals treated with the test item was compared with the body weight evolution of the control group.
- Other examinations performed: Macroscopic observations were entered on individual autopsy sheets. Only those organs likely to be modified in cases of acute toxicity were examined. No organ was removed and preserved in view to microscopic examinations.

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 mortality occurred during the study.

Clinical signs:

other: No clinical signs related to the administration of the test item were observed during the study.

Gross pathology:

The macroscopic examination of the animals at the end of the study did not reveal treatment related changes.

Any other information on results incl. tables

Table 1: Body weight and weight gain in grams. Steps 1 & 2 (2000 mg/kg bw)

Females	D0	D2	D2-D0	D7	D7-D0	D14	D14-D0
Rf4865	183	205	22	235	52	263	80
Rf4858	205	202	-3	234	29	263	58
Rf4859	191	211	20	240	49	257	66
Rf4860	189	206	17	228	39	244	55
Rf4861	189	198	9	221	32	238	49
MEAN	191.4	204.4	13.0	231.6	40.2	253.0	61.6
S.D.	8.2	4.8	10.2	7.3	10.1	11.4	12.0

Applicant's summary and conclusion

Interpretation of results:

other: No category (CLP Regulation EC no. 1272/2008)

Conclusions:

The LD50 of the test item is higher than 2000 mg/ kg body weight by oral route in the rat.

Executive summary:

The acute oral toxicity of the test item has been tested in accordance with OECD Test Guideline 420, following GLP. 5 female Sprague-Dawley rats were administered by oral gavage in 2 steps with test item diluted in vehicle DMSO. The sighting study was performed at the dose of 2000 mg/kg bw in one female rat. As no effects were observed in the preliminary test, the subsequent main study was performed with 4 females administered with test item at the same dose of 2000 mg/kg bw. No mortality occurred during the study. No clinical signs related to the administration of the test item were observed during the study. The body weight evolution of the animals remained normal throughout the study. The macroscopic examination of the animals at the end of the study did not reveal treatment related changes. Based on these results, the LD50 of the test item is determined to be higher than 2000 mg/ kg bw by oral route in the rat.