Boronic acid, B-(2-fluoro-3-methoxyphenyl)-

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

July 5 2018 - November 03 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 guideline

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

"Acute Oral Toxicity - Acute Toxic Class Method" (TG 423) published by the Ministry of Environmental Protection of People's Republic of China, 2013.

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

(2-fluoro-3-methoxyphenyl)boronic acid

EC Number:

609-099-0

Cas Number:

352303-67-4

Molecular formula:

FC6H3(OCH3)B(OH)2

IUPAC Name:

(2-fluoro-3-methoxyphenyl)boronic acid

Test material form:

solid: particulate/powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

female

Details on test animals or test system and environmental conditions:

Justification of Test System: Rats are the preferred species of choice as historically used for the safety evaluations studies and are specified in the appropriate test guidelines.

Test Conditions
Husbandry: Animals were housed in Room Dl20 of the facility's barrier system. Animals were raised in suspended, stainless steel cages (132.0cm xW28.0cmxH20.0cm) on cage racks (Ll67.0cmxW70.0cmxH171.0cm). There were 10 cages per layer, and 4 layers per rack. Animals were housed individually during the test.
Environmental Controls: Temperature and humidity were controlled automatically and daily recorded. The values in the animal room were 20-25°C for temperature, and 40%-70% for humidity. The lighting sequence was 12 hours light, 12 hours dark
Food and Water: Animals .were provided sterilized diet with complete nutrition supplied by Beijing Keaoxieli Feed Cd., Ltd. Analysis reports of diet were supplied by the supplier. All the nutrition components and contaminants were within the permitted limits described in the national standard (GB14924.3-2010 and GB14924.2°2001).
Water was purified by HT-R0l000 purity system. Water analysis was conducted routinely analyzed (annually), and all parameters were within the permitted limits described in the national drinking water standard (GB5749-2006). The diet and water were considered not to contain any contaminants that could reasonably be expected to affect the purpose or integrity of the study.
Water was available to the animals ad libitum during test.
Animal Welfare: Animal use complied with national animal welfare laws and regulations (instructive notions with respect to caring for laboratory animals) (2006, Ministry of Science, P.R.C.). Animals surviving to the end of the study were anesthetized by CO2 and bled by abdominal aorta ·to death. Spare animals were humanely killed by CO2 euthanasia. Their corpse treatments would be entrusted to specialized agencies. The animal care and use activities required for conduct of this study were reviewed and approved by the testing facility Animal .. Care and Use Committee (IACUC).

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

Administration Route
According to the potential route of human contact, oral gavage was selected for administration.

Dose Design
According to the Guidelines for the testing of chemicals "Acute Oral Toxicity-Acute Toxic Class Method" (TG 423) published by the Ministry of Environmental Protection of People's Republic of China in the year of 2013, and that the acute oral LD5o in rat of the test item's analog is 2460 mg/kg, the dose level of 2000 mg/kg b.w. was selected as the starting dose from one of four fixed dose levels (5,. 50, 300, 2000 mg/kg b.w., see Figure 1 in Appendix 2), and 3 animals were used in each step. The first step dosing was 2000 mg/kg b.w. and all animals died, so 300 mg/kg b.w. was selected as the second step dosing, and l animal died. Therefore 300 mg/kg b.w. was selected as the third step dosing and no animals died.

Grouping of Animals
After the acclimatization period, all healthy animals were randomly arranged by Excel 2007, and when administered each time three animals in each group were used sequentially. Each animal, at the commencement of its dosing, its weight fell in an interval within ±20% of the mean body weight of any previously dosed animals. Animals with ID beginning from .2100 to 2102 were used for the first dosing, and 2200 to 2202 were used for the second dosing, and 2300 to 2302 were used for the third dosing.

Animal Identification
All animals were marked by the special animal markers on the hair (the colour was different from the previous ones) and numbers written on cage cards. At the end of the necropsy, animals were also marked on the tails. A cage card was prepared with details.

1.1.2 Formulation Preparation
According to the dose designation and body weights weighed before dosing, the theoretical amounts of the test item were calculated. The test item was weighed in a grinding jar. Put a small amount of vehicle into the grinding jar, and then stirred with a glass rod, and subsequently diluted the test item with vehicle to the scale mark. The prepared formulations were fully homogenized and labeled for use. Computing Formula: Concentration (mg/mL) = Dose (mg/kg)/Dosing Volume (mL/kg b.w.), Theoretical Weighed Test Item (mg)= Prepared Volume (mL) x Concentration (mg/mL).

All formulations were used within two hours of preparation and were assumed to be stable for this period unless specified otherwise by the sponsor. The concentration and homogeneity of the formulations were not determined by analysis. The residual formulated test item after dosing was returned to Test Item Preparation Department and disposed totally.

1.1.3 Administration Method
All test animals were fasted overnight prior to dosing, but water was freely available. Formulations Stirring: Dosing formulations were stirred on the magnetic stirring apparatus for �t least ·10 minutes prior to dosing and were stirred during dosing. Each dosing formulation -·was administrated to animals' stomachs using a standard gavage tube attached to a disposal syringe.
Dosing Frequency: Each animal was dosed once.
Dosing Volume: The actual dosing volume of each animal was calculated according to the fasted body weight weighed before dosing. Dosing volume was 5 mL/kg b.w..
Dosing Time: In the morning
The time interval between treatment groups was determined by the onset, duration, and severity of toxic signs. The dosing interval of next step was determined according to the actual conditions.

Doses:

Dose 1: 2000 mg/kg b.w.
Dose 2: 300 mg/kg b.w.
Does 3: 300 mg/kg b.w.

No. of animals per sex per dose:

3 females per dose

Control animals:

no

Details on study design:

Moribund or Mortality Inspection
Inspections were made twice daily, morning and afternoon, during normal working days (except that it was made once in the dosing and necropsy days), and once daily at weekends and public holidays.

Clinical Observations
Clinical observations were performed once during the first 30 minutes and at 1, 2 and 4 hours after application and then once each day for up to 14 days.
General observations were made once daily for the animals. which have not been administrated with the test item.
Careful observations and records of animal fur changes, eyes and mucosa, digestive, respiratory, circulatory, autonomic and central nervous system, particularly limb activity and behavior changes were made. Attention was directed to observations of tremor, convulsions, salivation, diarrhea, lethargy, sleep and coma.

Body Weights
Individual weights of animals were determined within 24 hours after arrival, at grouping, on Day O (day of dosing), Day 7 and Day 14. At the end of the test surviving animals were weighed. Changes in weights were calculated and recorded when survival exceeding one day.

Necropsy
Animals surviving to the end of the study were anesthetized by CO2 and bled by abdominal aorta to death. A gross necropsy was performed on all animals under test. The necropsy· included carefully· eye examinations of the abdominal, thoracic organs and their contents of all animals.'1

Results and discussion

Effect levels

Effect levels 1

Key result

Sex:

female

Dose descriptor:

approximate 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:

Dose Level-The first dosing (2000 mg/kg b.w.): One animal died on the dosing day and the rest two animals died on the day after dosing day.
Dose Level-The second dosing (300 mg/kg b.w.): One animal died on the second day after dosing day and the rest two animals showed no deaths or moribund status during the test.
Dose Level-The third dosing (300 mg/kg b.w.): All animals showed no deaths or moribund status during the test.
Mortality summary results were given in Appendix 1-Table 1.

Clinical signs:

other: Dose Level-The first dosing (2000 mg/kg b.w.): One animal showed less movement at 1 hour observation and prostration at 2 hour observation after dosing. The rest 2 animals showed prostration at 2 and 4 hour observations after dosing. Dose Level-The secon

Gross pathology:

Not specified

Applicant's summary and conclusion

Interpretation of results:

Category 4 based on GHS criteria

Conclusions:

According to the GHS's classification criteria for acute oral toxicity the test item was classified as "Category 4".