Lithium 2-aminobenzothiazole-6-sulphonate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From January 16, 2019 to February 01, 2019

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Remarks:

Slight deviation from OECD guideline recommended humidity range - not expected to impact study findings or validity.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2019

Report date:

2019

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Adopted: 17th December 2001

Deviations:

yes

Remarks:

The relative humidity values were between 24-56%. OECD guidance states that "the relative humidity should be at least 30%". The investigators stated that "these deviations have no presumed impact on the outcome or integrity of the study".

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.1 tris (Acute Oral Toxicity - Acute Toxic Class Method)

Version / remarks:

No 440/2008 of 30 May 2008, B.1.tris

Deviations:

yes

Remarks:

The relative humidity values were between 24-56%. EU (2008) guidance states that "the relative humidity should be at least 30%". The investigators stated that "these deviations have no presumed impact on the outcome or integrity of the study".

GLP compliance:

yes (incl. QA statement)

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Lithium 2-aminobenzothiazole-6-sulphonate

EC Number:

265-367-3

EC Name:

Lithium 2-aminobenzothiazole-6-sulphonate

Cas Number:

65072-36-8

Molecular formula:

C7H6N2O3S2.Li

IUPAC Name:

lithium 2-amino-1,3-benzothiazole-6-sulfonate

Test material form:

solid: particulate/powder

Details on test material:

- Bulk Density (g/ml): 0.39
- Particle size distribution (μm): 19.6
- Water solubility: 20%

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material: IR2510181
- Expiration date of the lot/batch: 25 October 2019
- Purity test date: Not specified

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: Controlled room temperature (15-25 °C, ≤70 Relative Humidity %)
- Stability under test conditions: Not specified
- Solubility and stability of the test substance in the solvent/vehicle: 20% soluble in water

TREATMENT OF TEST MATERIAL PRIOR TO TESTING
- Treatment of test material prior to testing: 2-ABT lithium sulphonate (off white powder) was freshly formulated at a concentration of 200 mg/mL in distilled water (vehicle)
- Preliminary purification step: Not specified
- Final dilution of a dissolved solid, stock liquid or gel: 200 mg/mL

FORM AS APPLIED IN THE TEST
- Mixture of the off white powder , 2-ABT lithium sulphonate (20% solubility in water), and distilled water (vehicle)

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Research Models and Services, Germany GmbH, Sandhofer Weg 7, D-97633 Sulzfeld
- Females nulliparous and non-pregnant: yes
- Age at study initiation: 12 weeks
- Weight at study initiation: 228-260 g
- Fasting period before study: The animals were fasted the night before treatment
- Housing: 3 animals/cage. Cage type: Type II polypropylene/polycarbonate. Bedding: “Lignocel® 3/4-S Hygienic Animal Bedding” and “Arbocel® crinklets natural” nest building material produced by J. Rettenmaier & Söhne GmbH + Co.KG (D-73494 Rosenberg, Germany)
- Diet: Animals received ssniff® SM R/M "Autoclavable complete diet for rats and mice – breeding
and maintenance" produced by ssniff Spezialdiäten GmbH, D-59494 Soest, Germany (Batch
number: 639 38520, expiry date: 30 April 2019), ad libitum
- Water: tap water from the municipal supply, as for human consumption from 500 ml bottles, ad libitum
- Acclimation period: at least 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19.7 - 23.3
- Humidity (%): 24 - 56 (Investigators stated that "due to technical reason, relative humidity values (minimum of 24%) outside the expected range of 30-70% were recorded during the study. These deviations have no presumed impact on the outcome or integrity of the study").
- Air changes (per hr): 15 - 20
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 16 January 2019 To: 01 February 2019

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL
- Amount of vehicle: 10 mL/kg bw
- Justification for choice of vehicle: Based on trial formulations with the test item
- Lot/batch no.: 8181118
- Purity: Distilled

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg bw

CLASS METHOD
- Rationale for the selection of the starting dose: Limit dose

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

6 females

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were performed at 30 minutes, 1, 2, 3, 4 and 6 hours after dosing and daily for 14 days thereafter. Body weights were recorded on the day before treatment, the day of the treatment, after a week and before necropsy (right after the animal was found dead or on the final day of the observation period for the survivors)
- Necropsy of survivors performed: yes
- Other examinations performed: All animals were subjected to macroscopic examination

Statistics:

Not applicable

Results and discussion

Effect levels

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

>= 2 000 mg/kg bw

Based on:

test mat.

Remarks on result:

other: The method used was not intended to allow the calculation of a precise LD50 value

Mortality:

Out of the 6 animals that received the test material at 2000 mg/kg bw, 1 animal died on day 1

Clinical signs:

The animal that died displayed numerous clinical signs of toxicity, including: a hunched back, piloerection, decreased activity (slight or moderate), incoordination and clonic convulsion up to day 1.Those that survived showed hunched back (5/5), piloerection (3/5) and slightly decreased activity (2/5) up to day 4, but no adverse signs of toxicity were observed from day 5 up to the end of the 14 day observation period.

Body weight:

Normal body weight gain was observed

Gross pathology:

The dead animal had diffuse dark/red discoloration of the non-collapsed lungs and the thymus. These effects were regarded to be due to agonal death and were not substance related.

No adverse macroscopic findings were observed in the rats that were subjected to necropsy on day 14.

Applicant's summary and conclusion

Interpretation of results:

other: Does not warrant classification according to EU CLP criteria

Conclusions:

In an acute oral toxicity study in rats, conducted according to OECD test guideline 423 and to GLP, an LD50 value of equal to or greater than 2000 mg/kg bw was determined for lithium 2-aminobenzothiazole-6-sulphonate.

Executive summary:

In an acute oral toxicity study, conducted according to OECD test guideline 423 and to GLP, six female Wistar rats received a single dose of lithium 2-aminobenzothiazole-6-sulphonate at 2000 mg/kg bw by oral gavage and were observed for clinical signs of toxicity and body weight alterations for 14 days. All animals were then necropsied and underwent a macroscopic examination.

One rat died on day 1. The surviving animals showed hunched back (5/5), piloerection (3/5) and slightly decreased activity (2/5) up to day 4, but no adverse signs of toxicity were noted from day 5 onwards. There were no substance-related adverse effects on body weight gain or macroscopic findings at necropsy.

In this reliable study, the acute oral LD₅₀ value of lithium 2-aminobenzothiazole-6-sulphonate was determined to be equal or above 2000 mg/kg bw.