Manganese oxalate

Acute Toxicity: oral

Administrative data

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

05 August 2010 to 01 September 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Well performed GLP and OECD guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test type:

acute toxic class method

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Manganese Oxalate, dihydrate

IUPAC Name:

Manganese Oxalate, dihydrate

Test animals

Species:

rat

Strain:

Wistar

Sex:

female

Details on test animals or test system and environmental conditions:

Animals: Rat, RccHan: WIST(SPF)

Breeder: Harlan Laboratories B.V.; Kreuzelweg 53; 5961 NM Horst / The Netherlands

Number of Animals per Group: 3 females
Total Number of Animals: 6 females

Age (when treated): 10 weeks
Body Weight Range (when treated): 163.6 g - 195.7 g

Identification: Unique cage number and corresponding color-coded spots on the tail. The animals were marked at acclimatization start.
Randomization: Selected by hand at time of delivery. No computer generated randomization program.

Acclimatization: 5 (Group 1) or 8 (Group 2) days under laboratory conditions, after health examination. Only animals without any visible signs of illness were used for the study.

Conditions: Standard Laboratory Conditions. Air-conditioned with 10-15 air changes per hour, and continuously monitored environment with a room temperature of 22 ± 3 °C and a relative humidity between 30-70%, automatically controlled light cycle of 12 hours light and 12 hours dark and music played during the daytime light period.

Accommodation: In groups of three in Makrolon type-4 cages with wire mesh tops and standard softwood bedding (‘Lignocel’ J. Rettenmaier&Söhne GmbH&CoKG, 73494 Rosenberg / Germany, imported by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland). Paper enrichment, Reference no. 207057, batch no. -67, (Enviro-dri from Lillico, Biotechnology, Surrey / UK) was included.

Diet: Pelleted standard Teklad Rat-Mouse Diet 2914C, irradiated, batch no. 30/10 (Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) ad libitum (except for the overnight fasting period prior to intubation and approximately 3-4 hours post dose). Results of analyses for contaminants are archived at Harlan Laboratories Ltd.

Water: Community tap water from Füllinsdorf ad libitum. Results of bacteriological, chemical and contaminant analyses are archived at Harlan Laboratories Ltd.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on oral exposure:

Preparation of Dose Formulations:

Dose levels are in terms of the test item as supplied by the Sponsor. The dose formulations were prepared shortly before each dosing occasion using a magnetic stirrer and an Ultra-Turrax as homogenizers. The test item was weighed into a tared glass beaker on a suitable precision balance and the vehicle added (weight:volume). Homogeneity of the test item in the vehicle was maintained during administration using a magnetic stirrer.


Test Item Administration:

The animals received a single dose of the test item by oral gavage administration at 2000 mg/kg body weight after being fasted for approximately 17 to 19 hours (access to water was permitted). Food was provided again approximately 3 hours after dosing. Dosing started in three female animals at a dosage level of 2000 mg/kg. The test procedure followed the scheme as described in the guidelines: Test Procedure with a Starting Dose of 2000 mg/kg body weight, Annex 2d, OECD Guideline 423, adopted 17th December 2001. The dosing volume was 10 mL/kg body weight. Rationale: Oral administration was considered to be an appropriate application method as it is a possible route of human exposure during manufacture, handling and use of the test item.

Doses:

2000 mg/kg body weight (equivalent to 1597 mg of the anhydrous form of the substance/kg bodyweight)

No. of animals per sex per dose:

3 animals per dose group, 2 dose groups

Control animals:

no

Details on study design:

Observations:

Viability / Mortality: Daily during acclimatization. Once before treatment and within the first 30 minutes and at approximately 1, 2, 3 and 5 hours after treatment on test day 1 (in common with the clinical signs). Twice daily during days 2 – 15.
Clinical Signs: Daily during acclimatization and treatment. Additionally, within the first 30 minutes and at approximately 1, 2, 3 and 5 hours after administration on test day 1.
Body Weights: On test days 1 (prior to administration), 8 and 15.


Pathology / Necropsy
All animals were killed at the end of the observation period by carbon dioxide asphyxiation and discarded after macroscopic examinations were performed. An external examination and opening of the abdominal and thoracic cavities for examinations of major organs was performed. The appearance of any macroscopic abnormalities was recorded. No organs or tissues were retained.

Statistics:

None

Results and discussion

Effect levels

Sex:

female

Dose descriptor:

LD50

Effect level:

> 1 597 mg/kg bw

Based on:

other: the anhydrous form of the substance ( = submission substance)

Remarks on result:

other: equivalent to >2000 mg of the test item (= the dihydrous form) per kg body weight

Mortality:

No intercurrent deaths occurred during the course of the study.

Clinical signs:

No clinical signs were observed throughout the entire observation period.

Body weight:

The body weight of the animals was within the range commonly recorded for this strain and age.

Gross pathology:

No macroscopic findings were observed at necropsy.

Other findings:

None

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The median lethal dose of Manganese oxalate, dihydrate after single oral administration to female rats, observed over a period of 14 days, is:
LD50 (female rat): greater than 2000 mg/kg body weight

Executive summary:

Two groups, each consisting of three female RccHan:WIST (SPF) rats, were treated with Manganese oxalate, dihydrate by single oral gavage administration at a dosage of 2000 mg/kg body weight. The test item was formulated in purified water at a concentration of 0.2 g/mL and administered at a dosing volume of 10 mL/kg.

 

The animals were examined daily during the acclimatization period and mortality, viability and clinical signs were recorded. All animals were examined for clinical signs before treatment, within the first 30 minutes and approximately 1, 2, 3 and 5 hours after treatment on day 1 and once daily during test days 2-15. Mortality/viability was recorded before treatment, within the first 30 minutes and approximately 1, 2, 3 and 5 hours after administration on test day 1 (with the clinical signs) and twice daily during days 2-15. Body weights were recorded on day 1 (prior to administration) and on days 8 and 15. All animals were necropsied and examined macroscopically.

 

No intercurrent deaths occurred during the course of the study.

 

No clinical signs were observed during the course of the study.

 

The body weight of the animals was within the range commonly recorded for this strain and age.

 

No macroscopic findings were observed at necropsy.

 

The median lethal dose of Manganese oxalate, dihydrate after single oral administration to female rats, observed over a period of 14 days, is:

 

LD₅₀(female rat): greater than 2000 mg/kg body weight

Remark:

In this study dosing was not adjusted to the submission substance (Manganese Oxalate), which is the anhydrous form of the test item (Manganes Oxalate, dihydrate). As a consequence the LD50 of the submission substance is calculated to be greater than 1597 mg/kg bw..

However, since no lethality and no relevant toxicity occured in this study, the LD50 of the submission substance (Manganes oxalate) is considered to be greater than 2000 mg/kg body weight.