Tris[oxalato(2-)]dilutetium

Endpoint summary

Description of key information

Acute oral toxicity

The oral LD50 for rats was found to be > 2000 mg/kg bw in the key study, which was performed according to the acute toxic class method (OECD guideline 423) and in compliance with GLP requirements (Tarkai, 2017). This study was considered reliable without restrictions (Klimisch 1).

Key value for chemical safety assessment

Acute toxicity: via oral route

Link to relevant study records

Reference

Endpoint:

acute toxicity: oral

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 27 march 2017 to 15 September 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Remarks:

GLP compliance

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

22 September 2015

Test type:

acute toxic class method

Limit test:

yes

Specific details on test material used for the study:

Correction factor: 1.16

Species:

rat

Strain:

Wistar

Remarks:

Crl:WI

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: 9 weeks old
- Weight at study initiation: 184 - 212 g
- Fasting period before study: yes
- Housing: Type II polypropylene/polycarbonate
- Diet (e.g. ad libitum): ad libitum, except the night before treatment. 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 no.: 484 14771, expiry date: 30 June 2017).
- Water (e.g. ad libitum): ad libitum. Tap water from the municipal supply, as for human consumption was available from a 500 mL bottle.
- Acclimation period: yes, at least 13 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20.7 – 25.0°C
- Humidity (%): 35 – 58 %
- Air changes (per hr): 15 – 20 air exchanges/hour
- Photoperiod (hrs dark / hrs light): 12 hours daily, from 6.00 a.m. to 6.00 p.m.

IN-LIFE DATES: From: 28 March 2017 To: 12 April 2017

Route of administration:

oral: gavage

Vehicle:

methylcellulose

Remarks:

1%

Details on oral exposure:

VEHICLE
- Concentration in vehicle: 200 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg
- Justification for choice of vehicle: Prior to animal testing the solubility of the test item was assessed in a trial formulation. The order of the tested vehicles was according to the Study Plan until a suitable vehicle was found, therefore two vehicles, distilled water and 1% methyl cellulose (1% MC) were examined.
Formulation with distilled water resulted in a suspension with rapid sedimentation, thus 1% MC was also tested. Formulation with 1% MC resulted in a suspension with slow sedimentation. As this formulation was acceptable to use via oral gavage, 1% MC was found to be the appropriate vehicle. The formulations were stirred using a magnetic stirrer. The homogeneity of the formulation was assessed by visual inspection.
- Lot/batch no. (if required): 5115851

MAXIMUM DOSE VOLUME APPLIED: 10 mL/kg

DOSAGE PREPARATION: Test item was freshly formulated at appropriate concentrations in the vehicle in the Pharmacy of CiToxLAB Hungary Ltd. on the day of administration. The formulation was stirred with a magnetic stirrer until completion of treatment.
Correction of the purity was applied as described est item information. The used correction factor for all formulations was 1.16.

CLASS METHOD
- Rationale for the selection of the starting dose: The initial dose level was selected by the Study Director to be that which was most likely to produce mortality in some of the dosed animals. Based on the preliminary toxicological information from the Sponsor, a limit dose of 2000 mg/kg bw was selected as a starting dose.

Doses:

2000 mg/kg bw

No. of animals per sex per dose:

3 per group

Control animals:

no

Details on study design:

- Duration of observation period following administration: 14 days
- Frequency of observations and weighing: Clinical observations were performed on all animals at 30 minutes, 1, 2, 3, 4 and 6 hours after dosing and daily for 14 days thereafter. The body weight was recorded on the day before treatment (Day -1), on the day of the treatment (Day 0) and weekly thereafter.
- Necropsy of survivors performed: yes
- Other examinations performed:
* clinical signs: Individual observations were performed on the skin, fur, eyes, mucous membranes, respiratory, circulatory, autonomic and central nervous system, somatomotor activity and behaviour pattern. Particular attention was directed to observation of tremors, convulsions, salivation, diarrhoea,
lethargy, sleep and coma.
* necropsy: Macroscopic examination was performed on all animals. After examination of the external appearance, the cranial, thoracic and the abdominal cavities were opened and the organs and the tissues were observed. Macroscopic abnormalities were recorded if they were present.

Statistics:

Not applicable

Key result

Sex:

female

Dose descriptor:

LD50

Effect level:

> 2 000 mg/kg bw

Based on:

act. ingr.

Mortality:

Tris[oxalate(2-)]dilutetium did not cause mortality at a dose level of 2000 mg/kg bw.

Clinical signs:

other: All animals were symptom-free during the 14-day observation period at a dose level of 2000 mg/kg bw.

Gross pathology:

There was no evidence of the macroscopic observations in animals dosed at 2000 mg/kg bw and terminated on Day 14.

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of this study, the acute oral LD50 value of the test item Tris[oxalate(2-)]dilutetium was found to be above 2000 mg/kg bw in female Crl:WI rats.

Executive summary:

The single-dose oral toxicity of Tris[oxalate(2-)]dilutetium was performed according to the acute toxic class method (OECD 423 and Commission Regulation (EC) No 440/2008 of 30 May 2008, B.1.tris) in Crl:WI Wistar rats.

Two groups of 3 female Crl:WI rats were treated with the test item at a dose level of 2000 mg of Tris[oxalate(2-)]dilutetium (active ingredient)/kg body weight (bw) (Group 1 and Group 2).

A single oral treatment was carried out by gavage for each animal after an overnight food withdrawal. Food was made available again 3 hours after the treatment. The test item was formulated in 1% Methyl cellulose at a concentration of 200 mg/mL at a dose volume of 10 mL/kg bw.

Initially, three females (Group 1) were treated at a dose level of 2000 mg/kg bw. As no mortality was observed, a confirmatory group (Group 2) was treated at the same dose level. No mortality was observed in the confirmatory group; therefore no further testing was required according to OECD 423 and Commission Regulation (EC) No 440/2008 of 30 May 2008, B.1.tris.

Clinical observations were performed at 30 minutes, 1, 2, 3, 4 and 6 hours after dosing and daily for 14 days thereafter. Body weight was measured on Days -1, 0, 7 and 14 (before necropsy). All animals were subjected to a necropsy and a macroscopic examination.

The results of the study were summarized as follows:

Mortality: Tris[oxalate(2-)]dilutetium did not cause mortality at a dose level of 2000 mg/kg bw.

Clinical Observations:All animals were symptom-free during the 14-day observation period at a dose level of 2000 mg/kg bw.

Body Weight and Body Weight Gain: There were no effects on body weights or body weight gains that could be attributed to treatment with Tris[oxalate(2-)]dilutetium.

Necropsy: There was no evidence of the macroscopic observations in animals dosed at 2000 mg/kg bw and terminated on Day 14.

 

Conclusion: Under the conditions of this study, the acute oral LD50 value of the test item Tris[oxalate(2-)]dilutetium was found to be above 2000 mg/kg bw in female Crl:WI rats.

According to the GHS criteria, Tris[oxalate(2-)]dilutetium can be ranked as "Category 5 or Unclassified" for acute oral exposure.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

LD50

Value:

2 000 mg/kg bw

Acute toxicity: via inhalation route

Endpoint conclusion

Endpoint conclusion:

no study available

Acute toxicity: via dermal route

Endpoint conclusion

Endpoint conclusion:

no study available

Additional information

Acute oral toxicity

One study is available on the acute toxicity of lutetium oxalate in rats. This study was performed according to the acute toxic class method (OECD guideline 423) and conform GLP requirements (Tarkai, 2017). In this study, 6 female Wistar Crl:(WI) rats were dosed on a single occasion with the test substance formulated in 1% methylcellulose at 2000 mg/kg bw. During the subsequent 14-day observation period, no deaths or clinical signs were observed. Body weight gain and macroscopic examination at necropsy demonstrated no deviations. The LD50 was therefore > 2000 mg/kg bw. This study is considered reliable (Klimisch 1) and is the key study for endpoint coverage.

Justification for classification or non-classification

Acute oral toxicity

The LD50 is greater than 2000 mg/kg bw and therefore lutetium oxalate is considered not classified as acute oral toxicant according to the CLP Regulation.

Acute Inhalation toxicity

No reliable study is available

Acute dermal toxicity

No reliable study is available