Dihydrogen hexahydroxyplatinate

Endpoint summary

Description of key information

In an OECD Test Guideline 422 combined repeated dose and reproductive/developmental toxicity screening study in rats, involving the gavage administration of dihydrogen hexahydroxyplatinate for at least 35 days, no clinical signs of toxicity or any adverse pathological or histopathological effects were observed. The study NOAEL was the highest tested dose (1000 mg/kg bw/day) (Hansen, 2015).

 

No repeated dose toxicity studies by the inhalation or dermal route were identified, or are required.

Key value for chemical safety assessment

Repeated dose toxicity: via oral route - systemic effects

Link to relevant study records

Reference

Endpoint:

short-term repeated dose toxicity: oral

Remarks:

combined repeated dose and reproduction / developmental screening

Type of information:

experimental study

Adequacy of study:

key study

Study period:

18 September 2014 - 30 June 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study, conducted according to GLP.

Reason / purpose for cross-reference:

reference to other study

Qualifier:

according to guideline

Guideline:

OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/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, 97633 Sulzfeld, Germany.
- Age at study initiation: 67 days (at first test item administration).
- Weight at study initiation: males: 326.4 - 402.7 g; females: 189.4 - 246.0 g (at first test item administration).
- Fasting period before study: no data.
- Housing: animals were housed singly, except during the mating period.
- Diet (e.g. ad libitum): certified commercial diet, offered ad libitum.
- Water (e.g. ad libitum): tap water, offered ad libitum.
- Acclimation period: 8 days.

ENVIRONMENTAL CONDITIONS
- Temperature (°C): room temperature of 22degC +/- 3degC (maximum range).
- Humidity (%): relative humidity of 55% +/- 15% (maximum range).
- Air changes (per hr): no data.
- Photoperiod (hrs dark / hrs light): 12 hours dark/12 hours light, about 150 lux.

IN-LIFE DATES:
From: July 2014.
To: 23 October 2014 (males); 14 November 2014 (females).

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on oral exposure:

PREPARATION OF DOSING SOLUTIONS: test item formulations were prepared once weekly and stored in a tightly closed container at room temperature (+10 to +25 degC) until use.

DIET PREPARATION
- Rate of preparation of diet (frequency): not applicable.
- Mixing appropriate amounts with (Type of food): not applicable.
- Storage temperature of food: not applicable.

VEHICLE
- Justification for use and choice of vehicle (if other than water): the test substance was found to be unstable in water and other aqueous vehicles. Stability for 7 days in corn oil was demonstrated in an identity and stability investigation, and thus corn oil was taken forward as the vehicle for this study.
- Concentration in vehicle: 20, 60 or 200 mg test item/mL vehicle.
- Amount of vehicle (if gavage): 5 mL/kg bw/day.
- Lot/batch no. (if required): Batch nos. 13249003 and 13249006, Caesar & Loretz GmbH, 40721 Hilden, Germany.
- Purity: no data.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Samples of approximately 10 mL were collected once weekly, at the time of preparation of the formulation, and analysed for homogeneity and concentration.

Duration of treatment / exposure:

Males were dosed from test days 1-35 (inclusive), including 2 weeks prior to mating, the mating period and approximately 2 weeks post-mating. Females were dosed from test day 1 (2 weeks prior to mating), throughout mating and gestation, until day 3 post-partum or the day before sacrifice (from test day 41 for the first sacrificed females to test day 58 for the last sacrificed female).

Frequency of treatment:

Once daily.

Remarks:

Doses / Concentrations:
100 mg/kg bw/day
Basis:
actual ingested

Remarks:

Doses / Concentrations:
300 mg/kg bw/day
Basis:
actual ingested

Remarks:

Doses / Concentrations:
1000 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

12

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: dose levels were selected based a 14-day dose range finding study conducted at the same testing laboratory. In the dose range finding study, male and female rats were treated with 1000 mg test item/kg bw/day. No animal died prematurely, there were no test item-related adverse effects, and no test item-related changes noted at necropsy.
- Rationale for animal assignment (if not random): computer-generated randomisation programme.
- Rationale for selecting satellite groups: not applicable.
- Post-exposure recovery period in satellite groups: not applicable.
- Section schedule rationale (if not random): not applicable.

Positive control:

No.

Observations and examinations performed and frequency:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: before and after dosing and, additionally, regularly throughout the working day (7:00 to 15:45 on Monday to Friday; 7:00 to 11:00 with a final check at 15:00 on Saturday and Sunday).
- Cage side observations included any behavioural changes, signs of illness or reaction to treatment. Skin/fur, eyes, mucous membranes, respiratory and circulatory systems, somatomotor activity and behaviour patterns were recorded, together with the onset, intensity and duration of any signs observed.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once weekly, once before the first administration and once a week thereafter.
- Signs recorded included: changes in skin, fur, eyes, mucous membranes; occurrence of secretions, excretions and autonomic activity; changes in gait, posture and response to handling; behavioural changes.

BODY WEIGHT: Yes
- Time schedule for examinations: males and females were weighed on the first day of dosing, weekly thereafter, and at termination. During gestations, females were weighed on days 0, 7, 14 and 20, within 24 hours of parturition (day 1 post-partum), and day 4 post-partum.

FOOD AND WATER CONSUMPTION:
- Food consumption for each animal determined: Yes.
- Food intake per animal was determined using the total amount of food given to and left by each animal.
- Drinking water consumption for each animal determined: Yes, by daily visual appraisal throughout the study.

OPHTHALMOSCOPIC EXAMINATION: No.

HAEMATOLOGY: Yes.
- Time schedule for collection of blood: at the end of the pre-mating period.
- Anaesthetic used for blood collection: Yes (ether).
- Animals fasted: Yes, overnight.
- How many animals: 5 males and 5 females randomly selected from each group.
- Parameters checked in Table 1 were examined.

CLINICAL CHEMISTRY: Yes.
- Time schedule for collection of blood: at the end of the pre-mating period.
- Animals fasted: Yes, overnight.
- How many animals: 5 males and 5 females randomly selected from each group.
- Parameters checked in Table 2 were examined.

URINALYSIS: No.

NEUROBEHAVIOURAL EXAMINATION: Yes.
- Time schedule for examinations: males: test day 36; females: during lactation, between test days 41 and 51.
- Dose groups that were examined: 5 males and 5 females randomly selected from each group.
- Battery of functions tested: see Table 3.

Sacrifice and pathology:

GROSS PATHOLOGY: Yes.
- The weights of the organs in Table 4 of all animals were recorded before fixation. The organs or parts of organs in Table 5a of all animals were fixed in 7% formalin (apart from the testes and epididymides, fixed in Bouin's fixative). The organs or parts of organs in Table 5b of 5 randomly selected animals/sex/group were fixed in the same way.
HISTOPATHOLOGY: Yes.
- The organs in Table 6 of the 5 randomly selected animals/sex in the control and high-dose groups were examined histologically.

Other examinations:

No data.

Statistics:

Analysis of normal distribution and homogeneity of variances was performed using the Shapiro-Wilks test and the Bartlett test.
One-way analysis of variance was performed using Anova or the Kruskal-Wallis test.
Intergroup comparisons, in the case of significant differences, were made using the Dunnett test.
Statistical analyses of non-parametrical data were performed using Fisher's exact test or the Chi-squared test.

Clinical signs:

no effects observed

Mortality:

no mortality observed

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

no effects observed

Ophthalmological findings:

not examined

Haematological findings:

no effects observed

Clinical biochemistry findings:

no effects observed

Urinalysis findings:

not examined

Behaviour (functional findings):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Gross pathological findings:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Details on results:

CLINICAL SIGNS AND MORTALITY
No test item-related premature deaths were reported. Two female rats (one from the low-dose group and one from the mid-dose group) died during laboratory examination on test day 15, but their deaths were considered as not test item-related.

There were no changes in behaviour, external appearance, faeces or other clinical signs in any treated group, or the control, at any point during the study.

BODY WEIGHT AND WEIGHT GAIN
There were no test item-related changes in body weight or body weight gain in male rats, in the pre-mating, mating, and post-mating periods, or in females during the pre-mating period, gestation and lactation.

FOOD AND WATER CONSUMPTION
No test item-related changes in food consumption were noted between the control groups and any treated rats. There was a statistically significant decrease in food consumption in mid-dose females during the second week of the test; this showed no dose-response relationship and was considered not to be related to treatment.

The consumption of drinking water, assessed by daily visual appraisal, was not altered by treatment.

FOOD EFFICIENCY
Not examined.

OPHTHALMOSCOPIC EXAMINATION
Not examined.

HAEMATOLOGY
Test item administration was not considered to have an influence on any of the measured haematological parameters in male or female rats. The following statistically significant changes were reported, but considered to be spontaneous and not test item-related:
- Increased number of eosinophil granulocytes in low- and high-dose males.
- Decreased number of eosinophil granulocytes in mid- and high-dose females.
- Decreased number of basophil granulocytes in mid-dose females.
All values were within the range of background data for the testing laboratory.

CLINICAL CHEMISTRY
No test item-related influence was noted on the measured clinical chemistry parameters in any male or female rats. The following statistically significant changes were reported, but considered to be spontaneous and not test item-related:
- Increased globulin content in mid-dose males and all females.
- Decreased albumin/globulin ratio in mid-dose males and all females.
- Decreased blood glucose in low- and high-dose males.
- Increased total protein in mid-dose males and all females.
- Increased sodium in all females.
All values were within or only marginally below the range of background data for the testing laboratory.

URINALYSIS
Not examined.

NEUROBEHAVIOUR
No adverse effects were reported in observational or functional screening or assessment of spontaneous motility in males or females in any treatment group.

ORGAN WEIGHTS
No test item-related change in organ weights was reported in any treatment group. A statistically significant decrease in absolute liver weight was noted in low-dose females. This was within the range of the background data for the testing laboratory.

GROSS PATHOLOGY
No test item-related changes were observed in macroscopic examination of the internal organs and tissues of all test animals.

HISTOPATHOLOGY
No microscopic changes in the examined organs or tissues were seen in any treated animals.

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: No general systemic effects seen at highest tested dose

Critical effects observed:

not specified

Conclusions:

In an OECD Test Guideline 422 combined repeated dose and reproductive/developmental toxicity screening study in rats, involving the gavage administration of dihydrogen hexahydroxyplatinate for at least 35 days, no clinical signs of toxicity or any adverse pathological or histopathological effects were observed. The study NOAEL was the highest tested dose (1000 mg/kg bw/day).

Executive summary:

In a combined repeated dose toxicity and reproductive/developmental toxicity screening study, conducted according to OECD Test Guideline 422 and to GLP, CD rats (12/sex/group) were orally administered dihydrogen hexahydroxyplatinate by stomach tube (gavage) at doses of 0, 100, 300 or 1000 mg/kg bw/day. Males were dosed for 35 days (2 weeks pre-mating, during the mating period and for approximately 2 weeks post-mating). Females were dosed for 14 days pre-mating, through mating, gestation and up to post-partum day 3 (test day 41-58).

 

Daily administration of dihydrogen hexahydroxyplatinate by oral gavage to CD rats did not result in test item related mortality, clinical signs of toxicity, or changes in the body weight, food/water consumption, haematology or clinical chemistry parameters, or neurological observations at dose levels of up to 1000 mg/kg bw/day during the treatment period. There were no adverse treatment-related changes in organ weights, or following macroscopic examination and histopathology for the adult animals of either sex.

 

On this basis, a study NOAEL of 1000 mg/kg bw/day was established.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed

Dose descriptor:

NOAEL

1 000 mg/kg bw/day

Study duration:

subacute

Species:

rat

Quality of whole database:

Overall, good-quality database which meets REACH Standard Information Requirements.

Repeated dose toxicity: inhalation - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: inhalation - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - systemic effects

Endpoint conclusion

Endpoint conclusion:

no study available

Repeated dose toxicity: dermal - local effects

Endpoint conclusion

Endpoint conclusion:

no study available

Mode of Action Analysis / Human Relevance Framework

No data identified.

Additional information

No relevant human data were identified.

 

In a combined repeated dose toxicity and reproductive/developmental toxicity screening study, conducted according to OECD Test Guideline 422 and to GLP, CD rats (12/sex/group) were orally administered dihydrogen hexahydroxyplatinate by stomach tube (gavage) at doses of 0, 100, 300 or 1000 mg/kg bw/day. Males were dosed for 35 days (2 weeks pre-mating, during the mating period and for approximately 2 weeks post-mating). Females were dosed for 14 days pre-mating, through mating, gestation and up to post-partum day 3 (test day 41-58). Daily administration of dihydrogen hexahydroxyplatinate by oral gavage to CD rats did not result in test item related mortality clinical signs of toxicity or neurological observations, or changes in the body weight, food/water consumption, haematology or clinical chemistry parameters at dose levels of up to 1000 mg/kg bw/day during the treatment period. There were no adverse treatment-related changes in organ weights, or following macroscopic examination and histopathology for the adult animals of either sex. On this basis, a study NOAEL of 1000 mg/kg bw/day was established (Hansen, 2015).

 

According to REACH Annex VIII (EC 1907/2006), repeated dose toxicity studies only need to be conducted on one species taking into consideration the most appropriate route of administration regarding human exposure. The compound is not expected to reach the lungs in appreciable quantities (based on respiratory tract deposition modelling data). Thus, inhalation will not be a significant route of exposure. Similarly, skin contact during production and/or use is expected to be negligible. As the oral route of exposure is considered the most appropriate, repeated dose toxicity studies were not carried out for the dermal or inhalation routes.

Justification for classification or non-classification

No adverse systemic effects were seen in a reliable repeated dose toxicity study (combined with a reproductive/developmental screening assay) following gavage administration of rats for at least 35 days. As such, classification of dihydrogen hexahydroxyplatinate as STOT-RE is not required, according to EU CLP criteria (EC 1272/2008).