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EC number: 269-075-7 | CAS number: 68187-15-5 An inorganic pigment that is the reaction product of high temperature calcination in which praseodymium (III) oxide, praseodymium (IV) oxide, silicon oxide, and zirconium (IV) oxide in varying amounts are homogeneously and ionically interdiffused to form a crystalline matrix of zircon. Its composition may include any one or a combination of the modifiers alkali or alkaline earth halides.
- Life Cycle description
- Uses advised against
- Endpoint summary
- Appearance / physical state / colour
- Melting point / freezing point
- Boiling point
- Density
- Particle size distribution (Granulometry)
- Vapour pressure
- Partition coefficient
- Water solubility
- Solubility in organic solvents / fat solubility
- Surface tension
- Flash point
- Auto flammability
- Flammability
- Explosiveness
- Oxidising properties
- Oxidation reduction potential
- Stability in organic solvents and identity of relevant degradation products
- Storage stability and reactivity towards container material
- Stability: thermal, sunlight, metals
- pH
- Dissociation constant
- Viscosity
- Additional physico-chemical information
- Additional physico-chemical properties of nanomaterials
- Nanomaterial agglomeration / aggregation
- Nanomaterial crystalline phase
- Nanomaterial crystallite and grain size
- Nanomaterial aspect ratio / shape
- Nanomaterial specific surface area
- Nanomaterial Zeta potential
- Nanomaterial surface chemistry
- Nanomaterial dustiness
- Nanomaterial porosity
- Nanomaterial pour density
- Nanomaterial photocatalytic activity
- Nanomaterial radical formation potential
- Nanomaterial catalytic activity
- Endpoint summary
- Stability
- Biodegradation
- Bioaccumulation
- Transport and distribution
- Environmental data
- Additional information on environmental fate and behaviour
- Ecotoxicological Summary
- Aquatic toxicity
- Endpoint summary
- Short-term toxicity to fish
- Long-term toxicity to fish
- Short-term toxicity to aquatic invertebrates
- Long-term toxicity to aquatic invertebrates
- Toxicity to aquatic algae and cyanobacteria
- Toxicity to aquatic plants other than algae
- Toxicity to microorganisms
- Endocrine disrupter testing in aquatic vertebrates – in vivo
- Toxicity to other aquatic organisms
- Sediment toxicity
- Terrestrial toxicity
- Biological effects monitoring
- Biotransformation and kinetics
- Additional ecotoxological information
- Toxicological Summary
- Toxicokinetics, metabolism and distribution
- Acute Toxicity
- Irritation / corrosion
- Sensitisation
- Repeated dose toxicity
- Genetic toxicity
- Carcinogenicity
- Toxicity to reproduction
- Specific investigations
- Exposure related observations in humans
- Toxic effects on livestock and pets
- Additional toxicological data
![](https://echa.europa.eu/o/diss-blank-theme/images/factsheets/A-REACH/factsheet/print_toxicological-information.png)
Repeated dose toxicity: oral
Administrative data
- Endpoint:
- short-term repeated dose toxicity: oral
- Type of information:
- experimental study
- Adequacy of study:
- key study
- Study period:
- 2015-03-23 to 2015-04-20
- Reliability:
- 1 (reliable without restriction)
- Rationale for reliability incl. deficiencies:
- guideline study
Data source
Referenceopen allclose all
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 019
- Report date:
- 2019
- Reference Type:
- study report
- Title:
- Unnamed
- Year:
- 2 018
- Report date:
- 2018
Materials and methods
Test guideline
- Qualifier:
- according to guideline
- Guideline:
- OECD Guideline 407 (Repeated Dose 28-Day Oral Toxicity Study in Rodents)
- Version / remarks:
- 2008-10-03
- Deviations:
- no
- GLP compliance:
- yes (incl. QA statement)
- Remarks:
- signed 2014-05-14
- Limit test:
- yes
Test material
- Reference substance name:
- Zirconium praseodymium yellow zircon
- EC Number:
- 269-075-7
- EC Name:
- Zirconium praseodymium yellow zircon
- Cas Number:
- 68187-15-5
- Molecular formula:
- Pr(x)Zr(1-x)SiO4 0,03≤x≤0,09
- IUPAC Name:
- silicon(4+) zirconium(4+) λ⁴-praseodymium(4+) dipraseodymium(3+) nonaoxidandiide
- Test material form:
- solid: particulate/powder
- Details on test material:
- - Name: Colorante amarillo
- EC Name: Zirconium Praseodymium Yellow Zircon
- Substance type: inorganic pigment
- Physical state: solid, yellow powder, odourless
- Storage condition of test material: at room temperature
Constituent 1
- Specific details on test material used for the study:
- STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: at room temperature, kept dry and stored in a tightly closed container.
Test animals
- Species:
- rat
- Strain:
- other: Crl:CD(SD)
- Details on species / strain selection:
- Selected because of its proven suitability in toxicology studies and to comply with regulatory requirements for testing in a rodent animal species.
- Sex:
- male/female
- Details on test animals or test system and environmental conditions:
- TEST ANIMALS
- Source: Charles River Laboratories Germany GmbH, Sandhofer Weg 7, 97633 Sulzfeld, Germany
- Age at first dosing: males: 36 days; females: 36 days
- Weight at first dosing: males: 154.8 g - 171.6 g; females: 128.0 g - 143.2 g
- Housing: kept singly in MAKROLON cages (type III plus) with a basal surface of approx. 39 x 23 cm and a height of approx. 18 cm; bedding material: granulated textured wood (Granulat A2, J. Brandenburg, 49424 Goldenstedt, Germany).
- Diet (ad libitum): commercial ssniff® R/M-H V1530 diet (ssniff Spezialdiäten GmbH, 59494 Soest, Germany)
- Water (ad libitum): tap water
- Acclimation period: 5 days
DETAILS OF FOOD AND WATER QUALITY: no contaminants above the limitiations were noted for drinking water.
ENVIRONMENTAL CONDITIONS
- Temperature: 22 °C ± 3 °C (maximum range)
- Relative humidity: 55 % ± 15 % (maximum range)
- Photoperiod (hrs dark / hrs light): 12/12
Administration / exposure
- Route of administration:
- oral: gavage
- Details on route of administration:
- According to the expected route of exposure.
- Vehicle:
- other: 0.8 % aqueous hydroxyl propyl methylcellulose gel
- Details on oral exposure:
- PREPARATION OF DOSING SOLUTIONS:
The test item was suspended in the vehicle to the appropriate concentration. The administration formulation was continuously agitated by stirring throughout the entire administration procedure.
The administration formulation was freshly prepared every day.
Administration volume: 10 mL/kg bw/day
The amount of the test item was adjusted to each animal's current body weight daily.
VEHICLE
- Source: FAGRON GmbH & Co. KG, 22885 Barsbüttel, Germany
- Batch no.: 13D03-N03 - Analytical verification of doses or concentrations:
- yes
- Details on analytical verification of doses or concentrations:
- For the test item that was mixed with the vehicle, tests were conducted to determine the concentration, stability and homogeneity of the test item in the formulations (Fraunhofer IME, report no. EBR-153/6-27/y).
For the analysis of the test item-vehicle mixtures, samples of approximately 10 mL were taken at the following times and stored at ≤-20 °C:
1) At study initiation:
- analysis of stability and concentration: immediately after preparation of the administration formulation as well as after 8 and 24 hours storage at room temperature (number of samples: 3).
- homogeneity: at the start of administration, during (middle) administration and before administration to the last animal of the test item treated group (number of samples: 3).
2) at study termination:
- analysis of concentration: during treatment always before administration to the last animal of the test item treated group (number of samples: 1).
Before measurement of the dissolved zirconium and praseodymium in the test item-vehicle mixture the samples were retrieved from the cryogenic storage container and thawed at least overnight. Afterwards the samples were prepared for the measurements. For this the samples have to be diluted with 10% HNO3 due to the fact, that a quantity of undissolved test item was visible in the test sample vials. After dilution the samples were filtered to remove particles from the diluted samples. The dissolved samples were measured by ICP-MS.
The ICP-MS measurements were performed using an Agilent 7700 ICP-MS (Agilent Technologies, Waldbronn, Germany). For the determination of zirconium the isotopes 90Zr, 91Zr and 92Zr were measured; for praseodymium the isotope 141Pr was measured (monoisotopic element). Depending on the concentration range of the samples, the following standard solutions were used for the calibrations: blank, 0.1 μg/L, 0.25 μg/L, 0.5 μg/L, 0.75 μg/L, 1.0 μg/L, 2.5 μg/L, 5.0 μg/L, 7.5 μg/L, 10.0 μg/L, 12.5 μg/L, 15 μg/L, 17.5 μg/L, 20 μg/L, 22.5 μg/L and 25 μg/L. The calibration was performed before the measurement. The calibration formula was calculated using the linear regression algorithm of the ICP-MS
instrument software. The respective measurement mode (noGas, Helium mode or HiHelium mode) for interference-free measurement with recoveries in the range of the quality control parameters for the validation samples (certified reference material, quality control standards, recalibration standards, fortifications, digested certified reference material) in the measurement series and a correlation coefficient with at least 0.995 were used for calculating concentrations. For each sample, at least three internal measurements were performed and the mean was calculated and printed by the instrument software.
Instrumental and analytical set-up for the ICP-MS instrument:
Agilent 7700 ICP-MS, Agilent Technologies, Waldbronn Germany
Nebulizer: Concentric nebulizer, from Agilent
Spray chamber: Scott Type spray chamber, from Agilent
Carrier gas flow: 0.93 L/min
Make-up/Dilution Gas gas flow: 0.16 L/min
RF power: 1500 W
Isotopes: 90Zr, 91Zr, 92Zr, 141Pr and 103Rh (internal standard)
The applied LOD/LOQs were calculated as follows:
LOD: 3 * standard deviation of calibration blank divided by the slope of calibration line;
LOQ: 3 * LOD
The resulting LODs/LOQs are as follows:
- LOD: 0.00002 - 0.0001 µg/L (Pr); 0.002 - 0.009 µg/L (Zr)
- LOQ: 0.00007 - 0.0004 µg/L (Pr); 0.007 - 0.027 µg/L (Zr)
- correlation coefficient: 0.9987951 - 0.999923 (Pr); 0.9997754 - 0.999969 (Zr)
The quality control standards and recalibration standards were analyzed as quality assurance samples along with the test samples. To meet quality assurance requirements recovery needs to be in the range of ± 15 % of the respective value.
Results:
Analysis of stability and concentration (3 samples):
Recovery [%]:
Pr: 5.13 - 6.13
Zr: 0.014 - 0.016
Analysis of homogeneity (3 samples):
Recovery [%]:
Pr: 2.36 - 6.01
Zr: 0.009 - 0.013
Analysis of concentration (1 sample)
Recovery [%]:
Pr: 8.18
Zr: 0.016 - Duration of treatment / exposure:
- 28 days
- Frequency of treatment:
- once daily
Doses / concentrations
- Dose / conc.:
- 1 000 mg/kg bw/day (actual dose received)
- No. of animals per sex per dose:
- 5 males / 5 females
- Control animals:
- yes, concurrent vehicle
- Details on study design:
- - Dose selection rationale: in agreement with the Sponsor and based on available toxicity data a limit test was performed.
- Positive control:
- none
Examinations
- Observations and examinations performed and frequency:
- CAGE SIDE OBSERVATIONS: Yes
- Time schedule (clinical signs): before and after dosing at each time of dosing as well as regularly throughout the working day from 7.30 a.m. to 4.30 p.m. and on Saturdays and Sundays from 8.00 a.m. to 12.00 noon with a final check performed at approx. 4.00 p.m.
- Time schedule (mortality): early in the morning and again in the afternoon of each working day as well as on Saturdays and Sundays with a final check at approx 4.00 p.m.
- Cage side observations checked: clinical signs & mortality
DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once before the first exposure and once a week thereafter (1, 2, 4, 8 and 24 hours after administration) as well as in test week 4 prior to any laboratory investigations.
BODY WEIGHT: Yes
- Time schedule for examinations: at the time of group allocation, on the day of commencement of treatment and once a week thereafter (always on the same day of the week)
FOOD CONSUMPTION AND COMPOUND INTAKE:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
The quantity of food left by individual animals was recorded on a weekly basis throughout the experimental period. Food intake per rat (g/rat/week) was calculated using the total amount of food given to and left by each rat in each group on completion of a treatment week.
The relative food consumption (in g/kg bw/day) was determined
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: No
FOOD EFFICIENCY:
- Body weight gain in kg/food consumption in kg per unit time X 100 calculated as time-weighted averages from the consumption and body weight gain data: No
WATER CONSUMPTION AND COMPOUND INTAKE: Yes
- Time schedule for examinations: daily
OPHTHALMOSCOPIC EXAMINATION: Yes
- Time schedule for examinations: prior to the start of administration and at the end of test week 4
- Dose groups that were examined: all dose groups
HAEMATOLOGY: Yes
- Time schedule for collection of blood: at study termination (on the day of dissection)
- Anaesthetic used for blood collection: Yes, isoflurane anaesthesia
- Animals fasted: Yes, overnight
- How many animals: all animals
- Parameters examined: haemoglobin content, erythrocytes, leucocytes, differential blood count (relative and absolute; neutrophilic granulocytes, eosinophilic granulocytes, basophilic granulocytes, lymphocytes, monocytes, and large unstained cells), reticulocytes, platelets, haematocrit value, mean corpuscular volume, mean corpuscular haemoglobin, mean corpuscular haemoglobin concentration, thromboplastin time, and activated partial thromboplastin time
CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: at study termination (on the day of dissection)
- Animals fasted: Yes, overnight
- How many animals: all animals
- Parameters examined: albumin, globulin, albumin/globulin ratio, bile acids, bilirubin (total), cholesterol (total), creatinine, glucose, protein (total), urea (blood), calcium, chloride, potassium, sodium, alanine aminotransferase, alkaline phosphatase, aspartate aminotransferase, and lactate dehydrogenase
URINALYSIS: No
NEUROBEHAVIOURAL EXAMINATION: Yes
- Time schedule for examinations: in test week 4 approx. 1 to 2 hours after dosing and before any blood sampling
- Dose groups that were examined: all dose groups
- Battery of functions tested: sensory reactivity / grip strength / motor activity
1) Observational screening: righting reflex, body temperature, salivation, startle response, respiration, mouth breathing, urination, convulsions, pilo-erection, diarrhoea, pupil size, pupil response, lacrimation, impaired gait, stereotype, toe pinch, tail pinch, wire maneuver, hind leg splay, positional passivity, tremors, positive geotropism, limb rotation, and auditory function
2) Functional tests: grip strength and locomotor activity
IMMUNOLOGY: No
TOXICOKINETC: Yes (please refer to Fraunhofer IME, report no. EBR-153/6-27/y)
Urine and plasma samples were obtained at study termination. Urine and plasma samples were analysed for zirconium and praseodymium levels by ICP-MS.
- urine sample: individual urine samples were collected from all animals before scheduled sacrifice following the last administration on test day 28. The animals were placed in metabolic cages during a 24-hour collection period, directly after the last oral administration. The urine weight/animal was determined upon removal of the sample. Pooled blank urine were obtained from spare animals.
- plasma sample: on the scheduled day of sacrifice, a terminal blood sample was collected from all animals under isoflurane anaesthesia in order to obtain LiHeparin plasma/animal. Afterwards, the animals were sacrificed and dissected. - Sacrifice and pathology:
- GROSS PATHOLOGY: Yes
HISTOPATHOLOGY: Yes
On test day 29 (approx. one day after the last administration), the animals were sacrifice and macroscopically inspected. All superficial tissues were examined visually and by palpation and the cranial roof was removed to allow observation of the brain, pituitary gland and cranial nerves. After ventral midline incision and skin reflection all subcutaneous tissues were examined. The condition of the thoracic viscera was noted with due attention to the thymus, lymph nodes and heart.
The abdominal viscera were examined before and after removal, the urinary bladder was examined externally and by palpation. The gastro-intestinal tract was examined as a whole and the stomach and caecum were incised and examined. The lungs were removed and all pleural surfaces examined. The liver and the kidneys were examined. Any abnormalities in the appearance and size of the gonads, adrenal glands, uterus, intra-abdominal lymph nodes and accessory reproductive organs were recorded.
The weights of the following organs of all animals were determined before fixation: adrenal gland (2), brain, epididymis (2), heart, kidney (2), liver, ovary (2), spleen, testicle (2), thymus, as well as prostate and seminal vesicles with coagulating glands as a whole.
Paired organs were weighed individually and identified as left or right.
The following organs or parts of organs of all animals were fixed in 7% buffered formalin (exceptions: eyes fixed in Davidson's solution and testes in Bouin's solution): adrenal gland (2), bone (os femoris with joint), bone marrow (os femoris), brain (3 levels: cerebrum, cerebellum, medulla/pons), epididymis (2), eye with optic nerve (2), gross lesions observed, heart (3 levels: right and left ventricle, septum), large intestine (colon, rectum), small intestine (duodenum, jejunum, ileum, incl. Peyer´s patches; Swiss roll method), kidney and ureter (2), liver, lungs (with mainstem bronchi and bronchioles (preserved by inflation with fixative and then immersion)), lymph node (1, cervical), lymph node (1, mesenteric), mammary gland (male and female), muscle (skeletal, leg), nerve (sciatic), ovary (2), pituitary, prostate and seminal vesicles with coagulating glands, spinal cord (3 sections), spleen, stomach, testicle (2), thymus, thyroid (2) (incl. parathyroids), tissue masses or tumours (incl. regional lymph nodes), trachea (incl. larynx), urinary bladder, uterus (incl. cervix and oviducts), and vagina
The above-listed organs of all animals were examined histologically after preparation of paraffin sections and haematoxylin-eosin staining.
In addition, frozen sections of the heart, liver and one kidney were made, stained with Oil Red O and examined microscopically.
Parathyroids cannot always be identified macroscopically. They were examined microscopically if in the plane of section and in all cases where they were noted as grossly enlarged. - Statistics:
- The test item-treated group was compared with the vehicle control group:
The following statistical methods were used:
1) STUDENT's t-test: all numerical functional tests / body weight / food consumption / haematology and coagulation / clinical biochemistry / relative and absolute organ weights (p ≤ 0.05 and p ≤ 0.01)
The following limits were used:
p = 0.05/0.01 about t = 2.3060/3.3554 (for 8 degrees of freedom)
2) Exact test of R. A. FISHER: histology (p ≤ 0.05 and p ≤ 0.01)
Results and discussion
Results of examinations
- 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:
- no effects observed
- Haematological findings:
- no effects observed
- Clinical biochemistry findings:
- no effects observed
- Urinalysis findings:
- not examined
- Behaviour (functional findings):
- no effects observed
- Immunological findings:
- not examined
- Organ weight findings including organ / body weight ratios:
- no effects observed
- Gross pathological findings:
- no effects observed
- Neuropathological findings:
- no effects observed
- Histopathological findings: non-neoplastic:
- no effects observed
- Histopathological findings: neoplastic:
- not examined
- Other effects:
- not examined
- Details on results:
- CLINICAL SIGNS
- no changes in behaviour or external appearance were noted for the male and female rats treated with 1000 mg zirconium praseodymium yellow zircon/kg bw/day or for the animals treated with the vehicle control.
- faeces of the control and test item-treated animals were formed normally.
MORTALITY
- none of the animals died prematurely
BODY WEIGHT AND WEIGHT CHANGES
- no test item-related influence was observed for the body weight, the body weight gain and body weight at autopsy in the male and female rats treated with 1000 mg test item./day (data within the normal range).
- statistically significant differences in body weight of test item-treated animals compared to the control animals were recorded (not test item-related findings):
males (test week 0, 1, 2, 3, and 4): increased body weight (p ≤0.01 or p ≤ 0.05)
FOOD CONSUMPTION AND COMPOUND INTAKE
- no test item-related changes in relative food consumption were noted for the male and female rats treated with 1000 mg test item/kg bw/day compared to the control group.
WATER CONSUMPTION AND COMPOUND INTAKE
- visual appraisal of the drinking water consumption did not reveal any test item-related influence.
OPHTHALMOLOGICAL FINDINGS
- ophthalmological examination revealed no changes of the eyes and the optic region in the male and female rats treated with 1000 mg zirconium praseodymium yellow zircon/kg bw/day or for the animals treated with the vehicle control.
- no pathological changes were noted on the adnexa oculi, conjunctiva, cornea, anterior chamber, iris (pupil dilated), lens, vitreous body and fundus
HAEMATOLOGICAL FINDINGS
- no test item-related influence on haematological and coagulation parameters was noted for the male and female rats treated with 1000 mg zirconium praseodymium yellow zircon/kg bw/day compared to the control group.
- statistically significant differences (p ≤ 0.05) in haematological parameters of test item-treated animals compared to the control animals were recorded (not test item-related findings):
females (test day 29): increased platelets (control group: 934.0 ± 115.5 x10³/µL vs. treatment group: 1134.8 ± 81.5 x10³/µL)
males (test day 29): increased absolute monocytes (control group: 0.138 ± 0.033 x10³/µL vs. treatment group: 0.200 ± 0.034 x10³/µL) and increased absolute basophilic granulocytes (control group: 0.024 ± 0.005 x10³/µL vs. treatment group: 0.038 ± 0.008 x10³/µL)
However, the stated haematological findings are within in the normal range, typical for that strain and the age of the animals (see attached historical control data of the lab in the field "Attached background material" below). These findings should therefore not be regarded as adverse response but as normal biological variation.
CLINICAL BIOCHEMISTRY FINDINGS
- no test item-related influence in biochemical parameters was noted for the male and female rats treated with 1000 mg test item/kg bw/day compared to the control group.
- statistically significant differences (p ≤ 0.05) in biochemical parameters of test item-treated animals compared to the control animals were recorded (not test item-related findings):
females (test day 29): decreased albumin (control group: 29.08 ± 1.03 g/L vs. treatment group: 27.74 ± 0.73 g/L)
males (test day 29): increased glucose (control group: 5.014 ± 0.330 mmol/L vs. treatment group: 5.794 ± 0.463 mmol/L) and decreased chloride (control group: 102.6 ± 0.5 mmol/L vs. treatment group: 101.4 ± 0.9 mmol/L)
However, the stated clinical chemistry findings are within in the normal range, typical for that strain and the age of the animals (see attached historical control data of the lab in the field "Attached background material" below). These findings should therefore not be regarded as adverse response but as normal biological variation.
ORGAN WEIGHT FINDINGS INCLUDING ORGAN / BODY WEIGHT RATIOS
- no test item-related changes in relative and absolute organ weights were noted for the male and female rats treated with 1000 mg zirconium praseodymium yellow zircon/kg bw/day compared to the control group.
- statistically significant differences (p ≤ 0.05) in organ weights of test item-treated animals compared with the control animals were recorded (not test item-related findings):
males (test day 29): increased absolute left epididymis weight (control group: 0.398 ± 0.036 g vs. treatment group: 0.468 ± 0.041 g), increased absolut right testis weight (control group: 1.512 ± 0.087 g vs. treatment group: 1.664 ± 0.087 g), increased absolute left kidney weight (control group: 1.296 ± 0.108 g vs. treatment group: 1.446 ± 0.088 g), increased absolute right kidney weight (control group: 1.304 ± 0.056 g vs. treatment group: 1.454 ± 0.101 g), increased relative spleen weight (control group: 1.775 ± 0.129 g/kg bw vs. treatment group: 2.041 ± 0.179 g/kg bw), and increased absolute spleen weight (control group: 0.530 ± 0.066 g vs. treatment group: 0.660 ± 0.060 g).
females (test day 29): decreased relative heart weight (control group: 4.540 ± 0.309 g/kg bw vs. treatment group: 3.998 ± 0.306 g/kg bw)
The absolute and/or relative organ weights for the epididymis, testis, kidney, spleen and heart were statistical significantly different in the treated animals in comparison with the control animals. However, the reported values for the organ weights are within the normal range for that rat strain and age of the animals (see attached historical control data of the lab in the field "Attached background material" below). These findings should therefore not be regarded as adverse response but as normal biological variation.
BEHAVIOUR (FUNCTIONAL FINDINGS)
- neurological screening did not reveal any test item-related influence in the male and female rats treated with 1000 mg zirconium praseodymium yellow zircon/kg bw/day.
- examination results of the animals treated with the vehicle control were also in the normal range, although the values for the spontaneous motility appeared to be below the normal range.
- statistically significant differences (p ≤ 0.05) in neurological parameters of test item-treated animals compared to the control animals were recorded (not test item-related findings):
males (test week 4): decreased hindlimp grip strength (control group: 293.7 ± 16.9 g vs. treatment group: 226.7 ± 22.0 g)
The hindlimb grip strength was statistically significantly decreased in the treated animals compared with the control animals. The mean grip strength of the hindlimb of both control (293.7 g) and treated (226.7 g) animals are both in the mean historical control range (214.0 - 419.3 g). Based on this it is concluded that this finding should therefore not be regarded as adverse response but as normal biological variation.
Please also refer for the historical control data to the field "Attached background material" below.
GROSS PATHOLOGICAL FINDINGS
- none of the male and female rats treated with 1000 mg test item/kg bw/day revealed any test item-related macroscopic changes at necropsy on test day 29.
HISTOPATHOLOGICAL FINDINGS: NON-NEOPLASTIC
- histomorphological examination did not reveal any morphological changes which are considered to be related to the administration of the test item (no difference between the groups).
- inflammatory lesions in different organs are considered to be coincidental findings or spontaneous organ changes and are thus not test item-related (no differences were noted between the groups).
- fatty infiltration in the hepatocytes and in the tubular epithelial cells of the kidney in male and female rats of the control and the test item-treated group were within the physiological limits.
- involution of the thymus in the rats of both groups corresponded in type, incidence and severity to the age of the animals.
- coincidental findings from different organs in a small number of control and test item-treated animals are considered to be spontaneous organ changes and are thus not test item-related.
- no morphological differences were noted for any of the organs examined between the controls and the test item treated dose group. Type, incidence and severity of the lesions were comparable to the control animals.
OTHER
TOXICOKINETICS
The analyis of zirconium and praseodymium concentrations of 24 h-urine sampled after the last dosing demonstrated the negligible bioavailability of the test substance, with < 0.05 % of the dose being exceted via urine for both metals. Similar, there were either no appreciable or only negligible increases in blood plasma levels for both metals. Please also refer to the field "Attached background material" below.
Effect levels
- Key result
- Remarks on result:
- not determinable due to absence of adverse toxic effects
Target system / organ toxicity
- Critical effects observed:
- no
Applicant's summary and conclusion
- Conclusions:
- NOAEL (oral; rats) > 1000 mg zirconium praseodymium yellow zircon/kg bw/day
No test item-related changes were observed for clinical signs, mortality, neurologically screening, body weight, food consumption, water consumption, haematology, clinical chemistry, organ weights, ophthalmology, gross pathology, and histopathology. The analyis of zirconium and praseodymium concentrations of 24 h-urine sampled after the last dosing demonstrated the negligible bioavailability of the test substance, with < 0.05 % of the dose being exceted via urine for both metals. Similar, there were either no appreciable or only negligible increases in blood plasma levels for both metals.
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Reproduction or further distribution of this information may be subject to copyright protection. Use of the information without obtaining the permission from the owner(s) of the respective information might violate the rights of the owner.
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