Reaction mass of cerium phosphate and lanthanum phosphate and terbium phosphate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

from 26-NOV-2012 to 28-MAY-2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 422

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

cerium(3+) lanthanum(3+) terbium(3+) triphosphate

EC Number:

915-152-1

Molecular formula:

(La,Ce,Tb)PO4

IUPAC Name:

cerium(3+) lanthanum(3+) terbium(3+) triphosphate

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories Italia, Calco, Italy
- Age at study initiation: on the first day of treatment, the males were approximately 10 weeks old and the females were approximately 9 weeks old
- Weight at study initiation: on the first day of treatment, the males had a mean body weight of 387 g (range: 328 g to 436 g) and the females had a mean body weight of 222 g (range: 192 g to 249 g)
- Fasting period before study: no
- Housing: the females were individually housed, except during mating and lactation, in polycarbonate cages (Tecniplast 2154, 940 cm²) with stainless steel lids and containing autoclaved sawdust (SICSA, Alfortville, France). The males were individually housed, except during mating, in wire-mesh cages (43.0 x 21.5 x 18.0 cm). A metal tray containing autoclaved sawdust (SICSA, Alfortville, France) was placed under each cage. Toward the end of gestation and during lactation, autoclaved wood shavings (SICSA, Alfortville, France) were provided to females and their litter as nesting material.
- Diet: free access to SSNIFF R/M-H pelleted maintenance diet, batch Nos. 2537604 and 8788036 (SSNIFF Spezialdiäten GmbH, Soest, Germany), distributed weekly
- Water: free access to bottles containing tap water (filtered with a 0.22 µm filter)
- Acclimation period: the animals were acclimated to the study conditions for a period of 7 days before the beginning of the treatment period

ENVIRONMENTAL CONDITIONS
- Temperature: 22 ± 2°C
- Humidity: 50 ± 20%,
- Air changes: about 12 cycles/hour of filtered, non-recycled air
- Photoperiod: 12 hrs dark / 12 hrs light

IN-LIFE DATES: from 27 November 2012 (day of arrival of the animals) to 27 January 2013 (necropsy of last females)

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.5% (w/v) methylcellulose aqueous solution

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
The test item was administered as a suspension in the vehicle. The test item was ground to a fine powder, using a mortar and pestle, and then mixed with the required quantity of vehicle.
The test item dose formulations were prepared on a daily basis and delivered to the study room at room temperature.

VEHICLE
- Justification for use and choice of vehicle (if other than water): a stable suspension was obtained in this aqueous vehicle
- Concentration in vehicle: 20, 60 and 200 mg/mL, respectively for the dose levels of 100, 300 and 1000 mg/kg bw/day
- Amount of vehicle: a constant dosage-volume of 5 mL/kg/day was used
- Lot/batch no. (if required): the vehicle was prepared using: drinking water treated by reverse osmosis using ELIX 5 (Millipore SA) and methylcellulose (batch No. 079K0054)

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Concentrations of the test item in the dose formulations were quantified by ICP-MS, a validated analytical method. It consisted of sampling accurate volume of dose formulations, mineralized the sample using acid and micro wave, and diluting it appropriately with diluent to reach the nominal concentration of measurement.
Before the start of treatment, the suitability of the dose formulation process was confirmed. The homogeneity was determined on a range of dose formulations prepared at levels which covered the lowest and highest concentrations proposed for use in this study.
The concentration of the test item in samples of each control and test item dose formulation used in weeks 1, 3 and 6 was determined and were found within an acceptable range of variations (-11.3 % to -4.5 % when compared to nominal values (+/- 15%).

Details on mating procedure:

- M/F ratio per cage: 1
- Length of cohabitation: each female was placed with the same male until mating occurred (and with a second male when the first male died during the mating period).
- Proof of pregnancy: vaginal plug / sperm in vaginal smear referred to as day 0 p.c.
- Further matings after two unsuccessful attempts: not concerned
- After successful mating each pregnant female was caged: individually housed
- Any other deviations from standard protocol: no

Duration of treatment / exposure:

- in the males: 2 weeks before mating, during the mating period, and until sacrifice (at least 5 weeks in total)
- in the females: 2 weeks before mating, during the mating period, during gestation, during lactation until day 5 p.p. inclusive

Frequency of treatment:

Once a day, at approximately the same time.

No. of animals per sex per dose:

10 males and 10 females per dose-level group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: following the results of a previous 2-week toxicity study (CiToxLAB France/Study No. 39259 TSR) in which no obvious test item-related effects occurred during the study up to higher dose tested (1000 mg/kd bw/day).

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: each animal was checked for mortality and morbidity once a day before the treatment period and at least twice a day during the treatment period. Each animal was observed once a day, at approximately the same time, for the recording of clinical signs.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: once before the beginning of the treatment period and then once a week until the end of the study.
Observations included (but were not limited to) changes in the skin, fur, eyes, mucous membranes, occurrence of secretions and excretions and autonomic activity (e.g. lachrymation, piloerection, pupil size, unusual respiratory pattern). Changes in gait, posture and response to handling as well as the presence of clonic or tonic movements, stereotypes (e.g. excessive grooming, repetitive circling) or bizarre behavior (e.g. self-mutilation, walking backwards) were also recorded.
The first five surviving females to be sacrificed on day 6 p.p. from each group were evaluated with a functional observation battery once at the end of the treatment period. This included a detailed clinical examination, the assessment of reactivity to manipulation and to different stimuli and motor activity. All animals were observed in the cage, in the hand and in the standard arena.

BODY WEIGHT: Yes
- Time schedule for examinations: The body weight of each female was recorded on the first day of treatment (day 1), then once a week until mated (or until sacrifice) and on days 0, 7, 14 and 20 post-coitum and days 1 and 5 post-partum.

FOOD CONSUMPTION: Yes
The quantity of food consumed by each female was measured once a week, over a 7-day period, from the first day of treatment until the start of the mating period, during gestation for the intervals days 0-7, 7-14 and 14-20 post-coitum and during lactation for the intervals days 1-5 post-partum. During the mating period, food consumption was not measured.

WATER CONSUMPTION: No

POST-MORTEM EXAMINATIONS: Yes
On day 6 post-partum, after overnight fasting, at least 14 hours, all surviving parental females were deeply anesthetized by an intraperitoneal injection of sodium pentobarbital and sacrificed by exsanguination:
- A complete macroscopic post-mortem examination was performed on all animals. This included examination of the external surfaces, all orifices, the cranial cavity, the external surfaces of the brain and spinal cord, the thoracic, abdominal and pelvic cavities with their associated organs and tissues and the neck with its associated organs and tissues. Special attention was paid to the reproductive organs. The numbers of corpora lutea and implantation sites were also recorded.
- The tissues indicated in Table 1 were prepared for microscopic examination and weighed, respectively.

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
- Other: Mating index, fertility index, gestation index, number of pups delivered

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: No
- Skeletal examinations: No
- Head examinations: No
- Other: Live birth index, viability index on day 4 post-partum, mean litter size, and pup sex ratios

Statistics:

Data (body weight, food consumption and reproductive data) are compared by one-way analysis of variance analysis and Dunnett test, (mean values being considered as normally distributed, variances being considered as homogeneous) or by Fisher exact probability test (proportions).

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
CLINICAL SIGNS AND MORTALITY: There were no treatment-related mortalities or clinical signs in females from all groups.
There were no toxicological relevant effects on FOB and motor activity.

BODY WEIGHT AND FOOD CONSUMPTION: There were no statistically significant effects of treatment with the test item on mean body weight and mean body weight gain in females from all groups.
There were no effects of treatment with the test item on mean food consumption in females from all groups.

REPRODUCTIVE FUNCTION: There were no test item-related effects on mean mating and fertility data.
The slightly higher mean pre-coital time noted at 1000 mg/kg/day was due to one female which was blocked in diestrous for several days and mated with the second male (as the first male died during the mating period) after 13 days. This was considered to be incidental.

HISTOPATHOLOGY: NON-NEOPLASTIC: There were no microscopic test item-related findings in any females as compared to control animals.
The microscopic findings were considered not as related to the test item because they were consistent with spontaneously occurring findings described in the literature, the findings were distributed randomly among groups, or their appearance was similar to findings found in controls.

Effect levels (maternal animals)

1

Key result

Dose descriptor:

NOAEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOEL

Effect level:

1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
Mating performance, fertility indices, corpora lutea and implantation counts, duration of gestation, and the mean number of live pups born per litter, were similar between control females and females receiving the test item.

There were no effects of treatment on pup survival after birth or on pup sex. There were no effects of treatment with test item on mean body weight and mean body weight change. There were no test item-related macroscopic findings at pup necropsy (no dose-relationship and slight incidences).

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Remarks on result:

not measured/tested

Remarks:

There were no effects of treatment on pup survival.

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Applicant's summary and conclusion

Conclusions:

Based on the experimental conditions of this study, the test item did not affect the parent animals and the pups by day 5 p.p. after treatment up to 1000 mg/kg/day.

Executive summary:

In a combined repeated dose toxicity study with the reproduction/developmental toxicity screening test was performed according to OECD test guideline 422 and in compliance with GLP, (CiTOXLab, 2013). The potential general and reproductive or developmental toxicity of Reaction mass of Lanthanum Phosphate and Cerium Phosphate and Terbium Phosphate were tested following daily oral administration by gavage to 10-week old Sprague-Dawley rats (10/sex) from 2 weeks before mating, through mating and, for the females, through gestation until day 5 post partum (p.p.), at the dose levels of 0 (vehicle), 100, 300 or 1000 mg/kg/day in 0.5% methylcellulose aqueous solution. The study was scored at validity 1 according to Klimisch criteria.

No treatment-related death or clinical signs occurred during the study. There were no effects of the treatment on body weight, body weight gain, food consumption at any dose level. At histopathology, there were no test item-related mean organ weight differences, macroscopic or microscopic findings

There were no relevant differences from controls for pairing, mating, fertility and delivery parameters.

Pups showed no effects of treatment on survival and the test item did not have any effects on pup development in utero, pup survival, clinical signs or sex ratio. There were no treatment-related macroscopic abnormalities.

Mating performance, fertility indices, corpora lutea and implantation counts, duration of gestation, and the mean number of live pups born per litter were similar between control and treated females. Litter survival, litter weights and mean pup weights were similar between litters derived from control and treated females.

 

Based on the experimental conditions of this study, the test item did not affect the parent animals and the pups by day 5 p.p. after treatment up to 1000 mg/kg/day.

Thus the NOAEL for parental systemic toxicity is 1000 mg/kg bw/day.

As no effect were observed in the pups by day 5 p.p., NOEL for toxic effects on progeny was considered to be 1000 mg/kg/day.

No classification for developmental toxicity is warranted based on the absence of relevant effects in this study, according to the EU GHS criteria.

This study is classified as acceptable. It satisfies the OECD 422 guideline requirements on repeated dose toxicity testing and reproduction/developmental toxicity screening.