Registration Dossier

Administrative data

Description of key information

NOAEL, Rat, Oral (Gavage), 5 Weeks = 1000 mg/kg bw/day

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
Type of information:
experimental study
Adequacy of study:
key study
Study period:
11 August 2011 - 08 March 2012
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The study was performed according to OECD test guidelines, and in compliance with GLP, so the data is considered reliable without restriction.
Qualifier:
according to
Guideline:
OECD Guideline 422 (Combined Repeated Dose Toxicity Study with the Reproduction / Developmental Toxicity Screening Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)
Limit test:
no
Species:
rat
Strain:
Sprague-Dawley
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Age at study initiation: Approximately 72 days
- Weight at study initiation: 348 - 399g (males), 230 - 287g (females)
- Housing: Polycarbonate cages with either stainless steel grid floors during mating, and solid poly carbonate floors during other phases of testing.
- Diet (e.g. ad libitum): ad libitum / free access, except overnight before routine blood sampling
- Water (e.g. ad libitum): ad libitum / free access
- Acclimation period: 7 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 23°C
- Humidity (%): 40 to 70%
- Photoperiod (hrs dark / hrs light): 12 hours light: 12 hours dark

IN-LIFE DATES: From: 26 October 2011 (Treament commenced) To: 12 December 2011 (Last date of necropsy for main phase females)
Route of administration:
oral: gavage
Vehicle:
other: 1% Aqueous methylcellulose
Details on oral exposure:
PREPARATION OF DOSING SOLUTIONS:

VEHICLE
- Concentration in vehicle: 10 - 100 mg/mL
- Amount of vehicle (if gavage): 10 mL/kg bw/day
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Formulation samples were analysed by Atomic Absorption Spectrometry, to determine Iron in the samples.

Prior to the start of treatment, the analytical method was validated with respect to specificity, limit of detection, linearity of detector response over the calibration range, precision of measurement at the lowest and highest calibration standards, and the accuracy and precision of the method, by the determination of six procedural recoveries at 1 mg/mL and 100 mg/mL. A stability tiral was also performed; formulations were found to be stable and homogenous for up to 2 hours at ambient temperature with paddle stirring, and following 15 days' refrigerated storage.

Samples from all formulations prepared in the first and last weeks of the study were analysed; the test material concentrations were found to be within acceptable limits, confirming accurate preparation.
Duration of treatment / exposure:
Main phase males and toxicity phase females were dosed for five consecutive weeks.
Main phase females were treated daily for two weeks before pairing, throughout mating, gestation and until day 6 of lactation.
Frequency of treatment:
Daily
Remarks:
Doses / Concentrations:
100 mg/kg/day
Basis:
actual ingested
Remarks:
Doses / Concentrations:
300 mg/kg/day
Basis:
actual ingested
Remarks:
Doses / Concentrations:
1000 mg/kg/day
Basis:
actual ingested
No. of animals per sex per dose:
Main phase - 10 animals per sex per dose
Toxicity phase - 5 females per dose
Control animals:
yes, concurrent vehicle
Details on study design:
- Dose selection rationale: Dose levels were decided in a 7-day preliminary study in rats, conducted at the same laboratory - refer to "7 Day rangefinding_Huntingdon Life Sciences, 2011 (FGE0026)".
- Post-exposure recovery period in satellite groups: Not applicable
Observations and examinations performed and frequency:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: At least twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule:Prior to the start of treatment, and at least weekly for males and toxicity phase females. Main phase females were observed weekly before pairing, and on days 0, 6, 13 and 20 after mating, and days 1 and 7 of lactation.

BODY WEIGHT: Yes
- Time schedule for examinations: Main phase males and toxicity phase females were weighed on day 0 of treatment, then weekly and beofre necropsy. Main phase females were weighed on day 0 of treatment and weekly until mating was detected, and days 0, 6, 13 and 20 after mating, and on days 1, 4 and 7 of lactation.

FOOD CONSUMPTION:
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/week: Yes

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 data

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): No data

OPHTHALMOSCOPIC EXAMINATION: No data

HAEMATOLOGY: Yes
- Time schedule for collection of blood: Week 5 of treatment for 5 of the main phase males and for the toxicity phase females.
- Anaesthetic used for blood collection: Yes - isoflurane
- Animals fasted: Yes
- How many animals: As above
- Parameters checked in table 1 were examined.

CLINICAL CHEMISTRY: Yes
- Time schedule for collection of blood: conducted at the same time and using the same animals as Haematology, above.
- Parameters checked in table 2 were examined.

URINALYSIS: No

NEUROBEHAVIOURAL EXAMINATION: No

OTHER: Sensory reactivity and grip strength measured in the first five males for the main phase, and all five females of the toxicity phase during week 5 of treatment.
Sacrifice and pathology:
GROSS PATHOLOGY: Yes (see tables 3 and 4)
HISTOPATHOLOGY: Yes (see table 5)
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):
not examined
Ophthalmological findings:
not examined
Haematological findings:
no effects observed
Clinical biochemistry findings:
no effects observed
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
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:
not examined
Details on results:
CLINICAL SIGNS AND MORTALITY
During the study there were no signs that were considered to be related to the administration of Fe3P and no unscheduled deaths.

BODY WEIGHT AND WEIGHT GAIN
Bodyweight gain for males during the five weeks of treatment was unaffected by the administration of Fe3P.
Bodyweight gain for females during the first two weeks of treatment was considered to be unaffected by the administration of Fe3P. Toxicity phase females had lower bodyweight gain between weeks three and five of treatment (max 47% of Control) along with a lower overall bodyweight gain over the five weeks of treatment (max 60% of Control). However, there was no dose response and a relationship to treatment is uncertain.
Bodyweight gain for gestating females was considered the be unaffected by the administration of Fe3P, however lactating females given Fe3P at 300 and 1000 mg/kg/day had marginally lower bodyweight gain between days one and seven of lactation (max 82% of Control)

FOOD CONSUMPTION
Food consumption for males was considered to be unaffected by the administration of Fe3P.
During the first two weeks of treatment female food consumption was considered to be unaffected by the administration of Fe3P. Toxicity phase females showed some intergroup variation in food consumption during week 3 of treatment. During Weeks four and five food consumption was marginally lower in those animals given Fe3P (94% and 90% of Controls respectively). However, there was no dose response and a relationship to treatment is uncertain.
Food consumption for gestating and lactating females, with the exception of females given 1000 mg/kg/day, was considered to be unaffected by the administration of Fe3P. Females given 1000 mg/kg/day had marginally lower food consumption over the seven days of lactation when compared to Controls.

HAEMATOLOGY
Haematological parameters in both males and females in Week 5 of treatment were considered to be unaffected by the administration of Fe3P. Males given 300 or 1000 mg/kg/day had slightly low haematocrit and haemoglobin concentrations which attained statistical significance when compared to control, but there were no similar effects in females.

CLINICAL CHEMISTRY
Blood chemistry parameters in males and females in Week 5 of treatment were considered to be unaffected by the administration of Fe3P.

ORGAN WEIGHTS
There was no effect of treatment on organ weights for males receiving Fe3P.
Intergroup variability in uterine weight did not appear to follow any dose related pattern and may relate to differences in the stage of the oestrous cycle at necropsy.

GROSS PATHOLOGY
The macroscopic examination performed after 5 weeks of treatment revealed no test substance related lesions.
The nature and incidence of all findings were consistent with the commonly seen background of macroscopic changes.

HISTOPATHOLOGY
Microscopic examination was performed on the first five Main phase males killed at scheduled termination and Toxicity phase females in the Control and high dose group (1000 mg/kg/day).
In all the tissues examined, there was no evidence of changes considered related to the treatment with the test compound.
The seminiferous tubules of the testes were evaluated with respect to their stage in the spermatogenic cycle and the integrity of the various cell types present within the different stages. No cell or stage abnormalities were noted.
Dose descriptor:
NOAEL
Effect level:
1 000 mg/kg bw/day (actual dose received)
Based on:
test mat.
Sex:
male/female
Critical effects observed:
not specified
Conclusions:
Oral administration of Fe3P to Sprague-Dawley rats for at least 5 weeks at doses of 100, 300 and 1000 mg/kg/day was generally well tolerated with no toxicologically
significant systemic effects.

Based on the results from this study, for general toxicity the no-observed-adverse-effect level (NOAEL) was considered to be 1000 mg/kg/day.
Endpoint conclusion
Endpoint conclusion:
no adverse effect observed
Dose descriptor:
NOAEL
1 000 mg/kg bw/day
Study duration:
subacute
Species:
rat

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

Additional information

A combined repeat dose toxicity study and reproductive / developmental toxicity screening study in rats was conducted (Huntingdon Life Sciences, 2012) to assess the effect of Fe3P on rats following repeated oral administration. The study was conducted according to OECD test guideline 422, and in compliance with GLP.

Male and female rats were administered Fe3P by oral gavage for five weeks (males, and toxicity phase females), or for two weeks before mating, during mating and gestation, and until day six of lactation (main phase females). The dose groups were 100, 300, and 1000 mg/kg/day, and a concurrent control group was administered with untreated vehicle.

No clinical signs of toxicity were observed, and no animals died during the administration period. No changes in bodyweight gains, food consumption, haematology, clinical chemistry, organ weights, macropathology or hisopathology were observed which could be attributed to treatment with the test compound.

It was conclued that Fe3P was well tolerated and that no signs of systemic toxicity had been seen in rats when administered up to 1000 mg/kg bodyweight/day for up to 5 weeks. On this basis, the No Observed Adverse Effect Level (NOAEL) in rats is 1000 mg/kg/day.

Justification for classification or non-classification

In the above-mentioned subacute study (Huntingdon Life Sciences, 2012), no sign of systemic toxicity was observed following repeat oral administration of Fe3P to rats for up to 5 weeks; there is therefore no basis on which to classify Fe3P for Specific Target Organ Toxicity (repeated exposure).

No data are available regarding repeated exposure to Fe3P by dermal or inhaled routes.