Iodine pentafluoride

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

migrated information: read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: OECD guideline study following GLPs

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 422 (Combined repeated dose toxicity study with the reproduction/developmental toxicity screening test, 2002) and US EPA Guideline OPPTS 870.3650 (2000)

Deviations:

yes

Remarks:

The study integrity was not adversely affected by the deviations

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Iodine

EC Number:

231-442-4

EC Name:

Iodine

Cas Number:

7553-56-2

IUPAC Name:

iodine

Details on test material:

- Name of test material (as cited in study report): Iodine
- Substance type: Pure substance
- Physical state: Solid
- Analytical purity: 99.8%
- Impurities (identity and concentrations): None relevant
- Composition of test material, percentage of components: Pure substance (100%)
- Purity test date: 24th November 2009
- Lot/batch No.: Drum 182827052
- Expiration date of the lot/batch: 20 December 2010 (Allocated by testing laboratory)
- Stability under test conditions: Stable
- Storage condition of test material: At room temperature in the dark

Test animals

Species:

rat

Strain:

other: Crl:Wl (Han)

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, L'Arbresle Cedex, France
- Age at study initiation: Approximately 11 weeks
- Weight at study initiation: Males 329 g ± 20% of the sex mean, Females 192 g ± 20% of the sex mean
- Fasting period before study: Overnight
- Housing:
Pre-mating: Animals were housed in groups of 5 animals/sex/cage in Macrolon cages (MIV type, height 18 cm), except for Female 81 which was single housed.
Mating: Females were caged together with males on a one-to-one-basis in Macrolon cages (MIII type, height 18 cm).
Post-mating: Males were housed in their home cage (Macrolon cages, MIV type, height 18 cm) with a maximum of 5 animals/cage. Females were individually housed in Macrolon cages (MIII type, height 18 cm).
Lactation: Pups were kept with the dam until termination in Macrolon cages (MIII type, height 18 cm).
- Diet (e.g. ad libitum): Free access to pelleted rodent diet (SM R/M-Z from SSNIFF® Spezialdiäten GmbH, Soest, Germany)
- Water (e.g. ad libitum): Free access to tap-water.
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 ± 3.0
- Humidity (%): 40-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

DMSO

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Formulations of Group 4 and/or a stock solution (w/w) were prepared daily within 6 hours prior to dosing and were homogenised to a visually acceptable level. Adjustment was made for specific gravity of the vehicle. The Group 2 and 3 formulations were prepared by dilution of the Group 4 formulation or the stock solution. Solutions were stored at ambient temperature.

VEHICLE
- Justification for use and choice of vehicle: Dimethyl sulphoxide (DMSO), specific gravity 1.1 (Merck, Darmstadt, Germany). DMSO was selected based on trial formulations performed at NOTOX.
- Amount of vehicle (if gavage): 1 mL/kg body weight. Actual dose volumes were calculated according to the latest body weight. This dose volume was based on results of a 13 week oral study in the rat in which a NOEL of 1100 mg/kg body weight/day was established (information from MSDS).

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analyses were conducted on a single occasion during the treatment phase (24 March 2010), according to a validated method (NOTOX project 492834). Samples of formulations were analyzed for homogeneity (highest* and lowest concentration) and accuracy of preparation (all concentrations). Stability in vehicle over 6 hours at room temperature under protection from light and stability over 7 days in a refrigerator was also determined for the highest* and lowest concentrations.

*The highest concentration was 30 mg/mL (analyses were performed before change to 10 mg/mL).

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: one female/one male
- Length of cohabitation: 14 days
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 post-coitum
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged (how): Males were housed in their home cage with a maximum of 5 animals/cage. Females were individually housed in Macrolon cages.
- Any other deviations from standard protocol: Mating of female no. 50 was overlooked, since live offspring was delivered by this animal.

Duration of treatment / exposure:

Males were exposed for 29 days, ie. 2 weeks prior to mating, during mating, and up to termination. Females were exposed for 41-47 days, i.e. during 2 weeks prior to mating, during mating, during post-coitum, and during at least 4 days of lactation.

Frequency of treatment:

Once daily

Duration of test:

Parental males were necropsied at completion of mating period (minimum 28 days of treatment), females which delivered were necropsied in lactation days 5-7. Non-pregnant females were necropsied in day 26 post-coitum. Pups were examined (necropsied) in lactation days 5-7.

Doses / concentrations

Doses / concentrations 1

Remarks:

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

Doses / concentrations 2

Remarks:

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

Doses / concentrations 3

Remarks:

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

No. of animals per sex per dose:

10 animals/sex/group

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: In order to set the dose levels for the main study, a dose range finding study was performed. Groups of 3 females (11-13 weeks old) were dosed at 1, 10 or 100 mg/kg/day for 10 days by oral gavage. At 1 and 10 mg/kg no toxicologically significant toxicity was noted. Animals treated at 100 mg/kg from Day 2 onwards showed clinical signs consisted of lethargy, hunched posture, piloerection, lean appearance, and/or rales. All three female rats were killed in extremis on Day 4 of treatment.
- Rationale for animal assignment (if not random): by computer-generated random algorithm according to body weight, with all animals within ± 20% of the sex mean.

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Twice daily.

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Immediately after each dosing, once prior to start of treatment and at weekly intervals.

BODY WEIGHT: Yes
- Time schedule for examinations: Males and females were weighed on the first day of exposure and weekly thereafter. Mated females were weighed on days 0, 4, 7, 11, 14, 17 and 20 post-coitum, and during lactation on days 1 and 4.

FOOD CONSUMPTION AND COMPOUND INTAKE
- Time schedule for examinations: Weekly, except for males and females which were housed together for mating and for females without evidence of mating. Food consumption of mated females was measured on Days 0, 4, 7, 11, 14, 17 and 20 post-coitum and on Days 1 and 4 of lactation.


WATER CONSUMPTION AND COMPOUND INTAKE: Yes, Subjective appraisal was maintained during the study, but no quantitative investigation was introduced as no effect was suspected.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day: Parental males were necropsied at completion of mating period (minimum 28 days of treatment), females which delivered were necropsied in lactation days 5-7. Non-pregnant females were necropsied in day 26 post-coitum
- Organs examined: Table 1 and Table 2

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: No data
- Number of late resorptions: No data

Fetal examinations:

- External examinations: Yes: all per litter
- Soft tissue examinations: No
- Skeletal examinations: No
- Head examinations: No

Statistics:

- If the variables could be assumed to follow a normal distribution, the Dunnett-test based on a pooled variance estimate was applied for the comparison of the treated groups and the control groups for each sex.
- The Steel-test was applied if the data could not be assumed to follow a normal distribution.
- The Fisher Exact-test was applied to frequency data.
The following additional methods of statistical analysis were used:
The number of corpora lutea was transformed by using 1/x to obtain a normal distribution. This was followed by an ANOVA. The Dunnett-test (many-to-one t-test) based on a pooled variance estimate was applied for the comparison of the treated groups and the control group.
All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance.

Indices:

Percentage live males at first litter check: Number of live male pups at first litter check/Number of live pups at first litter check x 100
Percentage live females at first litter check: Number of live female pups at first litter check/Number of live pups at first litter check x 100
Percentage of postnatal loss days 0-4 of lactation: Number of dead pups on day 4 of lactation/Number of live pups at first litter check x 100
Viability index (%): Number of live pups on day 4 of lactation/Number of pups born alive x 100

Historical control data:

No data

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:no effects

Details on maternal toxic effects:
No toxicologically relevant effects on gestation index and duration, parturition, maternal care and early postnatal pup development (mortality, clinical signs, body weight and macroscopy) were observed.
Gestation
The gestation index and duration of gestation were similar between controls and all treated groups.

Parturition/Maternal care
No signs of difficult or prolonged parturition were noted among the pregnant females. Examination of cage debris of pregnant females revealed no signs of abortion or premature birth. No deficiencies in maternal care were observed.

Early postnatal pup development
Number of dead and living pups at first litter check, postnatal loss, viability index and sex ratio were unaffected by treatment, and clinical signs, body weight and external macroscopy did not reveal treatment-related findings.

Mortality
One pup of the control group, three pups at 3 mg/kg and two pups at 10 mg/kg were missing during Days 2-4 of lactation. No toxicological relevance was attributed to these missing pups since the mortality incidence did not show a dose-related trend and remained within the range considered normal for pups of this age. Missing pups were most likely cannibalised.

Clinical signs
Incidental clinical symptoms of pups consisted of small size, scabbing of the abdomen and pale appearance were noted. The nature and incidence of these clinical signs remained within the range considered normal for pups of this age, and were therefore considered to be of no toxicological relevance.

Body weights
Body weights of pups were considered to have been unaffected by treatment.

Macroscopy
The incidental macroscopic finding of small size was noted for one pup. The nature and incidence of these findings remained within the range considered normal for pups of this age, and was therefore not considered to be toxicologically relevant.

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

10 mg/kg bw/day (actual dose received)

Based on:

test mat.

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Analysis of Dose Preparations

The concentrations analysed in the formulations of Group 2 (0.273 mg/g), Group 3 (2.73 mg/g) and Group 4 (27.3 mg/g) were in agreement with target concentrations (i.e. mean accuracies between 90% and 110%). No test substance was detected in the Group 1 formulations.

The formulations of Group 2 and Group 4 were homogeneous (i.e. coefficient of variation ≤ 10%).

Formulations at the highest concentration level (i.e. 27.3 mg/g) were stable when stored in a refrigerator for at least 7 days. Formulations at the lowest concentration level (i.e. 0.273 mg/g) were stable when stored at room temperature for at least 6 hours, but not stable when stored in a refrigerator for 7 days.

Applicant's summary and conclusion

Conclusions:

No reproduction/developmental toxicity was observed at any dose level. Based on these results, a reproduction and developmental No Observed Adverse Effect Level. (NOAEL) of 10 mg/kg was derived.

Executive summary:

A combined 28-day repeated dose toxicity study with the reproduction/developmental toxicity screening test was conducted with Iodine in rats by oral gavage.

The study was based following guidelines from Organisation of Economic Co-operation and Development Guidelines (OECD) for testing of Chemicals Guideline 422, Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test (1996) and The United States Environmental Protection Agency (EPA) Health Effects Test Guidelines OPPTS 870.3650, Combined Repeated Dose Toxicity Study with the Reproduction/Developmental Toxicity Screening Test (2000).

Based on the results of a 10-day dose range finding study, the dose levels for this combined 28-day oral gavage study with reproduction/developmental toxicity screening test were selected to be 0.3, 3 and 30 mg/kg.

After acclimatisation, four groups of ten male and ten female Wistar Han rats were exposed by oral gavage to the test substance at 0, 0.3, 3 and 30 mg/kg. Due to severe toxicity at 30 mg/kg, the dose level of Group 4 was adjusted to 10 mg/kg from Day 4 of the study onwards.

Males were exposed for 29 days, i.e. 2 weeks prior to mating, during mating, and up to termination. Females were exposed for 41-47 days, i.e. during 2 weeks prior to mating, during mating, during post-coitum, and during at least 4 days of lactation.

The following parameters were evaluated: mortality/viability, clinical signs, functional observations, body weights, food consumption, reproduction/developmental parameters, observations pups, clinical pathology (including thyroid hormones), macroscopy, organ weights,

and histopathology. Chemical analyses of formulations were conducted once during the study to assess accuracy, homogeneity and stability.

The following parameters were evaluated in the parental animals: mortality/viability, clinical signs, functional observations, body weights, food consumption, reproduction/developmental parameters, observations pups, clinical pathology (including thyroid hormones), macroscopy, organ weights, and histopathology. Pups were examined for viability, clinical signs, and body weights were determined. All pups were sexed and descriptions of all external abnormalities were recorded at necropsy. Chemical analyses of formulations were conducted once during the study to assess accuracy, homogeneity and stability.

No relevant parental toxicity was observed up to 10 mg/kg.

No reproduction/developmental toxicity was observed at any dose level. Based on these results, a reproduction and developmental No Observed Adverse Effect Level. (NOAEL) of 10 mg/kg was derived.

Based on the absence of functional or morphological disturbances supporting the changes noted for clinical biochemistry parameters, a parental NOAEL of 10 mg/kg was established.