Perhydroazepine

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

experimental study

Adequacy of study:

supporting study

Study period:

From 02 FEB 2006 to 11 JUN 2006

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study (according to OECD 422 and GLP)

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2006

Report date:

2006

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

Deviations:

yes

Remarks:

Minor deviations (e.g. relative humidity ranged from 23 to 83% instead of 30 to 70% during the study, number of corpora lutea not recorded for all females) by which study integrity is not affected adversely

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Perhydroazepine

EC Number:

203-875-9

EC Name:

Perhydroazepine

Cas Number:

111-49-9

Molecular formula:

C6H13N

IUPAC Name:

azepane

Details on test material:

- Name of test material (as cited in study report): Hexamethyleneimine (HMI)
- Substance type: clear colourless liquid
- Physical state: fluid
- Analytical purity: 99.6 %
- Lot/batch No.: 06702JC
- Expiration date of the lot/batch: 2007-01-01
- Stability under test conditions: stable
- Storage condition of test material: at room temperature in the dark

Test animals

Species:

rat

Strain:

Wistar

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Deutschland, Sulzfeld, Germany
- Age at study initiation: approx. 10 weeks
- Housing: pre-mating: 5 animals/sex/cage, post mating: individually, lactation: offspring was kept with dam
- Diet: standard pelleted laboratory diet (from Altromin code VRF1), ad libitum
- Water: tap water, ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21 +- 3
- Humidity (%): 30-70
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Remarks:

Milli-U

Details on exposure:

VEHICLE
- Amount of vehicle (if gavage): 5 ml/kg bw, actual dose volumes were calculated according to the latest body weight

Details on mating procedure:

- M/F ratio per cage: one-to-one
- Length of cohabitation: over night
- Proof of pregnancy: vaginal plug referred to as day 0 of gestation
- After 10 days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no data
- After successful mating each pregnant female was caged: individually

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Sampling and analysis of formulations prepared during the treatment period was performed according to the following scheme:

Day of Date Group Analysis (type of sample)
study

Day 12* 17 February 1 acc (M)
2006 2 acc + hom + stab. 0 (TMB), stab. 5, RT (S)
3 acc (M)
4 acc + hom + stab. 0 (TMB), stab. 5, RT (S)
Day 26** 03 March 1 acc (M)
2006 2 acc + hom + stab.0 (TMB), stab. 5, RT (S)
3 acc (M)
4 acc + hom + stab.0 (TMB), stab.5, RT (S)
Day 32 09 March 1 acc (M)
2006 2 acc + hom + stab.0 (TMB), stab. 5, RT (S)
3 acc (M)
4 acc + hom + stab. 0 (TMB), stab. 5, RT (S)
Day 53 30 March 1 acc (M)
2006 2 acc + hom + stab. 0 (TMB), stab. 5, RT (S)
3 acc (M)
4 acc + hom + stab. 0 (TMB), stab. 5, RT (S)
Duplicate samples were analysed
acc=accuracy, hom=homogeneity, stab=stability (hours), T=top, M=middle, B=bottom position of container S=stability sample taken at middle position of container, RT=room temperature
The analytical method used was based on the results of a separate project for the development and validation of the analytical method (NOTOX project 456773).
* These samples were kept in the freezer as the analytical method was not completed at that time. These samples were (without being analysed) discarded on 12 April 2006.
** Because the criterion that mean recoveries of the procedural recovery samples should be between 70% and 110% was not met (they were 125 and 138%), the results for the test samples were not accepted. These results were not reported.

Duration of treatment / exposure:

males: 28 days (2 weeks prior to mating, during mating and up to termination)
females: 38-56 days (2 weeks prior to mating, during mating, during post-coitum, and at least 3 days of lactation)

Frequency of treatment:

Once daily for 7 days per week, approx. the same time each day. Animals were dosed up to the day prior to scheduled necroscopy.

Details on study schedule:

none

Doses / concentrations

Remarks:

Doses / Concentrations:
0, 10, 25, 50 mg/kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale:
Based on the results of a 5-day range finding study (NOTOX Project 457436), the dose levels for this study were selected to be 0, 10, 25 and 50 mg/kg/day. In the dose range finding study, severe toxicity (clinical symptoms, body weight loss, decreased organ weights, macroscopic and microscopic findings in the stomach and small intestine) was noted at 200, 400 and 500 mg/kg body weight. In animals treated at 50 mg/kg body weight/day, yellow urine was noted and microscopic examination revealed minimal hyperplasia of the forestomach in one male and minimal erosion of the forestomach in one female.

Positive control:

no

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice daily

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: daily

BODY WEIGHT: Yes
- Time schedule for examinations: weekly

Oestrous cyclicity (parental animals):

no data

Sperm parameters (parental animals):

Parameters examined in males from the parental generation: testis weight and epididymis weight

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: no, all pups sacrificed on day 4.

PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
number and sex of pups, live births, postnatal mortality, weight on day 1 and 4, physical or behavioural abnormalities

GROSS EXAMINATION OF DEAD PUPS:
All offspring were sexed and externally examined if practically possible. The stomach was examined for the presence of milk.
Descriptions of all macroscopic abnormalities were recorded. If possible, defects or cause of death were evaluated. Any abnormal pup was preserved in neutral phosphate buffered 4% formaldehyde solution, bouin or 96% ethanol, as appropriate. No further examination was performed.

Postmortem examinations (parental animals):

SACRIFICE
- Male parental animals: All surviving animals, 28 days after start of exposure
- Female parental animals: All surviving animals, 38 to 56 days after start of exposure, depending on the day when pups were born (females sacrificed 4 days after birth of pups)

GROSS NECROPSY
- Gross necropsy consisted of external and internal examinations

Postmortem examinations (offspring):

SACRIFICE
- all pups on day 4

Statistics:

The following statistical methods were used to analyse the data:

If the variables could be assumed to follow a normal distribution, 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 groups for each sex. The Student's t-test was applied for motor activity data.
The Steel-test (many-to-one rank test) was applied if the data could not be assumed to follow a normal distribution.
The Fisher Exact-test was applied to frequency data.
All tests were two-sided and in all cases p < 0.05 was accepted as the lowest level of significance. No statistical analysis was performed on histopathology findings. Group means were calculated for continuous data and medians were calculated for discrete data (scores) in the summary tables. Test statistics were calculated on the basis of exact values for means and pooled variances. Individual values, means and standard deviations may have been rounded off . Therefore, two groups may display the same printed means for a given parameter, yet display different test statistics values.

Reproductive indices:

For each dose group reproduction parameters were expressed in two ways:
- As a mean (with standard deviation) of the number observed for each litter
- Relative to a second parameter and calculated on a total group basis

For each group the following calculations were performed:
- percentage mating : (Number of females mated / Number of females paired) x 100
- fertility index: (Number of pregnant female / Number of females paired) x 100
- conception rate: (Number of pregnant females / Number of females mated) x 100
- gestation index: (Number of females bearinp live pups / number of pregnant females) x 100
- duration of gestation: Number of days between confirmation of mating and the beginning of parturition

Offspring viability indices:

- percentage live males at firts 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 firts litter check: (Number of live female pups at First Litter Check / Number of live pups at First Litter Check) x 100
- number of postnatal loss days 0-4 post partum: (Number of dead pups on day 4 post partum/ Number of live pups at First Litter Check) x 100
- Viability index: (Number of live pups on day 4 post partum / Number of pups born alive) x 100

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

details see below

Body weight and weight changes:

no effects observed

Food consumption and compound intake (if feeding study):

no effects observed

Organ weight findings including organ / body weight ratios:

no effects observed

Histopathological findings: non-neoplastic:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

no effects observed

Description (incidence and severity):

on weights of examined testis and epididymis

Reproductive performance:

no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY:
One female from the low dose group was killed in a moribund state which was due to failed parturitian. This was not considered to be caused by treatment of the test substance. All other rats survived the scheduled duration of the study.
Yellow discolouration of urine was observed for all animals treated at 25 and 50 mg/kg body weight/day from Week 2 of study onwards.
The animal that was killed in extremis showed piloerection and pale appearance on the day of death.
Incidental findings that were noted included alopecia of the forelegs, chromodacryorrhoea, and rales. These findings are commonly noted in rats of this age and strain which are housed and treated under the conditions in this study. At the incidence observed, these were considered signs of no toxicological significance.

CLINICAL CHEMISTRY:
Females of the 50 mg/kg dose group showed slightly decreased sodium levels. No other differences between control and treated animals occurred.

GROSS PATHOLOGY:
At the high dose group, four females showed stomach abnormalities. These consisted of glandular mucosa thickened, forestomach thickened, and/or glandular mucosa gelatinous. One female of the intermediate dose group showed an isolated dark red focus on the glandular mucosa of the stomach.
The animal that was killed in extremis showed pale discolouration of the liver, the uterus contained thirteen foetuses, the cervix was obstructed by one foetus, and the mandibular lymph nodes were enlarged.
Incidental findings included enlarged mandibular lymph nodes, many gray-white foci on the papillary process of the liver, cervix and uterus dilated and containing fluid, isolated tan focus on the right clitoral gland, watery-clear cyst on the ovaries, and adrenal glands grown together with the kidneys. These findings are occasionally seen among rats used in these types of studies. In the absence of a treatment-related distribution they were considered changes of no toxicological significance.

Effect levels (P0)

Dose descriptor:

NOAEL

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no changes for reproduction and breeding up to the highest dose tested

Results: F1 generation

General toxicity (F1)

Clinical signs:

no effects observed

Mortality / viability:

no mortality observed

Body weight and weight changes:

no effects observed

Sexual maturation:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

Effect levels (F1)

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

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

Based on:

test mat.

Sex:

male/female

Basis for effect level:

other: no effects on pups up to the highest dose tested

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

Acute oral toxicity data for HMI was reported as part of a range-finding study of combined repeated dose toxicity with reproductive and developmental toxicity screening report ([Notox Project 457436] (which was reported as Appendix 3 of this study report on OECD 422). In order to set the dose level, groups of 3 animals per sex received 5 daily doses of HMI (diluted with water). On the first day, one male and one female rat were administered HMI at 500 mg/kg via oral gavage. No lethality occurred, however, based on clinical signs (gasping, bloody mouth and nose area, lethargy, tremors, lethargy, etc.) animals were sacrificed and it was decided to decrease the dose to 400 mg/kg for the remaining 4 doses. No deaths occurred at 400 mg/kg but animals were killed in extremis on day 3 and 4 due to poor health. These data suggest an Oral LD50 in the 400 to 500 mg/kg range.

Applicant's summary and conclusion

Conclusions:

There were no changes for reproduction, breeding data and pup development that were considered to be an effect of treatment.

Executive summary:

In a guideline study (OECD 422) the test substance was administered by daily oral gavage to male and female Wistar rats at dose levels of 0, 10, 25 or 50 mg/kg body weight/day. The males were exposed for 2 weeks prior to mating, during mating, and up to termination (for 28 days). The females were exposed for 2 weeks prior to mating, during mating, during post-coitum,and at least 3 days of lactation (for 38 to 56 days).

There were no changes for reproduction, breeding data and pup development that were considered to be an effect of treatment. The definitive reproduction, breeding and developmental NOAEL was established as being 50 mg/kg body weight/day for the test material.