Registration Dossier

Diss Factsheets

Administrative data

Endpoint:
screening for reproductive / developmental toxicity
Data waiving:
study scientifically not necessary / other information available
Justification for data waiving:
the study does not need to be conducted because a pre-natal developmental toxicity study is available
Cross-reference
Reason / purpose for cross-reference:
data waiving: supporting information
Reference
Endpoint:
developmental toxicity
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
guideline study
Reason / purpose for cross-reference:
reference to same study
Qualifier:
according to guideline
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
Version / remarks:
- for inhalation exposure considering OECD - Guideline method 412
GLP compliance:
yes
Species:
rat
Strain:
Wistar
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: Boehringer Ingelheim Pharma KG, Biberach an der Riss, Germany
- Age at study initiation: about 9-10 weeks
- Weight at study initiation:
- Housing: singly in DK 111 stainless steel wire mesh cages
- Diet: rat/mouse/hamster laboratory diet, 10 mm pellets (Provimi Kliba SA, Kaiseraugst, Switzerland), ad libitum.
- Water: tap water ad libitum.
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24 °C
- Humidity (%): 30-70 %
- Photoperiod (hrs dark / hrs light): 12/12
Route of administration:
inhalation
Type of inhalation exposure (if applicable):
whole body
Vehicle:
unchanged (no vehicle)
Details on exposure:
GENERATION OF TEST ATMOSPHERE / CHAMBER DESCRIPTION
- Exposure apparatus: glass-steel inhalation chamber, volume of 1.4 m3 (BASF AG)
- Method of holding animals in test chamber: whole body exposure
- Temperature, humidity, in air chamber: 21.2 - 22.5 %; 50.5 - 62.0 %
- Air change rate: ca. 20 x h

TEST ATMOSPHERE
- Brief description of analytical method used: GC/FID after absorption in DMF
- Samples taken from breathing zone: yes


Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Gas chromatograph equipped with autosampler, split injector and flame ionization detector (FID) and adapted to a chromatography data system
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1-3
- Length of cohabitation: 4.00 pm - 7.30 am (15.5 h)
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
Duration of treatment / exposure:
days 6-19 p.c.
Frequency of treatment:
6 h/day
Duration of test:
20 days
Remarks:
Doses / Concentrations:
51.4 +-2.2; 151.8 +-9.2; and 460 +-17.5 mg/m3 [= 17, 50.1, and 151.8 mL/m3]
Basis:
analytical conc.
No. of animals per sex per dose:
25 (Implantation sites were present in 20, 23, 24 and 23 animals of test groups 0, 1, 2 and 3, respectively).
Control animals:
yes, sham-exposed
Details on study design:
- Dose selection rationale: pretest
Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: twice a day


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: at least 3 times on exposure days and, as a rule, once during the day 0, preflow period and post-exposure observation day.


BODY WEIGHT: Yes
- Time schedule for examinations: day 0, 1, 3, 6, 8, 10, 13, 15,17, 19 and 20 p.c..


POST-MORTEM EXAMINATIONS: Yes, gross pathology
- Sacrifice on gestation day # 20


OTHER: Histopathology of head with larynx
Ovaries and uterine content:
The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: Yes
- Number of corpora lutea: Yes
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes
Fetal examinations:
- External examinations: Yes: all per litter
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: Yes: all per litter
Statistics:
The Dunnett-test was used for a simultaneous comparison of several dose groups with the control. Fisher's Exact test was used for pairwise comparisons. The WILCOXIN test was used for a comparison of each dose with the control for the hypothesis of equal medians.
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):
not specified
Food efficiency:
not specified
Ophthalmological findings:
not examined
Haematological findings:
not examined
Clinical biochemistry findings:
not examined
Urinalysis findings:
not examined
Behaviour (functional findings):
not examined
Immunological findings:
not examined
Organ weight findings including organ / body weight ratios:
no effects observed
Description (incidence and severity):
gravid uterine weights were unaffected by exposure
Gross pathological findings:
effects observed, treatment-related
Description (incidence and severity):
Only local effects in the upper respiratory tract due to irritation, details see below
No gross effects were observed in the uterus. Further other organs were not examined
Neuropathological findings:
not examined
Histopathological findings: non-neoplastic:
effects observed, treatment-related
Description (incidence and severity):
Only local effects in the upper respiratory tract due to irritation, details see below
Histopathological findings: neoplastic:
not examined
Number of abortions:
no effects observed
Pre- and post-implantation loss:
no effects observed
Total litter losses by resorption:
no effects observed
Early or late resorptions:
no effects observed
Dead fetuses:
no effects observed
Changes in pregnancy duration:
not specified
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): not specified
Changes in number of pregnant:
no effects observed
Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
Treatment-related findings were confined to the anterior section (level 1) of the nasal cavity. Minimal to slight focal necrosis of the nasal mucosa was seen in five, necrosis of the underlying nasal bone in one female of the high concentration group. Necrosis was predominantly located at the nasoturbinates, thus affecting transitional epithelium. (Multi)focal squamous cell metaplasia and purulent to mixed inflammatory cell infiltration were found in all treatment groups in the anterior part of the nose (level 1). The predominant location were the turbinates and the lateral wall. Focal hyperplasia of the transitional epithelium was observed in 6 animals of the mid and one animal of the low concentration group. Predilection sites were the nasal turbinates and the lateral wall. Incidence and severity decreased from top concentration to low concentration group for all treatment-related findings.

Key result
Dose descriptor:
LOAEC
Effect level:
51 mg/m³ air (analytical)
Based on:
test mat.
Basis for effect level:
other: maternal toxicity
Key result
Dose descriptor:
NOAEC
Effect level:
460 mg/m³ air (analytical)
Based on:
test mat.
Basis for effect level:
other: developmental toxicity
Key result
Abnormalities:
effects observed, treatment-related
Localisation:
other: local irritation in the upper respiratory tract
Description (incidence and severity):
Effects were observed at all exposure concentrations
Fetal body weight changes:
no effects observed
Description (incidence and severity):
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): no effects observed
Reduction in number of live offspring:
no effects observed
Changes in sex ratio:
no effects observed
Changes in litter size and weights:
no effects observed
Changes in postnatal survival:
not specified
External malformations:
no effects observed
Skeletal malformations:
no effects observed
Visceral malformations:
no effects observed
Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects
Key result
Dose descriptor:
NOAEC
Effect level:
460 mg/m³ air (analytical)
Based on:
test mat.
Sex:
male/female
Basis for effect level:
other: developmental toxicity, highest dose tested
Key result
Abnormalities:
not specified
Key result
Developmental effects observed:
not specified

Mono-n-butylamine elicited maternal toxicity at all tested concentrations. Maternal toxicity was substantiated by changes of the respiratory epithelium in the nasal cavity.

There were no substance-induced, concentration-related influences on the gestational parameters and no signs of prenatal developmental toxicity, especially no substance induced indications of teratogenicity, up to the highest concentration.

Based an these results, the no observed adverse effect concentration (NOAEC) for prenatal developmental toxicity is 0.45 mg/L air (152 mL/m3).

Summary of maternal and fetal data after inhalation exposure to n-butylamine (from Gamer et al. 2002, Tab. 3)

Inhalation concentration [ppm]

0

17

50

152

Females mated

25

25

25

25

Number of maternal deaths, abortions, premature births and total resorptions

0

0

0

0

Females pregnant at scheduled necropsy

20

23

24

23

Mean gravid uterus weight (g)

78.4±13.0

82.5±12.5

82.7±11.6

80.8±13.9

Mean net maternal body weight gain from day 6 post coitum (g)

42.5±8.6

46.3±10.9

47.6±9.6

40.4±9.8

Mean corpora lutea

15.9±1.9

16.8±2.4

16.8±1.4

16.4±1.6

Mean implantation sites

15.1±2.8

15.7±2.2

16.3±1.9

15.4±2.4

Mean % pre-implantation loss

5.8

6.9

3.4

5.8

Mean % post-implantation loss

6.4

6.5

10.9

7.9

Mean % early resorptions

6.4

6.5

10.1

7.1

Mean % late resorptions

0.0

1.2

0.8

0.8

Mean number of live fetuses per litter

14.1±2.6

14.4±2.3

14.5±2.2

14.2±2.5

Number of dead fetuses

0

0

0

0

Mean placenta weight (g)

0.45±0.04

0.46±0.04

0.46±0.06

0.47±0.05

Mean fetal weight (g)

3.7±0.2

3.8±0.3

3.8±0.2

3.8±0.2

Percentage of litters with any malformation

5

13

17

17

Mean % of fetuses/litter with any malformation

0.4

1.2

1.1

1.2

Group means±standard deviation

Fetal and litter incidence of external, soft tissue and skeletal malformations after inhalation exposure

to n-butylamine (from Gamer et al. 2002, Tab. 4)

Inhalation concentration [ppm]

0

17

50

152

Number of litters with live fetuses

20

23

24

23

Total number of fetuses examined (soft tissue/skeletal examination)

282 (134/148)

332 (159/173)

348 (169/179)

327 (158/169)

Number (%) of litters with external malformation

0 (0 %)

0 (0 %)

1 (4 %)

0 (0 %)

Number of fetuses (mean % fetuses/litter) with external malformation

0 (0 %)

0 (0 %)

1(0.3 %)

0 (0 %)

Number (%) of litters with soft tissue malformation

0 (0 %)

1 (4 %)

1 (4 %)

0 (0 %)

Number of fetuses (mean % fetuses/litter) with soft tissue malformation

0 (0 %)

1 (0.5 %)

1 (0.5 %)

0 (0 %)

Number (%) of litters with skeletal malformation

1 (5 %)

2 (9 %)

3 (13 %)

4 (17 %)

Number of fetuses (mean % fetuses/litter) with skeletal malformation

1 (1 %)

3 (2 %)

3 (2 %)

4 (2 %)

Number (%) of litters with any malformation

1 (5 %)

3 (13 %)

4 (17 %)

4 (17 %)

Number of fetuses (mean % fetuses/litter) with any malformation

1 (0.4 %)

4 (1 %)

4 (1 %)

4 (1 %)

Group means±standard deviation

Conclusions:
Under the conditions of this study, local effects were observed in the nose of dams. No effects on gestational parameters and offspring were evident.
Executive summary:

Twenty-five mated female Wistar rats per test group were whole-body exposed to dynamic atmospheres of Mono-n-Butylamin vapors for 6 hours per day on day 6 through day 19 post coitum (p.c.; 14 exposures). The target concentrations were 50, 150 and 450 mg/m 3. A concurrent control group was exposed to clean air.

No treatment related clinical findings were observed. A concentration dependent increase in incidence and severity of changes in the epithelium of the anterior nasal cavity (necrosis, hyper- and metaplasia, inflammatory cell infiltration) occurred. Under the conditions of this prenatal developmental toxicity study, the inhalation exposure of pregnant Wistar rats to vapours of Mono-n-Butylamin from implantation to one day prior to the expected day of parturition (days 6 - 19 p.c.) elicited maternal toxicity at all tested concentrations. Maternal toxicity was substantiated by changes of the respiratory epithelium in the nasal cavity.

There were no substance-induced, concentration-related influences on the gestational parameters and no signs of prenatal developmental toxicity, especially no substance-induced indications of teratogenicity, up to and including the highest concentration (450 mg/m 3).

Data source

Materials and methods

Results and discussion

Applicant's summary and conclusion