2-propylheptan-1-ol

Developmental toxicity / teratogenicity

Administrative data

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2004

Report date:

2004

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Version / remarks:

(Jan. 22, 2001)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

2-propylheptan-1-ol

EC Number:

233-126-1

EC Name:

2-propylheptan-1-ol

Cas Number:

10042-59-8

Molecular formula:

C10H22O

IUPAC Name:

2-propylheptan-1-ol

Test material form:

liquid

Specific details on test material used for the study:

- Name of test material (as cited in study report): Propylheptanol
- Physical state: liquid/colorless;
- Analytical purity: 99.8%
- Lot/batch No.: Tk 2012
- Test substance No.: 02/0356-1
- Stability: The stability under storage conditions was confirmed by reanalysis. The stability of Propylheptanol in doubly distilled water + Cremophor EL for a period of 7 days at room temperature was demonstrated.
- Homogeneity: Homogeneous
- Storage condition of test material: Room temperature, under N2

Test animals

Species:

rat

Strain:

Wistar

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories, Germany
- Age at study initiation: 70 - 84 days at delivery
- Weight at study initiation: 145.5 - 187.9 g
- Housing: single (from day 0 - 20 p.c.)
- Diet: ground Kliba maintenance diet rat/mouse/hamster meal, supplied by PROVIMI KLIBA SA, Kaiseraugst, Switzerland; ad libitum;
- Water: drinking water of tap water quality from water bottles; ad libitum;
- Acclimation period: between the supply on day 0 and the first administration on gestational day 6

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 24°C
- Humidity (%): 30 - 70%
- Photoperiod (hrs dark / hrs light): 12 / 12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: doubly distilled water with Cremophor EL

Details on exposure:

- Concentration of the emulsion (mg/100 ml): 500, 2000, and 6000
- Dose volume: 10 ml/kg bw

PREPARATION OF DOSING SOLUTIONS:
The test substance emulsions in doubly distilled water were prepared at the beginning of the administration period and thereafter at intervals which took into account the analytical results of the stability verification. For the preparation of the emulsions, an appropriate amount of the test substance was weighed depending on the dose group in calibrated beakers, topped up with doubly distilled water and some drops Cremophor EL and subsequently thoroughly mixed using a high-speed homogenizer. A magnetic stirrer was used to keep the emulsions homogeneous during treatments.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

Analytical verifications of the stability of the test substance in doubly distilled water + Cremophor EL for a period of at least 7 days at room temperature were carried out before the study was initiated.
Samples of the test substance emulsions were sent to the analytical laboratory twice during the study period (at the beginning and towards the end) for verification of the concentrations. The samples which were taken for the first concentration control analyses at the beginning of the administration period were also used to verify the homogeneity for the samples of the low and the high concentrations (50 and 600 mg/kg body weight/day). Three samples (one from the top, middle and bottom in each case) were taken for each of these concentrations from the beaker with a magnetic stirrer running.
The test substance emulsions were analyzed by GC. The analytical values of the samples corresponded to the expected values within the limits of the
analytical method, i.e. were always above 90% of the nominal concentration.

Details on mating procedure:

The animals were mated by the breeder (time-mated) and supplied on day 0 post coitum (= detection of vaginal plug / sperm).

Duration of treatment / exposure:

day 6 through day 19 p.c.

Frequency of treatment:

daily

Duration of test:

20 days

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

50 mg/kg bw/day (nominal)

Doses / concentrations 2

Dose / conc.:

200 mg/kg bw/day (nominal)

Doses / concentrations 3

Dose / conc.:

600 mg/kg bw/day (nominal)

No. of animals per sex per dose:

25

Control animals:

yes, concurrent vehicle

Examinations

Maternal examinations:

DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: A check for mortality was made twice a day on working days or once a day (Saturday, Sunday or on public holidays) (days 0 - 20 p.c.). The animals were examined for clinical symptoms at least once a day, or more often when clinical signs of toxicity were elicited (days 0 - 20 p.c.).

BODY WEIGHT: Yes
- Time schedule for examinations: All animals were weighed on days 0, 1, 3, 6, 8, 10, 13, 15, 17, 19 and 20 p.c.. The body weight change of the animals was calculated from these results.
Corrected body weight gain (net maternal body weight change):
Furthermore, the corrected body weight gain was calculated after terminal sacrifice (terminal body weight on day 20 p.c. minus weight of the unopened uterus minus body weight on day 6 p.c.).

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes (With the exception of day 0, the consumption of food was determined on the same days as was body weight.)

WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): Yes
- Time schedule for examinations: With the exception of day 0, the consumption of drinking water was determined on the same days as was body weight.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day #20
- Organs examined: Weight of liver, kidneys and spleen, Weight of the unopened uterus
One test group 1 animal and two test group 3 animals that died or had to be sacrificed during the study period were examined according to the same procedures as the females killed on schedule (exception: no weight determinations of uterus, liver, kidneys and spleen).

Examinations of the dams at termination:
- Clinical Pathology:
Blood was taken from the retroorbital venous plexus in the morning from non-fasted animals without anesthesia. The blood sampling procedure and the subsequent analysis of the blood and serum samples were carried out in a randomized sequence.
The following examinations were carried out in all animals per test group at the end of the administration period.
Hematology: leukocytes, erythrocytes, hemoglobin, hematocrit, mean corpuscular volume, mean corpuscular hemoglobin, mean corpuscular hemoglobin concentration, platelets, differential blood count;
Furthermore, differential blood smears were prepared and stained according to Wright without being evaluated.
Clotting analyses: prothrombin time (Hepato Quick's test)
Clinical chemistry: alanine aminotransferase, aspartate aminotransferase, alkaline phosphatase, serum-gamma-glutamyltransferase, sodium, potassium, chloride, inorganic phosphate, calcium, urea, creatinine, glucose, total bilirubin, total protein, albumin, globulins, triglycerides, cholesterol, magnesium

Ovaries and uterine content:

The 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
- Other: Furthermore, calculations of conception rate and pre- and postimplantation losses were carried out.

Fetal examinations:

- External examinations: Yes: [all per litter]
- Soft tissue examinations: Yes: [half per litter]
- Skeletal examinations: Yes: [half per litter]

Statistics:

- Food consumption, water consumption, body weight, body weight change, corrected body weight gain (net maternal body weight change), carcass weight, weight of unopened uterus, number of corpora lutea, number of implantations, number of resorptions, number of live fetuses, proportions of preimplantation loss, proportions of postimplantation loss, proportions of resorptions, proportion of live fetuses in each litter, litter mean fetal body weight, litter mean placental weight: Simultaneous comparison of all dose groups with the control group using the DUNNETT-test (two-sided) for the hypothesis of equal means.
- Organ weights (liver, kidneys, spleen): Non-parametric one-way analysis using KRUSKAL-WALLIS-test (two-sided). If the p-value was equal or less than 0.05, a pairwise comparison of each dose group with the control group was performed using the WILCOXON-test (two-sided) for the equal medians.
- Female mortality, females pregnant at terminal sacrifice, number of litters with fetal findings: Pairwise comparison of each dose group with the control group using FISHER'S EXACT test (one-sided) for the hypothesis of equal proportions.
- Proportions of fetuses with malformations, variations and/or unclassified observations in each litter: Pairwise comparison of each dose group with the control group using the WILCOXON-test (one-sided) for the hypothesis of equal medians.
- Clinical pathology parameters, except differential blood count: Non-parametric one-way analysis using KRUSKAL-WALLIS test (two-sided) .If the resulting p-value was equal or less than 0.05, a pairwise comparison of each dose group with the control group was performed using Wilcoxon-test (two-sided) for the equal medians.

Indices:

In the present study the glossary of WISE et al. (Wise et al., 1997) was used as much as, possible to describe findings in fetal morphology. Classification of these findings was based on the terms and definitions proposed by CHAHOUD et al. (Phahoud et al., 1999; Solecki et al., 2001):
- Malformation: A permanent structural change that is likely to adversely affect the survival or health.
- Variation: A change that occurs also in fetuses of control animals and is unlikely to adversely affect the survival or health. This includes delays in growth or morphogenesis that has otherwise followed a normal pattern of development.
Moreover, the terms "unclassified observation" or "unclassified cartilage observation" were used for those fetal findings, which could not be classified as malformations or variations (e.g. focal liver necrosis in fetuses, isolated cartilage findings without any impact on the respective bony structure).

Historical control data:

The results were compared with historical control data.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- clinically observed transient salivation after treatment in all animals and occasionally urine smeared fur in 6/25 animals

Test group 2 (200 mg/kg body weight/day):
- clinically observed transient salivation after treatment in 8/25 animals

The observed temporary salivation of the animals is considered to be substance-induced. It is very likely, that this finding was induced by bad taste of the test substance or local irritation of the upper digestive tract . This type of salivation is not assessed as an adverse systemically toxic effect .

Mortality:

mortality observed, non-treatment-related

Description (incidence):

A number of low (1 animal) and high dose females (2 animals) either died or had to be sacrificed after gavage error. No relationship of these deaths to the test compound is assumed.

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- significantly reduced final body weight (7% below control )
- significantly reduced absolute (23% below control) and net (52% below control) body weight gain

Test group 2 (200 mg/kg body weight/day):
- significantly reduced final body weight (6% below control)
- significantly reduced absolute (15% below control) and net (19% below control) body weight gain

Food consumption and compound intake (if feeding study):

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- significantly reduced food consumption (11 % below control)

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- significantly increased water consumption (34% above control)

Ophthalmological findings:

not examined

Haematological findings:

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- decreased platelets

Clinical biochemistry findings:

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- decreased sodium, chloride, total protein, globulins and cholesterol
- increased inorganic phosphate and urea

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- increased absolute (12% above control) and relative (20% above control) liver weight (due to peroxisomal proliferation)

Test group 2 (200 mg/kg body weight/day):
- increased relative (5% above control) liver weight (due to peroxisomal proliferation)

Gross pathological findings:

no effects observed

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

no effects observed

Histopathological findings: neoplastic:

no effects observed

Other effects:

no effects observed

Maternal developmental toxicity

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:

no effects observed

Description (incidence and severity):

Migrated Data from removed field(s)
Field "Effects on pregnancy duration" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsMaternalAnimals.MaternalDevelopmentalToxicity.EffectsOnPregnancyDuration): no effects observed

Changes in number of pregnant:

no effects observed

Other effects:

no effects observed

Effect levels (maternal animals)

Dose descriptor:

NOAEL

Effect level:

50 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

body weight and weight gain

other: effects due to peroxisomal proliferation (no human hazard): increased relative liver weight

Results (fetuses)

Fetal body weight changes:

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- statistically significantly decreased fetal weights (11 % below control)

considered to be secondary to the clear disturbance of maternal homeostasis during pregnancy and not relevant in terms of developmental toxicity
Migrated Data from removed field(s)
Field "Fetal/pup body weight changes" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.FetalPupBodyWeightChanges): effects observed, treatment-related
Field "Description (incidence and severity)" (Path: ENDPOINT_STUDY_RECORD.DevelopmentalToxicityTeratogenicity.ResultsAndDiscussion.ResultsFetuses.DescriptionIncidenceAndSeverityFetalPupBodyWeightChanges): see above

Reduction in number of live offspring:

not examined

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

not examined

External malformations:

no effects observed

Skeletal malformations:

effects observed, treatment-related

Description (incidence and severity):

Test group 3 (600 mg/kg body weight/day):
- increased incidence of skeletal variations, in particular incompletely or non-ossified morphologically unchanged skeletal structures or unspecific variants of ossification (supernumerary thoracic vertebrae, supernumerary and/or wavy ribs)

considered to be secondary to the clear disturbance of maternal homeostasis during pregnancy and not relevant in terms of developmental toxicity

Visceral malformations:

no effects observed

Other effects:

no effects observed

Effect levels (fetuses)

1

Dose descriptor:

LOAEL

Effect level:

600 mg/kg bw/day (nominal)

Based on:

test mat.

Sex:

not specified

Basis for effect level:

fetal/pup body weight changes

skeletal malformations

Remarks on result:

other: considered to be secondary to the clear disturbance of maternal homeostasis during pregnancy and not relevant in terms of developmental toxicity

2

Dose descriptor:

NOAEL

Effect level:

200 mg/kg bw/day

Based on:

test mat.

Sex:

not specified

Basis for effect level:

fetal/pup body weight changes

skeletal malformations

Remarks on result:

other: considered to be secondary to the clear disturbance of maternal homeostasis during pregnancy and not relevant in terms of developmental toxicity

Fetal abnormalities

Abnormalities:

effects observed, treatment-related

Description (incidence and severity):

- statistically significantly decreased fetal weights (11 % below control)
- increased incidence of skeletal variations, in particular incompletely or non-ossified morphologically unchanged skeletal structures or unspecific variants of ossification (supernumerary thoracic vertebrae, supernumerary and/or wavy ribs)

These effects were regarded as secondary effects due to clear maternal toxicity.

Overall developmental toxicity

Developmental effects observed:

yes

Lowest effective dose / conc.:

600 mg/kg bw/day (nominal)

Treatment related:

yes

Relation to maternal toxicity:

developmental effects as a secondary non-specific consequence of maternal toxicity effects

Dose response relationship:

yes

Any other information on results incl. tables

Dose (mg/kg bw)	0	50	200	600
Mated females	25	25	25	25
Pregnant females	22	22	24	22
Mortality of dams	0	1	0	1
Pregnant on C section	22	22	24	22
Clinical symptoms	---	---	+	+
Food consumption day 6-19 p.c. (g)	20.6	19.9	19.7	18.4
Body weight day 0 (g)	174.4	171	170.9	175.5
Body weight day 6 (g)	204.3	268.8	259.6*	261.2*
Body weight gain (days 6-19), g	71.8	69.2	61.2**	55.5**
Uterus weight (g)	52.4	51.2	45.8	48.3
Liver weight rel. (%)	4.15	4.13	4.33*	4.97**
Kidney weight rel. (%)	0.15	0.51	0.52	0.53
Kidney weight rel. (%)	0.17	0.18	0.19*	0.16*
Platelets (giga/l)	788	797	761	682**
Na (mmol/l)	141	140.6	140.4	139.4*
Cl (mmol/l)	100.1	100.1	99.8	98.1**
Inorganic phosphate (mmol/l)	1.8	1.84	1.91	2.13**
Urea (mmol/l)	7	7.36	7.54	8.01**
Total protein (g/l)	66.1	65.1	65.3	60.7**
Globulin (g/l)	30.5	29.8	29.6	25.8**
Cholesterol (mmol/l)	2.29	2.15	5.15	1.84**
+ = salivation, urine smeared fur (high dose only)
* = p</=0.05; ** = p</= 0.01, Dunnett test or Kruskal-Wallis and Wilcoxon
Caesarian section / fetal examination:
Dose (mg/kg bw)	0	50	200	600
Mated females	25	25	25	25
Pregnant on C section	22	22	24	22
Corpora lutea (mean)	10.8	10.8	10.8	11
Implantation sites (mean)	9.8	9.8	8.8	10
Post-implantation loss (mean %)	3.4	4.5	8.2	5.1
Dead fetuses/litter (mean %)	0	0	0	0
Resorption sites/litter (mean)	0.3	0.5	0.4	0.5
Mean No. of live fetuses/litter	9.5	9.3	8.8	9.5
Mean fetal weights, males (g)	3.6	3.7	3.6	3.2**
Mean fetal weights, females (g)	3.5	3.5	3.4	3.1**
% of fetuses with external malformations	0	0.5	0	0
% of fetuses with visceral malformations	0	0	1.1	0
% of fetuses with skeletal malformations	0	2.8	1.9	3.6
% of fetuses with external variations	0	0	0	0
% of fetuses with visceral variations	9.3	10	9.5	6.1
% of fetuses with skeletal variations	96	95	99	100

Applicant's summary and conclusion

Executive summary:

Under the conditions of this prenatal developmental toxicity study, the oral administration of Propylheptanol to pregnant Wistar rats from implantation to one day prior to the expected day of parturition (days 6 - 19 p.c.) elicited clear signs of maternal toxicity at dose levels of 200 mg/kg body weight/day and above. The test compound caused a number of clinical observations, reduced bodyweight gain, and caused a mild thrombocytopenia, slight changes in serum electrolytes, a mild impairment of kidney function, changes in protein metabolism and a slight induction of peroxisomal enzymes during pregnancy in the dams.

There were no substance-induced, dose-related influences on the gestational parameters and no test substance-induced indications of teratogenicity as well as prenatal developmental toxicity, up to and including the highest dose level (600 mg/kg body weight/day) . A slight retardation of embryo-/fetal development (delay of ossification and increased incidence of supernumerary thoracic vertebrae and supernumerary/wavy ribs) along with a slight decrease of the mean weight of the fetuses which exclusively was observed at 600 mg/kg body weight/day was considered

to be secondary to the clear disturbance of maternal homeostasis during pregnancy and not relevant in terms of developmental toxicity.

Based on these results, the no observed adverse effect level (NOAEL) for maternal toxicity is 50 mg/kg body weight/day. The developmental NOAEL is 200 mg/kg body weight/day. No indications for a teratogenic potential of the test compound were noted.