Methyl undec-10-enoate

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Remarks:

based on test type (migrated information)

Type of information:

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

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

This read-across is based on a Klisch-1-rated study on a reproduction/developmental toxicity screening test OECD 421 of the structural analoue undecylenic acid. Justification for read-across : This study performed with undecylenic acid is used for read-across to evaluate methyl 10 -undecenoate. This read-across is based on the following justification. Referring to ECHA's "Guidance on information requirements and chemical safety assessment - Chapter R.6: QSARs and grouping of chemicals", endpoint information is read-across from a structural analogue. A structural analogue is a source chemical whose physico-chemical and toxicological properties are likely to be similar to the target chemical as a result of structural similarity. The similarity may be based on a common precursor and/or breakdown product, that results via physical or biological processes (metabolic pathway similarity). This is used to examine related chemicals, such as acid/ester/salt. Since the target chemical methyl-10-undecenoate is the methyl ester of the source chemical undecylenic acid, read-across between the two substances based on structural analogy therefore technically is possible. The scientific justification for the read-across of the study on oral repeat dose toxicity from undecylenic acid to methyl-10 –undecenoate is based on the similiar behaviour of the two substances observed during the six in-vivo studies on acute effects.

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2009

Report date:

2009

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 421 (Reproduction / Developmental Toxicity Screening Test)

Deviations:

yes

Remarks:

Some relatively minor deviations are discussed in the study report. These deviations were not considered to have compromised the validity or integrity of the study.

GLP compliance:

yes (incl. QA statement)

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Undec-10-enoic acid

EC Number:

203-965-8

EC Name:

Undec-10-enoic acid

Cas Number:

112-38-9

IUPAC Name:

undec-10-enoic acid

Constituent 2

Reference substance name:

Undecylenic acid

IUPAC Name:

Undecylenic acid

Details on test material:

- Name of test material (as cited in study report): undecylenic acid
- Substance type: organic
- Physical state: white solid
- Analytical purity: 98.79% on analytical certificate or 98.75% on test article description
- Impurities (identity and concentrations): no data
- Purity test date: 2009-04-04
- Lot/batch No.: 0607007
- Expiration date of the lot/batch: 22 December 2007
- Stability under test conditions: no data
- Storage condition of test material: at room temperature (do not stored above 25°C)
- Other:

Test animals

Species:

rat

Strain:

Sprague-Dawley

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Laboratories France, L’Arbresle, France
- Age at study initiation: (P) 11 wks
- Weight at study initiation: (P) Males: mean body weight of 441 g (range: 386 g to 506 g); females: mean body weight 251 g (range: 223 g to 280 g)
- Fasting period before study: no data
- Housing: The animals were individually housed (except during mating) in suspended wire-mesh cages (43.0 x 21.5 x 18.0 cm). A metal tray, containing autoclaved sawdust (SICSA, Alfortville, France), was placed under each cage. Shortly before parturition, the females were moved to polycarbonate cages (43.0 x 21.5 x 20.0 cm) with wood shavings as nesting material.
- Diet (e.g. ad libitum): The animals had free access to SsniffR/M-H pelleted maintenance diet, batch Nos. 6557303 and 9557111 (SSNIFF Spezialdiäten GmbH, Soest, Germany) which was distributed weekly.
- Water (e.g. ad libitum): The animals had free access to bottles containing tap water (filtered with a 0.22 μm filter).
- Acclimation period: 14 days before the beginning of the treatment period


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 2°C
- Humidity (%): 50 ± 20%
- Air changes (per hr): about 12 cycles/hour of filtered, non-recycled air
- Photoperiod (hrs dark / hrs light): 12h/12h (7:00 - 19:00)


IN-LIFE DATES: From: 2007-06-12 To: 2007-08-21

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

corn oil

Details on exposure:

DIET PREPARATION
- Rate of preparation of diet (frequency): Diet distributed weekly. Each batch of diet was analyzed by the supplier for composition and contaminant levels
- Storage temperature of food: no data

VEHICLE
- Justification for use and choice of vehicle (if other than water): no justification given
- Concentration in vehicle: 10, 30 and 90 mg/mL
- Amount of vehicle (if gavage): 5 mL/kg bw / day
- Lot/batch no. (if required): batch No. 065K0077, supplied by Sigma
- Purity: no data

Details on mating procedure:

- M/F ratio per cage: one female was placed with one male
- Length of cohabitation: Each female was placed with the same male until mating occurs or 14 days have elapsed.
- Proof of pregnancy: vaginal plug or sperm in vaginal smear referred to as day 0 post coitum
- After ... days of unsuccessful pairing replacement of first male by another male with proven fertility.
- Further matings after two unsuccessful attempts: no
- After successful mating each pregnant female was caged (how): Shortly before parturition, the females were moved to polycarbonate cages (43.0 x 21.5 x 20.0 cm) with wood shavings as nesting material.
- Any other deviations from standard protocol: none reported

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The test item concentration of samples taken from each dosage form (including the control) prepared for use in weeks 1, 2 and 4 (all groups) or week 8 (group 2, see § Study plan adherence) was determined. On 27th June 2007, the control dosage form was re-sampled and analyzed in duplicate further to abnormal values obtained during the first analysis. Only replicated data was reported. The analytical procedure used is presented in the study report.
Acceptance criterion: actual concentration: nominal value ± 10%.

Duration of treatment / exposure:

Males: 2 weeks before mating, during the mating period (2 weeks), until sacrifice (i.e. at least 4 weeks in total)
Females: 2 weeks before mating, during the mating period (2 weeks), during pregnancy, during lactation until day 4 post-partum inclusive (until sacrifice).

Frequency of treatment:

once a day, 7 days per week

Details on study schedule:

- F1 parental animals not mated until [...] weeks after selected from the F1 litters. not applicable
- Selection of parents from F1 generation when pups were [...] days of age. not applicable
- Age at mating of the mated animals in the study: 11 weeks

Doses / concentrations

Doses / concentrations 1

Remarks:

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

Doses / concentrations 2

Remarks:

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

Doses / concentrations 3

Remarks:

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

No. of animals per sex per dose:

10 males, 10 females

Control animals:

yes, concurrent vehicle

Details on study design:

- Dose selection rationale: The dose-levels were selected in agreement with the Sponsor, following the results of a previously conducted prenatal toxicity study (CIT/Study No. 31486 RSR) in which the test item, UNDECYLENIC ACID (batch No. 0607007), was administered daily by gavage to pregnant
Sprague-Dawley rats from day 6 to day 20 p.c. at the dose-levels of 150 or 450 mg/kg/day. At 750 mg/kg/day, the death of eight animals occurred before mid gestation and the surviving females were prematurely sacrificed. Therefore, the dose-level of 450 mg/kg/day is anticipated to produce minor signs of toxicity (750 mg/kg/day exceeded the MTD), and the two other dose-levels were selected using a factor of 3 between each dose.
- Rationale for animal assignment (if not random): Allocation to groups: during the pre-treatment period, the required number of animals (40 males
and 40 females) were selected according to body weight (recorded twice for planning reasons, see § Study plan adherence) and clinical condition and allocated to groups (by sex), according to a computerized stratification procedure (these data were not presented in the report), so that the average body weight of each group was similar.
- Other:

Positive control:

not applicable

Examinations

Parental animals: Observations and examinations:

CAGE SIDE OBSERVATIONS: Yes
- Time schedule: Each animal was checked at least twice a day for mortality and signs of morbidity. The pups were observed daily for clinical signs.
- Cage side observations checked in Appendices 4 to 7 of the original study report were included.


DETAILED CLINICAL OBSERVATIONS: Yes
- Time schedule: Each animal was checked at least twice a day for mortality and signs of morbidity. The pups were observed daily for clinical signs.


BODY WEIGHT: Yes
- Time schedule for examinations: Males: days 1, 8, 15, 29; Females: days 1, 8, 15 premating period; days 0, 7, 14, 20 pregnancy period; days 1, 4 post partum; days 1 - 4 of lactation


FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): not applicable


WATER CONSUMPTION AND COMPOUND INTAKE (if drinking water study): not applicable
- Time schedule for examinations:


OTHER:

Oestrous cyclicity (parental animals):

no data

Sperm parameters (parental animals):

no data

Litter observations:

STANDARDISATION OF LITTERS
- Performed on day 4 postpartum: no
- If yes, maximum of [...] pups/litter ([...]/sex/litter as nearly as possible); excess pups were killed and discarded.


PARAMETERS EXAMINED
The following parameters were examined in F1 offspring:
number and sex of pups, stillbirths, live births, postnatal mortality, presence of gross anomalies, weight gain, physical or behavioural abnormalities


GROSS EXAMINATION OF DEAD PUPS:
yes, for external and internal abnormalities; possible cause of death was not determined for pups born or found dead

Postmortem examinations (parental animals):

SACRIFICE
- Male animals: All surviving animals after the end of the mating period
- Maternal animals: All surviving animals from day 5 post-partum


GROSS NECROPSY
- A macroscopic post-mortem examination of the principal thoracic and abdominal organs (with special attention paid to the reproductive organs) was performed on all parent animals including any that died during the study. In all females, the number of implantation sites was recorded.


HISTOPATHOLOGY / ORGAN WEIGHTS
The tissues indicated in the following table were prepared for microscopic examination and weighed, respectively.
The macroscopic lesions and the following tissues from all parent animals were preserved in 10% buffered formalin (except for testes and epididymides which were fixed in Davidson’s fixative):
. epididymides,
. ovaries,
. prostate,
. seminal vesicles,
. testes,
. uterus (horns and cervix),
. vagina.

Postmortem examinations (offspring):

SACRIFICE
- The F1 offspring not selected as parental animals and all F2 offspring were sacrificed at 5 days of age.
- These animals were subjected to postmortem examinations (macroscopic and/or microscopic examination) as follows:
A gross external examination was performed on all pups including those that died during lactation or were sacrificed moribund. There was no preservation of tissues.

GROSS NECROPSY: not conducted


HISTOPATHOLOGY / ORGAN WEIGTHS: not applicable

Statistics:

Data other than organ weights
Mean values were compared by one-way variance analysis and Dunnett's test, (mean values being considered as normally distributed, variances being considered as homogeneous). Percentage values were compared by Fisher's exact probability test.

Organ weights
PathData software (version 6.2b5) was used for the statistical analysis of organ weight data (level of significance: 0.05 or 0.01).

Reproductive indices:

Data are expressed as group mean values ± standard deviation (body weight, food consumption, corpora lutea, implantations, fetuses, resorptions, pups, gestation length) or as proportions (pre-implantation loss, post-implantation loss, fetal observations, gestation index, live birth index, viability index). Whenever necessary, the experimental unit of comparison was the litter.
The calculations were performed for each group as follows:
Pre-implantation loss: ((Number of corpora lutea - Number of implantation sites) / (Number of corpora lutea)) x 100
Post-implantation loss: ((Number of implantation sites - Number of live concepti) / (Number of implantations)) x 100
Mating index: (Number of mated animals - Number of paired animals) / x 100
Fertility index: (Number of pregnant female partners / Number of mated pairs) x 100
Gestation index: (Number of females with live born pups / Number of pregnant females) x 100
Live birth index: (Number of live born pups / Number of delivered pups) x 100

Offspring viability indices:

Viability index on day 4 post-partum:
(Number of surviving pups on day 4 post-partum / Number of live born pups) x 100

Results and discussion

Results: P0 (first parental generation)

General toxicity (P0)

Clinical signs:

effects observed, treatment-related

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

Other effects:

no effects observed

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

not examined

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P0)

CLINICAL SIGNS AND MORTALITY (PARENTAL ANIMALS)
At 450 mg/kg/day, two males died on days 3 and 35 without ante-mortem clinical signs of toxicity and no evident cause of death were diagnosed at macroscopic examination.
At 150 mg/kg/day group, hypersalivation was observed in males and females and one male had loud breathing transiently.
At 50 mg/kg/day, hypersalivation was the single effect, but observed to a lower extent than in previous treated groups.

BODY WEIGHT AND FOOD CONSUMPTION (PARENTAL ANIMALS) no effects


TEST SUBSTANCE INTAKE (PARENTAL ANIMALS) no effects


REPRODUCTIVE FUNCTION: ESTROUS CYCLE (PARENTAL ANIMALS) not examined


REPRODUCTIVE FUNCTION: SPERM MEASURES (PARENTAL ANIMALS) not examined


REPRODUCTIVE PERFORMANCE (PARENTAL ANIMALS) no effects


ORGAN WEIGHTS (PARENTAL ANIMALS) no effects


GROSS PATHOLOGY (PARENTAL ANIMALS) no effects


HISTOPATHOLOGY (PARENTAL ANIMALS) no effects


OTHER FINDINGS (PARENTAL ANIMALS) no effects

Effect levels (P0)

1

Dose descriptor:

NOEL

Remarks:

reproductive performance

Effect level:

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

Sex:

male/female

Basis for effect level:

other: see 'Remark'

2

Dose descriptor:

NOAEL

Remarks:

parental toxicity

Effect level:

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

Sex:

male/female

Basis for effect level:

other: mortality: At 450 mg/kg/day, two males died on days 3 and 35 without ante-mortem clinical signs of toxicity and no evident cause of death were diagnosed at macroscopic examination.

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:

no effects observed

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Histopathological findings:

not examined

Details on results (F1)

s indicated above

VIABILITY (OFFSPRING)


CLINICAL SIGNS (OFFSPRING)


BODY WEIGHT (OFFSPRING)


SEXUAL MATURATION (OFFSPRING)


ORGAN WEIGHTS (OFFSPRING)


GROSS PATHOLOGY (OFFSPRING)


HISTOPATHOLOGY (OFFSPRING)


OTHER FINDINGS (OFFSPRING)

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

Tab. 2: Summary of relevant clinical signs

Sex	Male				Female
Dose level (mg/kg/d)	0	50	150	450	0	50	150	450
Male
Ptyalism	0	4	10	9	n.a.	n.a.	n.a.	n.a.
Loud breathing	0	0	1	4	n.a.	n.a.	n.a.	n.a.
Dyspnea	0	0	0	0	n.a.	n.a.	n.a.	n.a.
Female
Ptyalism	n.a.	n.a.	n.a.	n.a.	0	4	6	10
Loud breathing	n.a.	n.a.	n.a.	n.a.	0	4	7	9
Dyspnea	n.a.	n.a.	n.a.	n.a.	0	2	7	8

n.a.: not applicable

Hypersalivation was observed from week 1 of dosing in general and continued throughout the study, with dose-related increase in terms of onset, incidence and duration. This clinical sign was considered not to be adverse as it likely represents a reaction to the dosing procedure and not a direct effect of UNDECYLENIC ACID. Loud breathing was observed in a single male given 150 mg/kg/day and in four males given 450 mg/kg/day. One out of these four males experienced dyspnea. These signs of respiratory discomfort were transiently observed.

In all other observations made (body weight, body weight gain, mating data, female fertility, delivery data, observations on the pups, and pathology) no significant deviations of the dose groups compared to the control group were being noted.

Applicant's summary and conclusion

Conclusions:

This robust study summary is a read-across, based on a Klimisch-1-rated reproduction/developmental toxicity screening test OECD 421 with the structural analogon undecylenic acid. Based on the results of this study, the dose-level of 150 mg/kg/day was considered to be the No Observed Adverse Effect Level (NOAEL) for parental toxicity, and the dose-level of 450 mg/kg/day was the NOEL for reproductive performance. Since there is no need for classification of test item undecylenic acid as to its reprotoxic properties, the same is being proposed for methyl-10-undecenoate.

Executive summary:

The objective of this study was to evaluate the potential toxic effects of the test item, UNDECYLENIC ACID, following daily oral administration (gavage) to male and female rats from before mating, through mating and gestation until the end of the parturition period. This study should provide initial information on possible toxicological effects likely to arise from repeated exposure over a relatively limited period of time and on male and female reproductive performance, such as gonadal function, mating behavior, conception, development of the conceptus and parturition. The rat was chosen because it is a rodent species commonly accepted by regulatory authorities for this type of study and the Sprague-Dawley strain was selected since background data from previous studies are available at CIT. The oral route was selected since it is a route of administration which is requested by the regulatory authorities for this type of test item. The dose-levels were selected in agreement with the Sponsor, following the results of a previously conducted prenatal toxicity study (CIT/Study No. 31486 RSR).

The test item, UNDECYLENIC ACID was administered to male and female Sprague-Dawley rats by oral route (gavage), under the above detailed experimental conditions, at the dose-levels of 50, 150 or 450 mg/kg/day. At 450 mg/kg/day, two males died on days 3 and 35 without ante-mortem clinical signs of toxicity and no evident cause of death were diagnosed at macroscopic examination. Hypersalivation was observed in males and females, and respiratory difficulties (loud breathing and dyspnea) were noted transiently in males. At 150 mg/kg/day group, hypersalivation was observed in males and females and one male had loud breathing transiently. At 50 mg/kg/day, hypersalivation was the single effect, but observed to a lower extent than in previous treated groups. There were no substance-induced effects on the male and female reproductive performance, or on the progeny at any dose-level. No treatment-related effects were noted on testes or epididymides weights, at necropsy or on microscopic examination of the testes, epididymides or ovaries in treated rats. Based on the results of this study, the dose-level of 150 mg/kg/day was considered to be the No Observed Adverse Effect Level (NOAEL) for parental toxicity, and the dose-level of 450 mg/kg/day was the NOEL for reproductive performance. There is no need for classification of test item undecylenic acid as to its reprotoxic properties.

Justification for read-across:

This robust study summary is a read-across, based on a Klimisch-1-rated reproduction/development toxicity screening test OECD 421 with the structural analogue undecylenic acid. For this read-across the following justification is given.

Referring to ECHA's "Guidance on information requirements and chemical safety assessment - Chapter R.6: QSARs and grouping of chemicals", endpoint information is read-across from a structural analogue. A structural analogue is a source chemical whose physico-chemical and toxicological properties are likely to be similar to the target chemical as a result of structural similarity. The similarity may be based on a common precursor and/or breakdown product, that results via physical or biological processes (metabolic pathway similarity). This is used to examine related chemicals, such as acid/ester/salt.

Since the target chemical methyl-10-undecenoate is the methyl ester of the source chemical undecylenic acid, read-across between the two substances based on structural analogy therefore technically is possible. The scientific justification for the read-across of the prenatal development toxicity study from undecylenic acid to methyl-10 –undecenoate is based on the similiar behaviour of the two substances observed during the six in-vivo studies on acute effects (see following table). 

 

	Methyl-10-undecenoate (methyl ester of undecylenic acid)	Undecylenic acid
Acute toxicity: oral	Acute Oral 4 / Xn R22 LD 50 = 1563 mg/kg	No classification (LD 50 > 2000 mg/kg)
Acute toxicity: dermal	No classification	No classification
Acute toxicity: inhalation (4h)	Acute Inhal. 4 / Xn R20	Waived
Skin sensitisation	No classification	No classification
Skin irritation in vivo	No classification	Skin Irrit. 3, H316 (UN-GHS only) No classification under CLP
Eye irritation in vivo	No classification	Eye irrit. Cat. 2A / Xi R36
Prenatal development toxicity study	No classification proposed Read-across from undecylenic acid	No classification

 

- Acute oral toxicity: methyl-10 -undecenoate is classified as category 4, which is the lowest toxicity category. Since the LD50 of methyl-10 -undecenoate (1563 mg/kg) still is in the same order of magnitude compared to the LD50 of undecylenic acid (> 2000 mg/kg), the observed slight differences of the acute oral toxic effect should be insignificant in a prenatal development toxicity study.

- Acute dermal toxicity, and skin sensitization: both substances with the same results "not classified".

- Acute inhalative toxicity: methyl-10 –undecenoate is classified as category 4, which is the lowest toxicity category in CLP. This rather small inhalative toxic effect should be insignificant for the oral-application-based prenatal development toxicity study (note: for the undecylenic acid this study was waived, since undecylenic acid is a solid).

- Skin irritation: Undecylenic acid is classified as Xi R38 in the old EU classification system. This would translate to Skin Irrit. 3 (H316) in the UN-GHS system, but not in the EU-GHS (CLP), which has only category 1 and 2 for skin irritation. Therefore the skin irritating potential of the acid can be seen as negligible.

- Eye irritation: In contrast to methyl-10 -undecenoate, undecylenic acid is classified as Eye Irrit. 2. That the acid is somewhat more locally irritating than the methyl ester can be expected. Still, this effect should be insignificant when it comes to in-vivo studies which are based on oral test item application.

 

Conclusion: Even though the two substances were showing certain discrepancies during the in-vivo studies on different the acute toxic effects, eventually the similarities outweigh the differences, thus the read-across of the reproduction/developmental screening test should be permissible. It should also be noted that only some relatively minor toxic effects were being observed, not exceeding category 4 for acute toxicity (methyl-10-undecenoate) or category 2 for eye irritation (undecylenic acid), indicating the generally limited hazardous effects exhibited by the two substances. Since furthermore the physical-chemical properties of source and target substance mostly are comparable as well, to accepting the above suggested read-across is being proposed.