Reaction mass of sodium 1-methoxy-1-oxohexadecane-2-sulphonate and sodium methyl 2-sulphooctadecanoate

Toxicity to reproduction

Administrative data

Endpoint:

screening for reproductive / developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Study period:

May 2, 2000 to May 29, 2001

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference 1

Reference Type:

study report

Title:

Unnamed

Year:

2001

Report date:

2001

Reference 2

Reference Type:

publication

Title:

Unnamed

Year:

2003

Report date:

2003

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:

not specified

GLP compliance:

yes

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium 1-methoxy-1-oxohexadecane-2-sulphonate

EC Number:

223-676-0

EC Name:

Sodium 1-methoxy-1-oxohexadecane-2-sulphonate

Cas Number:

4016-24-4

Molecular formula:

There are different notations of the molecular formula, dependent on whether it is depicted as protonated or not: C17H34O5S.Na C17H33NaO5S C14H29CH(CO2CH3)SO3Na CH3(CH2)13CH(SO3Na)COOCH3

IUPAC Name:

sodium 1-methoxy-1-oxohexadecane-2-sulfonate

Test material form:

solid: particulate/powder

Details on test material:

- Physical state: white powder
- Storage condition of test material: cool dark place at 4ºC, airtight stopper (hygroscopical)

Test animals

Species:

rat

Strain:

Crj: CD(SD)

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- strain: Crj: CD (SD) IGS
- Source:Charles River Laboratories Japan, Inc
- Age at study initiation: 8 weeks
- Weight at study initiation: 364 to 420 g for males and 223 to 264 g for females.
- Fasting period before study: no
- Housing: in individual stainless steel cages
- Diet (e.g. ad libitum): ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 13 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 ± 3
- Humidity (%): 55 ± 10
- Air changes (per hr): >= 10
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

olive oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS:
Administered suspensions were prepared by mixing the substance with Japanese Pharmacopoeia-grade olive oil to designated concentration doses.

Details on mating procedure:

Estrous cycle test:
estrous cycle stages were determined microscopically

Observation of mating and delivery:
- on Day 15 of administration. Each pair was housed together in the same cage until mating was confirmed, with two weeks as the limit. The mating rate (%) [(number of animals that had mated/number of animals housed together) x 100] was calculated. Mating was confirmed with formation of the copulatory plug or sperm in vaginal smears (day 0 of pregnancy). Observation of the delivery state was also carried out at the same time, and the day upon which completion of delivery was confirmed was designated as Day 0 of lactation. Based on the observation results of mating and delivery, the conception rate (%) [(number of females conceiving/number of females that had mated) x 100] and birth rate (%) [(number of females giving birth/number of pregnant females) x 100] were calculated.

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

The hexadecanoic acid, 2-sulfo-, 1-methylester, sodium salt suspensions of 0.1 w/v% (for 5 mg/kg group), 0.4 w/v% (for 20 mg/kg group), 1.6 w/v% (for 80 mg/kg group) and 6.0 w/v% (for 300 mg/kg) prepared for the first and last times were analyzed using the HPLC method. The analysis was repeated three times, and the mean values were calculated.

Date of preparation Displayed value (w/v %)
0.1 0.4 1.6 6.0

May 30, 2000 0.10 0.40 1.7 6.2
July 8, 2000 0.09 0.40 1.6 5.8

The results shown below confirm that the suspensions were prepared at the designated concentrations.

Duration of treatment / exposure:

The administration duration ranged from 14 days before start of mating for both males and females, lasting 47 days for males and to 42 days at the shortest to 55 days at longest after birth just before day 4 of lactation for females.

Frequency of treatment:

once a day

Details on study schedule:

Premating exposure period for male and female: 14 days

Doses / concentrations

Doses / concentrations 1

Dose / conc.:

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

Doses / concentrations 2

Dose / conc.:

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

Doses / concentrations 3

Dose / conc.:

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

Doses / concentrations 4

Dose / conc.:

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

No. of animals per sex per dose:

10

Control animals:

yes, concurrent vehicle

Positive control:

Not applicable.

Examinations

Parental animals: Observations and examinations:

See Section 7.5.1 RA 223-676-0 (OECD 422)

Oestrous cyclicity (parental animals):

Estrous cycle
No. of pairs with successful copulation
No. of pregnant females
No. of pregnant females with live pups gestation lenght
No. of corpora lutea
No. of implantation sites

Sperm parameters (parental animals):

Parameters examined in all male parental generations: testis weight

Litter observations:

No. of pups born
No. of pups alive on day 0 of lactation
Sex ratio
No. of dead pups

Postmortem examinations (parental animals):

See Section 7.5.1 RA 223-676-0 (OECD 422)

Postmortem examinations (offspring):

The main organs in the chest and abdomen were observed macroscopically in dead pups at the time of death and in live pups, which were exsanguinated under ether anesthetic on Day 4 of lactation.

Statistics:

See Section 7.5.1 RA 223-676-0 (OECD 422)

Reproductive indices:

Copulation index (No. pairs with successful copulation/No. of pairs mated x 100)
fertility index (No. of pregnant animals/No. of animals with successful copulation x 100)
gestation index (No. of females with live pups/No. of pregnant females x 100)
implantation index (No. of implants/No. of corpora lutea x 100)
delivery index (No. of pups born/No. of implants x 100)

Offspring viability indices:

live birth index (No. of live pups born/No. of pups born x 100)
viability index on day 4 (No. of live pups on day 4 after birth/No. of live pups born x 100)

Results and discussion

Results: P0 (first parental generation)

Reproductive function / performance (P0)

Reproductive function: oestrous cycle:

no effects observed

Reproductive function: sperm measures:

not examined

Reproductive performance:

no effects observed

Details on results (P0)

See section 7.5.1 RA 223-676-0 (OECD 422)

Estrous cycle examination: No significant differences in the estrous cycle were noted between the study groups and the control group.

Mating and conception rates: All pairs successfully mated except for one in the 20 mg/kg group. No significant difference was seen in the time taken for mating. Conception in the control group was 70% because of failure in three pairs whose males exhibited abnormality of spermatogenesis, while the parameter was 100% for all study groups.

Corpora lutea count, number of implantations, and implantation rate:
No significant differences in corpora lutea count, the number of implantations, or implantation rate were found between any of the study groups and the control group.

Effect levels (P0)

Key result

Dose descriptor:

NOAEL

Effect level:

>= 300 mg/kg bw/day (actual dose received)

Based on:

test mat.

Sex:

male/female

Basis for effect level:

reproductive performance

Target system / organ toxicity (P0)

Critical effects observed:

not specified

Results: P1 (second parental generation)

Effect levels (P1)

Remarks on result:

not measured/tested

Target system / organ toxicity (P1)

Critical effects observed:

not specified

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:

not examined

Histopathological findings:

not examined

Details on results (F1)

No effects of the substance were observed on the viability and body weight of offspring. No malformations were found in offspring in any groups.

Effect levels (F1)

Key result

Dose descriptor:

NOAEL

Generation:

F1

Effect level:

>= 300 mg/kg bw/day (actual dose received)

Sex:

male/female

Basis for effect level:

other: for offspring development, no effects observed

Results: F2 generation

Effect levels (F2)

Remarks on result:

not measured/tested

Target system / organ toxicity (F2)

Critical effects observed:

not specified

Overall reproductive toxicity

Reproductive effects observed:

not specified

Any other information on results incl. tables

Reproductive and developmental parameters: No effects of this substance were observed on reproductive performance in males and females or on viability and body weight of offspring. No malformations were found in offspring in any groups.

Dose (mg/kg bw/day)	0	5	20	80	300
Estrous cycle (days)
Mean	4.2	4.0	4.0	4.0	4.0
SD	0.6	0.0	0.0	0.1	0.1
No. of pairs mated	10	10	10	10	10
No. of pairs copulated	10	10	9	10	10
Copulation index (%)	100	100	90	100	100
No. of pregnant females	7	10	9	10	10
Fertility index (%)	70	100	100	100	100
No. of pregnant females with parturition	7	8	9	10	10
No. of pregnant females with live pups	7	8	9	10	10
Gestation length(days)
Mean	22.4	22.5	22.4	22.6	22.5
SD	0.5	0.5	0.5	0.5	0.5
No. of corpora lutea
Mean	19.7	18.4	19.3	17.5	18.2
SD	2.8	4.1	3.3	1.9	2.6
No. of implantation sites
Mean	15.6	13.2	14.9	15.9	15.3
SD	1.6	6.3	2.4	1.5	2.4
No. of pups born
Mean	15.0	11.9	13.1	14.8	13.9
SD	1.7	6.4	4.0	2.0	1.7
Delivery index(%)
Mean	96.3	73.8	85.4	93.3	91.4
SD	4.8	39.4	20.0	10.1	6.1
Sex ratio(Male/female)	0.78	0.98	0.97	0.85	0.88
No. of pups alive on day 0 of lactation
Mean	15.0	14.9	13.0	14.4	12.3
SD	1.7	1.6	3.9	2.0	4.2
Live birth index(%)
Mean	100	100	99.3	97.4	88.3
SD	0	0	2.1	4.6	27.2
No. of pups alive on day 4 of lactation
Mean	14.7	14.9	12.9	14.2	12.0
SD	1.4	1.6	3.8	1.8	4.7
Viability index
Mean	98.3	100	99.3	98.7	89.3
SD	2.9	0	2.2	2.7	31.5

Applicant's summary and conclusion

Conclusions:

No effects of the substance were observed on reproductive performance in males and females or on viability and body weight of offspring. The NOAEL was determined to be 300 mg/kg bw/day for reproductive performance of parental animals and for offspring development.