Butanedioic acid, sulfo-, 4-[2-[(2-hydroxyethyl)amino]ethyl] ester, N-C18-unsatd. acyl derivs., disodium salts

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

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

Adequacy of study:

key study

Study period:

1976

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: see 'Remark'

Remarks:

only 2 doses tested. Allthough not all details on the study design were provided, the study was performed to the highest standards at the time of conduct. In the current study, a concurrent test article, dioctyl calcium sulfosuccinate (DCS) was also tested at 0.5, 1, 1.5 and 2% in the diet.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1976

Report date:

1976

Materials and methods

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Butanedioic acid, sulfo-, 1,4-bis (2-ethylhexyl) ester, sodium salt

IUPAC Name:

Butanedioic acid, sulfo-, 1,4-bis (2-ethylhexyl) ester, sodium salt

Test material form:

other: waxy solid

Details on test material:

- Name of test material (as cited in study report): Dioctyl caclium Sulfosuccinate
- Physical state: White, waxy solid
- Batch number: 07535.
- Analytical purity: >97%

Test animals

Species:

rat

Strain:

Sprague-Dawley

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Age at study initiation: About 2 months
- Weight at study initiation: Not provided
- Fasting period before study: Not provided
- Housing: Individually in hanging wire mesh cages
- Diet (e.g. ad libitum): Wayne Lab Meal ad libitum
- Water (e.g. ad libitum): Ad libitum
- Acclimation period: Not provided

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 24 ± 2°C
- Humidity (%): 50 ± 5%
- Air changes (per hr): Not provided
- Photoperiod (hrs dark / hrs light): 12/12

Administration / exposure

Route of administration:

oral: feed

Vehicle:

corn oil

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: 40% solution in corn oil

DIET PREPARATION
- Rate of preparation of diet (frequency): Not provided
- Mixing appropriate amounts with (Type of food): 1.0% and 2.0% admixed in Wayne Lab Meal
- Storage temperature of food: Not provided

VEHICLE
- Justification for use and choice of vehicle (if other than water):
- Concentration in vehicle: 40% solution in corn oil
- Amount of vehicle (if gavage):/
- Lot/batch no. (if required): Not provided
- Purity: Not provided

Details on mating procedure:

Not provided

Duration of treatment / exposure:

gestational days 6 through 15: dosing

Duration of test:

gestational days 6 through 15: dosing
gestational day 21: killing of the mothers and removing fetuses by cesarean section

Doses / concentrations

Remarks:

Doses / Concentrations:
1.0 % DSS , 2.0% DSS
Basis:

No. of animals per sex per dose:

22 female rats in dose 1.0% DSS
20 female rats in dose 2.0% DSS

Control animals:

yes, concurrent vehicle

Details on study design:

Not provided

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes (clinical condition and signs of illness)
- Time schedule: each day
- Cage side observations were not included.

BODY WEIGHT: Yes
- Time schedule for examinations:

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes
- Food consumption for each animal determined and mean daily diet consumption calculated as g food/kg body weight/day: Yes
- Compound intake calculated as time-weighted averages from the consumption and body weight gain data: Yes

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day #21
- Organs examined: Ovaries and uterine content

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Gravid uterus weight: No
- Number of corpora lutea: No
- Number of implantations: Yes
- Number of resorptions: Yes

Fetal examinations:

- External examinations: Yes (3336 of conceptuses)
- Soft tissue examinations: No
- Skeletal examinations: Yes (one half of the total number of fetuses)
- Head examinations: No
-Visceral examinations: Yes (one-half of the total number of fetuses were fixed in Bouin’s fluid for a detailed examination of visceral anomalies, using the slicing method of Wilson)

Statistics:

Maternal body-weight gains, maternal food consumptions and fetal weights were analyzed by Dunnett’s two-sided, multiple comparison test. Frequencies of resorptions and fetal abnormalities among litters were analyzed by the Mann-Whitney U test or the Chi-square test (with Yate’s correction), as appropriate.

Results and discussion

Results: maternal animals

Effect levels (maternal animals)

1

Dose descriptor:

NOAEC

Effect level:

1 other: %

Based on:

act. ingr.

Remarks:

in the diet

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOAEC

Effect level:

1 other: %

Based on:

act. ingr.

Remarks:

in the diet

Basis for effect level:

other: developmental toxicity

3

Dose descriptor:

NOAEL

Effect level:

1 074 mg/kg bw/day (nominal)

Based on:

act. ingr.

Basis for effect level:

other: maternal toxicity

4

Dose descriptor:

NOAEL

Effect level:

1 074 mg/kg bw/day (nominal)

Based on:

act. ingr.

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

TABLE 1. Maternal and fetal results of pregnant rats given various amounts if DSS in their diets during   

                gestational days 6 through 15.

Parameter	Dose:      Control	1.0% DSS	2.0% DSS
Maternal	Groups:            (I-A)	(II-A)	(II-B)
No. of pregnant rats	43	22	20
No. of pregnancies with total resorptions	0	0	1
No. of pregnancies with viable fetuses	43	22	19
Average weight gain of dams with viable fetuses(g):
Days 6 to 15	78	86	52*
Days 15 to 21	66	67	77
Avarage, apparent food intake of dams with viable fetuses (g/rat/day):
Days 6 to 15	22.5	24.8	21.4
Days 15 to 21	28.6	32.1	33.4
Calculated compound consumed (mg/kg/day)	--	1074	1988
Litters
Total number of: implantations	411	203	219
Resorptions (% occurence)	23 (5.6)	8 (3.9)	30*^a (13.7)
Dead fetuses (% occurrence)	3 (0.7)	0	1 (0.5)
Viable fetuses (% occurrence)	385 (93.7)	195 (96.1)	188 (85.5)
Fetal weight (g)	4.6	5.2	4.7
Litters size (viable fetuses)	8.9	8.9	9.9
External major malformations^1: No. of litters affected (% occurrence)	0	0	5* (25.0)
No. of fetuses affected (% occurrence)	0	0	36*^a (20.2)

* Significantly different from control (p< 0.05)

^a Significance by Chi-square, but not Mann-Whitney U test

¹ Primarily, exencephaly varying degrees and associated anomalies (See TABLE 2)

    

TABLE 2. Morphological observations of fetuses delivered from rats given DSS in their diets on

                gestational days 6 through 15.

Morphology	Dose:        Control	1.0% DSS	2.0% DSS
External observations^1:	Groups:    (I-A)	(II-A)	(II-B)
Total number examined	388^a	195	189
Major anomalies:   Adactyly	0	0	0
Hemimelia	0	0	0
Schistocelia	0	0	2
Dome shaped head	0	0	0
Cranial bubble (1-2mm)	0	0	9*
Exencephaly	0	0	18*
Exencephaly (cleft condition)	0	0	7*
Anencephaly	0	0	0
Spina bifida	0	0	6
Macroglossia	0	0	0
Micro- or anophtalmia	0	0	3
Defects:   Hematoma (subcutaneous)	2	0	0
Edamatous abdomen	0	0	0
Tail short & curled	0	0	0
Abducted fifth digit, left    Rear foot	0	0	1

¹ Fetuses may have more than one defect

^a Fifty-four fetuses examined grossly only. (Shipment c valid as controls only)

      *Significantly different from control (p< 0.05) by Chi-square only

 

TABLE 3. Visceral observations of fetuses delivered from rats given DSS in their diets on gestation days

                 6 through 15.

Visceral observations	Dose:      Control	1.0 % DSS	2.0% DSS
	Groups:       (I-A)	(II-A)	(II-B)
Total number of fetuses examined	165^a	98	91
Defects^1:   Exencephalous   characteristics	0	0	11*
Dilated lateral ventricles	1	3	5
Microphtalmia	0	1	0
Anolphtalmia	0	0	23*
Retinal foldings	0	0	0
Anotia or microtia	0	0	0
Cleft palate	0	0	1
Situs transversus – aorta, esophagus   & stomach	1	0	0
Intestinal agenesis	0	0	0
Arch of aorta absent or right sided	0	0	0
Diaphragmic hernia	0	0	1
Dilated renal pelves	2	0	3
Ectopic kidneys(s) &/or variation in size	1	0	0
Renal agenesis	0	0	2
Dilated ureters	6	0	3
Adrenal agenesis	0	0	1
Testes – ectopic or enlarged	1	0	1
Hermaphroditism	0	0	3

¹Fetuses may have more than one defect

^aExcludes 1 fetus lost

*Significantly different from control (p<0.05) by Chi-square only

TABLE 4. Skeletal observations of fetuses delivered from rats given DSS in their diets on gestation days

                6 through 15.

 

Skeletal observations	Dose:      Control	1.0 % DSS	2.0% DSS
	Groups:       (I-A)	(II-A)	(II-B)
Total number of fetuses examined	167^a	97	98
Defects^1:   Cranial bones,   incomplete to lack of ossification :    Nasal	0	0	4
Frontal	1	0	20*
Parietal	1	1	19*
Interparietal	1	2	18*
Supraoccipital	0	0	15*
Exoccipital	0	0	2
Atlas	0	0	1
Zygomatic	0	0	1
Premaxilla	0	0	1
Tympanic bullae	0	0	5
Mandibles	0	0	1
Hyoid	0	0	3
Eye orbit, reduction	0	0	0
Exoccipital, fused to atlas	0	0	0
Vertebrla column, curved &/or open	0	0	5
Vertebrae:
misshapened &/or retarded     development	0	0	5
thoracic, bipartite centra	2	1	5
lumbar, bipartite centra	0	0	2
Sternebrae:
fused	0	0	0
hypoplastic to absent	0	0	1
one or two absent	1	0	0
staircase	0	0	3
bipartite	0	0	2
Rib(s):
accesory	6	5	5
Absent or less developed	0	0	7*
wavy	2	2	0
fused	0	0	2
Pelvic, hypoplastic to absent	0	0	0
Brachydactyly	0	0	0
Syndactyly	0	0	0
Adactyly	0	0	0
Hemimelia & small scapula	0	0	0

¹Fetuses may have more than one defect

^aExcludes 1 fetus destroyed during cleaning process

*Significantly different from control (p<0.05) by Chi-square only

 

Applicant's summary and conclusion

Conclusions:

Subtoxic dietary levels of 1.0% docusate sodium ingested on gestational days 6 through 15 showed no adverse effects on the various maternal or fetal parameters. Near toxic or toxic dietary levels of 2.0% DSS produced significant incidences of resorptions (13.7%) and gross abnormalities either among litters (25.0%) or fetal populations (20.2%) as compared to controls. Interpretation of the results of the present experiments, in which only maternally toxic dose levels induce teratogenicity, indicates no real hazard with the recommended human use of these surfactants.

Executive summary:

Prenatal developmental toxicity was studied in rats dosed from day 6 to day 15 of gestation by dietary administration of docusate sodium at dose levels of 1.0 and 2.0 % in the diet.Subtoxic dietary levels of 1.0% showed no adverse effects on the various maternal or fetal parameters. Near toxic or toxic dietary levels of 2.0% docusate sodium produced significant depressions in maternal weight-gains and increased incidences of resorptions (13.7%) and gross abnormalities either among litters (25.0%) or fetal populations (20.2%) as compared the controls. These abnormalities consisted primarily of exencephaly of varying degrees with, at times, spina bifida, anophtalmia and associated skeletal defects. The visceral observations confirmed the significance of the exencephalous characteristics and anophtalmia for the group given dietary levels of 2.0%. In this group, skeletal observations revealed a significant incidence of incomplete ossification to absence of the various cranial bones, a curved or open vertebral column, and a variety of defects of the vertebrae and ribs. There were significant depressions in maternal weight gains in the 2.0% DSS-group . Interpretation of the results of the present experiment, in which only maternally toxic dose levels induce teratogenicity, indicates no real hazard with the recommended human use of these surfactants.

The concentration of 1% in the diet is considered as maternal and developmental NOAEL. This dose level corresponded with 1074 mg/kg body weight, as calculated in the study.