Didecyldimethylammonium chloride

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 1

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Reference 2

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2004

Reference 3

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Didecyldimethylammonium chloride

EC Number:

230-525-2

EC Name:

Didecyldimethylammonium chloride

Cas Number:

7173-51-5

Molecular formula:

C22H48N Cl

IUPAC Name:

didecyldimethylammonium chloride

Details on test material:

IUCLID4 Test substance: as prescribed by 1. 2 as typical marketed substance (act: 40%, water: 60%)
Composition: ca. 40% Didecyldimethylammonium chloride (CASno.: 7173-51-5) in water only. batchno: WIR03048

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Species: Rabbit
Strain: KBL New Zealand White, Specific Pathogen Free (S.P.F.).
Source: Charles River Laboratories (Elevage Scientifique des Dombes, Châtillon-sur-Chalaronne, France).
Sex: Female
Age/weight at study initiation: 18-20 weeks; mean body weight of 3494 g (range: 3105 g to 3940 g).
Number of animals per group: 22
The animals were individually housed in stainless steel cages, in a barriered rabbit unit, under specific pathogen free (SPF) standard laboratory
conditions: temperature : 18 ± 3°C; relative humidity : 50 ± 20%; light/dark cycle : 8h dark/16h light (5:00 - 21:00);
ventilation : about 8 to 10 cycles/hour of filtered, non-recycled air.
Control animals: Yes
Mating period: Were mated at the breeder's facilities. The day of confirmed mating (visual assessment) was designated as day 0 post-coitum (p.c.) or day 0 of gestation (GD 0). The animals were supplied to CIT on day 1 post-coitum; consequently they were acclimated for a period of 5 days before
the beginning of the treatment period.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

Administration/ Exposure: Oral
Duration of exposure Rabbit: day 6-28 of gestation
Postexposure period: None, as exposure period was until day prior to term.
Type: oral gavage
Concentration Gavage; 0, 4, 12 or 32 mg DDAC/kg bw . The choice of the dose-levels was based on a preliminary study of effects on embryo-fetal
development in rabbits (CIT/Study No. 26153 RSL), in which the test item, DDAC, was administered to pregnant female rabbits, from day 6 to day
28 of pregnancy at the dose-levels of 4, 16 or 32 mg DDAC/kg/day.
Vehicle: Aqueous solution with purified water.
Concentration in vehicle: 0, 1.33, 4, 10.66 mg/mL. The test item dosage forms were prepared daily and stored at room temperature prior to use.
Chemical analysis of DDAC in dosage form: The concentration of samples taken from each control and test item dosage form prepared for use on
the first day of treatment and on the last day of treatment was determined. Values were found to be in agreement with nominal concentration ± 10%.
Total volume applied: 3 mL/kg BW/day
Controls: Vehicle

Analytical verification of doses or concentrations:

yes

Details on analytical verification of doses or concentrations:

At the start and at end of the study.

Details on mating procedure:

Females were mated at breeder's facilities and the day of confirmed mating was designated as Day 0.

Duration of treatment / exposure:

Day 6 to 28 post coitum

Frequency of treatment:

Daily

Duration of test:

24 days

Doses / concentrations

Remarks:

Doses / Concentrations:
Gavage 0, 4, 12 or 32 mg a.i./kg bw/day
Basis:
actual ingested

No. of animals per sex per dose:

22

Control animals:

yes, concurrent no treatment

Details on study design:

Groups of 22 mated female KBL New Zealan White rabbits were gavaged the test substance at 4, 12 and 32 mg/kg/day from day 6 to day 28 post coitum. One group of 22 mated females received the vehicle alone. Clinical sign and mortality were checked daily. Bosy weight and food consumption were recorded at designated intervals. On day 29 post coitum, the does were sacrificed and subjected to macroscopic examination of the major organs. The gravid uterus was weighed. The fetuses removed and litter parameters were examined. The fetuses were then weighed and subjected to external and internal tissue, organs and bone examination.

Examinations

Maternal examinations:

Refer to study design

Ovaries and uterine content:

Refer to study design

Fetal examinations:

Refer to study design

Statistics:

Refer to study design

Indices:

Refer to study design

Historical control data:

Refer to study design

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
In absence of a dose-related increase of death/abortion at 4 and 12 mg DDAC/kg/day and with the abortion of one female in the control group, the mortality at 4 and 12 mg DDAC/kg/day were considered to be most probably incidental and not related to treatment with the test item. 32 mg DDAC mg/kg/day, death/abortion in 3 females were ascribed to the treatment with the test item. When given 12 mg DDAC/kg/day, colored urine and loud breathing was observed in one female from GD 22 each. Both animals however, showed no findings at autopsy.  At 32 mg DDAC/kg/day, the number of animals showing clinical signs was greater than in the control group, and most of these clinical signs (colored urine, soft feces, soiled urogenital area) were recorded at the end of the gestation period, along with an absence of feces observed for three animals. Presence of blood in the bedding was noted in two females on GD 16 or 22 and one female showed an emaciated appearance on GD 29. No other clinical signs were considered to be treatment-related; absence of feces is commonly recorded at the end of pregnancy and was therefore not considered to be treatment-related at 4 mg DDAC/kg/day. Overall, there seems to be a dose related effect, tending to lower body weights at higher dose levels which corresponding to lower food consumption related to palatability of the compound in the diet.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 4 mg/kg bw/day

Based on:

act. ingr.

Basis for effect level:

other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:yes

Details on embryotoxic / teratogenic effects:
There is a big variability in litter data. The low dose group shows higher number of dead fetuses, post implantation loss and lower fetal weight compared to control. On the other hand, the number of live fetuses is even higher than of control. At the mid-dose group comparable to control again. The high-dose group of 32 mg DDAC/kg/d resulted to an increased post-implantation loss, decrease in live fetuses with a decreased fetal body weight, and high number of dead fetuses. Upon examination of the soft tissue, presence of whitish fluid in the abdomens of 5/6 fetuses (one litter) was observed. No relevant malformations or variations were observed during the fetal evaluation. At lower concentrations, litter parameters were not affected by the test treatment and no evidence of treatment-related findings were noted at skeletal examinations of the fetuses.

Effect levels (fetuses)

Key result

Dose descriptor:

NOAEL

Effect level:

ca. 12 mg/kg bw/day

Based on:

act. ingr.

Sex:

male/female

Basis for effect level:

other: teratogenicity

Fetal abnormalities

Key result

Abnormalities:

not specified

Overall developmental toxicity

Key result

Developmental effects observed:

not specified

Any other information on results incl. tables

Result: no specific concerns for developmental toxicity by DDAC.

In absence of a dose-related increase of death/abortion at 4 and 12 mg DDAC/kg/day and with the abortion of one female in
the control group, the mortality at 4 and 12 mg DDAC/kg/day were considered to be most probably incidental and not
related to treatment with the test item. 32 mg DDAC mg/kg/day, death/abortion in 3 females were ascribed to the
treatment with the test item.
When given 12 mg DDAC/kg/day, colored urine and loud breathing was observed in one female from GD 22 each. Both
animals however, showed no findings at autopsy.  At 32 mg DDAC/kg/day, the number of animals showing clinical
signs was greater than in the control group, and most of these clinical signs (colored urine, soft feces, soiled
urogenital area) were recorded at the end of the gestation period, along with an absence of feces observed for three
animals. Presence of blood in the bedding was noted in two females on GD 16 or 22 and one female showed an emaciated
appearance on GD 29. No other clinical signs were considered to be treatment-related; absence of feces is commonly
recorded at the end of pregnancy and was therefore not considered to be treatment-related at 4 mg DDAC/kg/day.
Overall, there seems to be a dose related effect, tending to lower body weights at higher dose levels which corresponding
to lower food consumption related to palatability of the compound in the diet.

There is a big variability in litter data. The low dose group shows higher number of dead fetuses, post implantation
loss and lower fetal weight compared to control. On the other hand, the number of live fetuses is even higher than
of control. At the mid-dose group comparable to control again. The high-dose group of 32 mg DDAC/kg/d resulted to an
increased post-implantation loss, decrease in live fetuses with a decreased fetal body weight, and high number of dead
fetuses.
Upon examination of the soft tissue, presence of whitish fluid in the abdomens of 5/6 fetuses (one litter) was
observed. No relevant malformations or variations were observed during the fetal evaluation.
At lower concentrations, litter parameters were not affected by the test treatment and no evidence of treatment-related
findings were noted at skeletal examinations of the fetuses.

Applicant's summary and conclusion

Conclusions:

Based on the results of this study, there are no specific concerns for developmental toxicity by DDAC.

Executive summary:

A study was conducted in rabbits according to OECD Guideline and 414 and EPA OPPTS guideline to determine the prenatal developmental toxicity of the test substance. Groups of 22 mated female KBL New Zealand White rabbits were gavaged the test substance at 4, 12 and 32 mg/kg/day from day 6 to day 28post coitum. One group of 22 mated females received the vehicle alone. Clinical sign and mortality were checked daily. Body weight and food consumption were recorded at designated intervals. On day 29 post coitum, the does were sacrificed and subjected to macroscopic examination of the major organs. The gravid uterus was weighed. The foetuses removed and litter parameters were examined. The foetuses were then weighed and subjected to external and internal tissue, organs and bone examination. Based on the results of this study, there are no specific concerns for developmental toxicity by DDAC. LO(A)EL maternal toxic effects: 32 mg a.i./kg bw/day resulted from clear signs of maternal toxicity (mortality, abortion, clinical signs, body weight loss, increased incidence autopsy findings). At 12 mg/kg bw/day, one female displayed coloured urine and another female loud breathing, each from GD 22. There is no real critical effect, but more a general display of toxicity, possibly related to reduced food intake due to palatability. Based on this, the LOAEL could be set at 12 mg a.i./kg bw/day. NO(A)EL maternal = 4 mg/kg bw/day. LO(A)EL embryotoxic/teratogenic effects: 32 mg DDAC/kg/day. Effects observed are increased number of dead fetuses, lower number of live foetuses, increased post-implantation loss and a decreased foetal body weight. 5/6 foetuses had whitish fluid in the abdomens upon soft tissue examination. NO(A)EL embryotoxic / teratogenic effects = 12 mg a.i./kg bw/day