Registration Dossier

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:
27. Jan 1994 - 21. Feb 1994
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Guideline study (OECD 414), GLP compliant.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1995
Report Date:
1995

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 414 (Prenatal Developmental Toxicity Study)
GLP compliance:
yes
Limit test:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Triisopropanolamine
- Analytical purity: 92 %
- Lot/batch No.: 10-4852
- Storage condition of test material: Room temperature, under nitrogen atmosphere

Test animals

Species:
rat
Strain:
Wistar
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: THOMAE, Biberach an der Riss, FRG
- Age at study initiation: 77-89 days
- Weight at study initiation: 242 g (mean)
- Housing: singly in type DK III stainless steel wire mesh cage.
- Diet: ground Kliba 343 feed, Klingenthalmuehle AG, Kaiseraugst, Switzerland, ad libitum
- Water: tap water, ad libitum
- Acclimation period: at least 5 days


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
Details on exposure:
Doses of 0, 100, 400 and 1000 mg/kg bw/day were administered in a volume of 10 ml/kg, at a concentration of 0, 1000, 4000 and 10000 mg/100ml, respectively.
Analytical verification of doses or concentrations:
yes
Details on analytical verification of doses or concentrations:
Test substance: purity and stability were analyzed by gas chromatography (GC); and homogeneity was proven visually.
Test solutions: analysis of stability (for 3 hrs) in double distilled water was carried out in a range-finding study. Concentrations were analyzed twice during the study by GC. Test solutions were freshly prepared on the day of dosing.
Details on mating procedure:
- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1/1
- Length of cohabitation: overnight
- Proof of pregnancy: sperm in vaginal smear referred to as day 0 of pregnancy
Duration of treatment / exposure:
on day 6 through day 15 post coitum (p.c.)
(Sacrifice on day 20 p.c.)
Frequency of treatment:
once a day during the period of major organogenesis (day 6 to day 15 p.c.)
Duration of test:
20 days
Doses / concentrations
Remarks:
Doses / Concentrations:
0; 100; 400; 1000 mg/kg bw/d
Basis:
nominal conc.
No. of animals per sex per dose:
25
Control animals:
yes, concurrent vehicle

Examinations

Maternal examinations:
CAGE SIDE OBSERVATIONS: Yes
- Time schedule: once a day and more often when clinical signs of toxicity were elicited. Mortality was check twice a day on workdays and once a day during weekends and public holidays.

BODY WEIGHT and FOOD CONSUMPTION: Yes
- Time schedule for examinations: days 0 (only bw), 1, 3, 6, 8, 10, 13, 15, 17, 20 p.c.

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day # 20
- Organs examined: uterus and ovaries after gross pathology

OTHER: The correct body weight gain was calculated after terminal sacrifice.

Ovaries and uterine content:
The ovaries and 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: fetus was weighed, sexed, examined macroscopically for external findings, and viability, condition of the placentae, umbilical cords, fetal membranes and fluids were examined.
- Soft tissue examinations: Yes: half per litter
- Skeletal examinations: Yes: half per litter
- Head examinations: No
Statistics:
The data were evaluated statistically using the computer systems of the Department of Toxicology of BASF AG. The Dunnett-test was used for a simultaneous comparison of several dose groups with the control. The hypothesis of equal means was tested. This test was performed two-sided and was used for the statistical evaluation of the following parameters: food consumption, body weight, body weight change, corrected body weight gain (net maternal body weight change), weight of the uterus before it was opened, number of corpora lutea, number of implantations, number of resorptions and number of live fetuses, proportion of preimplantation loss, postimplantation loss, resorptions and live fetuses in each litter, litter mean fetal body weight and litter mean placental weight. Fisher's Exact Test was used for a pairwise comparison of each dose group with the control for the hypothesis of equal proportions. This test was performed one-sided and was used for female mortality, females pregnant at terminal sacrifice and the number of litters with fetal findings. The Wilcoxon-Test was used for a comparison of each dose group with the control for the hypothesis of equal medians. This test was performed one-sided and was used for the proportion of fetuses with malformations, variations, retardations and/or unclassified observations in each litter. If the results of these tests were significant, labels (* for p< 0.05, ** for p< 0.01) were printed in the summary tables.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:
Maternal toxic effects:yes

Details on maternal toxic effects:
In the 1000 mg/kg group statistically significantly decreased food consumption at the beginning of the treatment period (days 6-10 p.c.; about 13% (days 6 to 8 p.c.) or about 16% (days 8 to 10 p.c.) lower than the values of the concurrent control group. There were no statistically significant differences between the controls and the substance-treated dams concerning mean body weights. At the beginning of the treatment period (days 6-8 p.c.), however, the dams of the highest dose group (1,000 mg/kg body weight/day) showed a statistically significantly reduced body weight gain (only about 36% of the weight gain of the concurrent control group; see table in remarks on results). The corrected body weight gain (terminal body weight on day 20 p.c. minus weight of the uterus before it was opened minus body weight on day 6 p.c.) was statistically significantly lower in the high dose group (about 87% of the value of the concurrent control group), which is related to the test substance administration (see table in remarks on results). There were no substance-related and/or biologically relevant differences between the groups in conception rate, in the mean number of corpora lutea and implantation sites or in the values calculated for the pre- and the postimplantation losses, the number of resorptions and viable fetuses. The differences evident are considered to be incidental and within the normal range of deviations for animals of this strain and age.

Effect levels (maternal animals)

Dose descriptor:
NOAEL
Effect level:
400 mg/kg bw/day
Basis for effect level:
other: maternal toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:
Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
The few statistically significant differences on embryo-/fetotoxicity, which occurred were exclusively related to fetal skeletal variations and retardations. These findings consisted of: an increased rate of affected fetuses/litter and an increased litter incidence with shortened 13th rib(s) at 100, 400 and 1,000 mg/kg bw/day, respectively; a consequently increased rate of low and intermediate dose fetuses/litter with total skeletal variations; an increased litter incidence of incompletely ossified or smaller sternebra(e) in the 400 mg/kg body weight group. These findings are considered to be spontaneous in nature because no dose-response relationship is given and/or the respective values are fully in the historical control range.

Effect levels (fetuses)

Dose descriptor:
NOAEL
Effect level:
>= 1 000 mg/kg bw/day
Basis for effect level:
other: teratogenicity

Fetal abnormalities

Abnormalities:
not specified

Overall developmental toxicity

Developmental effects observed:
not specified

Any other information on results incl. tables

Mean maternal body weight change during gestation (grams):

   0 mg/kg bw/d(n = 25) 100 mg/kg bw/d(n = 24) 400 mg/kg bw/d(n = 25) 1000 mg/kg bw/d(n = 23)   
Days 0 - 1  4.3±3.76 3.7±3.60  4.3±3.41  4.3±2.89   
Days 1 - 3   11.7±3.56  11.9±3.41  11.7±3.77  11.8±2.95  
Days 3 - 6   13.0±4.56  12.1±4.40  13.1±4.37  12.5±3.39  
Days 6 - 8  7.5±3.90  7.4±4.21  5.0±4.26  2.7±3.93**  
Days 8 - 10  9.9±4.59  9.4±5.15  11.4±4.43 8.0±3.72   
Days 10 - 13   17.5±3.57  17.1±4.92  19.1±5.42  19.0±4.98  
Days 13 - 15  11.7±4.51  11.9±4.15  12.5±4.36  13.7±4.62  
Days 15 - 17  25.4±6.47  25.8±5.23  25.3±4.38  26.6±3.60  
Days 17 - 20  50.3±10.57  49.2±6.64 51.8±7.58   52.6±5.56  

**: p 0.01; Dunnett-test.

Mean gravid uterine Weights and net maternal body weight change (grams):

0 mg/kg bw/d(n = 25)   100 mg/kg bw/d(n = 24) 400 mg/kg bw/d(n = 25) 1000 mg/kg bw/d(n = 23)   
Gravid uterus  78.3±19.22  80.3±10.49 82.5±13.18   84.4±10.16  
Carcass  317.7±22.09  310.8±20.66 314.3±22.22   306.2±13.17  
Net weight change from day 6  44.1±8.54  40.4±7.52  42.6±7.06  38.2±6.72*  

*: p 0.05; Dunnett-test.

Under the conditions of this full-scale prenatal toxicity study, the administration of Triisopropanolamine to pregnant female Wistar rats during organogenesis elicited overt signs of maternal toxicity at 1000 mg/kg body weight/day, while 100 or 400 mg/kg body weight/day were tolerated by the dams without any substance-induced findings. The gestational parameters were not influenced by the test substance administration in any of the three test groups.

No signs of embryo-/fetotoxicity, especially no substance-induced indications of teratogenicity were noted up to and including the dose of 1,000 mg/kg body weight/day.

Therefore, the no observed adverse effect level (NOAEL) for the dams in this full-scale prenatal toxicity study is 400 mg/kg body weight/day, while it is 1000 mg/kg body weight/day for the fetal organism.

Applicant's summary and conclusion