4,4'-[(isopropylidene)bis(p-phenyleneoxy)]diphthalic dianhydride

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:

comparable to guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1983

Report date:

1983

Materials and methods

Test guideline

Test guideline 1

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 414 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

insufficient number of pregnant dams/dose group, dosing from days 6-18 of gestation

Test guideline 2

Qualifier:

equivalent or similar to guideline

Guideline:

EPA OPPTS 870.3700 (Prenatal Developmental Toxicity Study)

Deviations:

yes

Remarks:

insufficient number of pregnant dams/dose group, dosing from days 6-18 of gestation

GLP compliance:

yes

Limit test:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4,4'-[(isopropylidene)bis(p-phenyleneoxy)]diphthalic dianhydride

EC Number:

253-781-7

EC Name:

4,4'-[(isopropylidene)bis(p-phenyleneoxy)]diphthalic dianhydride

Cas Number:

38103-06-9

Molecular formula:

C31H20O8

IUPAC Name:

5,5'-[propane-2,2-diylbis(4,1-phenyleneoxy)]bis(2-benzofuran-1,3-dione)

Details on test material:

Bisphenol A Dianhydride (BPA-DA; CAS RN 38103-06-9)

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

Ninety mature New Zealand White female rabbits were obtained from Dutchland Laboratory Animals, Inc., Denver, PA for use in this study. The animals were acclimated for a minimum of 22 days prior to the initiation of the study. During the period of acclimation, the rabbits were examined for general health and appearance. The animals were uniquely identified by ear tag and provided commercial rabbit ration (Purina Lab Rabbit Chow) and tap water ad libitum. The environment of the study room was maintained at 70-78 °F, relative humidity of 53-86% and a 12-hour light/dark cycle.

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

CMC (carboxymethyl cellulose)

Details on exposure:

Five groups were included in this study; for the purposes of this summary, only three groups (control, positive control, and BPA-DA treated) will be discussed. Sixteen animals per group (to obtain at least 12 pregnant) were treated with vehicle (0.5% carboxymethyl cellulose), positive control (thalidomide; 150 mg/kg/day) or BPA-DA (1000 mg/kg/day). Thalidomide and BPA-DA were suspended in vehicle to provide dose volumes of 1.5 and 2.5 mL/kg, respectively. Control dose volume was 4.0 mL/kg.

Analytical verification of doses or concentrations:

not specified

Details on mating procedure:

At Day 0 of gestation, the body weights ranged from 2845 to 4700 grams. The animals were artificially inseminated with sperm from the laboratory breeding stock five hours after induction of ovulation with chorionic gonadotropin.

Duration of treatment / exposure:

Days 6 through 18 of gestation. ( The dose was administered from gestation day (gd) 6 through 18, approximately the same time each day, and was based on each individual body weight on gd 6 (starting on gd 11, two animals in the control group, four animals in the thalidomide group and three animals in the BPA-DA group were dosed based on gd 11 body weight).)

Frequency of treatment:

Daily

Duration of test:

29 Days

Doses / concentrations

Dose / conc.:

1 000 mg/kg bw/day (nominal)

No. of animals per sex per dose:

16/group

Control animals:

yes, concurrent vehicle

other: Positive Control (Thalidomide)

Examinations

Maternal examinations:

All of the animals were observed daily for mortality, moribundity and clinical signs. Body weights were recorded on gd 0, 6, 11, 15, 19 and 29. Individual food consumption was recorded weekly.

Ovaries and uterine content:

On gd 29, the animals were sacrificed, examined for gross pathology of the external surface and viscera, and the uterus excised and weighed. The fetuses were taken by cesarean section and the following recorded for each litter: the number of corpora lutea per ovary; the number and placement of uterine implantation sites; live and dead fetuses; early and late resorptions; and any other abnormalities.
Cesarean sections were also performed on dams that were found dead, sacrificed moribund or sacrificed due to early delivery. The number of corpora lutea, implantations, resorptions and live or dead fetuses was recorded.

Fetal examinations:

Fetuses were removed from the placenta, individually identified, examined externally, weighed and measured from the frontal-parietal suture to the base of the tail (crown-rump distance).
The unfixed fetuses underwent visceral examination according to the method of Staples. All of the fetuses were opened by longitudinal incision, the sex determined and examined grossly both externally and internally. Major organs were inspected in situ with special attention to the heart and major blood vessels. The heads of approximately one-third of the fetuses were removed, fixed in Bouin’s solution, sectioned by Wilson’s freehand sectioning technique for examination of the eyes, palate, nasal septum and brain. The prepared sections were then re-examined against a light box with the aid of magnification.
Following visceral examination, all fetuses (minus the head for approximately one-third of the fetuses) were eviscerated and placed in 95% ethyl alcohol. After fixation and dehydration, the skeletons were stained in a potassium hydroxide-alizarin red solution. The skull, vertebral column, rib cage, pectoral and pelvic girdles, long bones and extremities of each skeleton were examined for degree of ossification, bone alignment, and possible anomalies. Examinations were performed with the aid of magnification on a light box.

Statistics:

Mean maternal body weight changes, food consumption, percentage data (implantations, resorptions and males), and fetal viability were analysed in the following order: Levene’s test for homogeneity of variance; if the variances proved to be homogeneous, the data were analysed by one-way classification analysis of variance (ANOVA); if the variance proved to be heterogeneous, a series of transformations was performed until homogeneity was achieved followed by ANOVA. If ANOVA was significant, the Games and Howell modification of the Tukey-Kramer honestly significant difference test was used to compare groups. Pregnancy rates were analysed by Fisher’s exact test. External, visceral, and skeletal anomalies were evaluated by a multiple proportions test. Analysis of covariance (ANCOVA) was used to analyse mean fetal weights and lengths with the litter used as the experimental unit. Levene’s test and ANOVA were evaluated at the 5% one-tailed probability level. Control vs. treatment group mean comparisons were evaluated at the 5% two-tailed probability level.

Results and discussion

Results: maternal animals

General toxicity (maternal animals)

Clinical signs:

no effects observed

Dermal irritation (if dermal study):

not examined

Mortality:

no mortality observed

Body weight and weight changes:

effects observed, treatment-related

Description (incidence and severity):

Weight loss was observed in the test material treated groups during the treatment period. Statistical evaluation of body weight change did not, however, reveal any significant differences between treated and control groups.

Food consumption and compound intake (if feeding study):

no effects observed

Description (incidence and severity):

No effects on food consumption were observed.

Food efficiency:

not examined

Water consumption and compound intake (if drinking water study):

not examined

Ophthalmological findings:

not examined

Haematological findings:

not examined

Clinical biochemistry findings:

not examined

Urinalysis findings:

not examined

Behaviour (functional findings):

not examined

Immunological findings:

not examined

Organ weight findings including organ / body weight ratios:

not examined

Gross pathological findings:

no effects observed

Description (incidence and severity):

No effects in the gross pathology of the dams were observed.

Neuropathological findings:

not examined

Histopathological findings: non-neoplastic:

not examined

Histopathological findings: neoplastic:

not examined

Other effects:

not examined

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects: yes

Details on maternal toxic effects:
Weight loss was observed in the thalidomide- and BPA-DA-treated groups during the treatment period. Statistical evaluation of body weight change did not, however, reveal any significant differences between treated and control groups. No effects on food consumption or gross pathology of the dams were observed.
There were no differences from control in the thalidomide or BPA DA dose groups for maternal, ovarian or uterine data. The thalidomide treated group exhibited changes consistent with the known teratogenic effect of this compound.

Effect levels (maternal animals)

Key result

Dose descriptor:

NOAEL

Effect level:

> 1 000 mg/kg bw/day (nominal)

Based on:

test mat.

Basis for effect level:

body weight and weight gain

Results (fetuses)

Fetal body weight changes:

no effects observed

Reduction in number of live offspring:

no effects observed

Changes in sex ratio:

no effects observed

Changes in litter size and weights:

no effects observed

Changes in postnatal survival:

no effects observed

External malformations:

no effects observed

Skeletal malformations:

no effects observed

Visceral malformations:

no effects observed

Other effects:

not examined

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects: no effects

Details on embryotoxic / teratogenic effects: There were no effects on any fetal parameters from BPA-DA treatment.

Effect levels (fetuses)

Key result

Dose descriptor:

NOEL

Effect level:

> 1 000 mg/kg bw/day

Based on:

test mat.

Basis for effect level:

other: teratogenicity

Fetal abnormalities

Abnormalities:

no effects observed

Overall developmental toxicity

Developmental effects observed:

no

Any other information on results incl. tables

Summary of Mean Ovarian, Uterine, and Litter Data

Parameter	Control (Vehicle)	Thalidomide (Positive Control)	BPA-DA (1000 mg/kg/day)
Number of dams	16	16	16
Number pregnant	14	16	13
Pregnancy rate (%)	88	100	81
Number dams surviving to gd 29	13	15*	12
(survival  rate)	93%	100%	92%
Mean number of
Corpora lutea	13.4	12.2	11.4
Implantations	9.4	8.3	6.5
Resorptions-total	1.2	5.3	2.1
Fetuses - live	7.5	3.4	4.5
- dead	0.5	0	0.1
Indices (mean per litter)
Implantation  efficiency (%)	73.6	68.1	57
Incidence of resorption (%)	17.2	61	31
Incidence of fetal mortality (%)	3.8	0	0.9
Incidence of fetal viability (%)	79.2	39.1	68.1
Live fetuses
Mean body weight (g) - males	40.91	38.36	42.8
- females	39.9	37.6	41.78
Mean length (cm)        - males	9.49	9.03	9.42
- females	9.33	8.92	9.39
Percent Males	51.5	58	47.1
Mean uterine weights - gravid (g)	485.3	228.3	315.4

* One animal died accidentally on gd 8

Summary of Mean Incidence of Abnormal Fetuses per Litter

Parameter	Control (Vehicle)	Thalidomide (Positive Control)	BPA-DA (1000 mg/kg/day)
External
# of litters examined	12	11	9
# of litters with anomalous fetuses	2	10*	3
% of litters with anomalous fetuses	16.7	90.9	33.3
Mean values (per litter)
# of fetuses with variants	0	0.5	0
Incidence of variants (%)	0	14.4	0
# of fetuses with anomalies	0.3	2.7	0.6
Incidence of anomalies (%)	2.4	64.1	8.2
Visceral - Fetal Heads
# of litters examined	12	9	8
# of litters with anomalous fetuses	0	3	0
% of litters with anomalous fetuses	0	33.3	0
Mean values (per litter)
# of fetuses with variants	0	0.1	0
Incidence of variants (%)	0	3.7	0
# of fetuses with anomalies	0	0.4	0
Incidence of anomalies (%)	0	16.7	0
Visceral - Torso and Limbs
# of litters examined	12	11	9
# of litters with anomalous fetuses	0	8*	1
% of litters with anomalous fetuses	0	72.7	11.1
Mean values (per litter)
# of fetuses with variants	0.8	2.9	0.4
Incidence of variants (%)	11.1	63.9	8.7
# of fetuses with anomalies	0	1.5	0.1
Incidence of anomalies (%)	0	38.8	1.6
Skeletal - Skulls
# of litters examined	12	11	9
# of litters with anomalous fetuses	0	2	0
% of litters with anomalous fetuses	0	18.2	0
Mean values (per litter)
# of fetuses with variants	0.5	1.6	1.2
Incidence of variants (%)	11.3	60.9	33.7
# of fetuses with anomalies	0	0.2	0
Incidence of anomalies (%)	0	11.4	0
Skeletal - Torso and Limbs
# of litters examined	12	11	9
# of litters with anomalous fetuses	0	10*	1
% of litters with anomalous fetuses	0	90.9	11.1
Mean values (per litter)
# of fetuses with variants	0.6	3.9	0.8
Incidence of variants (%)	6.9	91.7	16.4
# of fetuses with anomalies	0	2.2	0.1
Incidence of anomalies (%)	0	54.4	1.2

* Statistically significantly different from vehicle control group (p < 0.05)

Applicant's summary and conclusion

Conclusions:

Based on the results of this study, the test material is not a developmental toxin.

Executive summary:

The developmental toxicity potential of BPA-DA in the rabbit was investigated in a study conducted using methodology equivalent to OECD 414 and EPA OPPTS 870.3700 under GLP conditions (Hazleton Laboratories America, Inc., 1983).

Sixteen New Zealand White rabbits were dosed with the test material at 1000 mg/kg bw by gavage in CMC (carboxymethyl cellulose) on Days 6 through 18 of gestation. A further 16 were dosed with the vehicle alone.

A reduction in maternal bodyweight was seen at 1000 mg/kg, however, it was not statistically significant. There were no effects on any foetal parameters from test material treatment and the NOAEL for developmental toxicity was considered to be ≥1000 mg/kg bw.

Based on the results of this study, the test material is not a developmental toxin.