Sodium calcium edetate

Developmental toxicity / teratogenicity

Administrative data

Endpoint:

developmental toxicity

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: Study meets scientifically accepted methods

Cross-reference

Reason / purpose for cross-reference:

reference to other study

Data source

Reference

Reference Type:

publication

Title:

Teratogenesis Studies with EDTA and its Salts in Rats

Author:

Schardein JL, Sakowski R, Petrere J, Humphrey RR

Year:

1981

Bibliographic source:

Toxicol. Appl. Pharmacol. 61, 423-428

Materials and methods

Principles of method if other than guideline:

EDTA and four of its salts, disodium, trisodium, calcium di-sodium, and tetrasodium edetate, were studied for teratogenic potential in rats. Equimolar doses based on 1000 mg/kg were given by gastric intubation on Days 7 to 14 of gestation. On day 21 of gestation the dams of each group were sacrificed and litter data for each dam collected.

GLP compliance:

no

Limit test:

no

Test material

Test material information

Constituent 1

Reference substance name:

Sodium calcium edetate

EC Number:

200-529-9

EC Name:

Sodium calcium edetate

Cas Number:

62-33-9

Molecular formula:

C10H12CaN2O8.2Na

IUPAC Name:

calcium disodium 2,2',2'',2'''-(ethane-1,2-diyldinitrilo)tetraacetate

Test material form:

other: dilution in 0.2 M phosphate buffer

Details on test material:

The EDTA-CaNa2 solution was near neutrality (pH 6.9).

Test animals

Species:

rat

Strain:

other: CD albino

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Breeding Laboratories
- Weight at study initiation: mean: 241 g
- Diet: Purina Lab Chow ad libitum
- Water: tap water ad libitum

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

other: 0.2 M phosphate buffer

Details on exposure:

pH of dosing solution: 6.9

Analytical verification of doses or concentrations:

no

Details on mating procedure:

- Impregnation procedure: cohoused
- If cohoused:
- M/F ratio per cage: 1:1
- Proof of pregnancy: vaginal plug, sperm in vaginal smear referred to as day 0 of pregnancy

Duration of treatment / exposure:

7 days (day 7 to day 14 of gestation)

Frequency of treatment:

equally divided doses twice daily

Duration of test:

21 days

Doses / concentrations

Remarks:

Doses / Concentrations:
1374 mg/kg bw/ day (divided into two equal doses)
Basis:
actual ingested

No. of animals per sex per dose:

20

Control animals:

yes, concurrent no treatment

yes, concurrent vehicle

Examinations

Maternal examinations:

CAGE SIDE OBSERVATIONS: Yes

BODY WEIGHT: Yes
- Time schedule for examinations: once a week

FOOD CONSUMPTION AND COMPOUND INTAKE (if feeding study): Yes

POST-MORTEM EXAMINATIONS: Yes
- Sacrifice on gestation day 21

Ovaries and uterine content:

The ovaries and uterine content was examined after termination: Yes
Examinations included:
- Number of implantations: Yes
- Number of early resorptions: Yes
- Number of late resorptions: Yes

Fetal examinations:

- External examinations: each fetus
- Gross inspection, slicing and visceral abnormalities: 1/3 of the litter
- Skeletal examinations: 2/3 of the litter

Statistics:

Means and standard errors were calculated for litter size, followed by analysis of variance. Pre- and postimplantation losses, embryonic viability, and fetal survival were evaluated by analysis of covariance. Fetal weights were also evaluated by analysis of covariance following calculation of mean weight/litter by sex, the values representing means and standard errors of mean litter weights. Significant variance by either analysis of variance or covariance was further evaluated by Dunnett's t test to locate the source of variance. Sex distribution was analyzed by partitioned Chi-square.

Results and discussion

Results: maternal animals

Maternal developmental toxicity

Details on maternal toxic effects:

Maternal toxic effects:yes

Details on maternal toxic effects:
- diarrhea in 10% of the animals: daily after application; it disappeared after the last day of dosing
- decreased food intake during treatment (see Table 1)
- reduced weight gain during treatment; recovery within the post treatment period

Effect levels (maternal animals)

1

Dose descriptor:

LOAEL

Effect level:

1 340 mg/kg bw/day (actual dose received)

Basis for effect level:

other: maternal toxicity

2

Dose descriptor:

NOAEL

Effect level:

>= 1 340 mg/kg bw/day (actual dose received)

Basis for effect level:

other: developmental toxicity

Results (fetuses)

Details on embryotoxic / teratogenic effects:

Embryotoxic / teratogenic effects:no effects

Details on embryotoxic / teratogenic effects:
- no effects on litter size, sex ratio or mortality index (see Table 2)
- no drug related statistically significant increase of malformation could be observed in the treated animals.
(A total of 1084 pups from drug-treated dams were examined. These were compared to 237 pups from 19 dams treated with the vehicle and 278 pups from 20 untreated dams. In addition, 752 pups from dams treated with edetic acid and its salts together with 165 and 191 pups from the vehicle and untreated control groups, respectively, were cleared and examined for skeletal defects. Twenty-four pups from the drug-treated groups had abnormalities. These included 20 with bifid vertebrae, 1 with agenesis of the ribs, 2 with inhibition of osteogenesis of the skull or ribs, and 1 with malformed ribs.
There was no definitive pattern regarding treatment with a particular compound and the occurrence of anomalies. None of the pups in the vehicle control group had abnormalities while 8 untreated control pups exhibited some major defect. One untreated control fetus was stunted and had multiple abnormalities including eye defect, ectrodactyly, and a curly tail. Histological examination of the eyes revealed a cataract in one eye and a dysmorphic lens
and retina in the other. Five additional control pups had bifid vertebrae while 2 had malformed vertebrae or sternebrae.)

Effect levels (fetuses)

1

Dose descriptor:

NOAEL

Effect level:

>= 1 340 mg/kg bw/day (actual dose received)

Basis for effect level:

other: teratogenicity

2

Dose descriptor:

NOAEL

Effect level:

>= 1 340 mg/kg bw/day (actual dose received)

Basis for effect level:

other: embryotoxicity

3

Dose descriptor:

NOAEL

Effect level:

>= 1 340 mg/kg bw/day (actual dose received)

Basis for effect level:

other: fetotoxicity

Fetal abnormalities

Abnormalities:

not specified

Overall developmental toxicity

Developmental effects observed:

not specified

Any other information on results incl. tables

Table 1: Food consumption and weight gain in rats treated with EDTA and EDTA salts on days 7 through 14 of gestation

Days	Control (untreated)	Vehicle Control	967 mg/kg bw/day EDTA	1243 mg/kg bw/day Na2 EDTA	1245 mg/kg bw/day Na3 EDTA	1340 mg/kg bw/day CaNa2 EDTA	1374 mg/kg bw/day Na4 EDTA
	Mean food consumption (g/day)
0-7	20.7	21.4	19.9	20.4	19.9	20.4	19.0
7-14	22.3	22.5	18.4	17.5	19.1	20.9	18.5
14-21	24.7	25.3	26.7	27.2	25.7	26.5	25.6
	Mean body weight gain (g)
0-7	31.9	35.1	37.6	35.6	33.2	37.2	26.9
7-14	28.5	26.1	16.5	13.7	20.4	25.1	18.3
14-21	102.7	93.3	104.4	100.2	98.4	108.1	94.2

Table 2: Reproductive data in dams receiving EDTA and EDTA salts on days 7 through 14 of gestation

				Fetuses
				Sex		Body weight (mean g ± SE)		Number
Treatment	No of dams	Litter size (mean ± SE)	Post implantation loss (%)	M	F	M	F	Dead	live	Resorbed
Control (untreated)	20	14.0 ± 0.4	4	52	48	5.3 ± 0.1	5.6 ± 0.1	1	278	12
Vehicle Control	19	12.5 ± 0.1	3	50	50	5.3 ± 0.1	5.7 ± 0.1	0	237	7
967 mg/kg bw/day EDTA	17	12.7 ± 0.6	3	49	51	5.5 ± 0.1	5.7 ± 0.1	0	216	6
1243 mg/kg bw/day Na2 EDTA	19	12.6 ± 0.4	1	56	44	5.4 ± 0.1	5.6 ± 0.1	0	202	3
1245 mg/kg bw/day Na3 EDTA	18	12.4 ± 1.0	8	48	52	5.4 ± 0.2	5.7 ± 0.1	0	210	11
1340 mg/kg bw/day CaNa2 EDTA	17	13.5 ± 0.4	2	52	48	5.3 ± 0.1	5.6 ± 0.1	0	230	4
1374 mg/kg bw/day Na4 EDTA	19	11.9 ± 0.7	4	47	52	5.2 ± 0.1	5.5 ± 0.1	0	226	10

2 dams had to be killed due to dosing errors

Applicant's summary and conclusion

Conclusions:

No teratogenic effects occurred when pregnant rats were given an oral dose of 1340 mg EDTA-CaNa2/kg bw on days 7 to 14 of gestation; slight maternal toxicity was noted at this level.