L-Aspartic acid, N,N'-1,2-ethanediylbis-

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics

Type of information:

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

Adequacy of study:

key study

Study period:

26 to 29 April 1995

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: GLP study, similar to guidelines, with acceptable deviations; on related material

Cross-reference

Reason / purpose for cross-reference:

reference to same study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1995

Report date:

1995

Materials and methods

Objective of study:

absorption

distribution

excretion

Test guideline

Qualifier:

equivalent or similar to guideline

Guideline:

OECD Guideline 417 (Toxicokinetics)

Deviations:

yes

Remarks:

only one low dose used

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Trisodium EDDS

IUPAC Name:

Trisodium EDDS

Constituent 2

Reference substance name:

l-aspartic acid, N,N'-1,2-ethanediylbis-, trisodium salt

IUPAC Name:

l-aspartic acid, N,N'-1,2-ethanediylbis-, trisodium salt

Constituent 3

Reference substance name:

178949-82-1

EC Number:

605-842-8

Cas Number:

178949-82-1

IUPAC Name:

178949-82-1

Constituent 4

Reference substance name:

-

EC Number:

416-530-4

EC Name:

-

IUPAC Name:

416-530-4

Details on test material:

- Name of test material (as cited in study report): radiolabelled-trisodium EDDS
- Molecular formula (if other than submission substance): C10-H13-N2-O8. 3Na
- Molecular weight (if other than submission substance): 358
- Smiles notation (if other than submission substance): [Na+].[Na+].[Na+].OC(=O)[C@H](CC([O-])=O)NCCNC(CC([O-])=O)C([O-])=O
- Substance type: technical product
- Physical state: clear liquid
- Radiochemical purity (if radiolabelling): 98.7%
- Specific activity (if radiolabelling): 16.1 uCi/mg
- Locations of the label (if radiolabelling): 14C
- Expiration date of radiochemical substance (if radiolabelling): 9 September 1993
- Stability under test conditions: no data
- Storage condition of test material: at about 4oC

Radiolabelling:

yes

Test animals

Species:

rat

Strain:

other: Crl: (WI)BR

Sex:

male/female

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Charles River Canada, St-Constant, Quebec
- Age at study initiation: 6-8 weeks
- Weight at study initiation: males: 191-303 g; females 173-253 g
- Fasting period before study: no data
- Housing: in glass metabolism cages
- Individual metabolism cages: yes
- Diet (e.g. ad libitum): conventional, ad libitum
- Water (e.g. ad libitum): tap water, ad libitum
- Acclimation period: 7 days


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3
- Humidity (%): 50 +/- 20
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12/12


IN-LIFE DATES: From: 26 April 1993 To: 29 April 1993

Administration / exposure

Route of administration:

oral: gavage

Vehicle:

water

Details on exposure:

PREPARATION OF DOSING SOLUTIONS: dosing solution pre-prepared at the appropriate concentration by the sponsor

HOMOGENEITY AND STABILITY OF TEST MATERIAL: no data

Duration and frequency of treatment / exposure:

single exposure

Doses / concentrations

Remarks:

Doses / Concentrations:
gavaged with 1 mL to give about 10 uCi/rat and 0.5 mg/rat (about 3 mg/kg bw) of 14C-[S,S]-EDDS trisodium salt

No. of animals per sex per dose / concentration:

5/sex

Control animals:

no

Positive control reference chemical:

none

Details on study design:

- Dose selection rationale: selected to provide sufficient material to determine the distribution, elimination and mass balance of radioactivity
- Rationale for animal assignment (if not random): random

Details on dosing and sampling:

PHARMACOKINETIC STUDY (Absorption, distribution, excretion)
- Tissues and body fluids sampled: urine, faeces, blood, plasma, cage washes, expired air, adipose tissue, brain, bone marrow (femur), femur bone, gonads, heart, GI (combined stomach, large and small intestine), GI contents, kidneys, liver, lungs, muscle (right leg adductor), pancreas, spleen, carcass
- Time and frequency of sampling: urine, faeces and cage washes were collected at 24, 48 and 72 h; expired air was trapped in potassium hydroxide and collected at 12, 24, 36, 48 and 72 h. Tissues and organs were sampled for radioactivity at study termination at 72 h.

Statistics:

Bartlett's test and t-tests were used to determine any gender differences in the recovery of radioactivity. A ln-transformation on the percent of dose was used to correct the non-homogeneity of the variances when appropriate.

Results and discussion

Preliminary studies:

none

Main ADME results

Main ADME results 1

Type:

absorption

Results:

after 72 h, at least 5% of the dose was considered absorbed

Main ADME results 2

Type:

distribution

Results:

after 72 h, a total of about 0.15% of the dose was recovered in the blood and organs (including carcass)

Main ADME results 3

Type:

excretion

Results:

after 72 h, about 75% of the dose was excreted in the faeces, and about 2 and 3% in the urine and expired air, respectively

Toxicokinetic / pharmacokinetic studies

Details on absorption:

Only about 5% of the dose was absorbed from the gastrointestinal tract as shown by the radioactivity recovered from urine, expired air and recovered in the tissues during the 72 h exposure period. The cage wash may have contained some further absorbed material (excreted as urine). See Tables 1 and 2 for further details.

Details on distribution in tissues:

The total radioactivity recovered from the organs and tissues examined are given in Table 1. The combined mean radioactivity content of blood and tissues (including carcass) was 0.136 and 0.153% in males and females, respectively.

Details on excretion:

Radioactivity was excreted mainly in the faeces and occurred rapidly with about 62% and 71% of the dose being recovered in faeces in males and females, respectively, during the first 24 h. In total, during the 72-h collection period, faecal excretion accounted for about 75% of the administered dose in males and females. Only a small fraction of the dose was recovered in the urine (about 1.7%) and expired air (3.25%). See Tables 1 and 2 for further details.

Metabolite characterisation studies

Metabolites identified:

not measured

Any other information on results incl. tables

Table 1. Total recovery (mass balance) of radioactivity in excreta and tissues

Sample	Males (% of dose)	Females (% of dose)
Urine	1.87 ± 1.58	1.49 ± 0.200
Faeces	75.6 ± 6.91	75.2 ± 7.92
Expired air	3.35 ± 2.21	3.19 ± 0.803
Cage wash	3.37 ± 2.86	9.38 ± 7.55
Blood	0.0041 ± 0.0093	0.000 ± 0.000
Liver	0.0424 ± 0.0353	0.037 ± 0.014
Kidneys	0.0092 ± 0.0084	0.004 ± 0.001
Heart	0.0003 ± 0.0008	0.000 ± 0.001
Lungs	0.0007 ± 0.0015	0.000 ± 0.000
Pancreas	0.0007 ± 0.0016	0.001 ± 0.002
Spleen	0.005 ± 0.0011	0.001 ± 0.002
Brain	0.0015 ± 0.0034	0.000 ± 0.000
Testes/ovaries	0.0010 ± 0.0023	0.000 ± 0.000
Muscle	0.0000 ± 0.0000	0.000 ± 0.000
Adipose tissue	0.0283 ± 0.0127	0.017 ± 0.026
Bone marrow	0.0000 ± 0.0000	0.000 ± 0.000
Bone femur	0.0000 ± 0.0000	0.000 ± 0.000
GI tract	0.0358 ± 0.0478	0.013 ± 0.012
GI contents	0.0345 ± 0.0771	0.000 ± 0.000
Carcass	0.114 ± 0.141	0.080 ± 0.083
Total	84.4 ± 1.52	89.5 ± 2.76

Table 2. Percentage recovery of radioactivity in excreta

	% of dose					Cumulative % of dose
Period (h)	Urine	Faeces	Cage wash	Expired air	Total	Urine	Faeces	Cage wash	Expired air	Total
Males
0-12	a	a	a	1.2228 ± 0.2709	1.2228 ± 0.2709	a	a	a	1.2228 ± 0.2709	1.2228 ± 0.2709
12-24	1.3003 ± 0.4784	62.2836 ± 26.9438	2.2841 ± 2.1168	0.7793 ± 0.3835	66.6474 ± 26.2117	1.3003 ± 0.4784	62.2836 ± 26.9438	2.2841 ± 2.1168	2.0021 ± 0.1764	67.8702 ± 26.3440
24-36	a	a	a	0.6048 ± 0.8138	0.6048 ± 0.8138	1.3003 ± 0.4784	62.2836 ± 26.9438	2.2841 ± 2.1168	2.6069 ± 0.9824	68.4750 ± 25.5306
36-48	0.4169 ± 0.8032	8.7869 ± 11.8536	0.4881 ± 0.6665	0.4913 ± 0.7762	10.2732 ± 13.9894	1.7173 ± 1.2524	71.1606 ± 15.3503	2.7722 ± 2.4431	3.0982 ± 1.7566	78.7482 ± 12.0645
48-72	0.1532 ± 0.3335	4.3958 ± 8.6421	0.5985 ± 1.3383	0.2484 ± 0.4581	5.3959 ± 10.7689	1.8705 ± 1.5803	75.5564 ± 6.9090	3.3707 ± 2.8555	3.3466 ± 2.2133	84.1441 ± 1.7590
Females
0-12	a	a	a	1.1357 ± 0.1808	1.1357 ± 0.1808	a	a	a	1.1357 ± 0.1808	1.1357 ± 0.1808
12-24	1.2509 ± 0.1869	70.6335 ± 5.9226	9.0715 ± 7.3306	1.4762 ± 0.4461	82.4320 ± 3.5779	1.2509 ± 0.1869	70.6335 ± 5.9226	9.0715 ± 7.3306	2.6119 ± 0.5366	83.5677 ± 3.6176
24-36	a	a	a	0.3144 ± 0.1596	0.3144 ± 0.1596	1.2509 ± 0.1869	70.6335 ± 5.9226	9.0715 ± 7.3306	2.9263 ± 0.6461	83.8821 ± 3.5258
36-48	0.2609 ± 0.2946	3.9687 ± 3.8809	0.2423 ± 0.3216	0.2029 ± 0.1229	4.6226 ± 3.8030	1.4596 ± 0.1392	74.6022 ± 7.7342	9.3138 ± 7.5307	3.1292 ± 0.7494	88.5047 ± 2.7321
48-72	0.0289 ± 0.0647	0.6468 ± 0.2785	0.0622 ± 0.0956	0.0614 ± 0.0666	0.7993 ± 0.3595	1.4885 ± 0.2003	75.2490 ± 7.9168	9.3760 ± 7.5495	3.1906 ± 0.8025	89.3041 ± 2.7273

a: not sampled

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): no bioaccumulation potential based on study results
In a GLP study, similar to OECD Guideline 417, a single dose of radiolabelled trisodium EDDS (about 2-3 mg/kg bw/day) administered by gavage to male and female rats was rapidly eliminated, mainly in the faeces (about 75% of the administered dose), with at least 5% considered absorbed from the gastrointestinal tract.

Executive summary:

In a GLP study conducted according to a protocol similar to OECD Guideline 417, the absorption, distribution and elimination of 14C-labelled trisodium EDDS was determined in male and female Wistar rats. The radiolabelled test substance was administered by single oral gavage (in water) to five rats of each sex at a dose level of 0.5 mg/rat (about 2-3 mg/kg bw) and the animals placed in individual metabolism cages. Urine, faeces and cage washes were collected at 24, 48 and 72 h and expired air was collected in 12, 24, 36, 48 and 72 h samples. At study termination (72 h), blood samples were taken and plasma separated and selected tissues and gastrointestinal contents were collected and the levels of radioactivity were determined by liquid scintillation counting (after solubilising the tissues as necessary).

Trisodium EDDS was rapidly excreted, mainly in the faeces. In the first 24 h, approximately 62 and 71% of the administered dose, respectively in males and females, was excreted in the faeces, and after 72 h about 75% was excreted in the faeces. Overall, at least 5% of the test substance was absorbed from the GI tract as determined by the amount of radioactivity in urine, expired air and in the tissues. Some further absorbed material may have been found in the cage wash and possibly any faeces produced after 36 hr. The combined mean radioactivity content of blood and tissues (including carcass) was 0.136 and 0.153% of the administered dose in males and females, respectively. No statistically significant gender differences were evident in the absorption, distribution or excretion patterns.

In conclusion, at least 5% of an administered dose of trisodium EDDS was considered absorbed from the gastrointestinal tract, with most being excreted in the faeces within the first 24 h after administration.

[Data on trisodium EDDS is considered relevant to use for understanding the basic toxicokinetics of EDDS acid, and is acceptable for using as read-across information.]