Registration Dossier

Toxicological information

Direct observations: clinical cases, poisoning incidents and other

Administrative data

Endpoint:
direct observations: clinical cases, poisoning incidents and other
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Meets generally accepted schientific standards, well documented and acceptable for assessment.

Data source

Reference
Reference Type:
publication
Title:
Nitrilotriacetate (NTA): Human Metabolism and its Importance in the Total Safety Evaluation Program
Author:
Budny, J.A., Arnold J.D.
Year:
1972
Bibliographic source:
Toxicology and Applied Pharmacology 25, 48-53 (1973)

Materials and methods

Study type:
study with volunteers
Endpoint addressed:
basic toxicokinetics
Test guideline
Qualifier:
no guideline available
Principles of method if other than guideline:
10 mg 14C-NTA (9.7 mCi/g, carboxyl-labelled) in gelatine capsules were administered orally to 8 volunteers
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Nitrilotriacetate (NTA), Trisodium nitrilotriacetate
- Locations of the label (if radiolabelling): 14C-NTA (9.7 µCi/g, carboxyl-labelled)
- Other: no details reported

Method

Type of population:
not specified
Subjects:
- Number of subjects exposed: 8
- Sex: male
- Age: no data
- Race: no data
- Demographic information: no data
- Known diseases: no data
- No other details reported
Route of exposure:
oral
Reason of exposure:
intentional
Exposure assessment:
measured

Results and discussion

Clinical signs:
No clinical signs were observed. 87 % of the urinary 14C was excreted in the first 24 h-period. Less than 0.1 % was recovered in the expired air. The total recovery was 89 % within 120 h. However, the amount of 14C remaining in the tissues was not included in the total recovery figure.

Applicant's summary and conclusion

Conclusions:
NTA is poorly absorbed and rapidly excreted by humans. A fraction of 12% was recovered in urine within 120 h (77% recovered in feces). Blood concentration peak occurred within 1-2 h. NTA is not metabolized to a significant extend. > 96% of the urinary radioactivity was found to be uncharged NTA. There was no evidence for enterohepatic circulation.