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Toxicological information

Basic toxicokinetics

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Administrative data

Endpoint:
basic toxicokinetics in vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Unpublished report which meets generally accepted scientific standards, acceptable for assessment

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1979
Report Date:
1979

Materials and methods

Objective of study:
absorption
distribution
excretion
Principles of method if other than guideline:
Investigation of the absorption, distribution and excretion of the substance after a single oral dose.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Radiolabelling:
yes
Remarks:
65Zn

Test animals

Species:
rat
Strain:
Sprague-Dawley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Charles River
- Weight at study initiation: 183-190 g

Administration / exposure

Route of administration:
oral: gavage
Vehicle:
water
Duration and frequency of treatment / exposure:
once
Doses / concentrations
Remarks:
Doses / Concentrations:
10.8 mg/kg bw (1 mL)
No. of animals per sex per dose:
3
Control animals:
no
Details on study design:
The test substance in water is administered by gavage.
For 72 hrs after dosing, the animals are housed in metabolism cages designed for the separation of urine, faeces, and expired CO2. Urine and faeces are collected at 24, 48, and 72 hrs and freezed until they are analyzed. C02 is collected at 8 hr intervals for 72 hrs (3 samples/day/rat). At the end of the 72 hr test period, the rats are sacrificed with ether after which organs and tissues are examined.

Results and discussion

Main ADME results
Type:
absorption
Results:
Oral absorption is low (< 2 %), most of the test substance was recovered in the feces (91.4%), the carcass contained only 1.12% of the test substance.

Toxicokinetic / pharmacokinetic studies

Details on absorption:
When the substance was dosed orally to rats most (91.4%) of the recovered 65Zn was in the faeces. The 0-24 hour faecal collection had 90.4% of this total.
Less than 0.5% of the 65Zn was found in the tissues collected at necropsy, although the bone concentration at 0.388 µg/g and the bone marrow concentration at 0.255 µg/g was around ten times higher than the blood concentration. The concentration of radioactivity in the blood (0.039 µg/g) was higher than that in the plasma (0.012 µg/g) at necropsy, indicating that the removal of radioactivity from the blood cells was not as rapid as from the plasma.
The carcass contained 1.12% of the 65Zn after the tissue removal.
The total Zn recovery was 96.1%.

Applicant's summary and conclusion