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Toxicological information

Dermal absorption

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Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
supporting study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
test procedure in accordance with national standard methods with acceptable restrictions

Data source

Reference
Reference Type:
publication
Title:
Distribution and metabolism of topically applied ethanolamine
Author:
Klain GJ, et al.
Year:
1985
Bibliographic source:
Fundam. Appl. Toxicol. 5, 127 -133

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
The skin resorption of ethanolamine was tested on isolated skin of pigs in vitro.
GLP compliance:
no

Test material

Reference
Name:
Unnamed
Type:
Constituent
Specific details on test material used for the study:
RADIOLABELLING INFORMATION
- Specific activity: 4 mCi/mmol)
- Locations of the label: [1.2-14 C] Ethanolamine - HCI



Radiolabelling:
yes

Test animals

Species:
pig
Strain:
not specified
Sex:
not specified

Administration / exposure

Doses:
5 µL to 0.8 cm² area of pig skin, resulting in a dose of 4 µg/cm² and a radioactive dose of approximately 0.05 µCi

Results and discussion

Percutaneous absorptionopen allclose all
Dose:
4 μg/cm2
Parameter:
percentage
Absorption:
ca. 1 %
Remarks on result:
other: 2 h
Dose:
4 μg/cm2
Parameter:
percentage
Absorption:
ca. 3 %
Remarks on result:
other: 24 h
Dose:
4 μg/cm2
Parameter:
percentage
Absorption:
ca. 5 %
Remarks on result:
other: 50 h

Any other information on results incl. tables

The in vitro data show that a relatively small percentage of the applied dose of ethanolamine was lost from the skin by evaporation and percutaneous penetration. At the end of the 50 hour test period the main bulk of the compound remained on the skin. In separate experiments 7 to 9 times as much radioactivity was recovered from the upper 100 µm layer (mostly epidermis) as compared to the recovery from the remaining dermis.

 

Disposition of ethanolamine after topical application to pig skin in vitro at a chemical dose of 4 µg/cm²

Time interval after application (hrs)

Evaporation

Percutaneous penetration

Skin residue

2

6 ± 7

1 ± 1

-*

24

17 ± 3

3 ± 2

-**

50

11 ± 7

5 ± 2

62 ± 18***

data presented as mean ± SD percentage of applied radioactive dose (n=3)

*not assayed

**assayed for transformation of ethanolamine into skin metabolites

***radioactivity recovered from combustion of the entire skin sample at the end of the time interval

 

Applicant's summary and conclusion