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Toxicological information

Dermal absorption

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Administrative data

Endpoint:
dermal absorption
Type of information:
other: literature review and safety assessment
Adequacy of study:
weight of evidence
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: The paper summarises a literature review and safety assessment performed by the Cosmetic Ingredient Review (CIR) Expert Panel.

Data source

Reference
Reference Type:
publication
Title:
Final Report of the Safety Assessment of Urea
Author:
CIR Panel
Year:
2005
Bibliographic source:
International Journal of Toxicology 24(s3): 1 - 56

Materials and methods

Test guideline
Qualifier:
no guideline followed
Principles of method if other than guideline:
Literature review: the design of individual studies is variable
GLP compliance:
no
Remarks:
: not relevant

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
Urea
Radiolabelling:
yes

Test animals

Species:
other: various

Results and discussion

Percutaneous absorption
Parameter:
percentage
Absorption:
9.5 %
Remarks on result:
other: intact human skin in vitro
Conversion factor human vs. animal skin:
Not calculated

Any other information on results incl. tables

The authors conclude that the dermal absorption of urea across intact human skin in vitro is 9.5%.

Applicant's summary and conclusion

Conclusions:
The absorption of urea across normal human skin in vitro is reported to be 9.5%.
Executive summary:

The permeability constant after treatment with urea of whole skin and the dermis of rabbits is reported to be 2.37 ± 0.13 (106) and 1.20 ± 0.09 (103) cm/min, respectively. The absorption of urea across normal and abraded human skin is reported to be 9.5% ± 2.3% and 67.9% ± 5.6%, respectively. Urea is known to increase the skin penetration of other compounds, including hydrocortisone.