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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:
key study
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Well documented study in peer-reviewed publication.
Cross-reference
Reason / purpose:
reference to same study

Data source

Reference
Reference Type:
publication
Title:
The percutaneous absorption of some anionic surfactants
Author:
Howes, D
Year:
1975
Bibliographic source:
J. Soc. Cosmet. Chem. 26: 47-63.

Materials and methods

Test guideline
Qualifier:
no guideline followed
GLP compliance:
not specified

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): sodium p-1-[1-14C]-dodecylbenzenesulphonate
- Analytical purity: determined to be chemically pure by thin layer chromatography
- Radiochemical purity (if radiolabelling): determined to be radioactively pure by isotope dilution analysis
- Specific activity (if radiolabelling): > 99%
Radiolabelling:
yes

Test animals

Species:
human
Sex:
female

Administration / exposure

Duration of exposure:
48 hrs
Doses:
0.1 ml of 3 mM solution
No. of animals per group:
four skin samples
Details on study design:
- Method for preparation of dose suspensions: The test substance was added to the vehicle and homogenized and equilibrated at 40 degrees C for 24 hrs. The pH was then adjusted to 9.5 by adding 0.01 n NaOH or HCl.
Details on in vitro test system (if applicable):
SKIN PREPARATION
- Source of skin: human cadavers
- Ethical approval if human skin:
- Type of skin: abdominal
- Preparative technique: Epidermal samples were heated at 58 degrees C for 2 min. Samples were placed in 1 cm diameter penetration cells, and saline with 0.012% penicillin, 0.01% streptomycin was placed on both surfaces of the cells. The cells were equilibrated at 37 degrees C for 24 hrs.
- Membrane integrity check: Only cells with electrical resistance greater than 50,000 ohms were used.
- Storage conditions: -70 degree C

Results and discussion

Signs and symptoms of toxicity:
not examined
Dermal irritation:
yes
Remarks:
some swelling was seen after 48 hrs of contact
Absorption in different matrices:
Only 30% of the test substance was removed by rinsing, with 70 % remaining associated with the skin.
Percutaneous absorptionopen allclose all
Dose:
152.9 micrograms/cm^2
Parameter:
percentage
Absorption:
< 0.07 %
Remarks on result:
other: 2 hrs
Dose:
152.9 micrograms/cm^2
Parameter:
percentage
Absorption:
< 0.07 %
Remarks on result:
other: 6 hrs
Dose:
152.9 micrograms/cm^2
Parameter:
percentage
Absorption:
< 0.07 %
Remarks on result:
other: 24 hrs
Dose:
152.9 micrograms/cm^2
Parameter:
percentage
Absorption:
< 0.07 %
Remarks on result:
other: 48 hrs

Applicant's summary and conclusion

Conclusions:
The in vitro penetration through human skin after a 48 hr exposure was < 0.07%.
Executive summary:

Radiolabelled test substance was applied (0.1 ml of a 3 mM solution) to samples of human abdominal skin from four female cadavers. Exposure time was 48 hrs. Analysis by liquid scintillation counting was done at 0.5, 1, 2, 3, 4, 6, 7, 8, 24, and 48 hrs. Penetration through human skin was negligible, with < 0.07% absorbed in 48 hrs.