Calcium dodecylbenzenesulphonate

Dermal absorption

Administrative data

Endpoint:

dermal absorption in vitro / ex vivo

Type of information:

other: published data

Adequacy of study:

supporting study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

study well documented, meets generally accepted scientific principles, acceptable for assessment

Justification for type of information:

Sodium dodecylbenzenesulfonate (CAS# 25155-30-0 , EC Number; 246-680-4 ) is a very close analogue of Calcium dodecylbenzenesulfonate (CAS No 26264-06-2, EC Number; 247-557-8) ) and read-across is valid.

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

Principles of method if other than guideline:

-Radiolabelled test substance was applied (0.1 ml of a 3 mM solution) to samples of human abdominal skin from four female cadavars. 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.
- 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.

GLP compliance:

not specified

Test material

Test material information

Constituent 1

Reference substance name:

Sodium dodecylbenzenesulfonate

EC Number:

246-680-4

EC Name:

Sodium dodecylbenzenesulfonate

Cas Number:

25155-30-0

Molecular formula:

C18H30NaO3S

IUPAC Name:

sodium dodecylbenzenesulfonate

Test material form:

solid: compact

Details on test material:

- Name of test material (as cited in study report): LAS (CAS #25155-30-0); activity: >99%
- 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 cadavars
- 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 diamter 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 absorption

Percutaneous absorption 1

Dose:

152.9 micrograms/cm^2

Parameter:

percentage

Absorption:

< 0.07 %

Remarks on result:

other: 2 hrs

Percutaneous absorption 2

Dose:

152.9 micrograms/cm^2

Parameter:

percentage

Absorption:

< 0.07 %

Remarks on result:

other: 6 hrs

Percutaneous absorption 3

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 cadavars. 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.