Sodium dodecylbenzenesulfonate

Exposure related observations in humans: other data

Administrative data

Endpoint:

exposure-related observations in humans: other data

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

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

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

Type of study / information:

In vitro penetration through human epidermis

Endpoint addressed:

dermal absorption

Test guideline

Qualifier:

no guideline followed

Principles of method if other than guideline:

Female abdominal skin samples obtained at autopsy were frozen and stored at- 70 o. Samples of the skin were allowed to thaw out and were heated at 58 o for 2 min and the epidermis removed in sheets The epidermal samples were mounted in 1 cm diameter penetration cells similar to those described by Ainsworth . Saline containing 0 .012 % Pencillin and 0.01% Streptomycin was placed in contact with both surfaces of the sample and the cells were equilibrated at 37 o for 24 h. The electrical resistance of the cells was measured and only cells with a resistanceg reater than 50 000 Ω were used. The saline from the corneum surface was removed and 0.1 ml of the [14C] surfactant solution was placed on the corneum. 1.0 ml aliquots of the saline in the sampling compartment (8.0 ml) were monitored for 14C at 0.5, 1, 2, 3, 4, 6, 7, 8, 24 and 48 h, each time 1.0ml of fresh saline was added to maintain the volume at 8.0 ml. At the end of the experiment the corneum was washed with excess of distilled water and the epidermal sample monitored for 14C by solubilizing in 'Soluene'.

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:

C18H29NaO3S

IUPAC Name:

sodium dodecylbenzenesulfonate

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%

Method

Ethical approval:

no

Details on study design:

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

Exposure assessment:

measured

Details on exposure:

Female abdominal skin samples obtained at autopsy were frozen and stored at- 70 o. Samples of the skin were allowed to thaw out and were heated at 58 o for 2 min and the epidermis removed in sheets The epidermal samples were mounted in 1 cm diameter penetration cells similar to those described by Ainsworth . Saline containing 0 .012 % Pencillin and 0.01% Streptomycin was placed in contact with both surfaces of the sample and the cells were equilibrated at 37 o for 24 h. The electrical resistance of the cells was measured and only cells with a resistanceg reater than 50 000 Ω were used. The saline from the corneum surface was removed and 0.1 ml of the [14C] surfactant solution was placed on the corneum. 1.0 ml aliquots of the saline in the sampling compartment (8.0 ml) were monitored for 14C at 0.5, 1, 2, 3, 4, 6, 7, 8, 24 and 48 h, each time 1.0ml of fresh saline was added to maintain the volume at 8.0 ml. At the end of the experiment the corneum was washed with excess of distilled water and the epidermal sample monitored for 14C by solubilizing in 'Soluene'.

Results and discussion

Results:

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.

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.