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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: according to guideline, review article, non GLP

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2009
Report date:
2009

Materials and methods

Test guideline
Qualifier:
according to guideline
Guideline:
OECD Guideline 428 (Skin Absorption: In Vitro Method)
Deviations:
no
GLP compliance:
not specified

Test material

Constituent 1
Chemical structure
Reference substance name:
Benzoic acid
EC Number:
200-618-2
EC Name:
Benzoic acid
Cas Number:
65-85-0
Molecular formula:
C7H6O2
IUPAC Name:
Benzoic acid
Details on test material:
No data given.
Radiolabelling:
yes
Remarks:
14C

Test animals

Species:
human
Strain:
not specified
Sex:
female
Details on test animals or test system and environmental conditions:
TEST ANIMALS
- Source: cryopreserved human abdominal skin
- Age at study initiation: aged 29–53 years (average 39 ± 7.4)

No information provided

Administration / exposure

Type of coverage:
open
Vehicle:
other: The receptor fluid consisted of a physiological salt solution (0.9% NaCl w/v) containing 0.01% sodium azide and 6% polyoxyethylene oleyl ether
Duration of exposure:
Finite dose experiments: 8 h
Doses:
- Nominal doses: 33 mg/mL(0.19)
- Dose volume: 16 μL aqueous dose solution/cm2
- Rationale for dose selection: The highest test concentrations were selected based on maximum solubility in water.
No. of animals per group:
4 of the epidermal membranes per test group
Control animals:
no
Details on study design:
VEHICLE
- Justification for use and choice of vehicle (if other than water): To ensure also lipophilic test substances would be readily soluble in it.

TEST SITE
- Area of exposure: 0.64 cm2

SITE PROTECTION / USE OF RESTRAINERS FOR PREVENTING INGESTION: no

REMOVAL OF TEST SUBSTANCE
- Washing procedures and type of cleansing agent: Washing off the test substance using four cotton swabs humidified with a 3% Teepol solution
- Time after start of exposure: 8 h

ANALYSIS
- Method type(s) for identification: liquid scintillation counting (LSC)

No information provided
Details on in vitro test system (if applicable):
SKIN PREPARATION
- Source of skin: nine female donors
- Type of skin: cryopreserved human abdominal skin
- Preparative technique: Epidermal membranes were used, which were prepared by incubating skin overnight in 2 M NaBr solution in saline, after which the epidermis was peeled from the dermis using forceps.
- Membrane integrity check: Integrity of the epidermal was assessed by determining the permeability coefficient (Kp) of tritiated water.

PRINCIPLES OF ASSAY
- Diffusion cell: static diffusion cells using cryopreserved human abdominal skin (exposed area 0.64 cm2)
- Receptor fluid: The receptor fluid (total volume 1.2 mL) consisted of a physiological salt solution (0.9% NaCl w/v) containing 0.01% sodium azide and 6% polyoxyethylene (20) oleyl ether.
- Solubility od test substance in receptor fluid: 33 mg/mL
- Static system: in static diffusion cells

No information provided

Results and discussion

Signs and symptoms of toxicity:
not specified
Dermal irritation:
not specified
Absorption in different matrices:
No information provided
Total recovery:
- Total recovery: 98 ± 0.8%

No data given.
Percutaneous absorptionopen allclose all
Dose:
10 μL
Parameter:
percentage
Absorption:
48 %
Remarks on result:
other: 8h
Remarks:
Measured
Parameter:
percentage
Absorption:
93 %
Remarks on result:
other: QSAR prediction
Conversion factor human vs. animal skin:
not applicable

Any other information on results incl. tables

Recovery of the label is 98%.

Applicant's summary and conclusion

Conclusions:
The measured absorption of test substance in an in vitro test with human skin was 48±7%.
Executive summary:

The finite dose experiment was made according to OECD Guideline 428.The test substance was exposed to cryopreserved human abdominal skin for 8 hours with concentration of 33 mg/mL. 14C-radioactivity, penetration rate and recovery were calculated.

The measured absorption of test substance is 48±7% with a revovery of radioactivity of 98%.