Registration Dossier

Administrative data

Endpoint:
dermal absorption in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2004
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: information on Colipa reporr n. C29

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2004
Report Date:
2004

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EU Method B.45 (Skin Absorption: In Vitro Method)
Deviations:
not specified
GLP compliance:
yes

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Details on test material:
No data
Radiolabelling:
no

Test animals

Species:
pig
Sex:
not specified

Administration / exposure

Vehicle:
physiological saline
Doses:
5 mg/ml in saline
No. of animals per group:
no data
Details on study design:
The skin absorption of Acid Yellow 23 was investigated on the outer skin of porcine ears (freshly obtained from the local slaughter-house, approx. 400 μm thick) with amountscorresponding to realistic use conditions. 5 mg of the pure dye (93% purity) dissolved in saline transferred to the donor chamber with 1 ml was applied to the skin.

Results and discussion

Signs and symptoms of toxicity:
no effects
Dermal irritation:
no effects
Percutaneous absorption
Time point:
24 h
Dose:
0.26 %
Parameter:
rate
Remarks:
penetration
Absorption:
ca. 13.2 other: µg/cm2

Any other information on results incl. tables

The conductivity over time ranged within the historical controls. No abrupt change in conductivity, indicating a loss of barrier properties of the skin, occurred in any chamber up to the maximal duration of the experiments. The mean recovery of the test item for experiment I and II were 94.5 ± 6.88 % and 97.5 ± 4.24 %. The majority of the test item (91 % in the first experiment, 78 % in the second experiment) was determined in the donor chamber solution. No measurable penetration through the skin was observed at any time point in the first and in the second study. Taking into account the detection limits a worst case of penetrated Acid Yellow 23 gives an upper limit of 5.0 μg of the test item (0.11 % of the applied total amount) in the first experiment and 5.9 μg of the test item (0.12 % of the applied total amount) in the second experiment. Together with the skin extracts (total skin) the worst case considerations of penetrated test item result in 5.4 μg/cm2 (0.11 % of the applied total amount) in the first and 13.2 μg/cm2 (0.26 % of the applied total amount) in the second study.

Applicant's summary and conclusion

Conclusions:
Low skin penetration
Executive summary:

Under the described test conditions, skin penetration of Acid Yellow 23 is low. A skin penetration rate of 5.4 μg Acid Yellow 23/cm² (about 0.11 % of the applied amount) and 13.2 μg Acid Yellow 23/cm² (0.26 % of the applied dose) within 24 hours has been calculated for the pure substance and a commercial formulation, respectively, including the amounts present in the stratum corneum and thus assuming worst case conditions. A penetration rate of 13.2 μg/cm² (0.26 %) representing the highest value derived from the above described test will be used as a worst case scenario for the final risk assessment.