Trisodium 5-hydroxy-1-(4-sulphophenyl)-4-(4-sulphophenylazo)pyrazole-3-carboxylate

Dermal absorption

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

Guideline:

EU Method B.45 (Skin Absorption: In Vitro Method)

Deviations:

not specified

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Trisodium 5-hydroxy-1-(4-sulphophenyl)-4-(4-sulphophenylazo)pyrazole-3-carboxylate

EC Number:

217-699-5

EC Name:

Trisodium 5-hydroxy-1-(4-sulphophenyl)-4-(4-sulphophenylazo)pyrazole-3-carboxylate

Cas Number:

1934-21-0

Molecular formula:

C16H12N4O9S2.3Na

IUPAC Name:

trisodium 5-hydroxy-1-(4-sulphophenyl)-4-(4-sulphophenylazo)pyrazole-3-carboxylate

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.