Disodium 1,5-dihydroxypentane-1,5-disulphonate

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 07 AUG 2017 to 20 SEP 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

Test Method following EU-Method B.46 resp. OECD 439.

Deviations:

no

Principles of method if other than guideline:

The pre-incubation time was 1 hour, instead 18-24 hours. This can be seen as uncritical, because the pre-incubation time must be at least 1 hour (in consultation with the tissue supplier; MatTek In Vitro Life Science Laboratories).

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Disodium 1,5-dihydroxypentane-1,5-disulphonate

Cas Number:

7420-89-5

Molecular formula:

C5H10Na2O8S2

IUPAC Name:

Disodium 1,5-dihydroxypentane-1,5-disulphonate

impurity 1

Reference substance name:

Sodium sulfate

Cas Number:

7757-82-6

IUPAC Name:

Sodium sulfate

impurity 2

Reference substance name:

Sodium hydrogen sulfite

Cas Number:

7631-90-5

IUPAC Name:

Sodium hydrogen sulfite

In vitro test system

Test system:

human skin model

Remarks:

Human-derived epidermal keratinocytes which habe been cultured to form a multi-layered, highly differentiated model of the human epidermis. EpiDermTM tissues were used.

Control samples:

yes, concurrent negative control

yes, concurrent positive control

Amount/concentration applied:

Negative control: Dulbecco's Phosphate Buffered Saline (0.2g KCL, 0.2g KH2PO4, 8.0g NaCl, 2.16g Na2HPO4*7H2O, ad 1L H2O)

Positive control: Sodium dodecyl sulphate (5% SDS in demineralised water)

Amount of Test Item:
Tissue 1: 24.3mg
Tissue 2: 24.9mg
Tissue 3: 24.5mg

Duration of treatment / exposure:

After the post-incubation the total incubation time was 38 hours and the MTT Assay was performed.

Duration of post-treatment incubation (if applicable):

Tissues were dosed in 1-minute-intervals. After dosing the last tissue, all plates were transferred into the incubator for 35 minutes at 37 ± 1°C and 5.0 ± 0.5% CO2. 1 hour after the first application, the inserts were removed from the plates using sterile forceps and rinsed immediately in 1-minute-intervals. After rinsing, each tissue was blotted with sterile cellulose tissue and then transferred into a new 6-well-plate with fresh assay medium (0.9 mL). Then, the tissues were set in the incubator for 22 hours at 37 ± 1°C and 5.0 ± 0.5% CO2.
After another medium renewal the tissues were set into the incubator for 16 hours for post-incubation at 37 ± 1°C and 5.0 ± 0.5% CO2.

Number of replicates:

Negative control: 3 Tissues were used
Positive control: 3 Tissues were used
Treatment: 3 Tissueswere used

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

% tissue viability

Run / experiment:

OD 570nm:
Tissue 1: 0.435 (mean of 2 measurements - blank)
Tissue 2: 0.479 (mean of 2 measurements - blank)
Tissue 3: 0.409 (mean of 2 measurements - blank)

Tissue viability:
Tissue 1: 22.1%
Tissue 2: 24.4%
Tissue 3: 20.8%
Mean: 22.4%

Value:

22.4

Negative controls validity:

valid

Remarks:

OD (570nm) Tissue 1: 2.043 (mean of 2 measurements - blank) Tissue 2: 2.003 (mean of 2 measurements - blank) Tissue 3: 1.849 (mean of 2 measurements - blank) Mean: 1.965

Positive controls validity:

valid

Remarks:

OD (570nm) Tissue 1: 0.053 (mean of 2 measurements - blank) Tissue 2: 0.046 (mean of 2 measurements - blank) Tissue 3: 0.046 (mean of 2 measurements - blank) Mean: 0.048

Applicant's summary and conclusion

Interpretation of results:

Category 2 (irritant) based on GHS criteria

Conclusions:

Glutardialdehyde bis-Sodiumbisulfite is considered as irritant to skin. After the treatment, the mean value of relative tissue viability was reduced to 22.4 %. This value is below the threshold for skin irritation (50%). The optical density of the negative control was well within the required acceptability criterion of 0.8 ≤ mean OD ≤ 2.8. The positive control has met the acceptance criterion too, for thus ensuring the validity of the test system. Variation within replicates was within the accepted range for negative control, positive control and test item (required: ≤ 18%). For these reasons, the result of the test is considered valid.