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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vivo (LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
2008-07-22
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: Non-GLP study.
Cross-referenceopen allclose all
Reason / purpose:
reference to same study
Reason / purpose:
reference to other study

Data source

Reference
Reference Type:
publication
Title:
Unnamed
Year:
2009
Report Date:
2008

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)
Principles of method if other than guideline:
The LLNA was performed according to a standard protocol: Kimber, I., Weisenberger, C.A.; A murine local lymph node assay for the identification of contact allergens. Assay, development, and results of an initial validation study. Arch. Toxicol. 1989: 63: 274 - 282
GLP compliance:
no
Type of study:
mouse local lymph node assay (LLNA)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material: potassium persulfate
- Molecular formula: K2 S2 O8
- Molecular weight: 270.3
- Substance type: inorganic
- Physical state: solid
- Analytical purity: not stated
- Purity test date: no information available
- Lot/batch No.: no information available
- Expiration date of the lot/batch: no information available
- Stability under test conditions: stable
- Storage condition of test material: cool and dry

In vivo test system

Test animals

Species:
mouse
Strain:
Balb/c
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Harlan; Horst, The Netherlands
- Age at study initiation: 6 weeks
- Weight at study initiation: abt. 20 g
- Housing: conventional animal cages
- Diet (e.g. ad libitum): pelleted diet; Trow Nutrition; Ghent, Belgium; ad libitum
- Water (e.g. ad libitum):lightly acidified water ad libitum
- Acclimation period: not stated


ENVIRONMENTAL CONDITIONS
- Temperature (°C): not stated
- Humidity (%): not stated
- Air changes (per hr): not indicated
- Photoperiod: 12 hrs dark / 12 hrs light


Study design: in vivo (LLNA)

Vehicle:
dimethyl sulphoxide
Concentration:
0; 0.1; 0.5; 1; 5 % (w/v) in Dimethyl sulphoxide.
No. of animals per dose:
five animals per dose group.
Details on study design:
Five animals per dose and test group received dermal application of 0.25 µL of various concentrations of dipotassium persulfate or same volume of the vehicle alone on each ear, daily for three consecutive days. The area around the exposure site was monitored for any signs of irritancy. Six days after the initiation of exposure, the mice were injected intravenously through the tail vein with (methyl-3H)-thymidine [3HTdR], 2 Ci/mmol from ICN Pharmaceuticals (Asse, Belgium) in 250 µL of phosphate-buffered saline (pH 7.2). Five hours later, the mice were killed by an overdose of pentobarbital (90 mg/kg) and the draining auricular lymph nodes were excised, pooled for each mouse, and weighed (lymph node weight, LNW). A single cell suspension of lymph node cells (LNC) was prepared and the LNC was washed twice. 3HTdR incorporation was measured by ß-scintillation counting (Beckman LS 5000 CE, Irvine, CA, USA) and expressed as disintegrations per minute (d.p.m.). The SI was calculated as the ratio of 3HTdR incorporation by lymphocytes from treated animals relative to that from concurrent vehicle-treated animals.
Positive control substance(s):
not specified
Statistics:
All data were analysed using parametric analysis of variance with a Dunnett's post hoc test (GRAPHARD PRISM 4.01, GRAPHARD Software Inc., San Diego, CA, USA). A level of P < 0.05 (two-tailed) was considered to be significant.

Results and discussion

Positive control results:
Not indicated.

In vivo (LLNA)

Resultsopen allclose all
Parameter:
SI
Remarks on result:
other: A maximal mean SI of 5.0 +/- 1.0 at the highest concentration tested (5 %) was calculated for dipotassium persulfate.
Parameter:
other: disintegrations per minute (DPM)
Remarks on result:
other: Concentration (% w/v)/disintegrations per minute (d.p.m.) 0 / 1630 +/- 284 0.1 / 1579 +/- 240 0.5 / 2130 +/- 323 1 / 3145 +/- 649 5 / 8179 +/- 1568

Any other information on results incl. tables

The following tables show the lymph node weights (LNW) and disintegrations per minute (d.p.m.) for mice treated with dipotassium persulfate for the LLNA assay:

 

Table 1: Lymph node weights in response to treatment:

Concentration ( % w/v)

LNW (mg)

0.0

3.4 +/- 1.7

0.1

4.1+/- 0.7

0.5

4.5 +/- 1.2

1

7.5 +/- 2.2

5

9.5 +/- 2.3

 

 

 

Table 2: Disintegrations per minute (d.p.m.) in the LLNA in response to treatment:

Concentration ( % w/v)

d.p.m.

0.0

1630 +/- 284

0.1

1579 +/- 240

0.5

2130 +/- 323

1

3145 +/- 649

5

8179 +/- 1568

Applicant's summary and conclusion

Interpretation of results:
sensitising
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Under the conditions of the present assay dipotassium persulfate was shown to have sensitisation potential (sensitiser) in the LLNA.
Executive summary:

Dipotassium persulfate was tested for skin sensitising potential in the mouse local lymph node assay (LLNA). Exposure to dipotassium persulfate resulted in a maximal mean SI of 5.0 +/- 1.0 at the highest concentration tested (5 %). Applying 5 % solution of dipotassium persulfate caused the LNW and the total number LNC to increase 2.8 times and 5 times, respectively compare to the DMSO control. From the calculated SI values, the estimated EC3 for dipotassium persulfate was 2.4 %. Based on the EC3 value, dipotassium persulfate was considered as a moderate skin sensitizer.