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Toxicological information

Skin irritation / corrosion

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Administrative data

Endpoint:
skin corrosion: in vitro / ex vivo
Remarks:
in vitro
Type of information:
experimental study
Adequacy of study:
weight of evidence
Study period:
2012-03-20 to 2012-03-22
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Valid without restriction; GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2012
Report Date:
2012

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Deviations:
no
Qualifier:
according to
Guideline:
OECD Guideline 431 (In Vitro Skin Corrosion: Human Skin Model Test)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): Peroxan NPO; Bis(3,5,5-trimethylhexanoyl)peroxide
- Substance type: organic peroxide
- Physical state: liquid
- Analytical purity: 75 % (iodometric titration)
- Composition of test material, percentage of components: 75 % Peroxan NPO, 25 % Isododecane
- Lot/batch No.: 10618310
- Expiration date of the lot/batch: 2012-04-20
- Storage condition of test material: -8 to 0°C, protected from light

Test animals

Species:
other: reconstituted three-dimensional human skin model EpiDerm (MatTek)
Strain:
other: not applicable
Details on test animals and environmental conditions:
Test system:
The test was carried out with the reconstituted three-dimensional human skin model EpiDermTM (MatTek). It consists of non-cancerous, human-derived epidermal keratinocytes (NHEK) which have been cultutred to form a multi-layered, highly differentiated model of the human epidermis. The NHEK are cultured are cultured on chemically modified, collagen-coated cell culture inserts (Millicell). The test systewm exhibits in vivo like morphological and growth characteristics and consists of organised basal, spinous, granular and cornified layers analogous to those found in vivo.

Test system

Type of coverage:
other: not applicable
Preparation of test site:
other: not applicable
Vehicle:
unchanged (no vehicle)
Controls:
other: EpiDerm Tissue was treated with distilled water and 8 N KOH
Amount / concentration applied:
The test item was applied undiluted. 50 µl of the test item were dispensed directly onto the EpiDerm tissue. The test item was spread to match size of the tissue.
Duration of treatment / exposure:
3 minutes and 60 minutes exposure
Observation period:
n.a.
Number of animals:
n.a.
Details on study design:
see "any other information on materials and methods incl. tables"

Results and discussion

In vitro

Resultsopen allclose all
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
3 min
Value:
90
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation
Irritation / corrosion parameter:
% tissue viability
Run / experiment:
60 min
Value:
83
Negative controls validity:
valid
Positive controls validity:
valid
Remarks on result:
no indication of irritation

In vivo

Other effects:
n.a.

Any other information on results incl. tables

Table1: 3 min Exposure

Name

Negative Control

Test item

Positive control

Tissue

1

2

1

2

1

2

Absolute OD550-Werte

2.080

2.087

1.959

1.787

0.309

0.269

2.082

2.088

1.962

1.784

0.315

0.271

2.068

2.061

1.945

1.770

0.312

0.269

Mean OD550

2.077

2.079

1.955

1.780

0.312

0.270

SD

0.008

0.015

0.009

0.009

0.003

0.001

Total mean OD550(mean of two replicate tissues)

2.078*

1.868

0.291

Mean relative tissue viability [%]

100

90

14**

Mean inter tissue viability difference [%]***

0.1

9.4

14.5

* mean OD550 ≥ 0.8

** mean relative tissue viability of the 3 min positive control ≤ 30 %

*** inter tissue viability difference ≤ 30 %

Table 2: 60 min Exposure

Name

Negative Control

Test item

Positive control

Tissue

1

2

1

2

1

2

Absolute OD550-Werte

1.955

1.763

1.815

1.454

0.114

0.119

1.983

1.790

1.692

1.376

0.117

0.129

2.000

1.782

1.706

1.361

0.115

0.121

Mean OD550

1.979

1.778

1.706

1.361

0.115

0.121

SD

0.023

0.014

0.067

0.050

0.002

0.005

Total mean OD550(mean of two replicate tissues)

1.879*

1.567

0.119

Mean relative tissue viability [%]

100

83

6

Mean inter tissue viability difference [%]***

10.7

21.7

6.4

* mean OD550 ≥ 0.8

*** inter tissue viability difference ≤ 30 %

Applicant's summary and conclusion

Interpretation of results:
not classified
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
In this study the test item Peroxan NPO is not considered to be corrosive.
Executive summary:

The potential of the test item to induce skin corrosion was analysed by using the three dimensional human skin model EpiDerm, comprising a reconstructed epidermis with a functional stratum corneum. Peroxan NPO was applied topically to the EpiDerm tissue for 3 min and 60 min, respectively followed by immediate determination of cytotoxic effects via MTT reduction assay.

The test item showed no corrosive potential. The mean relative tissue viability (% negative control) was >= 50% (90%) after 3 min treatment and >= 15% (83%) after 60 min treatment.

The controls confirmed the validity of the study. The mean OD550 of the two negative control tissues was >= 0.8 for each exposure period. The mean relative tissue viability of the positive control was =< (14%) after 3 min treatment. The maximum inter tissue difference of replicate tissues of all dose groups was =< 30 % (0.1%-21.7%).