Registration Dossier

Administrative data

Endpoint:
skin irritation: in vivo
Type of information:
experimental study
Adequacy of study:
other information
Study period:
November 11 to 19, 1985
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
Well documented and reported study, conducted equivalent or similar to internationally accepted technical guideline in recognized industrial research organization. A quality assurance inspection report with reference to GLP, but not a GLP compliance statement, was included in the study report.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1986
Report Date:
1986

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
EU Method B.4 (Acute Toxicity: Dermal Irritation / Corrosion)
Version / remarks:
of 1984
Deviations:
yes
Remarks:
exposure period was 24 hours instead of 4 hours
GLP compliance:
no
Remarks:
but Quality Assurance statement with reference to IKS GLP guidance document was included in the report

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): PBS 2354.0 (Iminodi-benzyl)
- Description: dark yellow flakes
- Expiration date of the lot/batch: December 1986
- Storage conditions: room temperature
Analyzed by Pharmaceuticals Production: Test Article Data Sheet of September 30, 1985


Test animals

Species:
rabbit
Strain:
other: albino, Chbb:HM (SPF)
Details on test animals and environmental conditions:
- Animal supplier: Thomae, FRG
- Age: Approximately 4 - 6 months.
- Number and Sex: 3 males and 3 females
- Weight on day of treatment (before application): Minimum 1.81 kg, maximum 2.15 kg.
- Housing: Individual housing in metal cages.
- Diet (ad libitum): Commercially available pelleted standard diet (NAFAG No. 814, batch 73/85, analysed by the
manufacturer, NAFAG, Gossau, Switzerland).
- Water (ad libitum): Tap water. (Periodically analysed for compliance with Swiss drinking water specifications) - Acclimation period: Approximately 2 weeks under laboratory conditions.


ENVIRONMENTAL CONDITIONS

Air conditioned room:
- Temperature (°C): 18 ± 2°C
- Relative Humidity (%): 60 ± 10%
- Photoperiod: 14 hrs light/day


Test system

Type of coverage:
occlusive
Preparation of test site:
shaved
Vehicle:
unchanged (no vehicle)
Controls:
not required
Amount / concentration applied:
0.5 g test material per approx. 6 cm2 skin per animal.
The unchanged test material was ground to a fine powder using a mortar. The ground test material was loaded on gauze pads moistened with distilled water.
Duration of treatment / exposure:
24 hours
Observation period:
From prior to treatment (i.e. pretest) until 7 days post patch removal
Number of animals:
6 (3 males and 3 females)
Details on study design:
TEST SITE PREPARATION:

3 days before treatment, both flanks of the rabbits were shaved with an electric clipper and an electric shaver.

- Area of treated skin: Approx. 6 cm2 (= 2.5 x 2.5 cm gauze patch).
- Type of wrap used: Gauze patches were covered with impermeable foil and fastened to the rabbit body with elastic bandage and adhesive tape.

TEST MATERIAL AND DOSE PREPARATION

- Administration Volume/animal (i.e. one gauze patch of 2.5 x 2.5 cm per animal):
Test material was ground to a fine powder using a mortar. 0.5 g of ground test material was loaded on a gauze patch moistened with distilled water.

TREATMENT PERIOD AND REMOVAL OF TEST SUBSTANCE

Epicutaneous, occlusive treatment lasted 24 hours. Then the dressings were removed and residual test material was gently washed off the skin with warm water

SCORING SYSTEM:

The treated skin patches were evaluated at pretest and 30 minutes 24, 48 and 72 hours and 7 days post patch removal. Skin reactions were evaluated for erythema/eschar formation and edema according to Draize (see Table 1). In addition, scaling was recorded.

Results and discussion

In vivo

Resultsopen allclose all
Irritation parameter:
overall irritation score
Remarks:
according to Draize as defined above
Basis:
mean
Remarks:
over 6 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
0.33
Max. score:
8
Reversibility:
fully reversible within: 7 days
Remarks on result:
other: Five of 6 animals were free from erythema/edema throughout the study. Only 1 (male no. 24) of 6 animals showed skin reactions.
Irritation parameter:
erythema score
Remarks:
according to Draize as defined above
Basis:
mean
Remarks:
over 6 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
0.22
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
other: Five of 6 animals were free from erythema/edema throughout the study. Only 1 (male no. 24) of 6 animals showed skin reactions (erythema and edema).
Irritation parameter:
edema score
Remarks:
according to Draize as defined above
Basis:
mean
Remarks:
over 6 animals and 3 time points
Time point:
other: 24, 48, 72 h
Score:
0.11
Max. score:
4
Reversibility:
fully reversible within: 72 h
Remarks on result:
other: Five of 6 animals were free from erythema/edema throughout the study. Only 1 (male no. 24) of 6 animals showed skin reactions (erythema and edema).
Irritation parameter:
overall irritation score
Remarks:
according to Draize as defined above
Basis:
other: male no. 24
Time point:
other: 24, 48, 72 h
Score:
2
Max. score:
8
Reversibility:
fully reversible within: 7 days
Remarks on result:
other: Male no. 24 was the only animal which showed skin reactions
Irritation parameter:
erythema score
Remarks:
according to Draize as defined above
Basis:
other: male no. 24
Time point:
other: 24, 48, 72 h
Score:
1.33
Max. score:
4
Reversibility:
fully reversible within: 7 days
Remarks on result:
other: Male no. 24 was the only animal which showed skin reactions
Irritation parameter:
edema score
Remarks:
according to Draize as defined above
Basis:
other: male no. 24
Time point:
other: 24, 48, 72 h
Score:
0.67
Max. score:
4
Reversibility:
fully reversible within: 72 h
Remarks on result:
other: Male no. 24 was the only animal which showed skin reactions
Irritant / corrosive response data:
Erythema and edema result tables for each individual animal are presented under "Remarks on results including tables and figures"
Other effects:
Skin scaling was seen in one animal (male No. 24) on the treated flank at 48 and 72 h after patch removal having fully reversed by 7 days.

Any other information on results incl. tables

 

Table 2: Gradings of Skin Reactions Attained for each Male Animal at Different Observation Time Points

Pretest /
Time after Patch Removal

Pretest

0.5 h

24 h

48 h

72 h

7 days

Animal (Identification) No.

22 23 24

22 23 24

22 23 24

22 23 24

22 23 24

22 23 24

Erythema / Eschar

0   0   0

0   0   1

0   0   2

0   0   1

0   0   1

0   0   0

Edema

0   0   0

0   0   0

0   0   1

0   0   1

0   0   0

0   0   0

 

 

 

Table 3: Gradings of Skin Reactions Attained for each Female Animal at Different Observation Time Points

Pretest /
Time after Patch Removal

Pretest

0.5 h

24 h

48 h

72 h

7 days

Animal (Identification) No.

52 53 54

52 53 54

52 53 54

52 53 54

52 53 54

52 53 54

Erythema / Eschar

0   0   0

0   0   0

0   0   0

0   0   0

0   0   0

0   0   0

Edema

0   0   0

0   0   0

0   0   0

0   0   0

0   0   0

0   0   0

 

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: EU
Conclusions:
Epicutaneous occlusive administration of PBS 2354.0 (Iminodi-benzyl) to intact skin of six albino rabbits led to erythema up to grade 2 (well defined), very slight edema (Grade 1, barely perceptible) and skin scaling, in 1 of 6 animals. By 7 days after patch removal all skin reactions had fully reversed to normal skin in the affected animal. The other animals were unaffected throughout the study. According to EU classification rules (DIRECTIVE 67/548/EEC and REGULATION (EC) 1272/2008) the findings attained in this study do not necessitate any labelling regarding skin irritation.
Executive summary:

PBS 2354.0 (Iminodi-benzyl) was tested for skin irritation similar to EU Method B.4 (Acute Toxicity: Skin Irritation) of 1984 (Dir. 84/449/EEC) in albino rabbits [Chbb:HM (SPF)]. The study was more comprehensive than foreseen in this test guideline in that six animals were exposed to the test material for 24 hours (instead of 4 hours).

 

Reliability grade 1 was assigned to the study. It was not conducted in compliance with GLP, but a Quality Assurance statement with reference to an IKS GLP guidance document*was included in the study report.

 

Intact shaved skin of each animal (3 males and 3 females) was treated on one flank by epicutaneous occlusive administration of 0.5 g of ground test material loaded on gauze patches (2.5 x 2.5 cm), the latter moistened with distilled water. The patches were covered with impermeable foil and fastened to the rabbit body with elastic bandage and adhesive tape. Shaved skin on the other flank served as a control. Skin reactions were recorded at pretest and 30 minutes 24, 48 and 72 hours and 7 days post patch removal and were evaluated for erythema/eschar formation and edema according to Draize. In addition, scaling was recorded.

 

There was no mortality. General symptoms or relevant changes in body weight were not evident. Erythema up to grade 2 (well defined), very slight edema (Grade 1, barely perceptible) and skin scaling were seen in 1 of 6 animals and were attributed to treatment with the test material. By 7 days after patch removal all skin reactions had fully reversed to normal skin in the affected animal. In the remaining 5 animals skin reactions were not evident throughout the study.

 

The primary skin irritation index (i.e. sum of mean irritation scores read 30 minutes and 48 hours after patch removal for erythema and edema divided by 2) attained during this study was 0.3 (maximum possible value: 8) reflecting “minimal irritation” according to the skin irritation/corrosion classification scheme adopted in the study report. However, the mean Draize scores (24, 48, 72 h over 6 animals) were 0.22 for erythema and 0.11 for edema. For the one affected animal, the respective mean scores (24, 48, 72 h) were 1.33 for erythema and 0.67 for edema. Therefore, according to EU classification rules (DIRECTIVE 67/548/EEC and REGULATION (EC) 1272/2008) the test material would be considered to be "not irritant" not necessitating any labelling regarding skin irritation.

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*"Wegleitung der IKS betreffend gute Laboratoriumspraxis für nichtklinische Laborversuche, Unterabschnitt B.4.a.v."