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Description of key information

Skin sensitisation: Not skin sensitising, based on a read across to gestonorone caproate (Schoebel 1979)

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Referenceopen allclose all

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
4.12.1978 - 19.01.1979
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
study well documented, meets generally accepted scientific principles, acceptable for assessment
Principles of method if other than guideline:
- Principle of test: Investigation on sensitizing potential of the test substance. During an induction phase the test substance as well as a positive and a negative control were intracutaneously applied for 10 times within 3 weeks. Freund's adjuvans was mixed to the test solutions in week 2 and 3. 13 days after the last induction dose, a single challenge dose was applied intradermally. A second challenge dose was applied epidermally 12 days thereafter (maximum subirritant dose). Animals were investigated for positive reactions.


- Parameters analysed / observed: skin thickness and the two largest diameter of reddend skin parts before treatment and 24 hours after treatment were determined during week one of induction phase and at the 1. challenge dose; a reaction volume [µl] was calculated based on thickness and diameter; values of week 1 (induction phase; local tolerance) were compared to value after 1. challenge; following the 2. challenge dose the reddening of the skin was taken as an allergic reaction.
GLP compliance:
not specified
Type of study:
Maurer optimisation test
Justification for non-LLNA method:
the guinea pig optimisation test was an adequate in vivo skin sensitisation test at the time of performance in 1979
Species:
guinea pig
Strain:
other: Pirbright White
Sex:
male/female
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Züchter Hagemann
- Weight at study initiation: 302 - 482 g
- Diet: ad libitum
- Water: ad libitum


ENVIRONMENTAL CONDITIONS
- Temperature (°C): 21.0 - 22.5
- Humidity (%): 35 - 70
- Photoperiod (hrs dark / hrs light): 12/12
Route:
intradermal
Vehicle:
other: Benzyl benzoate, castor oil
Concentration / amount:
0.1 mL (10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil)
Day(s)/duration:
Day 1, 3, 5
Adequacy of induction:
not specified
Route:
intradermal
Vehicle:
other: benzyl benzoate, castor oil
Concentration / amount:
2 mL (200 mg gestonorone caproate, 1218.8 mg benzyl benzoate, 700 mg castor oil) + 2 mL Freund's adjuvant
Day(s)/duration:
Day 8, 10, 12, 15, 17, 19
Adequacy of induction:
not specified
No.:
#1
Route:
intradermal
Vehicle:
other: benzyl benzoate, castor oil
Concentration / amount:
0.1 mL (10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil)
Day(s)/duration:
13 days after last induction dose (day 32)
Adequacy of challenge:
not specified
No.:
#2
Route:
epicutaneous, occlusive
Vehicle:
other: benzyl benzoate, castor oil
Concentration / amount:
0.1 mL (10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil)
Day(s)/duration:
day 44
Adequacy of challenge:
other: local tolerable
No. of animals per dose:
20 (10 males/10 females)
Details on study design:
MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 9
- Exposure period: 3 weeks
- Test groups: Depostat I (0.1 mL [10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil]), Depostat II (same formulation, but artificially aged; increase in peroxid value from 1.4 to 8.2)
- Control group: Negative control: 0.9% (w/v) NaCl (day 1, 3, 5); 2 mL 0.9% (w/v) NaCl + 2 mL Freund's adjuvant (day 8, 10, 12, 15, 17, 19)
Positive control: 0.1% (w/v) DNCB
- Site: back and lateral thoracic wall
- Frequency of applications: 2-3 days
- Concentrations: 10 % (w/v)

B. CHALLENGE EXPOSURE
Challenge #1
- No. of exposures: 1
- Day(s) of challenge: day 32
- Test groups: Depostat I (0.1 mL [10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil]), Depostat II (same formulation, but artificially aged; increase in peroxid value from 1.4 to 8.2)
- Control group: Negative control: 0.9% (w/v) NaCl
Positive control: 0.1% (w/v) DNCB
- Site: back and lateral thoracic wall
- Concentrations: 10 % (w/v)
- Evaluation (hr after challenge): 24
Challenge #2
- No. of exposures: 1
- Day(s) of challenge: day 44
- Test groups: Depostat I (0.1 mL [10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil]), Depostat II (same formulation, but artificially aged; increase in peroxid value from 1.4 to 8.2)
- Control group: Negative control: 0.9% (w/v) NaCl
Positive control: 25% (w/v) DNCB
- Site: occlusive tape (2x2 cm)
- Duration: 24 hours
- Concentrations: 10 % (w/v)
- Evaluation (hr after challenge): 24 after removal of occlusive tape


OTHER:
2 treatment groups: Depostat I, Depostat II
negative control
positive control
deviation from induction protocol: Depostat II - 2.5 ml Depostat II + 2.5 ml Freund's adjuvant were applied at day 8,10, 12, 15, 17, 19

Positive control substance(s):
yes
Remarks:
2,4-Dinitrochlorobenzene (DNCB)
Positive control results:
sensitizing
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0.9% NaCl
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
no indication of skin sensitisation
Reading:
rechallenge
Hours after challenge:
24
Group:
negative control
Dose level:
0.9% NaCl
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
0.1% DNCB
No. with + reactions:
20
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
positive indication of skin sensitisation
Reading:
rechallenge
Hours after challenge:
24
Group:
positive control
Dose level:
25% DNCB
No. with + reactions:
20
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
positive indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
10% (Depostat I)
No. with + reactions:
5
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
other: local intolerability
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
10% (Depostat I)
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
other: Depostat II (artificially aged)
Dose level:
10%
No. with + reactions:
3
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
other: local intolerability
Reading:
rechallenge
Hours after challenge:
24
Group:
other: Depostat II (artificially aged)
Dose level:
10%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
no indication of skin sensitisation

The observed positive reactions after the first challenge in the test item group Depostat I (5 of 20 animals) and in the additional artificially aged test item group Depostat II (3 of 20 animals) were not regarded as a sensitising effect because in both groups local intolerances were observed following intracutaneous treatment. The differences of the reaction volumes are slight compared to the ones during induction phase. Further, a sensitising effect could not be observed following a second challenge dose.

Interpretation of results:
other: not sensitising
Executive summary:

The test item gestonorone caproate (formulated as 0.1 ml Depostat - 10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil) did not show sensitising potential in an in vivo guinea pig optimisation test. The validity of the test procedure was confirmed by positive and negative controls.

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
read-across from supporting substance (structural analogue or surrogate)
Adequacy of study:
key study
Justification for type of information:
Justification for analogue approach:
As no acute toxicity data of gestonorone acetate is available, a read-across to gestonorone caproate (CAS 1253-28-7) was performed. A search for structure-analogue substances using the QSAR OECD Toolbox 4.0 recommended gestonorone caproate as one out of 19 category substances for a read-across approach (for additional information see QSAR OECD Toolbox Report on gestonorone acetate in "Attached justification"). Usually esters are hydrolysed in the presence of water or in organisms due to enzymatic degradation by esterases. As a result, the respective alcohol derivative (gestonorone (CAS 2137-18-0)) and carboxylic acid are generated. This is demonstrated by the QSAR toolbox 4.0 in the case of gestonorone acetate (CAS 2137-18-0) by the hydrolysis simulator (acidic, basic, neutral), the rat liver S9 metabolism simulator and the skin metabolism simulator.
Reason / purpose:
read-across source
Positive control results:
sensitizing
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0.9% NaCl
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
no indication of skin sensitisation
Reading:
rechallenge
Hours after challenge:
24
Group:
negative control
Dose level:
0.9% NaCl
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
0.1% DNCB
No. with + reactions:
20
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
positive indication of skin sensitisation
Reading:
rechallenge
Hours after challenge:
24
Group:
positive control
Dose level:
25% DNCB
No. with + reactions:
20
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
positive indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
10% (Depostat I)
No. with + reactions:
5
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
other: local intolerability
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
10% (Depostat I)
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
no indication of skin sensitisation
Reading:
1st reading
Hours after challenge:
24
Group:
other: Depostat II (artificially aged)
Dose level:
10%
No. with + reactions:
3
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
other: local intolerability
Reading:
rechallenge
Hours after challenge:
24
Group:
other: Depostat II (artificially aged)
Dose level:
10%
No. with + reactions:
0
Total no. in group:
20
Clinical observations:
not specified
Remarks on result:
no indication of skin sensitisation

The observed positive reactions after the first challenge in the test item group Depostat I (5 of 20 animals) and in the additional artificially aged test item group Depostat II (3 of 20 animals) were not regarded as a sensitising effect because in both groups local intolerances were observed following intracutaneous treatment. The differences of the reaction volumes are slight compared to the ones during induction phase. Further, a sensitising effect could not be observed following a second challenge dose.

Interpretation of results:
other: not sensitising
Executive summary:

The test item gestonorone caproate (formulated as 0.1 ml Depostat - 10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil) did not show sensitising potential in an in vivo guinea pig maximisation test. The validity of the test procedure was confirmed by positive and negative controls.

A read-across approach from gestonorone caproate to gestonorone acetate was justified by a OECD Toolbox structure analogue search.

Endpoint conclusion
Endpoint conclusion:
no adverse effect observed (not sensitising)

Respiratory sensitisation

Endpoint conclusion
Endpoint conclusion:
no study available
Additional information:

The test item gestonorone caproate (formulated as 0.1 ml Depostat - 10 mg gestonorone caproate, 60.94 mg benzyl benzoate, 35 mg castor oil) did not show sensitising potential in an in vivo guinea pig optimisation test. The validity of the test procedure was confirmed by positive and negative controls.

A read-across approach from gestonorone caproate to gestonorone acetate was justified by a OECD Toolbox structure analogue search.

Justification for classification or non-classification

Based on the study results the substance does not need to be classified according to Regulation EC No 1272/2008 (CLP).