9-(2-carboxyphenyl)-3,6-bis(diethylamino)xanthylium acetate

Endpoint summary

Description of key information

The skin sensitization potential of test chemical was assessed in various experimental studies conducted on guinea pigs. Based on the available data for the target and supporting studies, it can be concluded that the test chemical is not able to cause skin sensitization and thus cannot be considered as sensitizing. Comparing the above annotations with the criteria of CLP regulation, it can be classified under the category “Not sensitizing”.

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

read-across from supporting substance (structural analogue or surrogate)

Adequacy of study:

weight of evidence

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

data from handbook or collection of data

Remarks:

experimental data from various test chemicals

Justification for type of information:

Data is summarized based on the available information from various read across test chemicals.

Reason / purpose for cross-reference:

read-across source

Reason / purpose for cross-reference:

read-across source

Qualifier:

according to guideline

Guideline:

other: As mentioned below

Principles of method if other than guideline:

WoE report is based on 2 skin sensitization studies as - WoE 2 and WoE 3
Skin sensitization test was carried out to study the effects of the test chemicals on rodents.

GLP compliance:

not specified

Species:

guinea pig

Strain:

other: 2.Himalayan 3.Hartley

Sex:

male/female

Details on test animals and environmental conditions:

2.No data available.
3.Age: Young adult
Weight at study initiation : 353 - 569 grams

Route:

intradermal

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

2

Concentration / amount:

Intradermal Induction:
-Freund´s Complete Adjuvant (FCA) and physiological saline (1:1)
-Acid Red 52 at 5% in 1 % CMC
-5 % dilution of the Acid Red 52 in 1% CMC in a 1:1 mixture with FCA / physiological saline.

Day(s)/duration:

Intradermal Induction: 7 days

Route:

epicutaneous, occlusive

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

2

Concentration / amount:

Epidermal Induction:
-50% in 1% CMC solution

Day(s)/duration:

Epidermal Induction: 48 hrs

Route:

epicutaneous, occlusive

Vehicle:

other: acetone

Remarks:

3

Concentration / amount:

INTRADERMAL INDUCTION: 5% w/v TEST CHEMICAL in acetone at 0.1 ml

Day(s)/duration:

24 hours

Adequacy of induction:

other: concentrations determined from the preliminary primary irritation study

Route:

intradermal

Vehicle:

other: acetone

Remarks:

3

Concentration / amount:

EPICUTANEOUS INDUCTION: 50% w/v TEST CHEMICAL in acetone at 0.8 ml

Day(s)/duration:

24 hrs

Adequacy of induction:

other: concentrations determined from the preliminary primary irritation study

Route:

epicutaneous, occlusive

Vehicle:

CMC (carboxymethyl cellulose)

Remarks:

2

Concentration / amount:

10 %

Day(s)/duration:

24 and 48 hours

No.:

#1

Route:

epicutaneous, open

Vehicle:

other: acetone

Remarks:

3

Concentration / amount:

CHALLENGE: 50% w/v test chemical in acetone at 0.4 ml

Day(s)/duration:

24 hours

Adequacy of challenge:

other: concentrations determined from the preliminary primary irritation study

No. of animals per dose:

2.10 females: test group,
5 females :control group

3.75 Guinea pigs - 38 male, 37 female
25 test , 10 vehicle control, 10 naïve control, 10 positive control (alpha-hexylcinnamaldehyde), 5 naïve positive control group

Details on study design:

2.Details on study design
RANGE FINDING TESTS:

MAIN STUDY
A.1. INDUCTION EXPOSURE: Intradermal Induction:
- No. of exposures:1
- Exposure period:7 days
- Test groups:10 females
- Control group:5 females
- Site:
- Frequency of applications:
- Duration: 7 days
- Concentrations:
•Freund´s Complete Adjuvant (FCA) and physiological saline (1:1)
•Acid Red 52 at 5% in 1 % CMC
•5 % dilution of the Acid Red 52 in 1% CMC in a 1:1 mixture with FCA / physiological saline
A.2. INDUCTION EXPOSURE: Epidermal Induction
- No. of exposures:1
- Exposure period:48 hours
- Test groups: 10 females
- Control group: 5 females
- Site:
- Frequency of applications:
- Duration: 48 hours
- Concentrations: 50% in 1% CMC solution

B. CHALLENGE EXPOSURE
- No. of exposures:1
- Day(s) of challenge: on day 22
- Exposure period:24 hours
- Test groups: 10 females
- Control group: 5 females
- Site: different part of the skin
- Concentrations: 10% in 1% CMC solution
- Evaluation (hr after challenge): at 24 and 48 hours removal of the dressings

3.RANGE FINDING TESTS:

Primary Irritation: Doses for 0.25%, 0.5%, 1%, 2.5%, 5%, 10%,
25%, 50% TEST CHEMICAL in acetone at 0.1 ml

MAIN STUDY
A. 1.INDUCTION EXPOSURE
- No. of exposures: two
- Exposure period:24 hours, 48 hrs
- Test groups: 25 guinea pigs
- Control group: 10 vehicle control and 10 naïve control
- Site: no data available
- Frequency of applications: no data available
- Duration: no data available
- Concentrations: 5% w/v TEST CHEMICAL in acetone at 0.1 ml

A.2. EPICUTANEOUS INDUCTION EXPOSURE
- No. of exposures: One dosage per 24 to 48 hour observation period.
- Exposure period: no data available
- Test groups: 25 Guinea pigs
- Control group: 10 vehicle and 10 naïve control groups
- Site: no data available
- Frequency of applications: no data available
- Duration: no data available
- Concentrations: 50% w/v TEST CHEMICAL in acetone at 0.8 ml


B. CHALLENGE EXPOSURE
- No. of exposures:1
- Day(s) of challenge: no data available
- Exposure period: 24 hours
- Test groups: 25 guinea pigs
- Control group: 10 vehicle and 10 naïve control Guinea pigs
- Site: no data available
- Concentrations: 50% w/v TEST CHEMICAL in acetone at 0.4 ml
- Evaluation (hr after challenge): Assessment of damage/irritation was made 24 and 48 hours following treatment.

Challenge controls:

2.No data available
3.the vehicle control, and the naïve control groups

Positive control substance(s):

yes

Remarks:

2. Not specified 3.Alpha hexylcinnamaldehyde, tech 85% as a 5% w/v formulation in acetone was used as a positive control. Along with that a naïve control group was also used.

Positive control results:

2. Not specified
3. Following primary challenge using alpha-hexylcinnamaldehyde, tech 85% as a 5% w/v formulation in acetone, the incidence of grade 1 responses or greater in the positive control group and the naive positive control group was 5 of 10 and 0 of 10 respectively.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No effects observed

Remarks on result:

no indication of skin sensitisation

Remarks:

2

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

10%

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No effects observed

Remarks on result:

no indication of skin sensitisation

Remarks:

2

Reading:

1st reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50% w/v test chemical in acetone

No. with + reactions:

0

Total no. in group:

25

Clinical observations:

No dermal reactions observed

Remarks on result:

no indication of skin sensitisation

Remarks:

3

Reading:

1st reading

Hours after challenge:

48

Group:

positive control

Dose level:

5%w/v

No. with + reactions:

5

Total no. in group:

10

Clinical observations:

signs of dermal sensitization observed

Remarks on result:

positive indication of skin sensitisation

Remarks:

3

Interpretation of results:

other: Not sensitizing

Conclusions:

Based on all the observations and results, it was concluded that the test chemical is not sensitizing to skin.

Executive summary:

Various studies has been investigated for the test chemical to observe the potential for skin sensitization to a greater or lesser extent. The studies are based on in vivo experiments in guinea pigs for test chemical are summarized as below;

The skin sensitization study of test chemical was performed in Himalayan spotted albino guinea pigs to observe its sensitizing efficacy for the period of 25 days. In induction treatment 10 females in test group, 5 females in control group were used. Animals were induced with intradermal induction of Freund´s Complete Adjuvant (FCA) and physiological saline (1:1), test item at 5% in 1 % CMC and 5 % dilution of the test item in 1% CMC in a 1:1 mixture with FCA / physiological saline on day 1. After 7 days, epidermal induction of sensitization (day 8) was conducted under occlusion with the test item at 50 % in 1 % CMC for 48 hours. The challenge was performed at day 22 by application of the test item at 10 % in 1 % CMC under occlusive patch for 24 h at a different part of the skin. Observations were made at 24 and 48 hours removal of the dressings. After challenge no skin reactions were observed. Hence the test chemical was considered to be non sensitizing to the Himalayan spotted albino guinea pigs.

Another test was performed to ascertain the degree of delayed contact hypersensitivity caused by test chemical in guinea pigs. The study was performed according to the Maximization Technique (Magnusson and Kligman), which satisfies OECD Guidelines – 406.75 albino Hartley Guinea pigs (38 male, 37 female) were used for the study. A preliminary Primary irritation study was conducted in guinea pigs with doses of 0.1ml of 0.25%, 0.5%, 1%, 2.5%, 5%, 10%,25%, 50% test chemical in acetone to determine the concentration for the induction and challenge exposure. 5% w/v of test chemical in acetone and 50% w/v of test chemical in acetone were chosen as the concentrations for intradermal induction and epicutaneous induction and challenge exposure respectively. The guinea pigs were divided into the following groups: 25 test , 10 vehicle control, 10 naïve control, 10 positive control (alpha-hexylcinnamaldehyde), 5 naïve positive control group. In the intradermal induction exposure, 0.1 ml of 5% w/v test chemical in acetone was injected into the skin of 25 guinea pigs. The intradermal induction was followed by epicutaneous induction of 0.8 ml of 50% w/v of test chemical in acetone. Following a suitable result period, 0.4 ml of 50% w/v of test chemical in acetone was used in the primary challenge exposure. The dosage pattern was one dosage per 24 to 48 hour observation period. Assessment of damage / irritation was made 24 and 48 hours following treatment. Following primary challenge using alpha-hexylcinnamaldehyde, tech 85% as a 5% w/v formulation in acetone, the incidence of grade 1 responses or greater in the positive control group and the naive positive control group was 5 of 10 and 0 of 10 respectively. 0% incidence of grade 1 responses to test chemical as a 50% w/v formulation in acetone in the test group at challenge, relative to that of the appropriate controls, indicates a non sensitizer nature of the test chemical. Hence, test chemical can be considered to be not sensitizing to skin.

All these studies lead to a conclusion that Test chemical is indeed not sensitizing to skin. Hence, comparing the above annotations with the criteria of CLP regulation, Test chemical can be classified under the category “Not Classified”.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

Various studies has been investigated for the test chemical to observe the potential for skin sensitization to a greater or lesser extent. The studies are based on in vivo experiments in guinea pigs for test chemical are summarized as below;

The skin sensitization study of test chemical was performed in Himalayan spotted albino guinea pigs to observe its sensitizing efficacy for the period of 25 days. In induction treatment 10 females in test group, 5 females in control group were used. Animals were induced with intradermal induction of Freund´s Complete Adjuvant (FCA) and physiological saline (1:1), test item at 5% in 1 % CMC and 5 % dilution of the test item in 1% CMC in a 1:1 mixture with FCA / physiological saline on day 1. After 7 days, epidermal induction of sensitization (day 8) was conducted under occlusion with the test item at 50 % in 1 % CMC for 48 hours. The challenge was performed at day 22 by application of the test item at 10 % in 1 % CMC under occlusive patch for 24 h at a different part of the skin. Observations were made at 24 and 48 hours removal of the dressings. After challenge no skin reactions were observed. Hence the test chemical was considered to be non sensitizing to the Himalayan spotted albino guinea pigs.

Another test was performed to ascertain the degree of delayed contact hypersensitivity caused by test chemical in guinea pigs. The study was performed according to the Maximization Technique (Magnusson and Kligman), which satisfies OECD Guidelines – 406.75 albino Hartley Guinea pigs (38 male, 37 female) were used for the study. A preliminary Primary irritation study was conducted in guinea pigs with doses of 0.1ml of 0.25%, 0.5%, 1%, 2.5%, 5%, 10%,25%, 50% test chemical in acetone to determine the concentration for the induction and challenge exposure. 5% w/v of test chemical in acetone and 50% w/v of test chemical in acetone were chosen as the concentrations for intradermal induction and epicutaneous induction and challenge exposure respectively. The guinea pigs were divided into the following groups: 25 test , 10 vehicle control, 10 naïve control, 10 positive control (alpha-hexylcinnamaldehyde), 5 naïve positive control group. In the intradermal induction exposure, 0.1 ml of 5% w/v test chemical in acetone was injected into the skin of 25 guinea pigs. The intradermal induction was followed by epicutaneous induction of 0.8 ml of 50% w/v of test chemical in acetone. Following a suitable result period, 0.4 ml of 50% w/v of test chemical in acetone was used in the primary challenge exposure. The dosage pattern was one dosage per 24 to 48 hour observation period. Assessment of damage / irritation was made 24 and 48 hours following treatment. Following primary challenge using alpha-hexylcinnamaldehyde, tech 85% as a 5% w/v formulation in acetone, the incidence of grade 1 responses or greater in the positive control group and the naive positive control group was 5 of 10 and 0 of 10 respectively. 0% incidence of grade 1 responses to test chemical as a 50% w/v formulation in acetone in the test group at challenge, relative to that of the appropriate controls, indicates a non sensitizer nature of the test chemical. Hence, test chemical can be considered to be not sensitizing to skin.

All these studies lead to a conclusion that Test chemical is indeed not sensitizing to skin. Hence, comparing the above annotations with the criteria of CLP regulation, Test chemical can be classified under the category “Not sensitizing”.

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The skin sensitization potential of test substance were observed in various studies. From the results obtained from these studies it is concluded that the test chemical is not likely to cause skin sensitization and hence can be classified as “Not sensitizing”.