Dipotassium titanate(2-)

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

12 October 1993 - 13 November 1993

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1993

Report date:

1995

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

1981

Deviations:

yes

Remarks:

Ten animals were used in the test group and 5 in the control gorup. This is in line with the minimum requirements in the OECD guideline 406 adopted in 1992.

GLP compliance:

yes (incl. QA statement)

Remarks:

d.d. 11-6-1992

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

An appropriate guinea pig maximisation test is available which would not justify conducting an additional LLNA due to animal welfare.

Test material

Test material information

Constituent 1

Reference substance name:

Potassium titanium oxide (K2Ti6O13)

IUPAC Name:

Potassium titanium oxide (K2Ti6O13)

Test material form:

solid: particulate/powder

Details on test material:

Appearance: White powder
Storage conditions: Room temperature

In vivo test system

Test animals

Species:

guinea pig

Strain:

Dunkin-Hartley

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: David Hall Limited, Burton-on-Trent, Staffordshire, U.K.
- Age at study initiation: eight to twelve weeks old
- Weight at study initiation: 333 - 440 g
- Housing: Animals were housed in groups of up to three in solid-floor polypropylene cages furnished with softwood shavings.
- Diet: Guinea Pig FD1 Diet, Special Diet Services Limited, Witham, Essex, U.K.
- Water: ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS (set conditions)
- Temperature (°C): 19 - 22
- Humidity (%): 50 - 66
- Air changes (per hr): 15
- Photoperiod (hrs dark / hrs light): 12/12
- IN-LIFE DATES: From: 12 October 1993 To: 13 November 1993

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

water

Concentration / amount:

Freund's complete Adjuvant (FCA) plus distilled water, ratio 1:1, 0.1 mL
5% (w/v) of test material, 0.1 mL
5% (w/v) of test material in a 1:1 preparation of FCA plus distilled water, 0.1 mL

Day(s)/duration:

day 0

Adequacy of induction:

other: Highest concentration that did not cause local necrosis, ulceration or systemic toxicity

Induction 2

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

25% w/w, 0.2 - 0.3 mL

Day(s)/duration:

48 hours starting day 7

Adequacy of induction:

highest concentration used causing mild-to-moderate skin irritation and well-tolerated systemically

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

water

Concentration / amount:

25% w/w test material in distilled water, 0.1-0.2 mL
10% w/w test material in distilled water, 0.1-0.2 mL

Day(s)/duration:

24 hours starting day 21

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

test group: 10 animals
control group: 5 animals

Details on study design:

RANGE FINDING TESTS (sighting tests):
Selection of concentration for intradermal induction: Two animals were intradermally injected with preparations of test material (1% and 5% w/v in distilled water). The highest concentration that did not cause local necrosis, ulceration or systemic toxicity, was selected for the intradermal induction stage of the main study.
Selection of concentration for topical induction: Two guinea pigs (intradermally injected with Freund's Complete Adjuvant (FCA) sixteen days earlier) were treated with four preparations of the test material (25%, 10%, 5% and 2% w/w in distilled water). The highest concentration producing only mild to moderate dermal irritation after a 48-hour occlusive exposure, was selected for the topical induction stage of the main study.
Selection of concentration for topical challenge: Two preparations of the test material (25% and 10% in distilled water) were applied occlusively to the flanks of two guinea pigs for a period of 24 hours. These guinea pigs did not form part of the main study but had been treated identically to the control animals in the main study, up to day 14. The highest non-irritant concentration of the test material and one lower concentration were selected for the topical challenge stage of the main study.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: Two, once intradermally (day 0) and once topical (day 7)
- Exposure period: -
- Test groups: On day 0, a row of three injections (0.1 mL each) was made on each side of the mid-line. The injections were: FCA plus distilled water (ratio 1:1), 5% w/v test material in distilled water and 5% w/v test material in a mixture of FCA plus distilled water (1:1). On day 7 the animals were treated with a topical application of 0.2-0.3 mL of the test material formulation (25% w/w in distilled water) applied on filter paper and covered with aluminium foil. This occlusive dressing was kept in place for 48 hours.
- Control group: Intradermal injections were adminstered using an identical procedure to that used for the test animals, except the injections were: FCA plus distilled water (ratio 1:1), distilled water and FCA plus distilled water (ratio 1:1). The topical application was performed with vehicle alone (distilled water).
- Site: shoulder region on each site. The hair was removed from an area approx. 40 mm x 60 mm with veterinary clippers.

Approximately 24 and 48 hours after the intradermal injections and one and 24 hours following the removal of the patches, erythematous reactions were quantified using the scale from Draize J.H. (1959), "The appraisal of the Safety of Chemicals in Foods, Drugs and Cosmetics".


B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 21
- Exposure period: 24 hours, after which the dressing was removed and the site were swabed with cotton wool soaked in distilled water to remove residua material.
- Test group + control group: 0.1-0.2 mL of the test material formulations (25% and 10% w/w in distilled water) were applied a filter paper (approx. 20x20 mm) on the shorn right flank of each animal and occuled with aluminium foil. The vehicle alone was similarly applied on the left shorn flank.
- Evaluation (hr after challenge): Approx. 24 and 48 hours after challenge dressing removal erytematous reactions were quantified using the Draize scale.

OTHER:
- Bodyweight was recorded on days 0 and 24.

Positive control substance(s):

yes

Remarks:

Dinitrochlorobenzene (DNCB)

Results and discussion

Positive control results:

The reliability check with DNCB produced a 90% sensitisation rate. This was considered to be a satisfactory sensitisation response for this material under the conditions of the test and indicates that the model is appropriate for testing for contact hypersensitivity.

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

25%, 10% and vehicle

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No erythema or oedema observed

Remarks on result:

no indication of skin sensitisation

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

25%, 10% and vehicle

No. with + reactions:

0

Total no. in group:

10

Clinical observations:

No erythema or oedema observed

Remarks on result:

no indication of skin sensitisation

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

positive control

Dose level:

0.25% (w/v) DNCB

No. with + reactions:

9

Total no. in group:

10

Remarks on result:

positive indication of skin sensitisation

Results 4

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

25%, 10% and vehicle

No. with + reactions:

0

Total no. in group:

5

Remarks on result:

no indication of skin sensitisation

Any other information on results incl. tables

Intradermal and topical sighting tests

Selection of concentration for intradermal induction: Two animals were intradermally injected with preparations of test material (1% and 5% w/v in distilled water). Intra dermal injection of 10% and 25% formulations was not possible. Both 1% and 5% did not induce necrosis or evidence of systemic toxicity. Based on these results 5% (w/v) in distilled water was selected for the intradermal induction stage of the main study.

Selection of concentration for topical induction: Two guinea pigs (intradermally injected with Freund's Complete Adjuvant (FCA) sixteen days earlier) were treated with four preparations of the test material (25%, 10%, 5% and 2% w/w in distilled water). In this first animal very slight erythema was observed at the 5% induction site after 24 and 48 hours. In the other animal very slight erythema was observed at the 25% induction site after 1 hour only. Based on these results the concentration selected for the main study topical induction was 25% (w/w) in distilled water.

Selection of concentration for topical challenge: Two preparations of the test material (25% and 10% in distilled water) were applied occlusively to the flanks of two guinea pigs for a period of 24 hours. Very slight erythema was observed at the 25% and 10% challenge site in one animal and at the 25% in the other animal after 1 hour only. Based on these results the topical challenge was performed with 25% and 10% (w/w) in distilled water.

Resullts:

Skin reactions after intradermal induction: Very slight erythema was observed in 9/10 test group animals at the 24 and 48 hours observations.No skin reactions were observed in the control animals.

Skin reactions after topical induction: Very slight erythema was observed at the induction sites of five test group animals at the 24 hour observation. No skin reactions were observed after 48 hours in the test group animals and after 24 and 48 hours in the control animals.

Skin reactions after topical challenge: No skin reactions were noted at the challenges sites and vehicle control sites of teh test group and control group animals ate the 24 and 48 hour observations.

Bodyweights: Body weight gains of the guinea pigs in the test group were comparable to those of the control group animals.

Applicant's summary and conclusion

Interpretation of results:

other: Not classified

Remarks:

according to Regulation (EC) 1272/2008

Conclusions:

In a Guinea Pig Maximisation Test according to OECD gudeline and in accordance with GLP principles, TISMO-N produced a 0% (0/10) sensitisation rate and is considered a non-sensitiser.

Executive summary:

A Guinea Pig Maximisation Test was performed according to OECD TG 406 and in accordance with GLP principles. Ten test animals and five control animals were used for the main study. Concentrations used were based on the results of sighting tests. During the induction stage (day 0) animals received intradermal injections (0.1 mL each) with the 5% test material (w/v) in distilled water, 5% test material in Freund's Complete Adjuvant (FCA) and FCA only. Control animals receveid water, water + FCA and FCA. At day 7, 25% test material (w/w) in distilled water was applied topically for 24 hours using an occlusive dressing in test group animals, while controls were treated with distilled water. During the challenge on day 21, all animals were treated topically for 24 hours with test material (25% and 10% (w/w)) and vehicle using an occlusive dressing. A realibilty check with DNCB produced a satisfactory sensitisation response (90%) and indicates the model functions properly. Very slight erythema was observed in nine test group animals at 24 and 48 hours after intradermal induction and in 5 test groups animals at 24 hours after topcial induction. No skin reactions were noted at the challenge sites and vehicle control sites of the test and control group animals after the topical challenge, therefore the sensitisation rate was 0% (0/10). Based on these results TISMO-N is considered a non-sensitiser.