NITTA

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

29 April 1987 to 5 June 1987

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1987

Report date:

1987

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The study was conducted in 1987.

Test material

Test material information

Constituent 1

Test material form:

liquid: viscous

Details on test material:

- Appearance: amber-coloured, slightly viscous liquid
- 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: Interfauna (U.K.) Limited, Wyton, Huntingdon, Cambridgeshire
- Age at study initiation: ca. 7 - 12 weeks
- Weight at study initiation: 338 - 450 g
- Housing: Animals were housed in groups of up to four in solid-floor polypropylene cages furnished with softwood shavings
- Diet: ad libitum (Guinea Pig FD1 Diet, Special Diet Services Ltd, Witham, Essex)
- Water: ad libitum
- Acclimation period: 5 days (minimum)

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 - 25 °C
- Humidity (%): 58 - 68 %
- Air changes (per hr): ca 15 air changes per hour
- Photoperiod (hrs dark / hrs light): 12 hours dark / 12 hours light

Study design: in vivo (non-LLNA)

Induction

Route:

intradermal and epicutaneous

Vehicle:

other: Intradermal induction: - arachis oil B.P - Freund's Complete Adjuvant plus arachis oil B.P. (1:1) Topical induction: - undiluted (no vehicle)

Concentration / amount:

Intradermal induction:
- 25% (w/v)

Topical induction:
- Undiluted as supplied.

Day(s)/duration:

Epicutaneous induction 1 week after intradermal induction. Epicutaneous exposure duration was 48 hours.

Adequacy of induction:

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

Challenge

Route:

epicutaneous, occlusive

Vehicle:

other: petroleum jelly B.P.

Concentration / amount:

75% (w/w)

Day(s)/duration:

1

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

MAIN STUDY
Number of animals in test group: 20
Number of animals in negative control group: 10

Details on study design:

> RANGE FINDING TESTS:
The dose levels for the main study were determined in a range finding study during which one or two guinea pigs were used and up to two dose levels were tested on each group of animals.

> MAIN STUDY
INDUCTION - TEST ANIMALS
The hair was removed from an area of ca. 40 mm x 60 mm on the shoulder region of each animal with veterinary clippers and a row of three injections (0.1 mL each) was made on each side of the mid-line. The injections were:
i) Freund's Complete Adjuvant plus arachis oil B.P. in the ratio of 1:1
ii) a 25% (w/v) dilution of test material in arachis oil B.P.
iii) a 25% (w/v) dilution of test material in a 1:1 preparation of Freund's Complete Adjuvant plus arachis oil B.P.

One week later, the same area on the shoulder region used previously for intradermal injections was clipped again and treated with a topical application of the undiluted test material. The undiluted test material (0.2 - 0.3 mL) was applied on filter paper (ca. 40 mm x 20 mm) which was held in place by a strip of surgical adhesive tape and covered with an overlapping length of aluminium foil. the patch and foil were further secured by a strip of elastic adhesive bandage woud in a double layed around the torso of ech animals. this occlusive dressing was held in place for 48 hours.

Erythematous reactions were quantified immediately following removal of the patches.

INDUCTION - CONTROL ANIMALS
Intradermal injections were administered using an identical procedure to that used for the test animals except that the injections were:
i) Freund's Complete Adjuvant plus arachis oil B.P. in the ratio 1:1
ii) arachis oil B.P.
iii) Freund's Complete Adjuvant plus arachis oil B.BP. in the ratio 1:1

The topical applications followed the same procedure as fr the test animals except that nothing was applied to the filter paper.

Erythematous reactions were quantified immediately following removal of the patches.

B. CHALLENGE EXPOSURE
Two weeks after the topical inductions, an area, ca. 50 - 70 mm x 50 mm on both flanks of each animals, was clipped free of hair with veterinary clippers. 0.1 - 0.2 mL test material formulation (75% w/w in petroleum jelly B.P.) was applied to the shorn right flank of each animal on a 20 mm x 20 mm square of filter paper which was held in place with surgical tape. The vehicle alone was similarly applied to the left shorn flank. The patches were occluded with an overlapping length of aluminium foil and secured with a strip of elastic adhesive bandage.
After 24 hours the dressing wsa removed. After a further 24 and 48 hours any erythematous reactions were quantified.

Results and discussion

Positive control results:

The positive control substance produced a 95% (19/20) sensitisation rate and was classified as an extreme sensitiser to guinea pig skin.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

75 %

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 75 %. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

75 %

No. with + reactions:

0

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 75 %. No with. + reactions: 0.0. Total no. in groups: 20.0.

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

75 %

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 75 %. No with. + reactions: 0.0. Total no. in groups: 10.0.

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

75 %

No. with + reactions:

0

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 75 %. No with. + reactions: 0.0. Total no. in groups: 10.0.

Any other information on results incl. tables

Preliminary study

Maximum concentration not causing irritating effects in preliminary test: 75 % Signs of irritation during induction: No adverse skin reactions were noted in the control group.Slight skin reactions in 14/20 of the test animals and well-defined skin reactions  in 4/20 of the test animals was observed after topical induction. Evidence of sensitisation of each challenge concentration: Number of animals showing evidence of sensitisation at each challenge concentration: 0/20 Other observations: Bodyweight gains of animals in the test group, between Day 0 and Day 24, were comparable to those in the control group.

Main study

No adverse skin reactions were noted at the test material or vehicle control sites of any test or control group animals during the observation period.

The test material therefore produced a 0% (0/20) sensitisation rate.

Bodyweight gains of guinea pigs in the test group, between day 0 and day 24, were comparable to those obeserved in the control group animals over the same period.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the study the test material was found not to be a skin sensitiser.

Executive summary:

The potential of the test material to cause dermal sensitisation was investigated in a study which was conducted under GLP conditions and in accordance with the standardised guideline OECD 406 following the Magnusson & Kligman Maximisation Test methods.

During the study, 20 animals received 0.1 mL intradermal doses of test material (25% w/v). One week later, undiluted test material was applied to the same area of skin under occlusion. Two weeks after topical induction a quantity of test material (75% w/w) was applied to the same area of skin under occlusion. After 24 hours, the dressings were removed and skin reachtions recorded for a further 48 hours. the same procedures were followed for the 10 control animals but they did not receive treatment with the test material.

Under the conditions of the study bodyweight gains of guinea pigs in the test group, between day 0 and day 24, were comparable to those obeserved in the control group animals over the same period. No adverse skin reactions were noted at the test material or vehicle control sites of any test or control group animals during the observation period.

The test material therefore produced a 0% (0/20) sensitisation rate.

The substance does not fulfil the classification criteria for skin sensitisation according to European Regulation (EC) No 1272/2008.