Methyltriphenylphosphonium chloride

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

Jan 25 - March 24, 1994

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:

1994

Report date:

1994

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Version / remarks:

July 17, 1992

Deviations:

no

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Justification for non-LLNA method:

The available study was performed in 1994, the LLNA test was was not the standard in vivo method by this time. Therefore a GPMT test was performed.

Test material

Test material information

Constituent 1

Reference substance name:

Methyltriphenylphosphonium chloride

EC Number:

418-400-2

EC Name:

Methyltriphenylphosphonium chloride

Cas Number:

1031-15-8

Molecular formula:

C19H18ClP

IUPAC Name:

methyltriphenylphosphanium chloride

In vivo test system

Test animals

Species:

guinea pig

Sex:

male/female

Details on test animals and environmental conditions:

Strain: Pirbright white
Substrain: HsdlWin: DH
Source: Firma Harlan Winkelmann, Versuchstierzucht, Gartenstr.27 33178 Borchen
Acclimatization period: 7 days (range finding), 23 days (main test)
Animal selection: random
Animal identification: with colored markings; cage labelled with sex, date of study initiation, project no.
Weight range: male: 310 - 574 g / female: 275 - 597 g
Housing:
collective housing up to a maximum of 5 animals per cage (Makrolon@ type IV)
illumination:
artificial lighting (120 lux) from 7.00 a.m. -7.00 p.m.
Temperature:
22 +/- 3°C
Relative Humidity:
30-70%
Measurement:
twice daily

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal

Vehicle:

water

Concentration / amount:

5 %

Day(s)/duration:

7 days

Adequacy of induction:

non-irritant substance, but skin pre-treated with 10% SDS

Induction 2

Route:

epicutaneous, occlusive

Vehicle:

other: vaseline

Concentration / amount:

50% (w/w)

Day(s)/duration:

14 days

Adequacy of induction:

not specified

Challenge

No.:

#1

Route:

epicutaneous, occlusive

Vehicle:

other: vaseline

Concentration / amount:

50%

Day(s)/duration:

1 day

Adequacy of challenge:

highest non-irritant concentration

No. of animals per dose:

20 animals

Details on study design:

Prestudy:
Intradermal Injection
The test article was diluted with aqua ad iniect. and Freund's complete adjuvant (PCA; Sigma, 80241 Deisenhofen) to give a final concentration of 5 %. Two animals were employed, skin reactions being recorded 48 h after treatment.
Dermal Application
The test article was incorporated in vaseline to provide a final concentration of 50 % (w/w). A closed patch exposure was effected by means of an occlusive bandage using Hill-Top Chambers (Hill Top, Cincinnati, USA) and non-irritating tape Elastoplast@ (Beiersdorf AG, Hamburg), which enveloped the whole of the animal's trunk. Two animals were employed and skin reactions were recorded 48 h post applicationem.

Main study:
The main study was performed on 20 test and 10 control animals. On the basis of the results of the range finding the concentration of 5 % of the test article was considered to be suitable for intradermal injection and the concentration of 50 % for dermal application.
Induction Procedure: First stage - an area of 4 x 6 cm over the shoulders was clipped short with electric clippers and cleaned with 70 % (v/v) ethanol. lbree pairs of intradermal injections were then made symmetrically in two rows on either side of the spine.
Test group:
1. 0.1ml FCA 50 % (w/w) diluted inaqua ad iniect.
2. 0.1 ml test article diluted in aqua ad iniectabilia (final concentration: 5 %)
3. 0.1 ml test article diluted in FCNaqua ad iniect. (final concentration: 5 %)
Control group:
1. 0.1 ml FCA 50% (w/w) diluted in aqua ad iniect.
2. 0.1 ml aqua ad iniectabilia
3.0.1 ml aqua ad iniectabilia 50% (w/w) diluted in FCA
Second stage - 7 days after the intradermal injections, dermal application was initiated. Because the test article was non-irritating at the highest permissible concentration in the pilot study, the area was redipped and pretreated with 10 % sodium lauryl sulfate (SLS) in vaseline 24 h before application of the test article at a concentration of 50 % in vaseline. The test article was spread in a thick layer [to saturation] over a 4 x 5 cm patch (filter paper). The latter was firmly secured over the previous injection sites by an occlusive dressing for 48 h. Control animals received a patch loaded with the vehicle alone.
Challenge procedure
Both control and test animals were subjected to a challenge exposure 14 days after the second stage of induction. The challenge test was performed on a 5 x 5 cm clipped area on each flank. The maximal non-irritating concentration of the test article (50 % in vaseline) was applied to the left flank and vaseline to the right (0.5 g in each case) using the patch technique described under 4.3.2. The duration of exposure was 24 h under an occlusive dressing. 24 and 48 h after patch removal, the treated skin areas were evaluated on a numerical scale according to Draize.

Positive control substance(s):

yes

Results and discussion

Positive control results:

The reaction to the positive control substances 2,4 dinitrochlorobenzene (extreme sensitizer) and benzocaine (moderate sensitizer) is tested periodically. The last test with an acceptable level of response to each of these substances was performed in November, 1993.

In vivo (non-LLNA)

Results

Results 1

Key result

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50 % in vaseline

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No skin reactions were observed. Two test animals died within the induction phase on day 8 (no. 6) or day 11 (no. 14). The cause of death is not clear.

Remarks on result:

no indication of skin sensitisation

Results 2

Key result

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50 % in vaseline

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

No skin reactions were observed. Two test animals died within the induction phase on day 8 (no. 6) or day 11 (no. 14). The cause of death is not clear.

Remarks on result:

no indication of skin sensitisation

Results 3

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

50% in vaseline

No. with + reactions:

0

Total no. in group:

10

Results 4

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

50% in vaseline

No. with + reactions:

0

Total no. in group:

10

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Under the conditions of the study, the test item is considered to be a dermal sensitiser.

Executive summary:

The potential skin sensitizing properties of the test item were assessed in the guinea pig maximization test using 20 test and 10 control animals. Following induction exposure to the

test article or the vehicle, the animals were subjected two weeks later to a challenge exposure with the test article. The treated skin areas were evaluated 24 and 48 h after the end of the exposure period. According to the OECD guideline for testing of chemicals (OECD 406, July 17, 1992), since no animal showed an allergic response, the test article applied as a 50 % preparation, may be classified as a "non-sensitizer".