Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
02 July 1992 - 04 August 1992
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: see 'Remark'
Remarks:
The study report includes a formal claim of GLP compliance and the methodology described is a recognised test for skin sensitisation, however the study cannot be considered reliable without restrictions, as no formal test guideline was followed, and no purity value for the test material was specified.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1992
Report Date:
1992

Materials and methods

Test guideline
Qualifier:
equivalent or similar to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Deviations:
yes
Principles of method if other than guideline:
Magnusson-Kligman Maximisation test: Magnusson B, Kligman AM (1969), J Invest Dermat, 52, 268 - 276.: A group of guinea pigs were exposed to the test material by a two-part induction period, followed by a challenge procedure. The induction period consisted of an Injection phase, in which the shaved flanks of the guinea pigs were injected with an adjuvant, the test material at 10% in paraffin oil, and a 50/50 mixture of the test material and adjuvant. The second phase of the induction involved provoking a mild inflammatory response on the animals' skin using 10% aqueous sodium lauryl sulphate (SLS). 24 hours after the exposure to SLS, the neat test material was applied directly to the injection site and held there for 48 hours. During each phase of the induction procedure, observations were made to assess any irritant effects.
The Challenge procedure was conducted two weeks after the topical induction procedure, and involved a further topical application of the test material for 24 hours.
GLP compliance:
yes
Remarks:
The study report includes a statement of GLP compliance signed by the Study Director, however the report does not include an independant certificate of GLP accreditation issued by a competent authority or similar document.
Type of study:
guinea pig maximisation test

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Test Material MMB-Ac
- Batch No 32840
- State: Colourless liquid
- Stored in the dark under ambient conditions

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, Darley Oaks, Newchurch, Burton-on-Trent, Staffordshire
- Age at study initiation: less than 1 year old
- Weight at study initiation: 428 - 507 g
- Housing: aluminium cage grid floor, absorbent paper lined tray
- Diet: ad libitum FD1 Guinea Pig Diet, supplied by Special Diets Services Limited, 1 Stepfield, Witham, Essex, CM8 3AD, supplemented with hay
- Water: ad libitum tap water
- Acclimation period: 8 days for dose ranging animals and main study 14 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 20 - 22°C
- Humidity (%): 55
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
paraffin oil
Concentration / amount:
Dose ranging test - Injections at 100, 50, 25, and 10% in paraffin oil. Topical application at 100, 50, 25, and 10% in paraffin oil.
Main test, injection exposure - 10% in either paraffin oil or Freunds Complete Adjuvant.
Topical and challenge applications were performed using neat test material.
Challengeopen allclose all
Route:
epicutaneous, semiocclusive
Vehicle:
paraffin oil
Concentration / amount:
Dose ranging test - Injections at 100, 50, 25, and 10% in paraffin oil. Topical application at 100, 50, 25, and 10% in paraffin oil.
Main test, injection exposure - 10% in either paraffin oil or Freunds Complete Adjuvant.
Topical and challenge applications were performed using neat test material.
No. of animals per dose:
20 for main test + 4 guinea pigs total for challenge dose ranging group.
Details on study design:
RANGE FINDING TESTS:
Injections were in the shaved scapular region and topical application was on the shaved flanks. Two guinea pigs were subjected to intradermal injections and a further 2 guinea pigs were exposed to topical application for 48 h of the test material at 4 different concentrations.
- Injections - 100%, 50%, 25% and 10% v/v in paraffin oil
- Topical application - 100%, 50%, 25% and 10% v/v in paraffin oil
The injection sites were assessed for irritation 24, 48 and 72 h after injection, and the topical application sites were assessed for irritation 24 and 48 h after patch removal.

MAIN STUDY
A. INDUCTION EXPOSURE
- No. of exposures: 2
- Exposure period: Injection exposure was conducted 7 days prior to topical application (6 days prior to SLS provocation of inflammatory response). Topical application remained in place for 48 hours.
- Test groups: Test group received injections of
(a) 0.10 mL Freunds Complete Adjuvant,
(b) 0.10 mL Test Material, and
(c) 0.10 mL of a 50/50 emulsion of Freunds Complete Adjuvant and test material.
Topical application used a 2 x 4 cm patch of chomatography paper charged with 100% test material.
- Control group: Doses as per the test group, but with paraffin oil in place of test material.
- Site: Hair was shaved from an area 4 x 6 am across the scapular region. Injections were given 3 in a line each side of and parallel to the mid-line in the shaved region.
- Frequency of applications: Single injected and topical applications.

B. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 2 weeks after the start of the topical induction.
- Exposure period: 24 hours
- Test groups: Test and control groups were challenged both with patches of 100% test material, and with paraffin oil.
- Site: A 5 x 5 cm area of the left flank.
- Evaluation (hr after challenge): 24 and 48 hours.
Challenge controls:
The challenge procedure used patches treated with neat test material and paraffin oil.
Positive control substance(s):
yes
Remarks:
The sensitivity of this strain of guinea pig to a known sensitiser, 2,4-dinitro-chlorobenzene (DNCB), is checked at 6 monthly intervals.

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
100%
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: 100%. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0%
No. with + reactions:
3
Total no. in group:
20
Clinical observations:
One animal also gave a positive reaction to negative control patch (paraffin oil)
Remarks on result:
other: see Remark
Remarks:
Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0%. No with. + reactions: 3.0. Total no. in groups: 20.0. Clinical observations: One animal also gave a positive reaction to negative control patch (paraffin oil).
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
100%
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: 100%. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0%
No. with + reactions:
2
Total no. in group:
20
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0%. No with. + reactions: 2.0. Total no. in groups: 20.0.

Any other information on results incl. tables

None of the animals in the test group showed positive reactions to the challenge applications. Three of the animals in the control group, which had been induced only with the vehicle (paraffin oil) showed reactions to the test material during the challenge procedure. One animal in the control group showed a reaction to the vehicle in the challenge procedure.

Bodyweight gains recorded throughout the study were acceptable.

No clinical signs, other than skin reactions induced by treatment were noted.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
There was no evidence from the test results that the test material is a sensitiser in Guinea Pigs.
Executive summary:

The sensitisation potential of a test material, MMB-Ac, was investigated by means of the Magnusson-Kligman Maximisation Test in guinea pigs.

Induction with MMB-Ac was at concentrations of 10% v/v in paraffin oil (injection) and 100% (topical). Challenge was at a concentration of 100% .

At challenge, none of the test group animals treated with MMB-Ac at a concentration of 100% showed a positive response. An irritant

response was noted in 3 of the control group animals to the test material with one of them also reacting positively to the vehicle, paraffin oil. There is no evidence from the test results that MMB-Ac is a sensitiser in guinea pigs.