Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
1993-09-27 to 1993-11-08
Reliability:
2 (reliable with restrictions)
Rationale for reliability incl. deficiencies:
other: GLP and guideline compliant study report.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1994
Report Date:
1994

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EPA OTS 798.4100 (Skin Sensitisation)
Deviations:
no
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
one other study available

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): 2-Hydroxyacetophenone (2-HAP)

In vivo test system

Test animals

Species:
guinea pig
Strain:
Hartley
Sex:
male
Details on test animals and environmental conditions:
TEST ANIMALS
- Source: Sasco Inc., Madison, WI, USA
- Weight at study initiation: 377-490 g
- Housing: Individually housed in stainless steel, wire mesh bottom cages
- Diet: ad libitum, Fresh Agway Certified Guinea Pig Feed
- Water: ad libitum, tap water
- Acclimation period: 11 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 17.8 - 26.1
- Humidity (%): 40 - 70
- Air changes (per hr): at least 10
- Photoperiod (hrs dark / hrs light): 12/12

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
propylene glycol
Concentration / amount:
Induction I: 5 % (in propylene glycol)
Induction II: 100 %
Challenge: 100 %
Rechallenge: 100 %
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
propylene glycol
Concentration / amount:
Induction I: 5 % (in propylene glycol)
Induction II: 100 %
Challenge: 100 %
Rechallenge: 100 %
No. of animals per dose:
20
Details on study design:
RANGE FINDING TESTS: Intradermal and Topical Range finding study
Four v/v dilutions of the test article were prepared in propylene glycol and administered to each of five guinea pigs. The dilutions used were 5 %, 4 %, 2 %, and 1 %. Two pair of intradermal injections at a volume of 0.1 mL each were made along the spine (two injections per side) above the scapular region so that each animal received one injection of each test article concentration. Approximately 24 and 48 hours after dosing, all sites were scored for erythema and edema according to the Draize scoring method.
Four v/v mixtures of the test article were prepared in propylene glycol and administered to each of five guinea pigs. The concentrations used were: Neat, 50 %, 25 % and 10 %. A dose of 0.5 mL of each concentration of the test article was applied to a one square inch gauze patch which was then placed on the skin of the flank region, two on each side of the dorsal midline. The patches were taped in place and the trunk of the animal was wrapped with a non-reactive, occlusive wrapping. Approximately 24 hours following patch application, all wrappings were removed and the skin wiped to remove any remaining test article. Approximately 24 and 48 hours after patch removal, all sites were scored for erythema and edema according to the Draize scoring method


MAIN STUDY
A. INTRADERMAL INDUCTION EXPOSURE
- No. of exposures: 6
- Test groups: 3 different injections were given:
1. 0.1 mL of a 1:1 Freund's Complete Adjuvant/sterile water, U.S.P., emulsion
2. 0.1 mL of test article
3. 0.1 mL of a 1:1 mixture of the test article and a 1:1 Freund's Complete Adjuvant/sterile water, U.S.P., emulsion
- Control group: 3 different injections were given:
1. 0.1 mL of 1:1 Freund's Complete Adjuvant/sterile water, U.S.P., emulsion
2. 0.1 mL of propylene glycol
3. 0.1 mL of a 1:1 mixture of propylene glycol and a 1:1 Freund's Complete Adjuvant/sterile water, U.S.P., emulsion
- Site: one row of three injections on each side of the animals midline above the intrascapular region
- Frequency of applications: once
- Duration: 8 days
- Concentrations: 5 % of test substance in propylene glycol

B. TOPICAL INDUCTION EXPOSURE
- No. of exposures: 1
- Exposure period: 48 hours
- Test groups: topically dosed with a 2 x 4 cm patch of Whatman No. 3 mm filter paper saturated with neat test article
- Control group: topically dosed with a 2 x 4 cm patch of Whatman No. 3 mm filter paper saturated with propylene glycol.
- Site: animals midline above the scapular region
- Frequency of applications: once
- Duration: 48 hours
- Concentrations: 100 % of test substance

C. CHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: 16 days after topical induction
- Exposure period: 24 hours
- Test groups: topically dosed with 0.4 mL of neat test substance
- Control group: topically dosed with 0.4 mL of neat test substance
- Site: flank
- Concentrations: 100 %
- Evaluation (hr after challenge): 24, 48 hours after patch removal

D. RECHALLENGE EXPOSURE
- No. of exposures: 1
- Day(s) of challenge: Seven days after challenge
- Exposure period: 24 hours
- Test groups: topically dosed with 0.4 mL of neat test substance
- Control group: topically dosed with 0.4 mL of neat test substance
- Site: flank
- Concentrations: 100 %
- Evaluation (hr after rechallenge): 24, 48 hours after patch removal
Positive control substance(s):
yes
Remarks:
Dinitrochlorobenzene (DNCB)

Results and discussion

Positive control results:
Positive controls with DNCB demonstrated a 100 % positive response.

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
100 %
No. with + reactions:
1
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: 1.0. Total no. in groups: 20.0.
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:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
100 %
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: 100 %. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
100 %
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: 100 %. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
100 %
No. with + reactions:
1
Total no. in group:
20
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 24.0. Group: test group. Dose level: 100 %. No with. + reactions: 1.0. Total no. in groups: 20.0.
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
20
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 48.0. Group: test group. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 20.0.
Reading:
rechallenge
Hours after challenge:
24
Group:
negative control
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 24.0. Group: negative control. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
rechallenge
Hours after challenge:
48
Group:
negative control
Dose level:
100 %
No. with + reactions:
0
Total no. in group:
10
Remarks on result:
other: Reading: rechallenge. . Hours after challenge: 48.0. Group: negative control. Dose level: 100 %. No with. + reactions: 0.0. Total no. in groups: 10.0.
Reading:
1st reading
Hours after challenge:
24
Group:
positive control
Dose level:
0.1 %
No. with + reactions:
5
Total no. in group:
5
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: positive control. Dose level: 0.1 %. No with. + reactions: 5.0. Total no. in groups: 5.0.
Reading:
2nd reading
Hours after challenge:
48
Group:
positive control
Dose level:
0.1 %
No. with + reactions:
5
Total no. in group:
5
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: positive control. Dose level: 0.1 %. No with. + reactions: 5.0. Total no. in groups: 5.0.

Any other information on results incl. tables

During the intradermal range finding phase, the 5 %, 4 %, 2 %, and 1 % applications of test article produced irritation at both the 24 and 48 hour scoring periods. Since no significant difference in the degree and extent of irritation was observed between any of the concentrations used, the test article was administered as a 5 % concentration in propylene glycol at induction I. During topical range finding phase, the Neat, 50 %, 25 % and 10 % of test article in propylene glycol produced no dermal irritation at either the 24 or 48 hour scoring periods. Based on these results, the test article was administered neat at induction II and challenge. At challenge, one of the twenty animals (5 %) in the test article induction/challenge/rechallenge group exhibited dermal response at the 24 hour scoring period and none of the animals exhibited response at the 48 hour scoring period. None of the corresponding challenge irritation control group animals exhibited dermal irritation at either the 24 hour or 48 hour scoring period. In the DNCB positive control group, 100 % of the induction/challenge animals had scores greater than the scores observed in the DNCB challenge irritation control group at both the 24 and 48 hour scoring periods. To confirm the dermal response exhibited by the single test article induction/challenge/rechallenge group animal at challenge, the Sponsor elected to proceed with a rechallenge. During the rechallenge phase, the test article was topically administered neat to the test article induction/challenge/rechallenge and rechallenge irritation control group animals. At rechallenge, one of the twenty animals (5%) in the test article induction/challenge/rechallenge group (the same animal that exhibited a response at challenge) exhibited dermal response at the 24 hour scoring period and none of the animals exhibited dermal response at the 48 hour scoring period. None of the ten corresponding rechallenge irritation control group animals exhibited dermal irritation at either the 24 or 48 hour scoring periods.

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information