Registration Dossier

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Study period:
December 1997
Reliability:
1 (reliable without restriction)

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1997
Report Date:
1998

Materials and methods

Test guidelineopen allclose all
Qualifier:
according to
Guideline:
OECD Guideline 406 (Skin Sensitisation)
Version / remarks:
adopted 17 July 1992
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
GLP compliance:
yes (incl. certificate)
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
in vivo study was conducted prior to the availability of the LLNA or other in-vitro tet methods

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: bulk
Details on test material:
brown crystalline solid
Specific details on test material used for the study:
Brown Solid

In vivo test system

Test animals

Species:
guinea pig
Strain:
Dunkin-Hartley
Sex:
female
Details on test animals and environmental conditions:
At the start of the main study the animals weighed 301 to 353g, and were approximately eight to twelve weeks old. After an acclimatisation period of at least five
days, each animal was selected at random and given a number unique within the study which was written on a small area of clipped rump using a black indelible marker-pen.
The animals were housed singly or in pairs in solid-floor polypropylene cages furnished with woodflakes. Free access to mains tap water and food was allowed throughout the study. For the main study the animal room was maintained at a temperature of 19 to 22°C and relative humidity of 46 to 67%. The rate of air exchange was
approximately fifteen changes per hour and the lighting was controlled by a time switch to give twelve hours continuous light and twelve hours darkness.

Study design: in vivo (non-LLNA)

No. of animals per dose:
4
Details on study design:
Initial Test: Four concentrations of test material were investigated (1%, 5%, 10% and 25% w/v in arachis oil BP). A total of four guinea pigs were used, each guinea pig receiving four 0.1 ml injections of only one concentration of test material. The degree of erythema at the injection sites was assessed approximately 24, 48 and 72 hours and 7 days after injection according to the Draize scale shown in Appendix X. The degree of oedema was not evaluated. Any evidence of systemic toxicity was also recorded. The highest concentration that caused only mild to moderate skin irritation, and which was well tolerated systemically, was selected for the intradermal induction stage of the main study.
Positive control substance(s):
not specified

Results and discussion

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
25% w/w in arachis oil BP
No. with + reactions:
10
Total no. in group:
20
Clinical observations:
very slight to well-defined erythema with very slight to slight oedema
Remarks on result:
positive indication of skin sensitisation
Remarks:
Positive skin responses (very slight to well-defined erythema with very slight to slight oedema) were noted at the challenge sites of all test group animals at the 24-hour observations. Other adverse skin reactions noted included brown staining caused by the test material, small superficial scattered scabs, desquamation, superficial cracking of the epidermis and crust formation
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
25% w/w in arachis oil BP
No. with + reactions:
10
Total no. in group:
20
Clinical observations:
very slight to well-defined erythema with very slight to slight oedema
Remarks on result:
positive indication of skin sensitisation
Remarks:
Other adverse skin reactions noted included brown staining caused by the test material, small superficial scattered scabs, desquamation, superficial cracking of the epidermis and crust formation. These adverse skin reactions precluded an accurate assessment of the degree of oedema and for erythema at the challenge sites of three test group animals at the 48-hour observation
Reading:
rechallenge
Hours after challenge:
72
Group:
test group
Dose level:
25% w/w in Arachis Oil BP
No. with + reactions:
9
Total no. in group:
20
Clinical observations:
very slight to well-defined erythema with very slight to slight oedema
Remarks on result:
positive indication of skin sensitisation
Remarks:
Other adverse skin reactions noted included brown staining caused by the test material, small superficial scattered scabs, desquamation, superficial cracking of the epidermis and crust formation. These adverse skin reactions precluded an accurate assessment of the degree of oedema and for erythema at the challenge sites of five of the test group animals at the 72-hour observation
Reading:
rechallenge
Hours after challenge:
72
Group:
negative control
Dose level:
50% Arachis Oil BP
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
No erythema or oedema was noted at the challenge sites of control group animals at 24, 48 or 72 hours
Remarks on result:
no indication of skin sensitisation
Remarks:
incidents of brown staining were observed
Reading:
rechallenge
Hours after challenge:
24
Group:
test group
Dose level:
50% w/w in Arachis Oil B
No. with + reactions:
19
Total no. in group:
20
Clinical observations:
very slight to well-defined erythema (grades 1 to 2) and incidents of very slight oedema
Remarks on result:
positive indication of skin sensitisation
Reading:
rechallenge
Hours after challenge:
48
Group:
test group
Dose level:
50% in Arachis Oil BP
No. with + reactions:
19
Total no. in group:
20
Clinical observations:
Positive skin responses ,very slight to well-defined erythema (grades 1 to 2) and incidents of very slight oedema
Remarks on result:
positive indication of skin sensitisation
Remarks:
Other adverse reactions noted were desquamation, brown staining caused by the test material, small superficial scattered scabs, crust formation, superficial cracking of the epidermis and hardened, light-brown scab. These adverse reactions precluded accurate assessment of erythema and oedema at five challenge sites at the 48-hour observation
Reading:
rechallenge
Hours after challenge:
72
Group:
test group
Dose level:
50% in Arachis Oil BP
No. with + reactions:
19
Total no. in group:
20
Clinical observations:
Positive skin responses (very slight to well-defined erythema grades 1 to 2) and incidents of very slight oedema. An additional observation was made at 72 hours as some of these reactions had increased in severit
Remarks on result:
positive indication of skin sensitisation
Remarks:
Other adverse reactions noted were desquamation, brown staining caused by the test material, small superficial scattered scabs, crust formation, superficial cracking of the epidermis and hardened, light-brown scab. These adverse reactions precluded accurate assessment of erythema and oedema four challenge sites at the 72-hour observation.

Applicant's summary and conclusion