Registration Dossier

Toxicological information

Skin sensitisation

Currently viewing:

Administrative data

Endpoint:
skin sensitisation: in vivo (non-LLNA)
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: GLP guideline study

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
1991
Report Date:
1991

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
EU Method B.6 (Skin Sensitisation)
Deviations:
no
Principles of method if other than guideline:
Directive 84/449/EEC, B.6; adopted 1989
comparable to OECD Guideline 406
GLP compliance:
yes
Type of study:
guinea pig maximisation test
Justification for non-LLNA method:
GPMT available

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
thiodiglycol, purity 98.4%
stability of test substance (TS) preparations confirmed by analysis

In vivo test system

Test animals

Species:
guinea pig
Strain:
other: Pirbright White, Dunkin Hartley HOE DHPK [SPF-LAC] BÖ
Sex:
female
Details on test animals and environmental conditions:
Source: Versuchstierzucht, Hagemann GmbH & Co . KG, D-4923 Extertal 1, FRG
Initial weight:291-350 g
Acclimatisation period: 7 days
temperature: 20 - 24°C; relative humidity: 30 - 70%; light/dark cycle: 12h/12 h
certified diet and tap water ad libitum (analysed for contaminations)
5 animals per cage

Study design: in vivo (non-LLNA)

Inductionopen allclose all
Route:
intradermal and epicutaneous
Vehicle:
other: 0.9% physiol. saline for intradermal induction; no vehicle for percutaneous induction; aqua bidest for challenge (75% solution)
Concentration / amount:
- Preparation of TS for intradermal induction:
5% TS in 0.9% aqueous NaCl solution resp. in Freund's adjuvant/0.9% aqueous NaCl solution (1:1)
- Preparation of TS for percutaneous induction: unchanged (minimum irritant concentration)
- Preparation of TS for challenge: 75% TS in aqua bidest. (nonirritant concentration)
Challengeopen allclose all
Route:
epicutaneous, occlusive
Vehicle:
other: 0.9% physiol. saline for intradermal induction; no vehicle for percutaneous induction; aqua bidest for challenge (75% solution)
Concentration / amount:
- Preparation of TS for intradermal induction:
5% TS in 0.9% aqueous NaCl solution resp. in Freund's adjuvant/0.9% aqueous NaCl solution (1:1)
- Preparation of TS for percutaneous induction: unchanged (minimum irritant concentration)
- Preparation of TS for challenge: 75% TS in aqua bidest. (nonirritant concentration)
No. of animals per dose:
10 animals treated with TS and 5 controls
Details on study design:
1st application: Induction 5 % intracutaneous
2nd application: Induction undiluted occlusive epicutaneous
3rd application: Challenge 75 % occlusive epicutaneous

- Intradermal induction schedule:
total of 6 intradermal injections
a) 2 injections each of 0.1 ml Freund's adjuvant without TS emulsified with 0.9% aqueous NaCl-solution (1:1; left and right shoulder)
b) 2 injections each of 0.1 ml 5% TS in 0.9% NaCl (left and right shoulder)
c) 2 injections each of 0.1 ml 5% TS in Freund's adjuvant/0.9% NaCl (1:1)
Readings 24 h after application (grading see below).
Controls same exp. design without TS

- Percutaneous induction one week after intradermal induction:
filter paper strips soaked with ca. 0.3 g undiluted TS under occlusive dressing for 48 h; same area (shoulder) as with intradermal induction; readings 48 h after b eginning of exposure (grading see below).
Controls untreated (undiluted TS, no solvent used)

- Challenge schedule:
21 d after intradermal induction, filter paper strip soaked with ca. 0.15 g 75% TS applied for 24 h to the skin of intact clipped flank, occlusive;
readings 24 and 48 h after removel of the patch (grading see below).
Control group 1 treated with the TS and group 2 remained untreated.

- Positive control (historical):
1-chloro-2,4-dinitrobenzene (n=20), intradermal and
percutaneous induction, challenge: 1% in ethanol

EXAMINATIONS
- Grading system for assessment of skin findings:
Erythema
no erythema 0
very slight erythema (barely perceptible) 1
well-defined erythema 2
moderate to severe erythema 3
severe erythema to slight eschar formation 4
Edema
no edema 0
very slight edema (barely perceptible) 1
slight edema (edges of area well defined by definite raising) 2
moderate edema (raised ca. 1 mm) 3
severe edema (raised more than 1 mm and extending beyond exposure area) 4


Challenge controls:
Control group 1 treated with the TS and group 2 remained untreated.
Positive control substance(s):
yes
Remarks:
(1-chloro-2,4-dinitrobenzene)

Results and discussion

Positive control results:
- valid positive control (positive reaction in 20/20)

In vivo (non-LLNA)

Resultsopen allclose all
Reading:
1st reading
Hours after challenge:
24
Group:
test group
Dose level:
0.15 g of 75% test substance in water
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.15 g of 75% test substance in water. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no.
Reading:
2nd reading
Hours after challenge:
48
Group:
test group
Dose level:
0.15 g of 75% test substance in water
No. with + reactions:
0
Total no. in group:
10
Clinical observations:
no
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 0.15 g of 75% test substance in water. No with. + reactions: 0.0. Total no. in groups: 10.0. Clinical observations: no.
Reading:
1st reading
Hours after challenge:
24
Group:
negative control
Dose level:
0.15 g of 75% TS in water
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no
Remarks on result:
other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0.15 g of 75% TS in water. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no.
Reading:
2nd reading
Hours after challenge:
48
Group:
negative control
Dose level:
0.15 g of 75% TS in water
No. with + reactions:
0
Total no. in group:
5
Clinical observations:
no
Remarks on result:
other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0.15 g of 75% TS in water. No with. + reactions: 0.0. Total no. in groups: 5.0. Clinical observations: no.

Any other information on results incl. tables

RESULTS OF PILOT STUDY: 
- see section 7.3.1
RESULTS OF TEST
- Intradermal induction resulted in well defined erythema
(grade 2) and slight edema (grade 2) in experimental
design a) and c) in TS treated and in control animals;
no such effects were observed in controls of exp.
design b); but TS treated animals in exp. design
b) showed erythema grade 2 and 3 out of 10 animals in
exp. design c) revealed TS treatment related necrotic
skin changes.
- Percutaneous induction resulted in erythema and edema
grade 2, but these effects are related to intradermal
induction at the same site, dito with necrotic skin
changes.
- Challenge resulted in no skin reaction neither in TS
treated animals nor in controls
- valid positive control (positive reaction in 20/20)

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Remarks:
Migrated information
Conclusions:
Thiodiglycol does not have a sensitizing effect on the skin of the guinea pig.
Executive summary:

GLP guideline study.

In the guinea pig maximisation test according to current guidelines 10 females received for intradermal induction 5% TS in 0.9% aqueous NaCl solution resp. in Freund's adjuvant/0.9% aqueous NaCl solution (1:1). One week later animals received for percutaneous induction undiluted TS under occlusive dressing for 48 h. For challenge 0.15 g thiodiglycol (75 % solution in water; no irritating effect at this concentration in a pilot study) was applied to the intact skin for 24 hours (occlusive). The challenge resulted in no skin reaction, neither in thiodiglycol treated animals nor in negative controls. The positive control was valid.

Conclusion: Thiodiglycol does not have a sensitizing effect on the skin of the guinea pig.