Cyclohexapentylose

Endpoint summary

Key value for chemical safety assessment

Skin sensitisation

Link to relevant study records

Reference

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: Guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes

Type of study:

guinea pig maximisation test

Species:

guinea pig

Strain:

other: SPF-bred albino

Sex:

male/female

Details on test animals and environmental conditions:

Species: SPF-bred albino guinea pigs (Crl:(HA)BR)
Supplier: Charles River Wiga GmbH, F.R. Germany
Sex and age: males and females, young adult
Identification: earmarking
Date of arrival: September 15, 1992
Start date of study: September 29, 1992
Termination date of study: October 23, 1992
Body weight range prior to start of study: males 328-395 g; females 308-387 g
Caging: individually in suspended, stainless steel cages, fitted with wire mesh floor and front
Lighting: 12 hours light/12 hours dark cycle
Temperature: 22 +/- 3°C
Humidity: 42.5% - 90% (upper limit higher than the intended 70%, because of meteorological circumstances or because of wet cleaning of the animal room)
Ventilation: ca 10 air changes/hour
Diet: pelleted, natural ingredient diet for guinea pigs (Hope Farms, Woerden, The Netherlands) and tap water, ad libitum

Route:

intradermal

Vehicle:

water

Concentration / amount:

0.1 ml each

Test animals: two injections with Freund's Complete Adjuvant (FCA) and demi-water (1: 1); two injections with a 3% dilution of the test substance in demi-water; two injections with a 3% dilution of the test substance in demi-water and FCA (1:1)

control animals: two injections with FCA and demi-water (1:1); two injections with demi-water; two injections with FCA and demi-water (1:1).

Route:

epicutaneous, semiocclusive

Vehicle:

water

Concentration / amount:

0.1 ml each

Test animals: two injections with Freund's Complete Adjuvant (FCA) and demi-water (1: 1); two injections with a 3% dilution of the test substance in demi-water; two injections with a 3% dilution of the test substance in demi-water and FCA (1:1)

control animals: two injections with FCA and demi-water (1:1); two injections with demi-water; two injections with FCA and demi-water (1:1).

No. of animals per dose:

Preliminary test: 3 animals
Main study: 15 animals per sex per group
Test group: 10 per sex
Control group: 5 per sex

Details on study design:

The study consisted of an induction treatment, followed by a resting period of 14 days, which preceded the challenge treatment. Preliminary observations were made to establish the concentrations of the test substance for intradermal injection and for topical application in the main study.

Preliminary tests
The irritation response upon intradermal injection of various concentrations was examined in 3 guinea pigs. A sufficiently large area of the flanks was clipped free from hair with electric clippers. Amounts of 0.1 ml of a 10%, a 3%, and a 1% dilution of the test substance in demi-water were applied by intradermal injection. Due to viscosity, higher concentrations were not examined. A concentration causing slight to moderate irritation but otherwise well-tolerated by the animals, is usually taken for intradermal injection of the test substance in the induction phase of the main study.
The irritation response to topical treatment of a 30%, a 10%, and a 3% dilution of the test substance in vaseline was examined. Concentrations higher than 30% were not tested, because usually they form dry and tough pastes which are less suitable for topical application. The flanks of each of three animals were clipped free from hair with electric clippers.
Patches were loaded with the various test dilutions. The patches, each loaded with a different concentration, were placed separately on an intact area of the clipped skin of each animal, and covered with a piece of hypoallergenic paper bandage (Leukopor) that was secured by elastic adhesive bandage (Tensoplast, 7.5 cm in width), wound around the torso of the animal. The dressing was left in place for 24 hours. After removal of the dressing and 24 hours later, the animals were examined for signs of skin irritation. A concentration causing slight to moderate skin irritation is usually chosen for topical induction and a non-irritant concentration for topical challenge.

Main study
Fifteen male and 15 female guinea pigs were randomly divided into two groups, viz. a test group of 10 males and 10 females and a control group of 5 males and 5 females. The animals were weighed one day before the study was initiated and at the completion of the study.

Induction
Induction was effected in two different ways, firstly by intradermal injections and secondly, one week later, by topical application over the injection sites.

Intradermal injections
For this purpose an area of about 24 cm2 of dorsal skin in the scapular region was clipped free from hair with electric clippers.
Pairs of intradermal injections (0.1 ml each) were made simultaneously in the clipped area. The following preparations were injected:

test animals
- two injections with Freund's Complete Adjuvant (FCA) and demi-water (1: 1) ,
- two injections with a 3% dilution of the test substance in demi-water,
- two injections with a 3% dilution of the test substance in demi-water and FCA (1:1),
control animals
- two injections with FCA and demi-water (1:1),
- two injections with demi-water,
- two injections with FCA and demi-water (1:1).
Skin readings were made at 24 hours after the treatment.

Topical application
One week after the intradermal injections, the dorsal skin in the scapular region of the test and control animals was closely shaved again. The induction by topical application was made in this region. The test animals were treated as follows:
A circa 2 x 4 cm patch of Whatman No. 3 MM filter paper was loaded with a 30% dilution of the test substance in vaseline. The loaded patch was placed over the sites of the intradermal injections. The dressing was left in place for 48 hours. The control animals were similarly treated with patches loaded with vaseline only. Skin readings were made directly after removal of the patches.

Challenge controls:

The topical challenge was carried out two weeks after the topical induction as follows:
An area of circa 5 x 5 cm on both flanks of each test and control animal was clipped free from hair. Patches were loaded with a 30% or a 10% test dilution in vaseline, or with vaseline only. One patch loaded with the 10% test dilution was placed on the clipped area of the left flank of each test and control animal. The right flank was treated with the 30% test dilution in vaseline and with vaseline alone. The patches were covered with Leukopor bandage, and held in place by Tensoplast for 24 hours. Skin readings were made at 24 and 48 hours after removal of the patches.

Positive control substance(s):

yes

Remarks:

2,4-dinitrochlorobenzene

Positive control results:

preliminary tests
The degree of irritation observed after intradermal treatment with a 3% dilution in demi-water was considered acceptable for intradermal treatment during the induction phase.
The degree of irritation observed after topical treatment with the 30% test dilution in vaseline was considered acceptable for topical treatment during the induction phase of the study. The 30% and 10% test dilution in vaseline induced signs of skin irritation at 1 hour after treatment. The next day, the skin effects on all 10% test sites had cleared completely, while one 30% test site still showed very slight erythema. On the basis of these results, the 30% and 10% test concentrations were considered acceptable for topical treatment during the challenge phase of the study.

Main study
All animals remained in good health during the experimental period.

Induction
The intradermal injections generally caused the following skin reactions:
test animals
- with FCA and demi-water mixture (1:1): severe erythema,
- with the 3% dilution of the test substance in demi-water: slight erythema,
- with the 3% dilution of the test substance in a mixture of FCA and demiwater (1:1): moderate or severe erythema and abcesses,
control animals
- with FCA and demi-water mixture (1:1): severe erythema and abscesses,
- with demi-water alone: slight erythema (2 animals),
- with FCA and demi-water mixture (1:1): moderate or severe erythema and abscesses.
After topical application of the patches loaded with vaseline only, no signs of skin irritation were observed in the controls. Topical application of the 30% test dilution in vaseline induced very slight erythema in 6 test animals.

Reading:

1st reading

Hours after challenge:

24

Group:

negative control

Dose level:

0

No. with + reactions:

4

Total no. in group:

10

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: negative control. Dose level: 0. No with. + reactions: 4.0. Total no. in groups: 10.0.

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

10% dilution of .alpha.-CD in vaseline

No. with + reactions:

3

Total no. in group:

20

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 10% dilution of .alpha.-CD in vaseline. No with. + reactions: 3.0. Total no. in groups: 20.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

negative control

Dose level:

0

No. with + reactions:

1

Total no. in group:

10

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: negative control. Dose level: 0. No with. + reactions: 1.0. Total no. in groups: 10.0.

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

10% dilution of .alpha.-CD in vaseline

No. with + reactions:

2

Total no. in group:

20

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 10% dilution of .alpha.-CD in vaseline. No with. + reactions: 2.0. Total no. in groups: 20.0.

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

The challenge treatment with the 30% test dilution, the 10% test dilution, and with vaseline alone produced a similar skin response in animals of the test and control group. Therefore, the skin effects observed after the challenge treatment were attributed to skin irritation, rather than sensitization. Because none of the test animals showed positive signs of sensitization, it was concluded that under the conditions of this study and according to the EEC-standards (mentioned in EEC-Directive 91/325/EC and published in the Official Journal of the European Communities, L 180, Volume 34, 8 July 1991), .alpha.-cyclodextrin is not a sensitizer.

Executive summary:

The test substance .alpha.-cyclodextrin was examined for possible sensitizing properties by a maximization test in guinea pigs using 20 test animals and 10 controls.

 

The test comprised:

test animals

- induction treatment by intradermal injections of Freund's Complete Adjuvant (FCA) 1:1 diluted with demineralized water (demi-water), a 3% dilution of the test substance in demi-water, and a 3% dilution of the test substance in a 1:1 mixture of FCA and demi-water, followed one week later by topical application of a 30% dilution in vaseline,

- challenge treatment, 14 days after the last induction, by topical application of a 30% and a 10% dilution in vaseline, and of Vaseline alone,

controls

- induction treatment by intradermal injections of FCA 1:1 diluted with demi-water, demi-water alone, and a 1:1 mixture of FCA and demiwater, followed one week later by topical application of Vaseline alone, and

- challenge treatment, 14 days after the last induction, by topical application of a 30% and a 10% dilution of the test substance in vaseline, and of vaseline alone.

 

The challenge treatment with .alpha.-cyclodextrin did not induce signs of sensitization in the test animals. On the basis of the results, it was concluded that under the conditions of this study and according to the EEC-standards, the test substance .alpha.-cyclodextrin is not a sensitizer.

Endpoint conclusion

Endpoint conclusion:

no adverse effect observed (not sensitising)

Additional information:

The test substance .alpha.-cyclodextrin was examined for possible sensitizing properties by a maximization test in guinea pigs using 20 test animals and 10 control animals. The challenge treatment with .alpha.-cyclodextrin did not induce signs of sensitization in the test animals. On the basis of the results, it was concluded that under the conditions of this study and according to the EEC-standards, the test substance .alpha.-cyclodextrin is not a sensitizer.

Migrated from Short description of key information:
The substance .alpha.-cyclodextrin did not exhibit any signs of allergic skin reaction when applied on the skin of guinea pigs in a maximization test.

Justification for selection of skin sensitisation endpoint:
Guideline Study

Respiratory sensitisation

Endpoint conclusion

Endpoint conclusion:

no study available

Justification for classification or non-classification

The substance .alpha.-cyclodextrin did not exhibit any signs of allergic skin reaction when applied on the skin of guinea pigs in a maximization test.