Cetylpyridinium chloride

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

August 2004-May 2005

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study under GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2005

Report date:

2005

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2600 (Skin Sensitisation)

Test guideline 2

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

GLP compliance:

yes (incl. QA statement)

Type of study:

Buehler test

Test material

Test material information

Constituent 1

Reference substance name:

Cetylpyridinium chloride

EC Number:

204-593-9

EC Name:

Cetylpyridinium chloride

Cas Number:

123-03-5

Molecular formula:

C21H38N.Cl

IUPAC Name:

cetylpyridinium chloride

Constituent 2

Reference substance name:

CPC

IUPAC Name:

CPC

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

Test Substance Identification: Cetylpyridinium Chloride
Lot #00217966
Purity: 100.1% by assay
Test Substance Description: White Powder
Date Recieved: January 12, 2005
PSL Reference No.: 050112-ID
Study Initiation Date: January 24, 2005

In vivo test system

Test animals

Species:

guinea pig

Strain:

Hartley

Sex:

male/female

Details on test animals and environmental conditions:

Number of Animals: 36
Number of Groups: 3
Sex: Male and Female
Species/Strain: Guinea pigs/Hartley Albino

Housing: Aniamls were housed in suspended stainless steel caging with mesh floors or plastic perforated bottom caging. Litter paper was placed beneath the cage and was changed at least three times per week.
Animal Room Temperature Range: 19-23 Degrees C.
Photoperiod: 12-hour light/dark cycle
Food: Pelleted Purina Guinea Pig Chow #5025
Water: Filtered tap water

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

epicutaneous, occlusive

Vehicle:

water

Induction 2

Concentration / amount:

Induction Phase: Once each week for three weeks, four-tenths of a milliliter of a 5% w/w mixture of the test substance was applied
Challenge Phase: Twenty-seven days after the first induction dose, four-tenths of a milliliter of a 0.1% w/w mixture of the test stubstance was applied

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

water

Challenge 2

Concentration / amount:

Induction Phase: Once each week for three weeks, four-tenths of a milliliter of a 5% w/w mixture of the test substance was applied
Challenge Phase: Twenty-seven days after the first induction dose, four-tenths of a milliliter of a 0.1% w/w mixture of the test stubstance was applied

No. of animals per dose:

Number of Animals: 36
Preliminary Irritation Group: 6
Test Group: 20
Naive Control Group: 10

Details on study design:

The fur of a group of animals was removed by clipping the dorsal area and flanks 24 hours before testing. Once each week for three weeks, 0.4 ml of a 5% w/w mixture of the test substance in distilled water was applied to the left side of each test animal using an occlusive 25 mm Hill Top Chamber. The chambers were secured in place and wrapped with non-allergenic Durapore adhesive tape. After the 6-h exposure period, the chambers were removed and the test sites were gently cleansed of any residual test substance. Approximately 24 and 48 hours after each induction application, readings were made of local reactions (erythema) according to the scoring system described. Twenty-seven days after the first induction dose, 0.4 ml of a 0.1% w/w mixture of the test substance in distilled water (HNIC) was applied to a naive site on the right side of each animal as a challenge dose, using the procedures described above. These sites were evaluated for a sensitization response (erythema) approximately 24 and 48 hours after the challenge application according to the system described.
In addition to the test animals, 10 guinea pigs from the same shipment were maintained under identical environmental conditions and were treated with the HNIC of the test substance at challenge only. These animals constituted the "naive control" group.

Positive control substance(s):

yes

Remarks:

HCA

Results and discussion

Positive control results:

alpha-Hexylcinnamaldehyde Technical (HCA) as a positive control substance. The most recent validation, PSL Study #16901, was performed by Product Safety Laboratories and testing was completed on March 4, 2005.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

0.1%

No. with + reactions:

7

Total no. in group:

20

Clinical observations:

very faint erythema (0.5)

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 0.1%. No with. + reactions: 7.0. Total no. in groups: 20.0. Clinical observations: very faint erythema (0.5).

Results 2

Reading:

1st reading

Hours after challenge:

24

Group:

other: naive group

Dose level:

0.1%

No. with + reactions:

2

Total no. in group:

10

Clinical observations:

very faint erythema (score 0.5)

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: other: naive group. Dose level: 0.1%. No with. + reactions: 2.0. Total no. in groups: 10.0. Clinical observations: very faint erythema (score 0.5).

Any other information on results incl. tables

No skin reactions occurred in the test group that were more severe than that observed in the naive group, indicating the substance shows minor skin irritation. The conclusion is that CPC is not sensitising.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on these findings and on the evaluation system used, Cetylpyridinium Chloride is not considered to be a contact sensitizer.