Guanidine, N-methyl-N'-nitro-

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (non-LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

1996-07-29 till 1996-09-16

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline-conform study under GLP without deviations

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

1996

Report date:

1996

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 406 (Skin Sensitisation)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.6 (Skin Sensitisation)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Type of study:

guinea pig maximisation test

Test material

Test material information

Constituent 1

Reference substance name:

-

EC Number:

433-400-2

EC Name:

-

Cas Number:

4245-76-5

Molecular formula:

C2H6N4O2

IUPAC Name:

1-Methyl-3-nitro-guanidine

Constituent 2

Reference substance name:

N-methyl-N'-nitro-guanidine

IUPAC Name:

N-methyl-N'-nitro-guanidine

Details on test material:

- Name of test material (as cited in study report): CA 2342 A (Intermediate of CGA 293343)
- Substance type: intermediate
- Physical state: solid
- Analytical purity: 98%
- Purity test date: reanalysis date December 1997
- Lot/batch No.: P.601014
- Expiration date of the lot/batch: no data
- Stability under test conditions: no data
- Storage condition of test material: room temperature

In vivo test system

Test animals

Species:

guinea pig

Strain:

Pirbright-Hartley

Sex:

male/female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: CIBA-GEIGY Limited, Laboratory Animal Breeding Pharma Division, Stein / Switzerland
- Age at study initiation: no data
- Weight at study initiation: 330 to 421 g
- Housing: The animals were housed individually in Macrolon cages
- Diet (e.g. ad libitum): ad libitum standard guinea pig pellets - NAFAG 845
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 22 +/- 3°C
- Humidity (%): 30 to 70%
- Air changes (per hr): no data
- Photoperiod (hrs dark / hrs light): 12 hours light cycle day.

Study design: in vivo (non-LLNA)

Induction

Induction 1

Route:

intradermal and epicutaneous

Vehicle:

other: intradermal application: peanut oil; epidermal application: vaseline

Induction 2

Concentration / amount:

- Induction exposure: 5.0% CA 2342 A (Intermediate of CGA 293343)
- Challenge exposure : 50% CA 2342 A (Intermediate of CGA 293343)

Challenge

Challenge 1

Route:

epicutaneous, occlusive

Vehicle:

other: intradermal application: peanut oil; epidermal application: vaseline

Challenge 2

Concentration / amount:

- Induction exposure: 5.0% CA 2342 A (Intermediate of CGA 293343)
- Challenge exposure : 50% CA 2342 A (Intermediate of CGA 293343)

No. of animals per dose:

The test was performed on a total of 10 male and 10 female guinea pigs in the test group and 5 males and 5 females in the control group,
respectively.

Details on study design:

RANGE FINDING TESTS:

Intradermal Induction:
The concentration for intradermal injections was selected on account of the solubility of the test article in standard vehicles, the local irritant potency and the systemic tolerability of the test article in a pretest. The following concentrations of CA 2342 A were examined in pretest animals: 0.5, 1, 3 and 5% (wlv). Local reactions at the injection sites were examined 24 and 48 hours after duplicate intradermal injections.

Epidermal Applications (induction and challenge):
The concentration for the epidermal applications was selected on account of the primary irritation potential of the test article. The following concentrations of CA 2342 A were examined in pretest animals to determine the maximum subirritant concentration: 10, 30 and 50% (w/v). At least 7 days before application of CA 2342 A, two pairs of consecutive intradermal injections of an adjuvant saline/mixture were applied to the shaved neck of 2 guinea pigs. On each animal, 3 different concentrations of CA 2342 A were tested simultaneously on the left and right flank using Hilltop chambers. Naive skin site served as control. Occlusive dressing was applied for 24 hours. Skin responses were scored 24 and 48 hours after removal of the dressing according to the Draize scale.


MAIN STUDY

A. INDUCTION EXPOSURE

INTRADERMAL:
- No. of exposures: one intradermal injection
- Exposure period: 10 days
- Test group: - adjuvant/physiological saline mixture 1:1 (v/v)
- 5.0% CA 2342 A (Intermediate of CGA 293343) in peanut oil
- 5.0% CA 2342 A (Intermediate of CGA 293343) in the adjuvant/physiological saline mixture (w/v) and peanut oil (50%; w/v)
- Control group: - adjuvant/physiological saline mixture 1:l (v/v)
- peanut oil
- adjuvant/physiological saline mixture 1:1 (v/v) and peanut oil (50%; w/v)
- Site: on the left and right side of the shaved neck of the animals
- Frequency of applications: Three pairs of intradermal injections (0.1 ml per injection) were made consecutively in test and control group animals

EPIDERMAL:
- No. of exposures: one epidermal application
- Exposure period: 48 hours
- Test group: 50% CA 2342 A (Interned. of CGA 293343) in vaseline
- Control group: vaseline
- Site: neck of the animals
- Frequency of applications: Three pairs of intradermal injections (0.1 ml per injection) were made consecutively in test and control group animals


B. CHALLENGE EXPOSURE
- No. of exposures: one topical challenge exposure
- Day(s) of challenge: day 22
- Exposure period: 24 hours
- Test groups: 50% CA 2342 A (Intermediate of CGA 293343) in vaseline
- Control group: vaseline only
- Site: The animals were tested on one flank with CA 2342 A (Intermediate of CGA 293343) in vaseline and on the other flank with the vehicle alone
- Concentrations: 50% CA 2342 A; occlusive dressing
- Evaluation (hr after challenge): The challenge reactions were scored 24 and 48 hours after removing the dressings

Challenge controls:

no rechallenge

Positive control substance(s):

yes

Remarks:

mild to moderate sensitisers, such as mercaptobenzothiazole, benzocaine, hexyl cinnamic aldehyde or potassiumdichromate

Results and discussion

Positive control results:

The sensitivity of the guinea pig strain is checked twice a year with a known mild to moderate sensitiser, such as mercaptobenzothiazole,
benzocaine, hexyl cinnamic aldehyde or potassiumdichromate. The results of the latest positive control test are presented in the study report.

In vivo (non-LLNA)

Results

Results 1

Reading:

1st reading

Hours after challenge:

24

Group:

test chemical

Dose level:

50% CA 2342 A

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

none

Remarks on result:

other: Reading: 1st reading. . Hours after challenge: 24.0. Group: test group. Dose level: 50% CA 2342 A. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.

Results 2

Reading:

2nd reading

Hours after challenge:

48

Group:

test chemical

Dose level:

50% CA 2342 A

No. with + reactions:

0

Total no. in group:

20

Clinical observations:

none

Remarks on result:

other: Reading: 2nd reading. . Hours after challenge: 48.0. Group: test group. Dose level: 50% CA 2342 A. No with. + reactions: 0.0. Total no. in groups: 20.0. Clinical observations: none.

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Based on the sensitization rate of 0%, which is below the threshold of significance (i.e. below 30%) set in Commission Directive 93/21/EEC (18th
adaptation to technical progress of Council Directive 67/548/EEC), classification of CA 2342 A (Intermediate of CGA 293343) as to its sensitising
properties is not required. This classification still applies to the recent versions of both UN-GHS and EU-GHS (CLP).

Executive summary:

A guinea pig maximisation test was initiated to determine sensitising properties of CA 2342 A (Intermediate of CGA 293343) after challenge exposure by skin contact. The procedure of Magnusson and Kligman for adjuvant tests was followed. Epidermal challenge of 10 male and 10 female guinea pigs (test groups) resulted in no positive responses in all guinea pigs after 24 hours and 48 hours, corresponding to a sensitisation rate of 0%. No irritant skin reactions were recorded for control animals. All animals survived to the scheduled sacrifice. Body weights were unaffected by the treatment.

Based on the sensitization rate of 0%, which is below the threshold of significance (i.e. below 30%) set in Commission Directive 93/21/EEC (18th adaptation to technical progress of Council Directive 67/548/EEC), classification of CA 2342 A (Intermediate of CGA 293343) as to its sensitising properties is not required. This classification also applies to the recent versions of both UN-GHS and EU-GHS (CLP).