Lead cyanamidate

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: study was preformed according to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 429 (Skin Sensitisation: Local Lymph Node Assay)

GLP compliance:

yes (incl. QA statement)

Type of study:

mouse local lymph node assay (LLNA)

Test material

Test material information

Constituent 1

Reference substance name:

Lead cyanamidate

EC Number:

244-073-9

EC Name:

Lead cyanamidate

Cas Number:

20837-86-9

Molecular formula:

CN2.Pb

IUPAC Name:

λ²-lead(2+) (azanidylenemethylidene)azanide

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

Test system Mice, CBA/CaOlaHsd
Rationale Recognised as the recommended test system.
Source Harlan Laboratories B.V.
Postbus 6174
5960 AD Horst / The Netherlands
Number of animals for the pre-test 2 females
Number of animals for the main study 16 females (reserve animals will be used as needed and listed in raw data and report)
Number of animals per group 4 females (nulliparous and non-pregnant)
Number of test groups 3
Number of control (vehicle) group 1
(If possible, concurrent controls will be used for several Harlan CCR projects performed in parallel to save animals).
Age 8 - 12 weeks (beginning of treatment)
Body weight 15 - 25 g (beginning of treatment)
Identification
The animals will be distributed into the test groups at random. All animals belonging to the same experimental group will be kept in one cage. In the main experiment, the animals will be identified by tail tags. In the pre-experiment, animals will be identified by cage number.
Acclimatisation
At least 5 days prior to the start of dosing under test conditions after health examination. Only animals without any visible signs of illness will be used for the study.

Study design: in vivo (non-LLNA)

Positive control substance(s):

no

Study design: in vivo (LLNA)

Vehicle:

acetone/olive oil (4:1 v/v)

Concentration:

The highest test item concentration, which can be technically used was a 25 % (w/w) suspension in acetone:olive oil (4+1 v/v) after vortexing.
To determine the highest non-irritant test concentration that does at the same time not induce signs of systemic toxicity, a pre-test will be performed in two animals and stated in raw data and report. Two mice will be treated by (epidermal) topical application to the dorsal surface of each ear with test item concentrations of 10 and 25% once daily each on three consecutive days. Prior to the first application of the test item and before sacrifice the body weight will be determined. Clinical signs will be recorded at least once daily. Eventual signs of local irritation will be documented and a score will be used to grade a possible reddening of the ear skin. Furthermore, prior to the first application of the test item (day 1), on day 3 and before sacrifice (day 6) the ear thickness will be determined using a micrometer (S0247 Kroeplin, 36381 Schlüchtern, Germany). Additionally, for both animals, the ears will be punched after sacrifice (day 6) at the apical area using a biopsy punch (Stiefel, Ø 8 mm corresponding to 0.5 cm2) and will be immediately pooled per animal and weighed using an analytical balance. The results of the observations and measurements will be described in the report. Eventual ear irritation is considered to be excessive if reddening of the ear skin of a score value ≥3 is observed at any observation time and/or if an increase in ear thickness of ≥25% is recorded on day 3 or day 6. In case of induction of excessive irritation or systemic toxicity the chosen concentration range will shift to lower levels and will be described in the report.
The test item in the main study will be assayed at three consecutive concentrations. The highest concentration to be tested will be the highest level that can be achieved whilst avoiding systemic toxicity and excessive local irritation in the pre-experiment.

No. of animals per dose:

4 animals

Results and discussion

In vivo (LLNA)

Results

Parameter:

SI

Remarks on result:

other: see any other information on results incl. tables

Any other information on results incl. tables

Test item Name:	Cyanamide, lead(2+) salt (1:1)
Vehicle:	A:OO
Stimulation Index:
Test item concentration % (w/v)		Measurement DPM	Calculation			Result
			DPM-BG^a)	number of lymph nodes	DPM per lymph node^b)	S.I.
---	BG I	18	---	---	---	---
---	BG II	41	---	---	---	---
NK	1	2251	2222	8	277,7	1,00
5%	2	3589	3560	8	444,9	1,60
10%	3	4154	4125	8	515,6	1,86
25%	4	16136	16107	8	2013,3	7,25
	EC3-Berechnung:
		C		S.I.	EC3
		% (w/v)			% (w/v)
		Konzentration		S.I.
SI < 3	(a)	10	(b)	1,86	13,2
SI >3	(c)	25	(d)	7,25

Applicant's summary and conclusion

Interpretation of results:

sensitising

Remarks:

Migrated information

Conclusions:

The presented data are reliable and adequate.

Executive summary:

The substance Cyanamide, lead(2+) salt (1:1) can be regarded as sensitising.