3-aminopropane-1,2-diol

Skin sensitisation

Administrative data

Endpoint:

skin sensitisation: in vivo (LLNA)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 May 2010 to 9 June 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study conducted to internationally accepted guidelines and to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.42 (Skin Sensitisation: Local Lymph Node Assay)

Deviations:

no

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:

3-aminopropane-1,2-diol

EC Number:

210-475-8

EC Name:

3-aminopropane-1,2-diol

Cas Number:

616-30-8

Molecular formula:

C3H9NO2

IUPAC Name:

3-aminopropane-1,2-diol

Details on test material:

- Name of test material (as cited in study report): APD (Aminopropandiol)
- Physical state: liquid
- Other: pH(10%): 11.2

In vivo test system

Test animals

Species:

mouse

Strain:

CBA

Sex:

female

Details on test animals and environmental conditions:

TEST ANIMALS
- Source: Harlan UK Ltd.
- Age at study initiation: 8 to 12 weeks
- Weight at study initiation: 17.4 to 23.1 g
- Housing: Individually in polycarbonate cages with woodflake bedding. The mice were also given Nestlets and a plastic shelter for environmental enrichment.
- Diet (e.g. ad libitum): Rat and Mouse No. 1 Maintenance Diet ad libitum
- Water (e.g. ad libitum): ad libitum
- Acclimation period: 5 days

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 19 to 23
- Humidity (%): 40 to 70
- Air changes (per hr): Not stated
- Photoperiod (hrs dark / hrs light): 12 / 12

IN-LIFE DATES: From: 11 May 2010 To: 08 June 2010

Study design: in vivo (LLNA)

Vehicle:

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

Concentration:

Preliminary test: 10, 25, 50% v/v
Main phase: 5, 10, 25%

No. of animals per dose:

Preliminary test: 1
Main phase: 4

Details on study design:

RANGE FINDING TESTS:
- Irritation: Due to signs of irritation seen in the preliminary animal dosed at 50%, it was concluded that 25% v/v was a suitable high dose level for the main phase of the study.

MAIN STUDY
ANIMAL ASSIGNMENT AND TREATMENT
- Name of test method: Pooled treatment group approach
- Criteria used to consider a positive response: The test substance is regarded as a sensitizer if at least one concentration of the test substance results in a three-fold greater increase in 3HTdR incorporation compared to control values.

TREATMENT PREPARATION AND ADMINISTRATION:
The mice were treated by daily application of 25 μL of the appropriate concentration of the test substance to the dorsal surface of each ear for three consecutive days (Days 1-3). The test substance was applied to the dorsal surface of each ear using an automatic micropipette. The test substance was spread over the entire dorsal surface of the ear using the tip of the pipette. A further group of four mice received the vehicle alone in the same manner.
Five days following the first topical application of test substance (Day 6) all mice were injected via the tail vein with 250 μL of phosphate buffered saline containing 3H-methyl Thymidine (3HTdR: 80 μCi/mL) giving a nominal 20 μCi to each mouse. The injection into the tail vein was carried out using a plastic syringe and needle after the mouse had been heated in a warming chamber.

Termination:
Five hours following the administration of 3HTdR on Day 6 all mice were humanely killed by carbon dioxide asphyxiation and the draining auricular lymph nodes excised and pooled for each experimental group. 1.0 mL of phosphate buffered saline was added to the pooled lymph nodes for each group. The animals were then discarded and no further investigations were carried out. The following procedures were carried out with the lymph nodes from these animals only.

Preparation of cell suspensions:
A single cell suspension of lymph node cells (LNC) was prepared by gentle mechanical disaggregation through a stainless steel gauze (200 mesh size). The pooled LNC were then washed by adding 10 mL phosphate buffered saline, pelleted at 190 x g for 10 minutes and resuspended. The cells were washed twice again and resuspended in 3 mL trichloroacetic acid (TCA: 5%) following the final wash.

Determination of incorporated 3H-methyl Thymidine:
After overnight incubation with 5% TCA at 4°C, the precipitate was recovered by centrifugation and resuspended in 1 mL 5% TCA and transferred to 10 mL Ultima gold scintillation fluid on Day 7. 3HTdR incorporation was measured by β-scintillation counting. The proliferative response of LNC was expressed as radioactive disintegrations per minute per lymph node (dpm/node) and as the ratio of 3HTdR incorporation into LNC of test nodes relative to that recorded for control nodes (test/control ratio).

Positive control substance(s):

hexyl cinnamic aldehyde (CAS No 101-86-0)

Results and discussion

Positive control results:

Responses to the positive control substance hexyl cinnamic aldehyde (HCA), in contemporaneous studies demonstrate the reliability and sensitivity of this assay to detect skin sensitization potential in this laboratory. See attached background data below showing appendix two of the study report, summary of positive control data.

In vivo (LLNA)

Results

Parameter:

other: disintegrations per minute (DPM)

Remarks on result:

other: The test/control ratios obtained for 5, 10 and 25% v/v APD were 3944.7, 4538.3, and 6148.2 respectively.

Any other information on results incl. tables

Table 1 Group dpm/node and test/control ratios

Group	Concentration % v/v	dpm	Number of lymph nodes per group	dpm/node	Test/control ratio†	Result + = positive - = negative
4	AOO	2721.80	8.0	340.23	n/a	n/a
5	5	3944.70	8.0	493.09	1.4	-
6	10	4538.30	8.0	567.29	1.7	-
7	25	6148.20	8.0	768.53	2.3	-

†=Test/control of 3 or greater indicates a positive result

n/a=Not applicable

dpm=Disintegrations per minute (less background count of 46.10 dpm)

AOO=Acetone:olive oil (4:1 v/v) (vehicle control)

Applicant's summary and conclusion

Interpretation of results:

not sensitising

Remarks:

Migrated information

Conclusions:

Aminopropandiol is not regarded as a potential skin sensitizer.