Salbutamol

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:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

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:

Salbutamol

EC Number:

242-424-0

EC Name:

Salbutamol

Cas Number:

18559-94-9

Molecular formula:

C13H21NO3

IUPAC Name:

4-[2-(tert-butylamino)-1-hydroxyethyl]-2-(hydroxymethyl)phenol

Test material form:

solid: particulate/powder

In vivo test system

Test animals

Species:

mouse

Strain:

CBA/Ca

Sex:

female

Study design: in vivo (LLNA)

Vehicle:

dimethyl sulphoxide

Concentration:

Test item was examined in the main test at concentrations of 10 %, 5 %, 2.5 % and 1 % (w/v).The test item was weighed and formulations prepared daily on a weight: volume basis in a final volume of 1 mL using volumetric vials and mechanical agitation.

No. of animals per dose:

4 animals/treatment group.
28 animals/main test.

Positive control substance(s):

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

Results and discussion

In vivo (LLNA)

Results

Results 1

Parameter:

EC3

Value:

4.3

Results 2

Parameter:

SI

Value:

0.9

Test group / Remarks:

1% w/v

Results 3

Parameter:

SI

Value:

1.9

Test group / Remarks:

2.5% w/v

Results 4

Parameter:

SI

Value:

3.4

Test group / Remarks:

5% w/v

Results 5

Parameter:

SI

Value:

3.5

Test group / Remarks:

10% w/v

Any other information on results incl. tables

No mortality was observed during the main test. No significant, treatment related effect on body weights or any other sign of systemic toxicity were observed in any treatment group.

No signs of irritation or any other local effect were observed at the treatment site (ears) in any treatment group.

Significant lymphoproliferative response (SI ≥ 3) compared to the relevant vehicle control (DMSO) was noted for Salbutamol base at 10 % and 5 % (w/v) test concentrations. No significantly increased lymphoproliferation was observed in the 2.5 % and 1 % (w/v) dose groups. The observed stimulation index values were 3.5, 3.4, 1.9 and 0.9 at test item concentrations of 10 %, 5 %, 2.5 % or 1 % (w/v), respectively. The response was considered dose-related although no statistical significance was observed (p = 0.14, r = 0.86, evaluated by linear regression using the calculated SI values).

According to evaluation criteria of the relevant guidelines, the significantly increased lymphoproliferation (indicated by an SI ≥ 3) observed at the maximum feasible concentration of 10 % (w/v, based on solubility) and also at concentration of 5 % (w/v) and the dose-related response are considered evidence that Salbutamol base is a skin sensitizer.

Chemicals can be classified according to their relative skin-sensitization potency using EC3 value (dose calculated to induce a stimulation index of 3) calculated by linear interpolation using data points lying immediately above and below the SI value of 3 on the LLNA dose-response curve according to published method. The calculated EC3 value for the test item was 4.3 % (w/v) in this LLNA. Using this value Salbutamol base can be ranked among moderate skin sensitizers according to the published data for classification of contact allergens.

Applicant's summary and conclusion

Interpretation of results:

Category 1B (indication of skin sensitising potential) based on GHS criteria

Conclusions:

Under the conditions of the present assay, Salbutamol base tested at the maximum feasible concentration of 10 % (w/v, based on solubility) and at concentrations of 5 %, 2.5 % and 1 % (w/v) as formulations in a suitable vehicle (DMSO) was shown to have skin sensitization potential (skin-sensitizer) in the Local Lymph Node Assay.
Based on the EC3 value of 4.3% (w/v) calculated using the dose-response curve Salbutamol base was classified as a moderate skin sensitizer in this LLNA according to the published data.

Executive summary:

The aim of this study was to evaluate the skin sensitization potential of Salbutamol base following dermal exposure in the Local Lymph Node Assay.

A formulation evaluation and a Dose Range Finding test (DRF) were performed to find an appropriate vehicle and the maximum applicable concentration according to the relevant guidelines. Based on the results the test item was formulated in Dimethyl sulfoxide (DMSO) in the LLNA. The maximum achievable concentration (based on solubility) was 10 % (w/v). According to results of the DRF, where no adverse effects (systemic or local) were observed up to this maximum concentration, the test item was examined in the main test as 10 %, 5 %, 2.5 % or 1 % (w/v) formulations (apparently solutions) in DMSO. Appropriate positive control (α-Hexylcinnamaldehyde, HCA), furthermore two negative control groups dosed with the vehicles of the test and positive control groups, respectively, were employed.

The positive control item [25 % (w/v) HCA in Acetone: Olive oil 4:1 (v/v) mixture (AOO)] induced significant stimulation over the relevant control (SI = 5.2) thus confirming the validity of the assay.

No mortality was observed during the main test. No significant, treatment related effect on body weights or any other sign of systemic toxicity were observed in any treatment group. No signs of irritation or any other local effect were observed at the treatment site (ears) in any treatment group.

Significant lymphoproliferative response (SI ≥ 3) compared to the relevant vehicle control (DMSO) was noted for Salbutamol base at 10 % and 5 % (w/v) test concentrations. No significantly increased lymphoproliferation was observed in the 2.5 % and 1 % (w/v) dose groups. The observed stimulation index values were 3.5, 3.4, 1.9 and 0.9 at test item concentrations of 10 %, 5 %, 2.5 % or 1 % (w/v), respectively. The response was considered dose-related although no statistical significance was observed (p = 0.14, r = 0.86, evaluated by linear regression using the calculated SI values).

According to evaluation criteria of the relevant guidelines, the significantly increased lymphoproliferation (indicated by an SI ≥ 3) observed at the maximum feasible concentration of 10 % (w/v, based on solubility) and also at concentration of 5 % (w/v) and the dose-related response are considered evidence that Salbutamol base is a skin sensitizer.

Chemicals can be classified according to their relative skin-sensitization potency using EC3 value (dose calculated to induce a stimulation index of 3) calculated by linear interpolation using data points lying immediately above and below the SI value of 3 on the LLNA dose-response curve according to published method. The calculated EC3 value for the test item was 4.3 % (w/v) in this LLNA. Using this value Salbutamol base can be ranked among moderate skin sensitizers according to the published data for classification of contact allergens.

Under the conditions of the present assay, Salbutamol base tested at the maximum feasible concentration of 10 % (w/v, based on solubility) and at concentrations of 5 %, 2.5 % and 1 % (w/v) as formulations in a suitable vehicle (DMSO) was shown to have skin sensitization potential (skin-sensitizer) in the Local Lymph Node Assay.

Based on the EC3 value of 4.3% (w/v) calculated using the dose-response curve Salbutamol base was classified as a moderate skin sensitizer in this LLNA according to the published data.