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Toxicological information

Skin sensitisation

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Administrative data

Endpoint:
skin sensitisation: in vitro
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2011
Report Date:
2011

Materials and methods

Principles of method if other than guideline:
To test direct peptide reactivity which is a key pathway leading to skin sensitisation, the test substance was investigated for peptide depletion by chemical reaction. The assay method established by Natsch and Gfeller (2008) was validated and improved in the testing facility and utilised in this study.
GLP compliance:
yes
Type of study:
other: peptide binding assay

Test material

Reference
Name:
Unnamed
Type:
Constituent
Details on test material:
- Name of test material (as cited in study report): XU-12398.00
- Molecular formula (if other than submission substance): C4H11NO2
- Molecular weight (if other than submission substance): 105.1
- Analytical purity: 99.9%

Results and discussion

In vitro / in chemico

Results
Key result
Parameter:
other: AMPD was tested for peptide reactivity by monitoring peptide depletion. Under the conditions used in this study, there is no evidence of that AMPD contains direct protein reactivity that can result in skin sensitization.
Remarks on result:
no indication of skin sensitisation

Any other information on results incl. tables

The test substance was completely soluble in acetonitrile and was not precipitated by mixing with peptide solutions. After 24 h incubation, there was no colour change or a precipitate observed from the test substance. The test article did not have any UV absorbance at 220 nm through entire HPLC chromatography and therefore there was no interference with HPLC-UV analyses for peptides. Furthermore, the test substance did not interfere with the MS detections used in the test system that were monitoring higher than 700.0 m/z. Using the established calibration curve, the concentrations of free peptide were calculated for each sample (Table 1). Average peptide depletion by the test substance was 4.22 ± 1.84%. Negative and positive controls resulted in 4.83 ± 1.66% and 96.13 ± 0.21% peptide depletion, respectively. These results confirmed the assay was valid. Because there was no peptide depletion by the test substance, no further analysis was performed to measure dimerized- or oxidized-peptide by the test substance.

 

Table 1: Individual data from free peptide quantitation and average peptide depletion

Group

Replicate#

Analyte Peak Area (counts)

Peptide conc. (mM)

Peptide depletion (%)

Average depletion (%)

Test substance

1

15300000

98.03

1.97

4.22 ± 1.84

2

15200000

97.37

2.63

3

14700000

94.07

5.93

4

14700000

94.07

5.93

5

14900000

95.39

4.61

Negative control

1

14600000

93.40

6.60

4.83 ± 1.66

2

14900000

95.39

4.61

3

15100000

96.71

3.29

Positive control

1

1030000

3.78

96.22

96.13 ± 0.21

2

1080000

4.11

95.89

3

1020000

3.71

96.29

Applicant's summary and conclusion

Interpretation of results:
not sensitising
Conclusions:
Under the test conditions, there is no evidence that the test substance contains direct protein reactivity which would cause skin sensitisation.
Executive summary:

Direct peptide reactivity is a key component of the pathway leading to skin sensitisation, XU-12398.00 (AMPD) was tested for peptide reactivity by monitoring peptide depletion by chemical reactions using the assay method established by Natsch and Gfeller (2008) with minor modifications. After a 24-hour incubation with one tenth molar ratio of the standard peptide, XU-12398.00 (AMPD) resulted in minimal peptide depletion, which was within the range of the negative control. The positive control substance depleted most of free peptides. Under the conditions used in this study, there is no evidence of that XU-12398.00 (AMPD) contains direct protein reactivity that can result in skin sensitisation.