Registration Dossier

Administrative data

Endpoint:
skin irritation: in vitro / ex vivo
Type of information:
experimental study
Adequacy of study:
key study
Reliability:
1 (reliable without restriction)
Rationale for reliability incl. deficiencies:
other: Well documented study according to international acceoted guidelines and GLP compliant.

Data source

Reference
Reference Type:
study report
Title:
Unnamed
Year:
2013
Report Date:
2013

Materials and methods

Test guideline
Qualifier:
according to
Guideline:
OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)
Deviations:
no
GLP compliance:
yes (incl. certificate)

Test material

Reference
Name:
Unnamed
Type:
Constituent
Test material form:
solid: particulate/powder
Remarks:
migrated information: powder
Details on test material:
Test item: Tryptamine
CAS No.: 61-54-1
Batch No.: S37020N
Physical state: solid, amorphous powder
Colour: yellowish-brown
Active ingredient content: 99 %
Storage: 8-15 °C, protected from light and moisture

Test system

Details on study design:
Human skin model:
EpiSkinTM Small Model (EpiSkinTMSM), manufactured by EPISKIN SNC Lyon, France, is a three-dimensional human epidermis model. Adult human-derived epidermal keratinocytes are seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen. A highly differentiated and stratified epidermis model is obtained after 13-day culture period comprising the main basal, supra basal, spinous and granular layers and a functional stratum corneum (Tinois et al., 1994). Its use for skin irritation testing involves topical application of test materials to the surface of the epidermis, and the subsequent assessment of their effects on cell viability.
Justification for selection of the test system: The EPISKIN model has been validated for irritation testing in an international trial.

Results and discussion

In vivo

Irritant / corrosive response data:
Disks of EPISKIN (three units / chemical) were treated with test item and incubated for 15 minutes at room temperature. Exposure of test material was terminated by rinsing with PBS 1x solution. Epidermis units were then incubated at 37 °C for 42 hours in an incubator with 5% CO2. The viability of each disk was assessed by incubating the tissues for 3 hours with MTT solution at 37°C in 5% CO2 protected from light. The precipitated formazan was then extracted using acidified isopropanol and quantified spectrophotometrically.
SDS (5% aq.) and PBS treated epidermis were used as positive and negative controls respectively. For each treated tissue viability was expressed as a percentage relative to negative control.
The test item is considered to be irritant to skin, if the mean relative viability after 15 minutes exposure and 42 hours post incubation is less or equal (≤) to 50% of the negative control.
The test item did not show reduced cell viability in comparison to the negative control (mean value: 106 %). All obtained test item viability results were above 50 % when compared to the viability values obtained from the negative control, therefore the test item was considered to be non-irritant to skin.
Positive and negative controls showed the expected cell viability values within acceptable limits. The experiment was considered to be valid.
Irritation score cannot be given, because this in vitro skin irritation study is able to distinguish between skin irritating  and non- skin irritating  chemicals only.

Any other information on results incl. tables

Substance

Optical Density (OD)

Viability (%)

Negative Control:

1 x PBS

mean

0,720

100

standard deviation(SD)

6,14

Positive Control:

SDS (5%aq.)

mean

0,148

20

standard deviation(SD)

4,27

Test Item:

tryptamine

mean

0,762

106

standard deviation(SD)

0,98

 

Applicant's summary and conclusion

Interpretation of results:
not irritating
Remarks:
Migrated information Criteria used for interpretation of results: OECD GHS
Conclusions:
In this in vitro skin irritation test in the EPISKIN model with test item TRYPTAMINE (CAS 61-54-1) the results indicated that the test item is Non Irritant (NI) [UN GHS: No Category].