Pyridoxine hydrochloride

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

09 Feb 2015 - 15 feb 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: The study has been performed according to OECD and/or EC guidelines and according to GLP principles.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 439 (In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method)

Version / remarks:

adopted 26 July 2013

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test)

Version / remarks:

adopted 20 July 2012

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Pyridoxine hydrochloride

EC Number:

200-386-2

EC Name:

Pyridoxine hydrochloride

Cas Number:

58-56-0

Molecular formula:

C8H11NO3.ClH

IUPAC Name:

4,5-bis(hydroxymethyl)-2-methylpyridin-3-ol hydrochloride

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Pyridoxine Hydrochloride (Vitamin B6)
- Substance type: organic
- Physical state: white powder
- Storage condition of test material: At room temperature, protected from light and humidity

Test animals

Species:

human

Details on test animals or test system and environmental conditions:

ENVIRONMENTAL CONDITIONS
- Temperature (°C): 36.7 - 37.2
- Humidity (%): 63-89
- CO2 (%): 5.0 ± 0.5

Test system

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

TEST MATERIAL
- Amounts applied: 21.0 to 23.0 mg, the skin was moistened with 10 µl Milli-Q water.

NEGATIVE CONTOL:
- Amount applied: 25 µl Phosphate buffered saline

POSITIVE CONTROL
- Amount applied: 25 µl
- Concentration: 5% (aq) Sodium dodecyl sulphate

Duration of treatment / exposure:

15 ± 0.5 minutes

Number of animals:

3 (number of replicates)

Details on study design:

TEST SITE
- EPISKIN Small ModelTM (EPISKIN-SMTM, 0.38 cm2, Batch no.: 15-EKIN-006). This model is a three-dimensional human epidermis model, which consists of adult human-derived epidermal keratinocytes which have been seeded on a dermal substitute consisting of a collagen type I matrix coated with type IV collagen. The keratinocytes were cultured for 13 days, which results in a highly differentiated and stratified epidermis model comprising the main basal, supra basal, spinous and granular layers and a functional stratum corneum.

REMOVAL OF TEST SUBSTANCE
- Washing: phosphate buffered saline
- Time after start of exposure: 15 ± 0.5 minutes

POST INCUBATION PERIOD
- 42 hours

SCORING SYSTEM:
- Cytotoxicity is expressed as the reduction of mitochondrial dehydrogenase activity measured by formazan production from MTT at the end of the treatment. Cell viability was calculated for each tissue as a percentage of the mean of the negative control tissues.

Results and discussion

In vitro

Results

Irritation / corrosion parameter:

other: other: tissue viability

Value:

101

Remarks on result:

other:

Remarks:

Basis: other: percentage of control. Time point: 15 minutes. Remarks: Negative control = 100%; Positive control = 11%. (migrated information)

Any other information on results incl. tables

Pyridoxine Hydrochloride (Vitamin B6) was checked for colour interference in aqueous conditions and possible direct MTT reduction by adding the test substance to MTT medium. Because no colour changes were observed it was concluded that Pyridoxine Hydrochloride (Vitamin B6) did not interact with the MTT endpoint.

Applicant's summary and conclusion

Interpretation of results:

not classified

Remarks:

Criteria used for interpretation of results: EU

Conclusions:

An in vitro skin irritation test was conducted according to OECD/EC guidelines and GLP principles. It is concluded that this test is valid and that Pyridoxine Hydrochloride (Vitamin B6) is not irritating in the in vitro skin irritation test.

Executive summary:

In an in vitro skin irritation test using a human skin model ( EPISKIN Standard Model), the influence of the test substance on the viability of human skin was tested. The test substance was applied directly to 0.38 cm² cultured skin (21.0 to 23.0 mg, in presence of 10 μl Milli-Q water). After 15 minutes, the substance was removed and cells were cultured for 42 hours. The viability of the cells was tested by reduction of MTT. Survival of unexposed skin was set at 100%, the positive control had a mean cell viability of 11% whereas the test substance showed cell viability of 101%. Since the mean relative tissue viability after exposure to the test substance was above 50%, it can be concluded that the test substance is non-irritant in the in vitro skin irritation test.