Guanidinium phosphate (1:1)

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

other: EU method B.46 (In Vitro Skin Irritation: Reconstructed Human Epidermis Model Test), adopted 24 August 2009

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: OECD Guideline no. 439: In Vitro Skin Irritation: Reconstructed Human Epidermis Test Method, adopted 22 July 2010

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Guanidinium phosphate (1:1)

EC Number:

226-551-9

EC Name:

Guanidinium phosphate (1:1)

Cas Number:

5423-22-3

Molecular formula:

CH8N3O4P

IUPAC Name:

(diazaniumylmethylidene)azanium phosphate

Test material form:

solid: crystalline

Details on test material:

- Name of test material (as cited in study report): Guanidine phosphate (1:1)
- Physical state: White crystal solid
- CAS no.: 5423-22-3
- Storage condition of test material: In refrigerator (2-8°C) in the dark in well-sealed container

Test animals

Species:

human

Details on test animals or test system and environmental conditions:

ENVIRONMENTAL CONDITIONS
- Temperature (°C):35.9 – 37.6
- Humidity (%): 85-96

Test system

Vehicle:

unchanged (no vehicle)

Amount / concentration applied:

TEST MATERIAL
- Amounts applied: 10.8 to 13.6 mg (evenly distributed over the tissue)

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 minutes

Details on study design:

TEST SITE
- EPISKIN Standard ModelTM(EPISKIN-SMTM, 0.38 cm2, Batch no.: 12-EKIN-39).This model is a three-dimensional human epidermis model, which consists of adult human-derived epidermal keratinocytes which have been seeded in 12-well plates 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 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 vivo

Results

Irritation parameter:

other: tissue viability

Basis:

other: percentage of control

Time point:

other: 15 minutes

Score:

112

Remarks on result:

other: Negative control = 100%; Positive control =9%

Any other information on results incl. tables

Guanidine phosphate (1:1) was checked for possible direct MTT reduction by adding the test substance to MTT medium. Because no colour change was observed it was concluded that Guanidine phosphate (1:1) did not interact with MTT.

 

Mean tissue viability for the test substance was > 50%, therefore the test substance is considered not to be irritant to the skin.

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based on an in vitro skin irritation test performed according to OECD 439 guideline and GLP principles, it is concluded that guanidinium phosphate (1:1) 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 guanidinium phosphate (1:1) on the viability of human skin was tested. The test substance was applied directly to 0.38 cm² cultured skin ( 10.8 to 13.6 mg). 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 9% whereas the test substance showed cell viability of 112%. Since the mean relative tissue viability after exposure to the test substance was above 50%, it can be concluded that the guanidinium phosphate (1:1) is not irritating in the in vitro skin irritation test.