3-aminopyrazine-2-carboxylic acid

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

December 10 - December 11, 2012

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: OECD guideline 437 “Bovine corneal opacity and permeability (BCOP) test method for identifying ocular corrosives and severe irritants”

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

other: EU Method B.47 “Bovine corneal opacity and permeability method for identifying ocular corrosives and severe irritants

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Amiloride Compound 5

IUPAC Name:

Amiloride Compound 5

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Amiloride Compound 5
- CAS Number: 5424-01-1
- Description: Tan powder

Test system

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 316 to 396 mg per cornea (undiluted)
Since no workable suspension of the test substance in physiological saline could be obtained, the test substance was used as such and added as such on top of the corneas.

NEGATIVE CONTROL
- Amount(s) applied (volume or weight with unit): 750 µl of physiological saline per cornea

POSITIVE CONTROL
Amount(s) applied (volume or weight with unit): 750 µl per cornea
Concentration (if solution): 20% (w/v) Imidazole in physiological saline

Duration of treatment / exposure:

240 minutes (4 hours)

Details on study design:

TEST SITE
- Isolated bovine cornea

REMOVAL OF TEST SUBSTANCE
- Washing (if done): yes
- Time after start of exposure: 240 minutes

SCORING SYSTEM:
- After exposure the cornea is thoroughly rinsed to remove the test substance followed by immediate opacity measurement and permeability evaluation of the cornea.

- The mean opacity and mean permeability values (OD490) were used for each treatment group to calculate an in vitro score:

In vitro irritancy score (IVIS) = mean opacity value + (15 x mean OD490 value).


TOOL USED TO ASSESS SCORE:
- opacitymeter and microplate reader

DATA EVALUATION:
A test substance that induces an IVIS ≥ 55.1 is defined as a corrosive or severe irritant

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Run / experiment:

mean

Value:

146

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

0.0

Positive controls validity:

valid

Remarks:

111

Remarks on result:

positive indication of irritation

Any other information on results incl. tables

- The corneas treated with the substance showed opacity values ranging from 136 to 158 and permeability values ranging from -0.006 to 0.235

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Amiloride Compound 5 is corrosive in the Bovine Corneal Opacity and Permeability test.

Executive summary:

The negative control responses of the opacity and permeability values were less than the upper limits of the laboratory historical range indicating that the negative control did not induce irritancy on the corneas.The mean in vitro irritancy score of the positive control (20% (w/v) Imidazole) was 111 and within the historical positive control data range. It was therefore concluded that the test conditions were adequate and that the test system functioned properly.

Amiloride Compound 5 induced ocular irritation through the opacity endpoint only, resulting in a mean in vitro irritancy score of 146 after 240 minutes of treatment.