Aspartic acid

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2002

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Guideline study with GLP.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2002

Report date:

2002

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU Method B.5 (Acute Toxicity: Eye Irritation / Corrosion)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Aspartic acid

EC Number:

200-291-6

EC Name:

Aspartic acid

Cas Number:

56-84-8

Molecular formula:

C4H7NO4

IUPAC Name:

aspartic acid

Constituent 2

Reference substance name:

L-Asparaginsäure

IUPAC Name:

L-Asparaginsäure

Constituent 3

Reference substance name:

S-(+) amino succinic acid

IUPAC Name:

S-(+) amino succinic acid

Test material form:

solid: crystalline

Details on test material:

Supplier: Sponsor.
Batch No.: PRCA 015.
CAS No. 56-84-8.
Appearance: White, crystalline.
Purity: Approx. 99 %.
pH: 2.5 – 3.5 (4 g/L at 20 °C).
Melting range: 265 – 271 °C.
Solubility in water: 5 g/L at 25°C.
Conditions of storage: In the refrigerator, in the dark, may be used under light.
Date of expiry: 31 December 2002.

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Supplier: Charles River Wiga, D-97633 Sulzfeld.
Weight: 2.1 to 2.4 kg at the start of the study.
Hygiene: Optimal hygienic conditions.
Room temperature: Average of 19.3 °C (continuous control and recording).
Relative humidity: Average of 52.6 % (continuous control and recording).
Air exchange: 12 per hour.
Light: Artificial light from 6 a.m. to 6 p.m.
Cages: Individual caging in metal wire cages, 79 cm x 59 cm bottom area, 38 cm height, with a wooden rest shelf, 15 cm x 59 cm.
Feed: Altromin 2023 diet for rabbits, ad libitum. Hay-briquetteswere offered additionally as a dietary supplement.
Water: Tap water from an automatic watering system, ad libitum.
Acclimatisation: 5 days.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

The approximate equivalent of 0.1 mL of the test substance was administered per animal into the conjunctival sacs of the right eyes by gently pulling the lower lids away from the eyeballs for instillation. The eyes were held closed for about one second to prevent a loss of test substance.
The weighed amounts of the individual doses were 85, 80 and 80 mg.

Duration of treatment / exposure:

Single application. The test substance was administered into the conjunctival sacs of the right eyes by gently pulling the lower lids away from the eyeballs for instillation. The eyes were held closed for about one second to prevent a loss of test substance.

Observation period (in vivo):

72 h for 2 animals; 6 d for 1animal.

Number of animals or in vitro replicates:

3 females.

Details on study design:

The left eyes remained untreated and served as a control.
Firstly, the test substance was given to one animal. As no evidence for a serious damage to the eye of this animal was found until 72 h p.a. (no corrosive effect), the test substance was administered to the other two animals too.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal: #1 and #3

Time point:

other: 1 to 72 h

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Results 2

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

other: mean of 24 to 72 h

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 48 h

Remarks on result:

other: for details see below.

Results 3

Irritation parameter:

iris score

Basis:

animal: #1, #2 and #3

Time point:

other: 1 - 72 h p.a.

Score:

0

Max. score:

0

Reversibility:

other: not applicable

Results 4

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

other: mean (24-72 h)

Score:

0.7

Max. score:

1

Reversibility:

fully reversible within: 72 h

Remarks on result:

other: For details see below.

Results 5

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

other: Mean (24-72 h)

Score:

1

Max. score:

1

Reversibility:

fully reversible within: 6 d

Remarks on result:

other: For details see below.

Results 6

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

other: Mean (24-72 h)

Score:

0.3

Max. score:

1

Reversibility:

fully reversible within: 48 h

Remarks on result:

other: For details see below.

Results 7

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

other: Mean (24-72 h)

Score:

0

Max. score:

2

Reversibility:

fully reversible within: 24 h

Remarks on result:

other: For details see below.

Results 8

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

other: Mean (24-72 h)

Score:

1.3

Max. score:

3

Reversibility:

fully reversible within: 72 h

Remarks on result:

other: For details see below.

Results 9

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

other: Mean (24-72 h)

Score:

0

Max. score:

3

Reversibility:

fully reversible within: 24 h

Remarks on result:

other: For details see below.

Irritant / corrosive response data:

The untreated eyes ("control eyes") were normal at each observation time.
The eyes, treated with the test substance ("test eyes") were normal before the instillation.
After the instillation of the test substance, the following findings were made:
Cornea: A score of "1" from 1 h to 24 h p.a. in 1/3 animals. The affected area was one quarter to one half of the cornea. 25 % of the cornea were homogeneously stained after an additional examination by instillation of fluorescein 24 h p.a. This indicates a damage of the anterior corneal epithelium. 48 h p.a. the cornea was normal again.
The corneae of the other two animals were unaffected.
Iris: Not affected.
Conjunctivae, redness: A score of "1" from 1 h p.a. until a maximum of 72 h p.a. in all animals.
Conjunctivae, chemosis: Initial scores of "2" or "3" from 1 h p.a., degrading afterwards, until a maximum of 48 h p.a. in all animals.
Additional findings: Discharge with moistening of the lids and hairs just adjacent to the lids 1 h p.a. in 2/3 animals.

Other effects:

No other than ocular alterations were noted.

Applicant's summary and conclusion

Interpretation of results:

slightly irritating

Remarks:

Migrated information Criteria used for interpretation of results: not specified

Conclusions:

According to the results obtained and the criteria of CLP and of 67/548/EC, the substance is not classified as irritant.

Executive summary:

The possible irritating or corrosive effects of the substance, following a single administration into a conjunctival sac of rabbits, was investigated in conformance with the OECD-Guideline 405 and the Directive 92/69/EEC, method B.5.

Some alterations were noted but according to the criteria of CLP and of 67/548/EC, the substance is not classified as irritant.