Ethyl 2-methylbutyrate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

08 May to 16 May 2000

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2000

Report date:

2000

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:

Ethyl 2-methylbutyrate

EC Number:

231-225-4

EC Name:

Ethyl 2-methylbutyrate

Cas Number:

7452-79-1

Molecular formula:

C7H14O2

IUPAC Name:

ethyl 2-methylbutanoate

Constituent 2

Reference substance name:

Ethyl Methylbutyrate-2

IUPAC Name:

Ethyl Methylbutyrate-2

Constituent 3

Reference substance name:

Ethyl-2-methylbutyrate

IUPAC Name:

Ethyl-2-methylbutyrate

Test material form:

other: liquid

Details on test material:

- Name of test material (as cited in study report): Ethyl Methylbutyrate-2
- Physical state: Colourless to slight yellowish, liquid
- Analytical purity: 99.4%
- Lot/batch No.: 20010036
- Stability: 360 days
- Storage condition of test material: cool and dry
- Other:
- Test concentration: undiluted
- Arrival of test article: 17/4/2000

Test animals / tissue source

Species:

rabbit

Strain:

other: SPF Albino rabbits of stock Chbb:HM (SPF) – Littlerussian

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: BI Pharma KG, 88397 Biberach
- Age at study initiation: No details provided in report
- Weight at study initiation: 1.9 - 2.1 kg bw
- Housing: During a pre-period of at least one week and throughout the experiment the rabbits were caged individually in PPO cages (floor area: 2576 sq.cm) with perforated floor.
- Diet (e.g. ad libitum): A pelleted complete rabbit diet “Altroimin 2123” from Altromin, D-32791 Lage, Lippe, was available ad libiturn. Analyses for major nutritive components and relevant possible contaminants are performed regularly on the diet. Certificates of analysis are retained.
- Water (e.g. ad libitum): The animals had free access to bottles with domestic quality drinking water acidified with hydrochloric acid to pH 2.5 in order to prevent microbial growth. Analyses for relevant possible contaminants are performed regularly. Certificates of analysis are retained.

ENVIRONMENTAL CONDITIONS
The study took place in animal room No. 6 provided with filtered air at the following conditions:
- Temperature (°C): 20 ± 3
- Humidity (%): 55 ± 15
- Air changes (per hr): 10
- Photoperiod (hrs dark / hrs light): 12 hours light and 12 hours darkness. Light was on from 6 am to 6 pm

Test system

Vehicle:

not specified

Controls:

other: The untreated right eye

Amount / concentration applied:

0.1 ml

Duration of treatment / exposure:

24 hours

Observation period (in vivo):

7 days

Number of animals or in vitro replicates:

4 female (The study was initiated with one rabbit. Since no marked eye irritation was seen in this animal another three rabbits were included in the study with time difference).

Details on study design:

REMOVAL OF TEST SUBSTANCE
- Washing (if done): The eyes were examined and the grade of ocular reaction was recorded one hour and 24 hours later. After the first 24 hour reading Fluorescein was instilled. After rinsing with 20 ml 0.9% sodium chloride solution the eyes were examined again using UV-light to detect possible corneal damage.
- Time after start of exposure: 24 hours

SCORING SYSTEM: See attached report for details

TOOL USED TO ASSESS SCORE: The day before testing both eyes of the animals were examined with a hand held inspection lamp fitted with white and UV light and magnifying glass with, 2 x magnification to ensure there were no defects or irritation. The examination was performed before and after instillation of Fluorescein.

The eyes were examined and the grade of ocular reaction was recorded one hour and 24 hours later. After the first 24 hour reading Fluorescein was instilled. After rinsing with 20 ml 0.9% sodium chloride solution the eyes were examined again using UV-light to detect possible corneal damage.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Reversibility:

fully reversible within: 7 days

Results 2

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Reversibility:

fully reversible within: 7 days

Results 3

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

1.1

Reversibility:

fully reversible within: 7 days

Results 4

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0.8

Reversibility:

fully reversible within: 7 days

Any other information on results incl. tables

See Table 1 of attached report for individual results.

- One hour after application of the test article animals No. 1770 and No. 1773 showed a diffuse, crimson red conjunctiva with individual vessels not easily discernible, an obvious swelling with partial eversion of lids and a discharge with moistening of the lids and hairs just adjacent to lids in animals No. 1771 and No. 1772 were observed a diffuse, crimson red conjunctiva with individual vessels not easily discernible, an obvious swelling with partial eversion of lids and a discharge different from normal.

 

- 24 hours after application of the test article animals No. 1770 and No. 1772 showed some conjunctival vessels definitely injected and a swelling above normal. In animal No. 1771 were observed a diffuse, crimson red conjunctiva with individual vessels not easily discernible as well as an obvious swelling with partial eversion of lids. Animal No. 1773 showed a diffuse, crimson red conjunctiva with individual vessels not easily discernible as well as a swelling above normal.

 

- 48 hours after application of the test article in animals No. 1770 and No. 1771 were observed some conjunctival vessels definitely injected and a swelling above normal. Animals No 1772 and No. 1773 showed some conjunctival vessels definitely injected.

 

- 72 hours after application of the test article in animals No. 1770 and No. 1773 were observed some conjunctival vessels definitely. Animal No. 1771 showed some conjunctival vessels definitely injected and a swelling above normal. In animal No. 1772 was observed a conjunctival swelling above normal.

 

- 7 days after application of the test article all four animals were free of any signs of eye irritation.

 

The following mean values were obtained from the data presented in Table 1 of attached report:

 

cornea opacity         0.0

iris lesion                  0.0

redness of conjunctiva   1.1

oedema of conjunctiva (chemosis) 0.8

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

According to the directive of the EEC commission 93/21/EEC of May 4, 1993 ETHYL METHYLBUTYRATE-2, Batch No 20010036, shall not be classified as eye irritating.

Executive summary:

The local effect of ETHYL METHYLBUTYRATE-2 was investigated according to the method recommended in the OECD Guideline No. 405, “Acute Eye Irritation/Corrosion”, Feb. 1987, and EEC Guideline B.5 “Acute Toxicity (Eye irritation)”, Jan. 1997.

Four female albino rabbits were exposed to 0.1 ml of the test article in the left eye. The eyes were examined and the changes were graded according to a numerical scale one hour, 24, 48 and 72 hours as well as 7 days after dosing.

 

Slight to well-defined signs of irritation were observed on the treated eyes. All effects were fully reversible within 7 days.

 

The following mean values, based on the results from the 24, 48 and 72 hour readings, were calculated:

 

Animal No. Cornea opacity Iris lesion Redness of conjunctiva Oedema of conjunctiva

1770 0.00 0.00 1.00 0.67

1771 0.00 0.00 1.33 1.33

1772 0.00 0.00 0.67 0.67

1773 0.00 0.00 1.33 0.33

 

According to the directive of the EEC commission 93/21/EEC of May 4, 1993 ETHYL METHYLBUTYRATE-2, Batch No. 20010036, shall not be classified as eye irritating.