N,N-dimethyl-3-(trimethoxysilyl)propylamine

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

June - July 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2017

Report date:

2017

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 438 (Isolated Chicken Eye Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

N,N-dimethyl-3-(trimethoxysilyl)propylamine

EC Number:

219-786-3

EC Name:

N,N-dimethyl-3-(trimethoxysilyl)propylamine

Cas Number:

2530-86-1

Molecular formula:

C8H21NO3Si

IUPAC Name:

dimethyl[3-(trimethoxysilyl)propyl]amine

Test material form:

liquid

Details on test material:

- Name (as cited in the report): SAT 170001
- Chemical Name: N,N-dimethyl-3-(trimethoxysilyl)propylamine
- CAS No.: 2530-86-1
- Batch No.: 186020160504
- Aggregate State at RT: liquid
- Colour: colourless
- Storage Conditions: room temperature
- Expiry Date: 30.08.2017

Test animals / tissue source

Species:

chicken

Strain:

other: Ross

Details on test animals or tissues and environmental conditions:

Approximately 7 weeks old, male or female chickens (ROSS, spring chickens), body weight range approximately 1.5-2.5 kg, were used as eye donors. Heads of these animals were obtained from poultry slaughterhouse v.d. Bor, Nijkerkerveen, the Netherlands. Heads of the animals were cut off immediately after sedation of the animals by electric shock and incision of the neck for bleeding, and before they reached the next station on the process line. The heads were placed in small plastic boxes on a bedding of paper tissues moistened with isotonic saline. Next, they were transported to the testing facility. During transportation, the heads were kept at ambient temperature.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

30 µL

Duration of treatment / exposure:

10 s

Observation period (in vivo):

240 min

Number of animals or in vitro replicates:

3

Details on study design:

Within 2 hours after kill, eyes were carefully dissected and placed in a superfusion apparatus using the following procedure: First the eye-lids were carefully removed without damaging the cornea and a small drop of Fluorescein sodium 2.0% w/v (Minims, Chauvin, England) was applied to the corneal surface for a few seconds and subsequently rinsed off with isotonic saline at ambient temperature. Next, the head with the fluorescein-treated cornea was examined with a slit-lamp microscope (Slit-lamp.900 BP, Haag-Streit AG, Liebefeld-Bern, Switzerland) to ensure that the cornea was not damaged. If undamaged (e.g., fluorescein retention and corneal opacity scores of < 0.5), the eye was further dissected from the head without damaging the eye or cornea. Care was taken to remove the eye-ball from the orbit without cutting off the optical nerve too short.

The enucleated eye was placed in a stainless steel clamp with the cornea positioned vertically and transferred to a chamber of the superfusion apparatus (Triskelion, Zeist, the Netherlands. The clamp holding the eye was positioned in such a way that the entire cornea was supplied with isotonic saline from a bent, stainless steel tube, at a target rate of 0.10-0.15 mL/min (peristaltic pump set at speed 5.00, Watson-Marlow 205CA, Rotterdam, the Netherlands). The chambers of the superfusion apparatus as weil as the saline were
temperature controlled at approximately 32°C (water pump set at 36.4°C; Lauda 103, Germany).

After placing in the superfusion apparatus, the eyes were examined again with the slit-lamp microscope to ensure that they were not damaged. Corneal thickness was measured using the Depth Measuring Attachment No. I for the Haag-Streit slit-lamp microscope, set at 0.095 mm. Corneal thickness was expressed in instrument units. An accurate measurement was taken at the corneal apex of each eye. Eyes with a corneal thickness deviating more than 10% of the average corneal thickness of the eyes, eyes showing opacity (score higher than 0.5), or were unacceptably stained with fluorescein (score higher than 0.5) indicating the cornea to be permeable, or eyes that showed any other signs of damage, were rejected as test eyes and replaced.

Each eye provided its own baseline values for corneal swelling, corneal opacity and fluorescein retention. For that purpose, after an equilibration period of 45-60 minutes, the corneal thickness of the eyes was measured again to determine the zero reference value for corneal swelling calculations.
At time t = 0 (i.e. immediately after the zero reference measurement), the following procedure was applied for each test eye: The clamp holding the test eye was placed on paper tissues outside the chamber with the cornea facing upwards. Next, the eyes (corneas) were treated with the study substance for 10 seconds, followed by rinsing with 20 mL saline. After rinsing, each eye in the holder was returned to its chamber.

The eyes were examined at approximately 0, 30, 75, 120, 180 and 240 minutes after treatment, using the criteria and scoring system acc. to guideline. Fluorescein retention was only scored at approximately 30 minutes after treatment. All examinations were carried out with the slit-lamp microscope. After the final examination, the test substance treated eyes, the negative and positive control eyes were preserved in a neutral aqueous phosphate-buffered 4% solution of formaldehyde. The corneas were embedded in paraffin wax, sectioned at ca 4 µm and stained with PAS (Periodic Acid-Schiff). The microscopic slides were subjected to histopathological examination.

Results and discussion

In vitro

Results

Results 1

Irritation parameter:

cornea opacity score

Run / experiment:

Mean

Value:

3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

0.0 (ICE I)

Positive controls validity:

valid

Remarks:

3.0 (ICE IV)

Remarks on result:

other: ICE IV

Results 2

Irritation parameter:

fluorescein retention score

Run / experiment:

Mean

Value:

3

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

0.0 (ICE I)

Positive controls validity:

valid

Remarks:

3.0 (ICE IV)

Remarks on result:

other: ICE IV

Results 3

Irritation parameter:

percent corneal swelling

Run / experiment:

Mean

Value:

32

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Remarks:

0 (ICE I)

Positive controls validity:

valid

Remarks:

30 (ICE III)

Remarks on result:

other: ICE III

Any other information on results incl. tables

The test item caused corneal effects consisting of moderate or severe corneal swelling (mean of 32%), severe opacity (mean score of 3.0) and severe fluorescein retention (mean score of 3.0). In addition, Ioosening (veil-like) of the epithelium was observed.

The negative control eye did not show any corneal effect and demonstrated .that the general conditions during the tests were adequate.

The positive control BAC 5% caused severe corneal effects and demonstrated the ICE test valid to detect severe eye irritant.

Microscopic examination of the corneas treated with SAT 170001 revealed moderate or severe erosion, moderate necrosis and moderate vacuolation of the epithelium.

Microscopic examination of the cornea treated with the negative control (saline) did not reveal any abnormalities.

Microscopic examination of the corneas treated with the positive control BAC 5% generally revealed moderate erosion of the epithelium, the epithelium partly detached from the basal membrane and endothelial necrosis.

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye) based on GHS criteria

Conclusions:

Applying the classification criteria of the ICE, the following irritation classifications can be assigned :
Category 1: "Irreversible effects on the eye/serious damage to the eye " (UN-GHS and EU-CLP classifications).

Executive summary:

The test item was evaluated neat for eye irritation potential in the Isolated Chicken Eye (ICE) test. In addition, the test included a negative control (saline) and a positive control (BAC 5%). Chicken eyes were obtained from slaughter animals used for human consumption. The isolated chicken eyes were exposed to a single application of 30 µL of the test substance for 10 seconds followed by a 20 mL saline rinse. Three main parameters were measured to disclose possible adverse eye effects: corneal thickness (expressed as corneal swelling), corneal opacity and fluorescein retention of damaged epithelial cells. In addition, histopathology of the corneas was performed.

The test item caused corneal effects consisting of moderate or severe corneal swelling (mean of 32%), severe opacity (mean score of 3.0) and severe fluorescein retention (mean score of 3.0). In addition, Ioosening (veil-like) of the epithelium was observed. Microscopic examination of the corneas revealed moderate or severe erosion, moderate necrosis and moderate vacuolation of the epithelium.

The negative control eye did not show any corneal effect and demonstrated that the general conditions during the tests were adequate. Microscopic examination of the cornea did not reveal any abnormalities.

The positive control BAC 5% caused severe corneal effects and demonstrated the ICE test valid to detect severe eye irritants. Microscopic examination of the corneas qenerally revealed moderate erosion of the epithelium, the epithelium partly detached from the basal membrane and endothelial necrosis.

Applying the classification criteria of the ICE, the following irritation classifications can be assigned :

Category 1: "Irreversible effects on the eye/serious damage to the eye " (UN-GHS and EU-CLP classifications).