1-amidino-2-thiourea

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

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:

1-amidino-2-thiourea

EC Number:

218-308-0

EC Name:

1-amidino-2-thiourea

Cas Number:

2114-02-5

Molecular formula:

C2H6N4S

IUPAC Name:

1-(Diaminomethylidene)thiourea

Test material form:

solid: crystalline

Specific details on test material used for the study:

Supplier: Changzou Foreign Trade Corp.Batch No.: 0041A25 (20141211)Physical state: Solid substance, crystalline powderColour: WhiteStorage: in a cool, dry place, protected from light

Test animals / tissue source

Species:

chicken

Strain:

other: COBB 500

Details on test animals or tissues and environmental conditions:

Source: TARAVIS KFT. Sárvár, HungaryHead collection was performed by a slaughter house technician. Heads were removed immediately after sedation of the chickens (sedation was happened by electric current). The heads were transported to TOXI-COOP ZRT. at the earliest convenience for use approximately within 2 hours from collection. The ambient temperature was optimal (20.1 ºC to 20.9 ºC) during the transport. All eyes used in the assay were from the same groups of eyes collected on one specific day.After collection, the heads were inspected for appropriate quality and wrapped with paper moistened with saline, then placed in a plastic box that can be closed (4-5 heads/box).After removing the head from the plastic box, it was put on soft paper. The eyelids were carefully cut away with scissors, avoiding damaging the cornea. One small drop of fluorescein solution 2 (w/v) % was applied onto the cornea surface for a few seconds and subsequently rinsed off with 20 mL isotonic saline. Then the fluorescein-treated cornea was examined with hand-held slit lamp or slit lamp microscope, with the eye in the head, to ensure that the cornea was not damaged. If the cornea was in good condition, the eyeball was carefully removed from the orbit.The eyeball was carefully removed from the orbit by holding the nictitating membrane with a surgical forceps, while cutting the eye muscles with bent scissors without cutting off the optical nerve too short. The procedure avoided pressure on the eye in order to prevent distortion of the cornea and subsequent corneal opacity. Once removed from the orbit, the eye was placed onto damp paper and the nictitating membrane was cut away with other connective tissue. The prepared eyes were kept on the wet papers in a closed box so that the appropriate humidity was maintained.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

AMIDINOTHIOUREA: 0.03 g/eyeImidazole (positive control): 0.03 g/eye

Duration of treatment / exposure:

After an exposure period of 10 seconds from the end of the application the cornea surface was rinsed thoroughly with 20 mL saline solution at ambient temperature.

Number of animals or in vitro replicates:

Three test item treated eyes and three positive control eyes were used in this study.

Details on study design:

After the zero reference measurements, one out of three test item treated eyes was taken out of its chamber and placed on a layer of tissue with the cornea facing upwards. The eye was held in horizontal position over a container to catch waste, while the test item was applied onto the centre of the cornea. The AMIDINOTHIOUREA was applied in an amount of 0.03 g by attempting to cover the cornea surface uniformly with the test substance, while taking care not to damage or touch the cornea with the application equipment. This procedure was repeated for each test item treated eyes.The three positive control eyes were treated in a similar way with 0.03 g Imidazole. One negative control eye was treated with saline solution. The saline solution was applied in a volume of 30 μL from micropipette, in such a way that the entire surface of the cornea was covered with negative control, taking care not to damage or touch the cornea with the application equipment.

Results and discussion

In vitro

Results

Remarks on result:

no indication of irritation

Other effects / acceptance of results:

In this in vitro eye irritation study using the isolated chicken eyes test with AMIDINOTHIOUREA, no ocular corrosion or severe irritation potential was observed. The test item was not a severe irritant.

Any other information on results incl. tables

Observation	Value	ICE Class
Mean maximum corneal swelling at up to 75 min	0 %	I
Mean maximum corneal swelling at up to 240 min	0 %	I
Mean maximum corneal opacity	0.5	I
Mean fluorescein retention	0.3	I
Other Observation	None

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

In this in vitro eye corrosives and severe irritants study, using the Isolated Chicken Eye model with AMIDINOTHIOUREA, no ocular corrosion or severe irritation potential was observed. According to the guideline OECD 438, AMIDINOTHIOUREA has been categorized as “No Category”.