1-methyl-3-((methyl-λ2-azanyl)methyl)-1H-pyrazole-5-carbonitrile hydrochloride

Eye irritation

Administrative data

Endpoint:

eye irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

26 April 2016 to 11 May 2016

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2016

Report date:

2016

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

Organization for Economic Co-operation and Development (OECD), OECD Guidelines for Testing of Chemicals, Section 4, Health Effects, No.405, "Acute Eye Irritation / Corrosion", Paris, 2012.

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Version / remarks:

Commission Regulation (EC) No 440/2008 Part B: Methods for the Determination of Toxicity and other Health Effects; B5: "Acute Toxicity: Eye Irritation/Corrosion". Official Journal of the European Union No. L142, May 2008, including most recent amendments.

Deviations:

no

Test guideline 3

Qualifier:

according to guideline

Guideline:

EPA OPPTS 870.2400 (Acute Eye Irritation)

Version / remarks:

United States Environmental Protection Agency (EPA). Health Effects Test Guidelines, OPPTS 870.2400, Acute Eye Irritation. Office of Prevention, Pesticides and Toxic Items (7101), EPA 712-C-98-195, August 1998.

Deviations:

no

Test guideline 4

Qualifier:

according to guideline

Guideline:

other: JMAFF No 8147

Version / remarks:

Japanese Ministry of Agriculture, Forestry and Fisheries (JMAFF), 12 Nousan, Notification No 8147, November 2000; including the most recent partial revisions

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

1-methyl-3-[(methylamino)methyl]-1H-pyrazole-5-carbonitrile hydrochloride

EC Number:

943-430-2

Cas Number:

1643141-20-1

Molecular formula:

C7H10N4Cl

IUPAC Name:

1-methyl-3-[(methylamino)methyl]-1H-pyrazole-5-carbonitrile hydrochloride

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

Purity (by HPLC @ 225 nm) 100.0 % [a/a]

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Species Albino rabbit, New Zealand White, (SPF-Quality). Recognized by international guidelines as the recommended test system (e.g. EC, OECD)

Source: Charles River France, L’Arbresle, France

Number of animals 1 Male, 2 Females.

Age and body weight At start of dosing, the animals were between 9 and 23 weeks old and body weights were at least 1.5 kg.

Identification Earmark.

Health inspection At least prior to dosing. It was ensured that the animals were healthy and that the eyes were free from any abnormality.

6.3. Animal Husbandry
Conditions
Environmental controls for the animal room were set to maintain 18 to 24°C, a relative humidity of 40 to 70%, at least 10 air changes/hour, and a 12-hour light/12-hour dark cycle. Any variations to these conditions were maintained in the raw data and had no effect on the outcome of the study.

Accommodation
Animals were individually housed in labeled cages with perforated floors (Ebeco, Germany, dimensions 67 x 62 x 55 cm) and shelters (Ebeco, Germany, dimensions 40 x 32 x 23 cm). Acclimatization period was at least 5 days before start of treatment under laboratory conditions.

Diet
Pelleted diet for rabbits (Global Diet 2030 from Harlan Teklad®, Mucedola, Milanese, Italy) approximately 100 grams per day. Hay (TecniLab-BMI BV, Someren, The Netherlands) and wooden sticks (Swedish aspen wood, Bioservices, Uden, The Netherlands) were available during the study period.

Water
Free access to tap water.

Diet, water, bedding and cage enrichment evaluation for contaminants and/or nutrients was performed according to facility standard procedures. There were no findings that could interfere with the study.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

66.4 mg (range 66.2 – 66.5 mg) of the test item (a volume of approximately 0.1 mL)

Duration of treatment / exposure:

one second

Observation period (in vivo):

24-hour observation

Number of animals or in vitro replicates:

1 Male, 2 Females

Details on study design:

The study was performed in a stepwise manner and was started by treatment of a single rabbit (sentinel). The two other animals were treated in a similar manner two weeks later, after considering the degree of eye irritation observed in the first animal.

6.6. Preemptive Pain Management
One hour prior to instillation of the test item, buprenorphine (Buprenodale®, Dechra Ltd., Stoke-on-Trent, United Kingdom) 0.01 mg/kg was administered by subcutaneous injection in order to provide a therapeutic level of systemic analgesia. Five minutes prior to instillation of the test item, two drops of the topical anesthetic alcaine 0.5% (SA Alcon-Couvreur NV, Puurs, Belgium) were applied to both eyes.

6.7. Treatment
Animals were treated by instillation of, on average, 66.4 mg (range 66.2 – 66.5 mg) of the test item (a volume of approximately 0.1 mL), in the conjunctival sac of one of the eyes after gently pulling the lower lid away from the eyeball. The lids were then gently held together for about one second to prevent loss of the test item. The other eye remained untreated and served as the reference control.

Immediately after the 24-hour observation, a solution of 2% fluorescein (Merck, Darmstadt, Germany) in water (adjusted to pH 7.0) was instilled into both eyes of each animal to quantitatively determine corneal epithelial damage. Any bright green stained area, indicating epithelial damage, was estimated as a percentage of the total corneal area.

Immediately after fluorescein examination on Day 2, in order to provide a continued level of systemic analgesia, buprenorphine 0.01 mg/kg and meloxicam (Metacam®, Boehringer Vetmed GmbH, Ingelheim/Rhein, Germany) 0.5 mg/kg were administered by subcutaneous injection.

After the final observation, two of the animals were sacrificed by intra-venous injection of Euthasol® 20% (AST Farma BV, Oudewater, The Netherlands). The other animal was removed from the study alive.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

conjunctivae score

Basis:

mean

Time point:

24/48/72 h

Score:

1.3

Max. score:

2

Reversibility:

fully reversible within: 7 days

Remarks on result:

no indication of irritation

Results 2

Irritation parameter:

chemosis score

Basis:

mean

Time point:

24/48/72 h

Score:

0.3

Max. score:

2

Reversibility:

fully reversible within: 48 hours

Remarks on result:

no indication of irritation

Results 3

Irritation parameter:

cornea opacity score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Remarks on result:

no indication of irritation

Results 4

Irritation parameter:

iris score

Basis:

mean

Time point:

24/48/72 h

Score:

0

Max. score:

0

Reversibility:

fully reversible

Remarks on result:

no indication of irritation

Irritant / corrosive response data:

8.1. Irritation
Instillation of approximately 66 mg of PF-06478031-01 (a volume of approximately 0.1 mL) into one eye of each of three rabbits resulted in irritation of the conjunctivae, which consisted of redness, chemosis and discharge. The irritation had completely resolved within 7 Days after instillation in all animals.
No iridial irritation or corneal opacity were observed, and treatment of the eyes with 2% fluorescein 24 hours after test item instillation revealed no corneal epithelial damage.

8.2. Corrosion
There was no evidence of ocular corrosion.

Other effects:

8.3. Coloration / Remnants
No staining of (peri) ocular tissues by the test item was observed and no test item remnants were seen.

8.4. Toxicity / Mortality
No signs of systemic toxicity were observed in the animals during the test period and no mortality occurred.

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Based on these results, PF-06478031-01 does not have to be classified and has no obligatory labelling requirement for eye irritation according to the:
- Globally Harmonized System of Classification and Labelling of Chemicals (GHS) of the United Nations (2015) (including all amendments),
- Regulation (EC) No 1272/2008 on classification, labelling and packaging of items and mixtures (including all amendments).