Piperidine, 4-(4-iodo-1H-pyrazol-1-yl)-

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

From 12 to 13 Jul 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Study run to a method comparable with current guidelines and to GLP

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guideline 437: "Bovine comeal opacity and permeablility (BCOP) test method for identifying ocular corrosives and severe irritants" (adopted September 07, 2009)

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

4-(4-iodo-1H-pyrazol-1-yl)piperidine

EC Number:

639-824-6

Cas Number:

1229457-94-6

Molecular formula:

C8H12IN3

IUPAC Name:

4-(4-iodo-1H-pyrazol-1-yl)piperidine

Details on test material:

- Purity: 99.7% area (GC)
- Batch No.: YN524101495106

Test animals / tissue source

Species:

other: cattle

Strain:

other: an isolated bovine cornea

Details on test animals or tissues and environmental conditions:

TEST ANIMALS
- Source: Bovine eyes from young cattle were obtained from the slaughterhouse, where the eyes were excised by a slaughterhouse employee as soon as possible after slaughter.
- Age at study initiation:
- Weight at study initiation:
- Housing:
- Diet (e.g. ad libitum):
- Water (e.g. ad libitum):
- Acclimation period: minimium of 1 hour

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 301.8 to 302.4 mg

Duration of treatment / exposure:

240±10 minutes

Observation period (in vivo):

Immediate opacity measurement and permeability evaluation of the cornea

Number of animals or in vitro replicates:

Three corneas for each treatment group (total 9 corneas)

Details on study design:

Negative control: Physiological saline
Positive control: 20% (w/v) Imidazole in physiological saline

Treatment of corneas and opacity measurements:
The medium from the anterior compartment was removed and 750 l of the negative control and 20% (w/v) Imidazole solution (positive control) were introduced onto the epithelium of the cornea. Three corneas were covered with 301.8 to 302.4 mg the test substance. The holder was slightly rotated, with the cornea maintained in a horizontal position, to ensure uniform distribution of the solutions over the entire cornea. Corneas were incubated in a horizontal position for 240±10 minutes at 32±1℃. After the incubation the solutions and the test compound were removed and the epithelium was washed at least three times with MEM with phenol red. Possible pH effects of the test substance on the corneas were recorded. The anterior and the posterior compartment were refilled with fresh cMEM and an opacity determination was performed without any further incubation. After the completion of the incubation period each cornea were inspected visually for dissimilar opacity patterns and the opacity determination was performed.

Opacity measurement:
The opacitometer determined the difference in the light transmission between each control or treated cornea and an air filled chamber. The numerical opacity value (arbitrary unit) was displayed and recorded. The change in opacity for each individual cornea (including the negative control) was calculated by subtracting the initial opacity reading from the final post treatment reading. The corrected opacity for each positive control or test substance treated cornea was calculated by subtracting the average change in opacity of the negative control corneas from the change in opacity of each positive control or test substance treated cornea. The mean opacity value of each treatment group was calculated by averaging the corrected opacity values of the treated corneas for each treatment group.

Application of sodium fluorescein:
Following the final opacity measurement, permeability of the cornea to Na-fluorescein (Merck) was evaluated.
The medium of both compartments (anterior compartment first) was removed. The posterior compartment was refilled with fresh cMEM. The anterior compartment was filled with 1 ml of 5 mg Na-fluorescein/ml cMEM solution. The holders were slightly rotated, with the corneas maintained in a horizontal position, to ensure uniform distribution of the sodium-fluorescein solution over the entire cornea. Corneas were incubated in a horizontal position for 90±5 minutes at 32±1℃.

Permeability determinations:
After the incubation period, the medium in the posterior compartment of each holder was removed and placed into a sampling tube labelled according to holder number. 360 l of the medium from each sampling tube was transferred to a 96-well plate. The optical density at 490 nm (OD490) of each sampling tube was measured in triplicate using a microplate reader. Any OD490 that was 1.500 or higher was diluted to bring the OD490 into the acceptable range (linearity up to OD490 of 1.500 was verified before the start of the experiment). OD490 values of less than 1.500 were used in the permeability calculation.
The mean OD490 for each treatment was calculated using cMEM corrected OD490 values. If a dilution was performed, the OD490 of each reading was corrected for the mean negative control OD490 before the dilution factor was applied to the readings.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

other: In vitro irritancy score

Basis:

mean

Time point:

other: 240±10 minutes

Score:

144

Results 2

Irritation parameter:

other: Opacity score

Basis:

mean

Time point:

other: 240±10 minutes

Score:

41

Results 3

Irritation parameter:

other: Permeability score

Basis:

mean

Time point:

other: 240±10 minutes

Score:

6.866

Any other information on results incl. tables

Summary of opacity, permeability and in vitro scores

Treatment	Mean Opacity	Mean Permeability	Mean In vitro Irritation^1,2
Negative control	0	0.000	0
Positive control	75	2.236	109
The test substance	41	6.866	144

1 Calculated using the negative control mean opacity and mean permeability values.

2 In vitro irritancy score (IVIS) = mean opacity value + (15 x mean OD490value).

Applicant's summary and conclusion

Interpretation of results:

Category 1 (irreversible effects on the eye)

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

It is concluded that the test substance is corrosive or severe irritant in the Bovine Corneal Opacity and Permeability test under the experimental conditions described in this report.