(3-endo)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl methanesulfonate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

14 November 2003.

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

other: no test guidelines, in-house validated and GLP compliant

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2003

Report date:

2003

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

This test concerns an in-house validated method, GLP compliant
The standard test method for this study type (“General Study Plan” in OECD terminology) was reviewed for compliance once only on initial production. Inspection of the routine and repetitive procedures that constitute the study is carried out as a continuous process designed to encompass the major phases at or about the time this study was in progress.
This report has been audited by Safepharm Quality Assurance Unit, and is considered to be an accurate account of the data generated and of the procedures followed.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

(3-endo)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl methanesulfonate

EC Number:

700-367-3

Cas Number:

35130-97-3

Molecular formula:

C9 H17 N O3 S

IUPAC Name:

(3-endo)-8-methyl-8-azabicyclo[3.2.1]oct-3-yl methanesulfonate

Details on test material:

Sponsor's identification
:
SB-322065
Description
:
cream coloured solid with orange coloured pieces
Batch number
:
MTN-B-07C
Date received
:
12 November 2003
Storage conditions
:
room temperature in the dark

Test animals / tissue source

Species:

rabbit

Strain:

not specified

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent no treatment

Amount / concentration applied:

A volume of 0.1 ml of the test material, which was found to weigh approximately 92 mg (as measured by gently compacting the required volume into an adapted syringe)

Duration of treatment / exposure:

10 seconds

Observation period (in vivo):

Assessment of corneal cloudiness was made pre-enucleation, post equilibration and approximately 60, 120, 180 and 240 minutes following treatment, according to the numerical evaluation adopted from Advances in Modern Toxicology: Dermatoxicology, 4th Ed, (F Marzulli and H Maibach, eds) Hemisphere Publishing Corporation, Washington DC, 1991, pp 749-815.

Number of animals or in vitro replicates:

3 treated eyes and 2 control eyes

Details on study design:

Three eyes were treated with test material, two additional eyes remained untreated for control purposes. The treatment eye was removed from the superfusion apparatus whilst still being held in the perspex clamp. The clamp/eye was then placed horizontally into a petri dish.
A volume of 0.1 ml of the test material, which was found to weigh approximately 92 mg (as measured by gently compacting the required volume into an adapted syringe) was sprinkled as evenly as possible over the surface of the cornea. After ten seconds the test material was washed off the cornea using a minimum of 20 ml of saline solution (approximately 32°C).
Immediately following washing of the corneal surface, the treated eye was returned to the superfusion chamber and the saline drip repositioned to irrigate the eye. The untreated eyes were similarly washed and used for control purposes.

Assessment of corneal cloudiness was made pre-enucleation, post equilibration and approximately 60, 120, 180 and 240 minutes following treatment, according to the numerical evaluation given in Appendix 2 adopted from Advances in Modern Toxicology: Dermatoxicology, 4th Ed, (F Marzulli and H Maibach, eds) Hemisphere Publishing Corporation, Washington DC, 1991, pp 749-815.
Examination of the eye was facilitated by use of a slit-lamp biomicroscope. The thickness of the cornea was measured using an ultrasonic pachymeter. For each enucleated eye a measurement was made at the optical centre, and at a further four locations at the apex of the cornea. A mean value for corneal thickness was then calculated. Measurements for corneal thickness were carried out pre-enucleation, post equilibration and approximately 60, 120, 180 and 240 minutes following treatment. The condition of the corneal epithelium was assessed approximately 60, 120, 180 and 240 minutes following treatment. Assessment was facilitated by the use of the slit-lamp biomicroscope.

The uptake of fluorescein by the corneal epithelium was assessed pre-enucleation, post equilibration and approximately 240 minutes following treatment, according to the numerical evaluation given in Appendix 2. This was carried out using the cobalt blue filter of the slit-lamp biomicroscope, following application of Fluorescein Sodium drops.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

other: 1h, 2 h, 3h and 4h

Score:

>= 1 - <= 2

Max. score:

1

Reversibility:

not specified

Results 2

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

other: 1h, 2h, 3h and 4h

Score:

>= 1 - <= 2

Max. score:

2

Reversibility:

not specified

Results 3

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

other: 1h, 2h, 3h and 4h

Score:

>= 1 - <= 2

Max. score:

2

Reversibility:

not specified

Irritant / corrosive response data:

Corneal opacity: Some loss of transparency was noted in the test eyes 60, 120 and 180 minutes after dosing with moderate loss of transparency 240 minutes after dosing. No corneal effects were noted in the control eyes during the study period.

Corneal Thickness and Condition: Corneal swelling of the test eyes during the study period was considerably greater than that observed in the control eyes over the same period. Epithelial sloughing was noted on the cornea of all test eyes at all observations.
The condition of the corneal epithelium of the control eyes appeared normal at all observations.

Moderate fluorescein staining confined to a small focus was noted in all test eyes 240 minutes after treatment. No fluorescein uptake was noted in the control eyes 240 minutes after treatment.

Applicant's summary and conclusion

Interpretation of results:

highly irritating

Remarks:

Migrated information Criteria used for interpretation of results: other: REET parameter cut off values

Conclusions:

Following assessment of the data for all endpoints, the test material was considered to have the potential to cause severe ocular irritancy in vivo.