Pentyl D-glucoside

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

weight of evidence

Study period:

03 Feb 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

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying i) Chemicals Inducing Serious Eye Damage and ii) Chemicals Not Requiring Classification for Eye Irritation or Serious Eye Damage)

Version / remarks:

26 July 2013

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

EU method B.47 (Bovine corneal opacity and permeability test method for identifying ocular corrosives and severe irritants)

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

THE DEPARTMENT OF HEALTH OF THE GOVERNMENT OF THE UNITED KINGDOM, Medicines & Healthcare products Regulatory Agency

Test material

Test material information

Constituent 1

Reference substance name:

Pentyl D-glucoside

EC Number:

309-363-2

EC Name:

Pentyl D-glucoside

Cas Number:

100231-63-8

Molecular formula:

(C6H10O5)nC5H12O, n - number of D-glucopyranose units

IUPAC Name:

(2R,3S,4S,5R,6R)-2-(hydroxymethyl)-6-{[(2R,3S,4S,5R,6R)-3,4,5-trihydroxy-6-(pentyloxy)oxan-2-yl]methoxy}oxane-3,4,5-triol; (2S,3R,4R,5S,6S)-2-(hydroxymethyl)-6-(pentyloxy)oxane-3,4,5-triol

Test animals / tissue source

Species:

cattle

Strain:

not specified

Details on test animals or tissues and environmental conditions:

SOURCE OF COLLECTED EYES
- Source: local abattoir
- Characteristics of donor animals: adult animals (typically 12 to 60 months old)
- Storage, temperature and transport conditions of ocular tissue (e.g. transport time, transport media and temperature, and other conditions): Isolated eyes were stored in Hanks’ Balanced Salt Solution (HBSS) supplemented with antibiotics (penicillin at 100 IU/mL and streptomycin at 100 μg/mL). They were transported to the test facility over ice packs on the same day of slaughter.
- Time interval prior to initiating testing: The corneas were refrigerated on arrival and used within 24 hours of receipt.
- indication of any existing defects or lesions in ocular tissue samples: All eyes were macroscopically examined before and after dissection. Only corneas free of damage were used.
- Indication of any antibiotics used: penicillin at 100 IU/mL and streptomycin at 100 μg/mL

Test system

Vehicle:

unchanged (no vehicle)

Controls:

yes, concurrent positive control

yes, concurrent negative control

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied: 0.75 mL

NEGATIVE CONTROL
- Amount(s) applied: 0.75 mL

POSITIVE CONTROL
- Amount(s) applied: 0.75 mL
- Purity: > 99.8%

Duration of treatment / exposure:

10 min at 32 ± 1 °C

Duration of post- treatment incubation (in vitro):

120 min at 32 ± 1 °C

Number of animals or in vitro replicates:

triplicates for each treatment and control groups

Details on study design:

SELECTION AND PREPARATION OF CORNEAS
The cornea from each selected eye was removed leaving a 2 to 3 mm rim of sclera to facilitate handling. The iris and lens were peeled away from the cornea. The isolated corneas were immersed in a dish containing Hanks’ Balanced Salt Solution (HBSS) until they were mounted in special BCOP holders. The anterior and posterior chambers of each BCOP holder were filled with complete Eagle’s Minimum Essential Medium (EMEM) without phenol red and plugged. The holders were incubated at 32 ± 1 ºC for 60 minutes.

QUALITY CHECK OF THE ISOLATED CORNEAS
At the end of the incubation period each cornea was examined for defects. Only corneas free of damage were used. A pre-treatment opacity reading was taken for each cornea using a calibrated opacitometer. The average opacity for all corneas was calculated. Three corneas with opacity values close to the median value of all corneas were allocated to the negative and positive control as well as to the test item.

APPLICATION DOSE AND EXPOSURE TIME
The EMEM was removed from the anterior chamber of the BCOP holder and 0.75 mL of the test item or control items were applied to the appropriate corneas. The holders were gently tilted back and forth to ensure a uniform application of the item over the entire cornea. Each holder was incubated, anterior chamber uppermost, at 32 ± 1 ºC for 10 minutes.

REMOVAL OF TEST SUBSTANCE
- Number of washing steps after exposure period: 4
- POST-EXPOSURE INCUBATION: Test item and control items were removed from the anterior chamber and the cornea was rinsed three times with fresh complete EMEM containing phenol red before a final rinse with complete EMEM without phenol red. The anterior chamber was refilled with fresh complete EMEM without phenol red. The holders were incubated, anterior chamber facing forward, at 32 ± 1 ºC for 120 minutes.

METHODS FOR MEASURED ENDPOINTS:
- Corneal opacity: The change in opacity for each cornea was calculated by subtracting the initial opacity reading from the final opacity reading. These values were then corrected by subtracting the average change in opacity observed for the negative control corneas. The mean opacity value of each treatment group was then calculated by averaging the corrected opacity values of each cornea for that treatment group.
- Corneal permeability: passage of sodium fluorescein dye measured with the aid of Anthos 2001 microplate reader (OD492)

SCORING SYSTEM: In Vitro Irritancy Score (IVIS) :
In Vitro Irritancy Score (IVIS) = mean opacity value + (15 x mean permeability OD492 value)

DECISION CRITERIA:
Test substance with an IVIS > 55 was regarded as severe irritant/corrosive and labelled Category 1.
Test substance with an IVIS ≤ 3 was regarded as non-irritant and labelled in no category.
Test substance with an IVIS > 3; ≤ 55: no prediction can be made.

Results and discussion

In vitro

Results

Irritation parameter:

in vitro irritation score

Value:

21.4

Vehicle controls validity:

not applicable

Negative controls validity:

valid

Positive controls validity:

valid

Other effects / acceptance of results:

OTHER EFFECTS:
The corneas treated with the test item were cloudy post treatment and post incubation. The corneas treated with the negative control item were clear post treatment and post incubation. The corneas treated with the positive control item were cloudy post treatment and post incubation.

ACCEPTANCE OF RESULTS:
- Acceptance criteria met for negative control: yes, opacity = 2.7, permeability = 0.030 (criterion: opacity ≤ 2.8 and permeability ≤ 0.115)
- Acceptance criteria met for positive control: yes, IVIS = 43.3 (criterion: IVIS within two standard deviations of the historical mean collated during 2015 for this testing facility [IVIS 27.2 to 53.4])

Any other information on results incl. tables

 

Table 1: Individual and Mean Corneal Opacity and Permeability Measurements

Treatment	Cornea number	Opacity					Permeability (OD)		In Vitro Irritancy Score (IVIS)
		Pre-Treatment	Post-Treatment	Post-Incubation	Post-Incubation – Post-Treatment	Corrected value		Corrected value
Negative control	10	3	4	6	3		0.052
	12	4	5	6	2		0.016
	14	4	4	7	3		0.021
					2.7*		0.030**		3.1
Positive control	11	2	25	29	27	24.3	1.336	1.306
	13	5	28	31	26	23.3	1.319	1.289
	15	2	31	30	28	25.3	1.256	1.226
						24.3***		1.274***	43.4
Test item	16	5	16	22	17	14.3	0.798	0.768
	17	5	16	21	16	13.3	0.418	0.388
	18	3	14	18	15	12.3	0.480	0.450
						13.3***		0.536***	21.4

 

OD = Optical density

*: Mean of the post-incubation – pre-treatment values

**: Mean permeability

***: Mean corrected value

 

Applicant's summary and conclusion

Interpretation of results:

other: no prediction of eye irritation can be made

Conclusions:

Under the conditions of this in vitro Bovine Corneal Opacity and Permeability Test (BCOP), the test item caused an increase of the corneal opacity and of the permeability above the values characteristic for substances not requiring classification as eye irritants according to the criteria of Regulation (EC) No. 1272/2006 (CLP). The calculated mean in vitro irritancy score (IVIS) was 21.4. However, the values determined are not sufficiently high to indicate the test item to cause serious eye damage. In conclusion, no prediction of the eye irritation potential of the test item can be made and further data are required.

The test item was shown to have an irritating or corrosive potential towards reconstructed human epidermis tissue. Moreover, in a Bovine Corneal Opacity and Permeability Test capable of identifying substances that can induce serious eye damage and substances not requiring classification for eye irritation or serious eye damage, no prediction could be made for the registered substance. In conclusion, accounting for both in vitro investigations in a Weight-of-Evidence approach, the registered substance is considered to meet the criteria for classification as Eye Irrit. 2, H319, according to the CLP Regulation (EC) No. 1272/2008.