Propyl 4-hydroxybenzoate

Eye irritation

Administrative data

Endpoint:

eye irritation: in 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:

2012

Report date:

2012

Materials and methods

Test guideline

Test guideline 1

Qualifier:

according to guideline

Guideline:

OECD Guideline 405 (Acute Eye Irritation / Corrosion)

Version / remarks:

adopted in 2002

Deviations:

no

Test guideline 2

Qualifier:

according to guideline

Guideline:

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

Deviations:

no

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Propyl 4-hydroxybenzoate

EC Number:

202-307-7

EC Name:

Propyl 4-hydroxybenzoate

Cas Number:

94-13-3

Molecular formula:

C10H12O3

IUPAC Name:

propyl 4-hydroxybenzoate

Details on test material:

Identification: Propylparaben
Alternative test item name: NIPASOL M (=Propylparaben)
Description: White crystalline powder

Test animals / tissue source

Species:

rabbit

Strain:

New Zealand White

Details on test animals or tissues and environmental conditions:

Test System:

Animals: Young Adult New Zealand White Rabbit, SPF
Rationale: Recognized by international guidelines as a recommended test system. An in vitro eye irritation study (CCR Study Number 1466000, Harlan Laboratories Study D48537, BCOP test) was performed and did not show any relevant effect.
Breeder: Harlan Laboratories U.K. Ltd., Hillcrest, Dodgeford Lane, Belton, Loughborough, Leics, LE12 9TE / UK
Number of Animals per Test: 3 males, nos. 1-3
Age (when treated): 15 - 16 weeks
Body Weight Range (when treated): 2434 - 2686 g
Identification: Unique cage number and corresponding ear number.
Randomization: Selected by hand at time of delivery. No computer generated randomization program.
Acclimatization: Under laboratory conditions after health examination. Only animals without any visual signs of illness were used for the study.

Husbandry:

Room Number: 137 / Harlan Laboratories Ltd., Itingen
Conditions: Standard laboratory conditions. The animal room was air-conditioned with 10 - 15 air changes per hour. The air was continuously monitored for temperature and relative humidity. The ranges for room temperature and relative humidity were 20 ± 3 °C and 30 - 70%, respectively. The animals were provided with an automatically controlled light cycle of 12 hours light and 12 hours dark. Music was played during the daytime light period.
Accommodation: Individually in stainless steel cages equipped with feed hoppers and drinking water bowls.
Diet: Pelleted standard Teklad Global High Fiber Rabbit Diet 2031C (batch no. 35/11, provided by Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) ad libitum. Results of analyses for contaminants will be archived at Harlan Laboratories Ltd. A piece of wood (batch no. 122201, imported by Indulab AG, Gams / Switzerland from ABEDD® - LAB & VET GmbH, 1160 Vienna / Austria) and a haystick 4642 (batch no. 45/11, Provimi Kliba AG, 4303 Kaiseraugst / Switzerland) will be provided for environmental enrichment.
Water: Community tap water from Itingen ad libitum in water bottles. Results of bacteriological, chemical and contaminant analyses are archived at Harlan Laboratories Ltd.

Test system

Vehicle:

unchanged (no vehicle)

Controls:

other: The right eye remained untreated and was used for control purposes.

Amount / concentration applied:

The test item was used as delivered by the Sponsor.

The test item was applied as a weight of 0.1 g/animal, the dose specified in the test guidelines for solid test items.

Observation period (in vivo):

Approximately 1 hour and 24, 48 and 72 hours as well as 7 days following treatment

Number of animals or in vitro replicates:

3 animals were tested in total. (After consideration of the ocular responses produced in the first treated animal, two additional animals were treated. )

Details on study design:

Test Item Administration:

The test item was applied as a weight of 0.1 g/animal, the dose specified in the test guidelines for solid test items.

The eyes of the animals were examined one day prior to test item administration.

On the day of treatment, the test item was applied with an eye glass to the conjunctival sac of the left eye of each animal 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 test item. The right eye remained untreated and served as the reference control. The treated eyes were not rinsed after instillation.

One animal was treated first. As neither a corrosive effect nor a severe irritant effect was observed after the 1- and 24-hour examinations, the test was completed using the two remaining animals.

Rationale: The application form and dose were used to detect an irritating potential of the test item applied.

Observations

Viability / Mortality: Daily
Clinical Signs: Daily
Eye Reactions: See below
Body Weights: At start of acclimatization, on test day 1 and at termination of observation.

Assessment of Eye Reactions:

The eye reactions were assessed according to the numerical scoring system listed in the Commission Regulation (EC) No 440/2008, B.5, at approximately 1, 24, 48 and 72 hours, as well as 7 days after administration. Scleral reddening and ocular discharge were also assessed. Eye examinations were made with a Varta Cliptrix diagnostic-lamp (Roth AG, 4153 Reinach / Switzerland)

Data was summarized in tabular form, showing for each animal the irritation scores for the designated observation time, a description of the degree and nature of irritation, the presence of serious lesions and non-ocular effects. The scores of each animal at the following reading times (24, 48, 72 hours) were used in calculating the respective mean values (with the exception of the sclerae) for each type of lesion.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

cornea opacity score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Results 2

Irritation parameter:

cornea opacity score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Results 3

Irritation parameter:

cornea opacity score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Results 4

Irritation parameter:

iris score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: reversibility: not applicable

Results 5

Irritation parameter:

iris score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

2

Reversibility:

other: reversibility: not applicable

Results 6

Irritation parameter:

iris score

Basis:

animal #3

Time point:

other: mean score over 24, 48 and 72 hours

Score:

0

Max. score:

2

Reversibility:

other: reversibility: not applicable

Results 7

Irritation parameter:

conjunctivae score

Basis:

animal #1

Time point:

24/48/72 h

Score:

1

Max. score:

3

Reversibility:

fully reversible within: 7 days

Results 8

Irritation parameter:

conjunctivae score

Basis:

animal #2

Time point:

24/48/72 h

Score:

2

Max. score:

3

Reversibility:

fully reversible within: 7 days

Results 9

Irritation parameter:

conjunctivae score

Basis:

animal #3

Time point:

24/48/72 h

Score:

1.67

Max. score:

3

Reversibility:

fully reversible within: 7 days

Results 10

Irritation parameter:

chemosis score

Basis:

animal #1

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Results 11

Irritation parameter:

chemosis score

Basis:

animal #2

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Results 12

Irritation parameter:

chemosis score

Basis:

animal #3

Time point:

24/48/72 h

Score:

0

Max. score:

4

Reversibility:

other: reversibility: not applicable

Irritant / corrosive response data:

The instillation of propylparaben into the eye resulted in mild, early-onset and transient ocular changes, such as reddening of the conjunctivae, sclerae and ocular discharge. These effects were reversible and were no longer evident 7 days after treatment, the end of the observation period for all animals. No abnormal findings were observed in the cornea or for the iris light reflex of any animals at any of the examinations. No corrosion was observed at any of the examinations. No staining of the treated eyes by the test item was observed. No test item remnants were observed in the treated eyes of any animal at any examination. No clinical signs were observed.

Thus, the test item did not induce significant or irreversible damage to the rabbit eye.

The mean score was calculated separately for each animal across three scoring times (24, 48 and 72 hours after instillation) for corneal opacity, iris light reflex, redness and chemosis of the conjunctivae, respectively. The individual mean scores for corneal opacity and iris light reflex were 0.00 for all three animals. The individual mean scores for the conjunctivae were 1.00, 2.00 and 1.67 for reddening and 0.00 for chemosis for all animals, respectively.

Other effects:

Viability / Mortality: No intercurrent deaths occurred during the course of the study.

Clinical Signs: No clinical signs were recorded throughout the entire observation period.

Body Weights: The body weight of the animals was within the range commonly recorded for this strain and age.

Any other information on results incl. tables

Table 1. Results of eye irritation study.

Rabbit #	Time [h]	conjunctivae		iris	cornea		conjunctivae		iris	cornea
		redness	swelling				redness	swelling
1	1	1	0	0	0
	24	1	0	0	0
	48	1	0	0	0
	72	1	0	0	0
	average	1.0	0	0	0	Time to reversion	7 d	0	0	0
2	1	1	0	0	0
	24	2	0	0	0
	48	2	0	0	0
	72	2	0	0	0
	average	2.0	0	0	0	Time to reversion	7 d	0	0	0
3	1	2	0	0	0
	24	2	0	0	0
	48	2	0	0	0
	72	1	0	0	0
	average	1.67	0	0	0	Time to reversion	7 d	0	0	0

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

Based upon the referred classification (Regulation (EC) No 1272/2008 of 16 December 2008), propylparaben is considered to be “not irritating” to the rabbit eye.

Executive summary:

The primary eye irritation potential of propylparaben was investigated according to OECD test guideline no. 405 and Commission Regulation 440/2008/EC. The test item was applied by instillation of 0.1 g into the left eye of each of three young adult New Zealand White rabbits. Scoring of irritation effects was performed approximately 1, 24, 48 and 72 hours, as well as 7 days after test item instillation.

 

The instillation of propylparaben into the eye resulted in mild, early-onset and transient ocular changes, such as reddening of the conjunctivae, sclerae and ocular discharge. These effects were reversible and were no longer evident 7 days after treatment, the end of the observation period for all animals. No abnormal findings were observed in the cornea or for the iris light reflex of any animals at any of the examinations. No corrosion was observed at any of the examinations. No staining of the treated eyes by the test item was observed. No test item remnants were observed in the treated eyes of any animal at any examination. No clinical signs were observed.

 

Thus, the test item did not induce significant or irreversible damage to the rabbit eye.

 

The mean score was calculated separately for each animal across three scoring times (24, 48 and 72 hours after instillation) for corneal opacity, iris light reflex, redness and chemosis of the conjunctivae, respectively. The individual mean scores for corneal opacity and iris light reflex were 0.00 for all three animals. The individual mean scores for the conjunctivae were 1.00, 2.00 and 1.67 for reddening and 0.00 for chemosis for all animals, respectively.

 

Based upon the referred classification criteria (Regulation (EC) No 1272/2008 of the European Parliament and of the Council of 16 December 2008), propylparabendoes not have to be classifiedwith respect to eye irritation in rabbits.