Xylanase, endo-1,4-

Skin irritation / corrosion

Administrative data

Endpoint:

skin irritation: in vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

January 9, 2013 to March 25, 2013

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2013

Report date:

2013

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

OECD Guideline 404 (Acute Dermal Irritation / Corrosion)

Version / remarks:

2002

Deviations:

yes

Remarks:

The protocol requires that a single patch be applied to one animal and dose site be scored immediately after the 4-hour patch removal. Due to an oversight evaluation was also completed for 2nd and 3rd animal dosed. This has no impact on the study outcome.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Xylanase, endo-1,4-

EC Number:

232-800-2

EC Name:

Xylanase, endo-1,4-

Cas Number:

9025-57-4

Molecular formula:

Not applicable, see remarks.

IUPAC Name:

endo-1,4-beta-xylanase

Constituent 2

Reference substance name:

Protein as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available

IUPAC Name:

Protein as a constituent of enzyme deriving from the fermentation or extraction process

Constituent 3

Reference substance name:

Inorganic salts as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available.

IUPAC Name:

Inorganic salts as a constituent of enzyme deriving from the fermentation or extraction process

Constituent 4

Reference substance name:

Carbohydrates constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available.

IUPAC Name:

Carbohydrates constituent of enzyme deriving from the fermentation or extraction process

Constituent 5

Reference substance name:

Lipids as a constituent of enzyme deriving from the fermentation or extraction process

Molecular formula:

Not available.

IUPAC Name:

Lipids as a constituent of enzyme deriving from the fermentation or extraction process

Test material form:

liquid

Remarks:

Clear brown liquid

Details on test material:

- Substance type: UVCB
- Physical state: liquid
- pH: 4.98
-Specific Gravity: 1.05 g/mL
-Stability (XBU/g): Room Temperature (25°C) stable at 5 hours; % of T=0 was 100%; Refrigerated (4°C) stable at 7 days; % of T=0 was 98.7%; Freezer (-20°C) stable at 90 days; % of T=0 was 96.5%

Test animals

Species:

rabbit

Strain:

New Zealand White

Details on test animals or test system and environmental conditions:

TEST ANIMALS
- Source: Received from Robinson Services, Inc. Mocksville or Clemmons, NC on January 4 and 16, 2013.
- Age at study initiation: Young adult
- Housing: The animals were singly housed in suspended stainless steel caging with mesh floors which conform to the size recommendations in the most recent Guide for the Care and Use of Laboratory Animals (Natl. Res. Council, 2011). Enrichment (e.g. toy) was placed in each cage. Litter paper was placed beneath the cage and was changed at least three times per week.
- Diet (e.g. ad libitum): Harlan Teklad Global High Fiber Rabbit Diet® #2031. A designated amount of the diet was available to each rabbit (approximately 150 grams/day).
- Water (e.g. ad libitum): Filtered tap water was supplied ad libitum by an automatic water dispensing system.
- Acclimation period: 6 or 11 days

ENVIRONMENTAL CONDITIONS
- Temperature: 19-20ºC
- Humidity: 14-37%
- Photoperiod: 12-hour light/dark cycle

Test system

Type of coverage:

semiocclusive

Preparation of test site:

clipped

Vehicle:

unchanged (no vehicle)

Controls:

not required

Amount / concentration applied:

TEST MATERIAL
- Amount(s) applied (volume or weight with unit): 0.5mL of the test substance

Duration of treatment / exposure:

4 hours

Observation period:

Individual dose sites were scored according to the Draize scoring system immediately following patch removal, all animals were scored immediately after patch removal (small deviation, see below study design) and at approximately 30-60 minutes, 24, 48, and 72 hours after patch removal.

Number of animals:

3

Details on study design:

-Preparation and Selection of Animals:
Approximately 24 hours prior to application, the animals were prepared by clipping the dorsal area and the trunk. On the day of dosing, but prior to application, the animals were examined for health and the skin checked for any abnormalities. Three healthy naive animals (not previously tested) without pre-existing skin irritation were selected for test. Initially, only one rabbit was placed on test. Since no dermal irritation was observed at the dose site on this animal, the test was completed with two additional rabbits.

-Application of Test Substance:
0.5mL of the test substance was applied to one 6-cm2 intact dose site on each animal and covered with a 1-inch x 1-inch, 4-ply gauze pad. The pad and entire trunk of each animal were then wrapped with semi-occlusive 3-inch Micropore tape to avoid dislocation of the pad. Elizabethan collars were placed on each rabbit and they were returned to their designated cages. No other substances were tested on these rabbits. After 4 hours of exposure to the test substance, the pads and collars were removed and the test sites were gently cleansed of any residual test substance.

-Evaluation of Test Sites/Classification Scheme:
Individual dose sites were scored according to the Draize scoring system immediately following patch removal, all animals were scored immediately after patch removal and at approximately 30-60 minutes, 24, 48, and 72 hours after patch removal. The protocol requires that a single patch be applied to one animal and the dose site be scored immediately after the 4-hour patch removal. Due to a scientist oversight the evaluation was also completed for the second and third animal dosed. This deviation had no impact on the outcome of the study.

Results and discussion

In vivo

Results

Results 1

Irritation parameter:

erythema score

Basis:

animal: 1, 2, 3

Time point:

other: Mean of 24-, 48-, and 72-hour dermal responses

Score:

0

Max. score:

0

Results 2

Irritation parameter:

edema score

Basis:

animal: 1, 2, 3

Time point:

other: Mean of 24-, 48-, and 72-hour dermal responses

Score:

0

Max. score:

0

Irritant / corrosive response data:

There was no dermal irritation observed at any treated dose site during the study.

Other effects:

All animals appeared active and healthy and gained body weight during the study. There were no clinical signs observed.

Any other information on results incl. tables

 TABLE 1: INDIVIDUAL BODY WEIGHTS

Animal No.	Sex	Initial	Terminal
3501	F	2071	2161
3502	F	2068	2220
3503	F	2376	2448

 

TABLE 2: INDIVIDUAL SKIN IRRITATION SCORES (ERYTHEMA/EDEMA)

Animal No.	Sex	Time After Patch Removal
		Immediately after patch removal	30-60 mins	24 hrs	48 hrs	72 hrs
3501	F	0/0	0/0	0/0	0/0	0/0
3502	F	0/0	0/0	0/0	0/0	0/0
3503	F	0/0	0/0	0/0	0/0	0/0

TABLE 3: SUMMARY OF MEAN SCORES FOR DERMAL RESPONSES

RABBIT NUMBER	ERYTHEMA	EDEMA
3501	0.0	0.0
3502	0.0	0.0
3503	0.0	0.0
Calculated from the 24-, 48-, and 72-hour dermal responses (EEC/GHS)

Applicant's summary and conclusion

Interpretation of results:

GHS criteria not met

Conclusions:

Xylanase should not be classified as a skin-irritant.

Executive summary:

A primary skin irritation test was conducted with rabbits to determine the local skin irritant effect of the test substance. This study was conducted according to the method recommended in the OECD Guideline No. 404, April 2002.

Approximately 24 hours prior to application, all animals were prepared by clipping the dorsal area and the trunk. 0.5mL was applied to one 6 cm2 intact dose site and covered with 1 inch x 1 inch, 4-ply gauze pad. The pad and entire trunk of each animal were then wrapped with semi-occlusive tape. Collars were placed on each rabbit. After 4 hours of exposure, the pads and collars were removed and the test sites were cleansed of any residual test substance. The grade of skin reaction was scored according to the Draize’s scoring system immediately following patch removal and at 30-60 minutes, 24, 48 and 72 hours after patch removal. This study was conducted in a stepwise manner. Initially, 0.5mL of the test substance was applied to the skin of one rabbit for 4 hours. Since no dermal irritation was noted in this rabbit, a confirmatory test was completed with two additional healthy rabbits. No dermal irritation was observed at any dose site during the study.