Reaction mass of hexadecyl dihydrogen phosphate and dihexadecyl hydrogen phosphate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2012-02-27 to 2012-06-04

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2012

Report date:

2012

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

other: OECD Guidline 437 (Bovine Corneal Opacity and Permeability Test Method for Identifying Ocular Corrosives and Severe Irritants), adopted: 7 September 2009

Deviations:

no

GLP compliance:

yes (incl. QA statement)

Remarks:

Bayerisches Landesamt für Gesundheit und dLebensmittelsicherheit, München, Germany)

Test material

Test material information

Constituent 1

Reference substance name:

Hexadecyl dihydrogen phosphate

EC Number:

222-581-1

EC Name:

Hexadecyl dihydrogen phosphate

Cas Number:

3539-43-3

Molecular formula:

C16H35O4P

IUPAC Name:

hexadecyl dihydrogen phosphate

Test system

Vehicle:

physiological saline

Amount / concentration applied:

The test item was diluted with physiological saline 0.9% NaCl to gain a 20% concentration.

Duration of treatment / exposure:

750 microL of the test item preparation or the control substance was introduced into the anterior chamber (closed-chamber method).
After 4 hours ± 5 minutes incubation at 32 +/- 1 °C either the test substance or the control substance was removed.

Details on study design:

Test System

Preparation of the Corneas:
The assay uses isolated corneas obtained as a by-product from an abattoir from freshly slaughtered animals
(from Attenberger Fleisch GmbH & Co. KG).
On the test day, fresh eyes were collected from the slautherhouse and were transported in HBSS containing Pen/Strep
on ice to the laboratories. Immediately after arrival of the eyes, cornea preparation was initiated.
The eyes were carefully examined for defects and any defective eyes were discarded.
The tissue surrounding the eyeball was carefully pulled away and the cornea was excised leaving a 2 to 3 mm rim of sclera.
The isolated corneas were stored in a petri dish containing HBSS. Before the corneas were mounted in corneal holders
(MC2, Clermont, France) with the endothelial side against the O-ring of the posterior chamber, they had been visually
examined for defects and any defective cornea had been discarded. The anterior chamber was then positioned on top
of the cornea and tightened with screws. The chambers of the corneal holder were then filled with RPMI (without phenol red)
containing 1% FBS and 2 mM L-glutamine (complete RPMI). The posterior chamber was always filled first. The corneas were
incubated for one hour at 32 +/- 1 °C in a water bath.

Calibration of the Opacitometer:
The opacitometer had been switched on 15 min before the calibration procedure was started. Empty cornea holders were
placed into the opacitometer and the readout was adjusted to zero using the “BAL”-turning knob. For calibration the polyester
foil no. 1 was introduced into the test chamber and the readout was adjusted to 75 using the “CAL”-turning knob.
To test the linearity of the measurement, two additional calibration foils, polyester foil no. 2 and polyester foil no. 3,
were measured. For these, the opacitometer was supposed to display 150 and 225, respectively (± 3%).
If this had not been the case, the calibration procedure would have had to be repeated. The calibration procedure
was performed before each test and was documented in the raw data.

Treatment of the Corneas:
After the equilibration period, the medium was removed from both chambers and replaced with fresh Complete RPMI.
An initial opacity measurement was performed on each of the corneas using an opacitometer (MC2, Clermont, France).
Three corneas with opacity readings approximately equivalent to the median opacity of all corneas were selected
as negative-control corneas. The opacity of each cornea was read against an air-filled chamber and recorded.
Corneas that have an initial opacity reading above 7 units were not dosed. The medium was removed from the anterior
chamber and replaced with the test item or control.
750 microL of the test item preparation or the control substance was introduced into the anterior chamber (closed-chamber method).
After 4 hours ± 5 minutes incubation at 32 +/- 1 °C either the test substance or the control substance was removed
and the epithelium washed at least three times with MEM (containing phenol red). Once the medium was free of test substance,
the cornea was finally rinsed with complete RPMI (without phenol red). The anterior chamber was refilled with complete RPMI
and an opacity measurement was performed.
After the opacity measurement the medium was removed from both chambers of the holder. The posterior chamber was
refilled with fresh complete RPMI. 1 mL of a 5 mg/mL sodium fluorescein solution was added to the anterior chamber and
the corneas were incubated for 90 minutes at 32 +/- 1 °C. Then the medium from the posterior chamber was removed and
its optical density at 490 nm (OD490) was determined, using a spectrophotometer.

Test Groups:
3 corneas for the test item
3 corneas as negative controls treated with physiological saline 0.9% NaCl
3 corneas as positive control treated with imidazole 20% in physiological saline 0.9% NaCl
The BCOP assay is considered to be valid if the in vitro score obtained with the positive control falls within the two
standard deviations of the current historical mean.

Evaluation of Results:
The change in opacity for each cornea was calculated by subtracting the initial opacity reading from the final opacity reading.
These values were corrected by subtracting from each the average change in opacity observed for the negative-control corneas.
The mean opacity value for each treatment was calculated by averaging the corrected opacity values of each cornea for a given treatment.
The mean OD490 for the blank wells were calculated. The mean blank OD490 was subtracted from the OD490 of
each well (corrected OD490). Any dilutions that were made to bring the OD490 values into the linear range of the s
pectrophotometer (OD490 should be less than 1.500), were taken into account by multiplying the OD490 value of
the dilution by the dilution factor. The final-corrected OD490 of the test article and the positive control were calculated
by subtracting the average corrected OD490 of the negative control corneas from the corrected OD490 value of each treated cornea:
Final-corrected OD490 = (OD490 – mean blank OD490) – average-corrected negative control OD490
The mean OD490 value of each treatment group was calculated by averaging the final corrected OD490 values of the
treated corneas for that treatment condition.
The following formula was used to determine the in vitro score:
In vitro score = mean opacity value + (15 x mean OD490 value)

Results and discussion

In vivo

Results

Irritation parameter:

other: in vitro irritation score (IVIS)

Basis:

mean

Score:

130.92

Irritant / corrosive response data:

The eye irritancy potential of the test item was investigated in the bovine corneal opacity and permeability assay.
The test item was diluted with physiological saline 0.9% NaCl to gain a 20% concentration.

The following mean in vitro score was calculated: 130.92
Therefore the test item was classified as very severe irritant.

The in vitro score obtained with the positive control fell within the two standard deviations of the current historical mean and
therefore this assay is considered to be valid.

Any other information on results incl. tables

Opazität
Cornea-No.	Test Item	Opacity	Opacity	Change of	Corrected
		blank value	post dose	opacity values	opacity values
1	Negative	3	3	0
2	Control	3	2	-1
3		3	2	-1
MV		3.00	2.33	-0.67
4	Positive	2	222	220	220.67
5	Control	2	194	192	192.67
6		3	210	207	207.67
MV		2.33	208.67	206.33	207.00
7	Test item	2	139	137	137.67
8		2	123	121	121.67
9		2	136	134	134.67
MV		2.00	132.67	130.67	131.33

Permaebilität
Cornea-No.	Test Item	OD490	Corrected
			OD490 values
1	Negative	0.098
2	Control	0.005
3		0.015
MV		0.039
4	Positive	2.090	2.051
5	Control	2.069	2.030
6		2.062	2.023
MV		2.074	2.034
7	Test item	0.014	-0.025
8		0.008	-0.031
9		0.013	-0.026
MV		0.012	-0.028

in vitroScore
Cornea-No.	Test Item	Corrected	Corrected	in vitro
		opacity value	OD490 value	Score
1	Negative	0	0.098
2	Control	-1	0.005
3		-1	0.015
MV		-0.67	0.039	-0.08
4	Positive	220.67	2.051
5	Control	192.67	2.030
6		207.67	2.023
MV		207.00	2.034	237.52
7	Test item	137.67	-0.025
8		121.67	-0.031
9		134.67	-0.026
MV		131.33	-0.028	130.92

Applicant's summary and conclusion

Interpretation of results:

highly irritating

Remarks:

Migrated information Criteria used for interpretation of results: OECD GHS

Conclusions:

According to the evaluation criteria the test item is classified as very severe eye irritant.

Executive summary:

The eye irritancy potential of the test item was investigated in the bovine corneal opacity and permeability assay.

Preparation of the test item: diluted with physiological saline 0.9% NaCl to gain a 20% concentration.

Meanin vitroscore: 130.92

Classification:                         

X	very severe irritant

 

Thein vitroscore obtained with the positive control fell within the two standard deviations of the current historical mean

and therefore this assay is considered to be valid.

Conclusion

According to the evaluation criteria the test item is classified as very severe eye irritant.