Magnesium carbonate

Eye irritation

Administrative data

Endpoint:

eye irritation: in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

06 July 2010 to 08 July 2010

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study performed to accepted scientific standards

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2010

Report date:

2010

Materials and methods

Test guideline

Qualifier:

no guideline available

Principles of method if other than guideline:

The purpose of this study was to determine the eye irritation potential of the test material using the SkinEthic Reconstituted Human Corneal model (HCE, SkinEthic Laboratories, Nice, France) after a treatment period of 10 minutes. The test is based on the hypothesis that irritant chemicals are able to penetrate the corneal epithelial tissue and are sufficiently cytotoxic to cause cell death.

GLP compliance:

yes (incl. QA statement)

Test material

Test material information

Constituent 1

Reference substance name:

Magnesium carbonate

EC Number:

208-915-9

EC Name:

Magnesium carbonate

Cas Number:

546-93-0

Molecular formula:

CH2O3.Mg

IUPAC Name:

magnesium carbonate

Details on test material:

- Name of test material (as cited in study report): Magnesium Carbonate
- Physical state: white powder
- Lot No.: 078K0138
- Expiration date of the lot: 30 August 2013
- Storage condition of test material: room temperature in the dark

Test animals / tissue source

Species:

other: Reconstituted Corneal Epithelium

Test system

Amount / concentration applied:

TEST MATERIAL
- Amount applied: Tissues were treated with 30 mg of the test material.

VEHICLE
Test material was used as supplied

CONTROLS:
- Amount applied: 30 µL of Solution A was applied as a negative control and 30 µL of SDS 1.0% (w/v) as a positive control. Solution A was comprised of Na2HPO4 0.142 g/L, Glucose 1.802 g/L, HEPES 7.149 g/L, KCl 0.224 g/L and NaCl 7.597 g/L. Sodium Dodecyl Sulphate (SDS) was prepared as a 1% w/v solution in sterile distilled water.

Duration of treatment / exposure:

Cultures were exposed for 10 minutes to the test material.

Observation period (in vivo):

Skin cultures were examined after three hours.

Number of animals or in vitro replicates:

All test substances were tested in triplicate (including controls)

Results and discussion

In vivo

Results

Irritation parameter:

other: relative mean tissue viability

Basis:

mean

Time point:

other: 10 minutes

Score:

110.9

Remarks on result:

other: %

Irritant / corrosive response data:

The relative mean viability of the test material treated tissues after a 10 minute exposure was 110.9%.
It was considered unnecessary to proceed with tissue histopathology.

The test material and negative control material treated tissues appeared blue which was considered to be indicative of viable tissue. The positive control material treated tissues appeared blue/white which was considered to be indicative of semi viable tissue.

Any other information on results incl. tables

Table 1: Assessment of Eye Irritation Potential – Viability of RHC Tissues

Material	Mean Tissue Viability	Mean OD540	Relative Mean Viability (%)
Negative Control	0.898	0.918	100*
	0.937
Positive Control	0.331	0.294	32.0
	0.257
Test Material	0.988	1.018	110.9

*=      The mean viability of the negative control tissues is set at 100%

 

Table 2: Qualitative Evaluation of Tissue Viability (MTT uptake visual evaluation)

Material	Score
	Tissue 1	Tissue 2
Negative Control	-	-
Positive Control	+	+
Test Material	-	-

MTT Visual Scoring Scheme of SkinEthic Tissues

-     =  Blue tissue (viable)

+    =  Blue/White tissue (semi viable)

++  =  Tissue completely white (dead)

Applicant's summary and conclusion

Interpretation of results:

not irritating

Remarks:

Migrated information Criteria used for interpretation of results: EU

Conclusions:

According to the protocol followed, magnesium carbonate was considered to be a Non Irritant The quality criterion required for the acceptance of results in the test was satisfied.