Zinc m-toluate

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Test according to state-of-the-art operating procedures for testing of metal bioelution.

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2015

Report date:

2015

Materials and methods

Objective of study:

bioaccessibility (or bioavailability)

Principles of method if other than guideline:

The release/dissolution of zinc from zinc oxide in artificial lysosomal fluid was measured. The resulting value is termed bio-accessibility, and is defined as the fraction of a substance that is soluble under physiological conditions and therefore potentially available for absorption into systemic circulation. The simulated lysosomal fluid represents an exposure-relevant exposure route (inhalation exposure.). The compound was introduced as powder in a test item / solution ratio of 2g/L during 24, 48 and 72 hours.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Zinc oxide

EC Number:

215-222-5

EC Name:

Zinc oxide

Cas Number:

1314-13-2

Molecular formula:

ZnO

IUPAC Name:

oxozinc

Test material form:

other: nanomaterial (coated)

Details on test material:

- Name of test material (as cited in study report): Z-COTE® HP1
- Physical state: white powder, solid, odourless
- non-flammable
- melting point: approx. 1970 °C
- density: 5.47g/cm3
- solubility in water: practically insoluble: 1.6 mg/L (21 °C); soluble in diluted mineral acids , solubility in M4 medium: 2.4 mg/l
- particle size <200 nm
- particle surface area of 12-24 m²/g
- Lot/batch No: NPL Ref#: ZB250#65
- Expiration date of the lot/batch: at least until June 2014

Radiolabelling:

no

Test animals

Details on test animals or test system and environmental conditions:

not applicable

Administration / exposure

Details on exposure:

not applicable

Results and discussion

Preliminary studies:

not applicable

Main ADME results

Type:

other: bioaccessibility

Results:

artificial lysosomal fluid (ALF) - as %Zn released of total Zn content: >90

Toxicokinetic / pharmacokinetic studies

Details on absorption:

not applicable

Details on distribution in tissues:

not applicable

Details on excretion:

not applicable

Bioaccessibility (or Bioavailability)

Bioaccessibility (or Bioavailability) testing results:

lysosomal bioaccessibility - as %Zn released of total Zn content: >90%

Any other information on results incl. tables

pH 4.5 artificial lysosomal fluid:

test item	%Zn released of total Zn content
blank	<0.01
Z-COTE HP1	>90
Z-COTE	>90
microscaled	>90

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): other: High bioaccessibility of Zn2+ from ZnO. The dissolution in artificial lysosomal fluid is used to estimate bioavailability after inhalation exposure
Bio-elution test according to state-of-the-art procedures, useful for determining dissolution capacity of Zn in artificial lysosomal fluid.

Executive summary:

During this study on ZnO in different forms (nano- (coated, non-coated) and microscaled ZnO) at a loading of 2 g/L in artificial lysosomal fluid (pH 4.5), it was shown that high amounts of zinc were measured. For nano ZnO, coated a zinc release of >90% was found.