Indium

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:

test procedure in accordance with generally accepted scientific standards and described in sufficient detail

Remarks:

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

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2014

Report date:

2014

Materials and methods

Objective of study:

bioaccessibility (or bioavailability)

Test guideline

Qualifier:

according to guideline

Guideline:

other: ASTM D5517-07: Standard Test Method for determining the extractability of metals from art materials - ASTM, 2007 (American Society for Testing and Materials).

Principles of method if other than guideline:

The release/dissolution of indium from indium in simulated gastric 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 gastric fluid represents an exposure-relevant exposure route (oral exposure). The compound was introduced as powder in a test item / solution ratio of 200 mg/L during 2 hours.

GLP compliance:

yes

Test material

Test material information

Constituent 1

Reference substance name:

Zinc chloride

EC Number:

231-592-0

EC Name:

Zinc chloride

Cas Number:

7646-85-7

Molecular formula:

ZnCl2

IUPAC Name:

Zinc dichloride

Test material form:

other: shot

Details on test material:

- Product name: indium shot
- Physical state: solid (powder), silver grey
- Purity: 99.99%
- Lot/batch No.: F10164
- Expiration date of the lot/batch: stable over time
- Storage condition of test material: room temperature, in the dark
- Particle size (typical): <100μm after milling and sieving
- Relative densitiy: 7.31 g/cm³

Test animals

Details on test animals or test system and environmental conditions:

not applicable

Results and discussion

Preliminary studies:

not applicable

Main ADME results

Type:

other: bioaccessibility

Results:

gastric fluid (2hours): as %In released of total In content: 9.3

Toxicokinetic / pharmacokinetic studies

Details on absorption:

not applicable

Details on distribution in tissues:

not applicable

Details on excretion:

not applicable

Metabolite characterisation studies

Metabolites identified:

not measured

Details on metabolites:

not applicable

Bioaccessibility (or Bioavailability)

Bioaccessibility (or Bioavailability) testing results:

gastric fluid (2hours): as %In released of total In content: 9.3

Any other information on results incl. tables

Indium, loading 0.2 g/L              2h gastric at pH 1.5
Analyte                                                              X±σ                        CV
Indium (In)	dissolution	18667 ± 6807 μg/L	36%
	eluted	92772 ± 33556 μg/g	36%
% Indium eluted		9.3%

X= Average of 3 test vessels (0.2µm filtration)

σ = Standard deviation

CV: Coefficient of variation (%)

Applicant's summary and conclusion

Conclusions:

Bio-elution test according to state-of-the-art procedures, useful for determining dissolution capacity of In in gastric fluid.
Interpretation of results: Moderate bioaccessibility of In from indium. The dissolution in gastric fluid is used to estimate bioavailability after oral exposure

Executive summary:

During this study on Indium at a loading of 0.2 g/L in simulated gastric fluid (pH 1.5), it was shown that significant amounts of indium were measured. For indium an average value of 18667 μg/L In (CV=36%) or 92772 μg In per g test item was found after 2 hours of extraction. This corresponds with indium release of 9.3%.