Tantalum carbide

Basic toxicokinetics

Administrative data

Endpoint:

basic toxicokinetics in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-12-05 to 2014-02-21

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: Meets generally accepted scientific standards, well documented and acceptable for assessment.

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:

no guideline available

Deviations:

not applicable

Principles of method if other than guideline:

This report measured bioaccessibility of tantalum carbide in body fluid simulants as a surrogate for bioavailability.

GLP compliance:

no

Test material

Test material information

Constituent 1

Reference substance name:

Tantalum carbide

EC Number:

235-118-3

EC Name:

Tantalum carbide

Cas Number:

12070-06-3

Molecular formula:

CTa

IUPAC Name:

methyltantalum

Test material form:

solid: particulate/powder

Remarks:

migrated information: powder

Details on test material:

- Name of test material (as cited in study report): Tantalum Carbide
- Analytical purity: 93.8% Tantalum

Radiolabelling:

no

Test animals

Species:

other: not applicable

Strain:

other: not applicable

Details on test animals or test system and environmental conditions:

not applicable

Administration / exposure

Route of administration:

other: in vitro study

Vehicle:

other: in vitro study

Details on exposure:

not applicable

Duration and frequency of treatment / exposure:

not applicable

Doses / concentrations

Remarks:

Doses / Concentrations:
0.1 g of test substance in 50 mL of simulated fluid

No. of animals per sex per dose / concentration:

not applicable

Control animals:

other: not applicable

Positive control reference chemical:

not applicable

Details on study design:

Tantalum carbide was extracted in leaching fluids for different time periods: 2 hrs and 24 hrs in simulated gastric and lysosomal fluid, 24 hrs in simulated interstitial fluid and 12 hrs in artificial perspiration. The extractions were performed using 0.1 gram of sample in 50 ml of simulated fluid. A shaker water bath at a temperature of 37± 2°C was used. All extractions were performed in duplicate. The extracts were analyzed for soluble Tantalum using EPA Method #200.8 (ICP/MS). Results were reported as µg Ta/g sample, % Ta/g sample and as % of total Ta released/Tantalum content.

Details on dosing and sampling:

not applicable

Statistics:

not applicable

Results and discussion

Preliminary studies:

not applicable

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:

see tables in section " any other information on results incl. tables"

Any other information on results incl. tables

Table 1: Soluble Tantalum in Gastric fluid

Extraction time in h	Weight used	µg Tantalum /g Sample	% Tantalum release/ Tantalum content
2 hours	0.1034	<25.0	--
(dup)	0.1010	<25.0	--
24 hours	0.1059	<25.0	--
(dup)	0.1007	<25.0	--

 

Table 2: Soluble Tantalum in Interstitial fluid

Extraction time in h	Weight used	µg Tantalum /g Sample	% Tantalum release/ Tantalum content
2 hours	0.1000	<25.0	--
(dup)	0.1008	<25.0	--
24 hours	0.1043	<25.0	--
(dup)	0.1016	<25.0	--

 

Table 3: Soluble Tantalum in Lysosomal fluid

Extraction time in h	Weight used	µg Tantalum /g Sample	% Tantalum release/ Tantalum content
2 hours	0.1036	<25.0	--
(dup)	0.1024	<25.0	--
24 hours	0.1042	43.0	0.005
(dup)	0.1048	33.0	0.004

 

Table 4: Soluble Tantalum in Artificial Perspiration

Extraction time in h	Weight used	µg Tantalum /g Sample	% Tantalum release/ Tantalum content
2 hours	0.1010	<25.0	--
(dup)	0.1019	<25.0	--
24 hours	0.1032	<25.0	--
(dup)	0.1014	<25.0	--

 

Table 5: Soluble Tantalum in PBS

Extraction time in h	Weight used	µg Tantalum /g Sample	% Tantalum release/ Tantalum content
2 hours	0.1037	<25.0	--
(dup)	0.1051	<25.0	--
24 hours	0.1008	25.0	0.003
(dup)	0.1040	34.0	0.004

 

Applicant's summary and conclusion

Conclusions:

Interpretation of results (migrated information): low bioaccumulation potential based on study results
The release of tantalum ions from tantalum carbide is very low in artificial body fluids. For simulated gastric fluid, simulated interstitial fluid and arteficial perspiration no release of tantalum ions was observed as the results were below the detection limit of the method.
Only in simulated lysosomal fluid 0.005% tantalum ions were released within 24 hours from tantalum carbide.

Executive summary:

This report measured bioaccessibility of tantalum carbide as a surrogate for bioavailability. Thus, the soluble tantalum was measured by using EPA Method #200.8 (ICP/MS) after incubation of tantalum carbide in different simulated body fluids (simulated gastric fluid, simulated interstitial fluid, simulated lysosomal fluid, and artificial perspiration). Results were reported as µg Ta/g sample, % Ta release/Ta content.

 

Overview of Tantalum released in the different simulated body fluids:

Medium	t in h	% Ta-release
Simulated gastric fluid	2	BDL
	24	BDL
Simulated interstitial fluid	2	BDL
	24	BDL
Simulated lysosomal fluid	2	BDL
	24	0,005%
Artificial perspiration	2	BDL
	24	BDL
PBS	2	BDL
	24	0,004%

BDL – Below method detection limit

 

In summary, release of tantalum ions from tantalum carbide is very low. The actually measured release of tantalum in lysosomal fluid is in the same magnitude as the reference fluid (PBS). Based on the results, the bioavailability of tantalum carbide is expected to be very low for all routes of administration.