Aluminium nitride

Endpoint summary

Link to relevant study record(s)

Reference

Endpoint:

basic toxicokinetics in vitro / ex vivo

Type of information:

experimental study

Adequacy of study:

key study

Study period:

2013-10-08 to 2014-03-26

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

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

Objective of study:

bioaccessibility (or bioavailability)

Qualifier:

no guideline available

Principles of method if other than guideline:

This report measured bioaccessibility of aluminium nitride in body fluid simulants as a surrogate for bioavailability.

GLP compliance:

no

Radiolabelling:

no

Details on test animals or test system and environmental conditions:

not applicable

Details on exposure:

not applicable

Duration and frequency of treatment / exposure:

not applicable

Remarks:

Doses / Concentrations:
0.1 g 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:

Aluminium nitride was extracted in simulated leaching fluids for two time periods: 2 hrs and 24 hrs. 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 aluminium using EPA Method #200.8 (ICP/MS). Results were reported as µg Al/g sample, % Al release/Al content.

Details on dosing and sampling:

not applicable

Statistics:

not applicable

Preliminary studies:

not applicable

Details on absorption:

not applicable

Details on distribution in tissues:

not applicable

Details on excretion:

not applicable

Details on metabolites:

not applicable

Bioaccessibility (or Bioavailability) testing results:

see below (Table 1-5)

Table 1: Soluble Aluminum in Simulated Gastric fluid

Extraction time in h	Weight used	µg Aluminum /g Sample	% Aluminum release/ Aluminum content
2 hours	0.1003	14,955	2.27
	0.1002	17,166	2.61
24 hours	0.1000	69,300	10.5
	0.1005	61,443	9.34

 

Table 2: Soluble Aluminum in Simulated Interstitial fluid

Extraction time in h	Weight used	µg Aluminum /g Sample	% Aluminum release/ Aluminum content
2 hours	0.1002	469	0.07
	0.1001	549	0.08
24 hours	0.1008	685	0.10
	0.1001	729	0.11

 

Table 3: Soluble Aluminum in Simulated Lysosomal fluid

Extraction time in h	Weight used	µg Aluminum /g Sample	% Aluminum release/ Aluminum content
2 hours	0.1002	1.262	0.19
	0.1009	1.303	0.20
24 hours	0.1030	23.738	3.61
	0.1036	23.745	3.61

 

Table 4: Soluble Aluminum in Artificial Perspiration

Extraction time in h	Weight used	µg Aluminum /g Sample	% Aluminum release/ Aluminum content
2 hour	0.1003	319	0.05
	0.1008	288	0.04
24 hours	0.1000	1.590	0.24
	0.1001	1.913	0.29

 

Table 5: Soluble Aluminum in PBS

Extraction time in h	Weight used	µg Aluminum /g Sample	% Aluminum release/ Aluminum content
2 hour	0.1009	50	0.01
	0.1010	45	0.01
24 hours	0.1004	55	0.01
	0.1005	65	0.01

 

 

Conclusions:

In conclusion, the release of aluminium ions from aluminium nitride is low in artificial body fluids. The more acidic the simulated fluid, the more aluminium ions are released, i.e. up to 9.92 % in simulated gastric fluid (pH 1.5), and 3.61 % in simulated lysosomal fluid (pH 4.5) after 24 hours.

Executive summary:

This report measured bioaccessibility of aluminium nitride as a surrogate for bioavailability. To do this the soluble aluminium was measured using EPA Method #200.8 (ICP/MS) after incubation of aluminium nitride in simulated body fluids (simulated gastric fluid, simulated interstitial fluid, simulated lysosomal fluid, and artificial perspiration). Results were reported as µg Al/g sample and % Al release/Al content.

Overview of Al released in the different simulated body fluids:

Medium	t in h	% Al-release
Simulated gastric fluid	2	2,44%
	24	9,92%
Simulated interstitial fluid	2	0,08%
	24	0,11%
Simulated lysosomal fluid	2	0,20%
	24	3,61 %
Artificial perspiration	2	0,05%
	24	0,27 %
PBS	2	0,01%
	24	0,01 %

 

The bioavailability in artificial body fluids ranged from 0.05% (artificial perspiration and interstitial fluid) to 9,92 % (simulated gastric fluid). The maximum solubility was determined at acidic pH. Based on the results, the bioavailability of aluminium nitride would be expected to be low in all tested artificial body fluids except gastric acid. Bioavailability strongly depends on the route of administration.

Description of key information

In vitro bioavailability studies in artificial body fluids were conducted with aluminium nitride.

Key value for chemical safety assessment

Bioaccumulation potential:

low bioaccumulation potential

Additional information

The solubility of aluminium nitride was determined in artificial body fluids (gastric fluid, interstitial fluid, lysosomal fluid and artificial perspiration). Results were reported as µg Aluminium/g Sample and % Aluminium release/Aluminium content.

The bioavailability ranged from 0.05 % (2 h, artificial perspiration) to 9.92 % (24 h, gastric fluid). Based on the results, the bioavailability of aluminium nitride would be expected to be low for all body fluids.