2-amino-6-methyl-1,2,4-triazolo[1,5-a]pyrimidin-5(1H)-one

Particle size distribution (Granulometry)

Link to relevant study record(s)

Reference

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

01 September 2015 - 25 September 2015

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

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

Qualifier:

according to guideline

Guideline:

other: European Commission Technical Guidance Document EUR 20268 'Determination of Particle Size Distribution, Fibre Length and Diameter Distribution of Chemical Substances' (2002)

Deviations:

no

GLP compliance:

no

Remarks:

No formal claim. Study conducted in a facility operating to GLP.

Type of method:

cascade impaction

Type of particle tested:

primary particle

Type of distribution:

mass based distribution

Remarks on result:

not determinable

Remarks:

Too few particles were of a size less than 10.0 μm to allow accurate assessment of the mass median aerodynamic diameter.

No.:

#1

Size:

< 100 µm

Distribution:

79.8 %

Remarks on result:

other: Sieve screening test

No.:

#2

Size:

< 10 µm

Distribution:

4.1 %

No.:

#3

Size:

< 5.5 µm

Distribution:

1.3 %

Sieve screening test

The percentage of test substance with an inhalable particle size <100 µm was determined to be 79.8%.

Table 1: Sieve Analysis Results

Measurement	Result
Mass of test item transferred to sieve	10.49 g
Mass of test item passed through sieve	8.37 g
Percentage of test item less than 100 µm	79.8%

Cascade Impactor: The percentage of test substance with a thoracic particle size less than 10.0 µm was determined to be 4.1%. The percentage of test item with a respirable particle size less than 5.5 µm was determined to be 1.3%. The full results of the cascade impactor test are presented in the tables below.

Table 2: Cascade Impactor Collected Masses

Collection Stage	Particle Size Range Collected (µm)	Collected Mass (g)
		Run 1	Run 2	Run 3
Artificial throat	n/a	0.49	0.32	0.86
Cup 1	>10.0	2.4213	2.4399	2.0866
Cup 2	5.5 to 10.0	0.0758	0.0986	0.0784
Cup 3	2.4 to 5.5	0.0114	0.0197	0.0188
Cup 4	1.61 to 2.4	0.0041	0.0091	0.0088
Cup 5	0.307 to 1.61	0.0032	0.0052	0.0062
Final Filter	<0.307	0.0044	0.0148	0.0117
Total mass of collected test item		3.0102	2.9073	3.0705

Table 3: Cascade Impactor Calculated Masses

Particle Size Cut Points (µm)	Cumulative Mass (g)			Cumulative Percentage (%)
	Run 1	Run 2	Run 3	Run 1	Run 2	Run 3
<10.0	0.0989	0.1474	0.1239	3.29	5.07	4.04
<5.5	0.0231	0.0488	0.0455	0.77	1.68	1.48
<2.4	0.0117	0.0291	0.0267	0.39	1.00	0.87
<1.61	0.0076	0.0200	0.0179	0.25	0.69	0.58
<0.307	0.0044	0.0148	0.0117	0.15	0.51	0.38

Conclusions:

By sieve analysis, the percentage of test substance having an inhalable particle size of less than 100 µm was determined to be 79.8%. By cascade impactor analysis, the percentage of test substance having a thoracic particle size of less than 10.0 µm and respirable particle size of less than 5.5 µm was determined to be 4.1% and 1.3% respectively.

Executive summary:

The study was performed to determine the particle size distribution of the test substance. The method employed was designed to be compatible with European Commission Technical Guidance Document EUR 20268 'Determination of Particle Size Distribution, Fibre Length and Diameter Distribution of Chemical Substances' (2002).

By sieve analysis, the percentage of test substance having an inhalable particle size of less than 100 µm was determined to be 79.8%. By cascade impactor analysis, the percentage of test item having a thoracic particle size of less than 10.0 µm and respirable particle size of less than 5.5 µm was determined to be 4.1% and 1.3% respectively. Too few particles were of a size less than 10.0 μm to allow accurate assessment of the mass median aerodynamic diameter.

Description of key information

The study was performed to determine the particle size distribution of the test substance. The method employed was designed to be compatible with European Commission Technical Guidance Document EUR 20268 'Determination of Particle Size Distribution, Fibre Length and Diameter Distribution of Chemical Substances' (2002).

By sieve analysis, the percentage of test substance having an inhalable particle size of less than 100 µm was determined to be 79.8%. By cascade impactor analysis, the percentage of test item having a thoracic particle size of less than 10.0 µm and respirable particle size of less than 5.5 µm was determined to be 4.1% and 1.3% respectively. Too few particles were of a size less than 10.0 μm to allow accurate assessment of the mass median aerodynamic diameter.