5'-O-[bis(4-methoxyphenyl)benzyl]-2'-deoxy-N-(2-methyl-1-oxopropyl)guanosine

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:

2018-01-18 to 2018-02-12

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions - Method A: Particle Size Distribution (effective hydrodynamic radius)

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Qualifier:

according to guideline

Guideline:

other: CIPAC MT 187: Particle Size Analysis by Laser Diffraction

GLP compliance:

no

Type of method:

Laser scattering/diffraction

Type of particle tested:

agglomerate

Type of distribution:

volumetric distribution

Mass median aerodynamic diameter:

>= 38 - <= 81 µm

Percentile:

D50

Mean:

>= 38 - <= 81 µm

Remarks on result:

other: Standard deviation not reported

Percentile:

D10

Mean:

>= 10 - <= 12 µm

Remarks on result:

other: Standard deviation not reported

Percentile:

D90

Mean:

>= 203 - <= 240 µm

Remarks on result:

other: Standard deviation not reported

The test item consisted of irregular formed particles which had a very strong tendency for agglomeration. The particles had a sticky behavior and seemed to be electrostatically charged after sieving. These effects obstructed a measurement via sieve analysis and influenced the results of the study using laser diffraction. A large part of the test item was present as agglomerates with a diameter above 1 mm. Hence, the test item was sieved with a mesh size of 1000 µm. Only 23% (w/w) of the test item passed the sieve and only this fraction was measured by laser diffraction. A significant part of the coarse fraction consisted of fine particles that agglomerated and blocked the sieve due to the sticky behaviour of the sample.

Median particle size D (v, 0.5): 50% of particle volume or particle mass with lower particle diameter

1st measurement: 73 µm

2nd measurement: 38 µm

3rd measurement: 81 µm

Measured range: 38 - 81 µm

Particle size D (v, 0.1): 10% of particle volume or particle mass with lower particle diameter

1st measurement: 12 µm

2nd measurement: 10 µm

3rd measurement: 12 µm

Measured range: 10 - 12 µm

Particle size D (v, 0.9): 90% of particle volume or particle mass with lower particle diameter

1st measurement: 243 µm

2nd measurement: 203 µm

3rd measurement: 240 µm

Measured range: 203 - 240 µm

The particle size distribution showed a polymodal distribution. Four maxima were observed. These maxima were at approximately 2 µm, 20 µm, 100 µm and 1000 µm. The third and fourth maximum presented most likely

agglomerates. The three measurements differed in the fractions of the different particle sizes. This was a result of the behaviour of the sample.

Conclusions:

The particle size distribution of the test item was determined by laser diffraction (light scattering):
Range of median particle size D (v, 0.5): 38 - 81 µm
Range of particle size D (v, 0.1): 10 - 12 µm
Range of particle size D (v, 0.9): 203 - 240 µm

Executive summary:

The particle size distribution of the test item was determined by laser diffraction (light scattering). A large part of the test item was present as agglomerates with a diameter above 1 mm. Hence, the test item was sieved with a mesh size of 1000 µm. Only 23% (w/w) of the test item passed the sieve and only this fraction was measured by laser diffraction.

Range of median particle size D (v, 0.5): 38 - 81 µm

Range of particle size D (v, 0.1): 10 - 12 µm

Range of particle size D (v, 0.9): 203 - 240 µm

Description of key information

The particle size distribution of the test item was determined by laser diffraction (light scattering). A large part of the test item was present as agglomerates with a diameter above 1 mm. Hence, the test item was sieved with a mesh size of 1000 µm. Only 23% (w/w) of the test item passed the sieve and only this fraction was measured by laser diffraction.

Range of median particle size D (v, 0.5): 38 - 81 µm

Range of particle size D (v, 0.1): 10 - 12 µm

Range of particle size D (v, 0.9): 203 - 240 µm