Disodium 3-[(5-chloro-2-phenoxyphenyl)azo]-4-hydroxy-5-[[(p-tolyl)sulphonyl]amino]naphthalene-2,7-disulphonate

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:

The 5th of November, 2013

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:

no guideline followed

Principles of method if other than guideline:

The study was performed according to SOP STR 071 analytical method.Laser light scattering. The particle size distribution was analyzed using the Mastersizer 2000 tool, which uses the technique of laser diffraction to measure the size of particles. It measures the intensity of light scattered as a laser beam passes through a dispersed particulate sample. This data is then analyzed to calculate the size of the particles that created the scattering pattern.

GLP compliance:

no

Type of method:

Laser scattering/diffraction

Type of distribution:

volumetric distribution

Percentile:

D10

Mean:

ca. 11.74 µm

Remarks on result:

other: after 1 minute of ultrasonication

Percentile:

D50

Mean:

ca. 43.688 µm

Remarks on result:

other: after 1 minute of ultrasonication

Percentile:

D10

Mean:

ca. 11.207 µm

Remarks on result:

other: after 2 minutes of ultrasonication

Percentile:

D50

Mean:

ca. 41.257 µm

Remarks on result:

other: after 2 minutes of ultrasonication

After 1 minute of ultrasonication:

Specific Weighted mean D (3,2): 24.907 µm

Vol. Weighed mean D (4,3): 51.222 µm

After 2 minutes of ultrasonication:

Specific Weighted mean D (3,2): 23.733 µm

Vol. Weighed mean D (4,3): 47.465 µm

See graph for details.

Conclusions:

D50 = 41.257 µm after 2 min of ultrasonication

Executive summary:

Granulometry of the sample was performed with SOP-STR 071 method without and with 1 and 2 minutes of ultrasonication.

The particle size recorded are:

Particle size after 1 minute of ultrasonication

D10 > 11.48 < 13.48 µm

D50 > 39.811 < 45.709 µm (mean value 43.688 µm)

D90 > 91.201 < 104.713 µm

Particle size after 2 minutes of ultrasonication

D10 > 10.0 < 11.48 µm

D50 > 39.811 < 45.709 µm (mean value 41.257 µm)

D90 > 91.201 < 104.713 µm

Description of key information

D50 mean 43.688  µm (1 minute of ultrasonication)
D50 mean 41.257  µm (2 minute of ultrasonication)

Additional information

Granulometry of the sample was performed with SOP-STR 071 method without and with 1 and 2 minutes of ultrasonication.

Particle size after 1 minute of ultrasonication

D10 > 11.48 < 13.48 µm

D50 > 39.811 < 45.709 µm (mean value 43.688 µm)

D90 > 91.201 < 104.713 µm

Particle size after 2 minutes of ultrasonication

D10 > 10.0 < 11.48 µm

D50 > 39.811 < 45.709 µm (mean value 41.257 µm)

D90 > 91.201 < 104.713 µm

Granulometry is of considerable importance for the toxic properties of a substance as it influences aspects such as the route of exposure of humans and toxicity by inhalation; the choice of route of administration for animal testing; the efficiency of uptake in an organism and the distribution in the environment.

For this purpose fractions can be divided in:

• Inhalable fraction (the mass fraction of particles that can be inhaled by nose and mouth. Particles >100 μm are not included in the inhalable convention;

• Thoracic fraction (the mass fraction of the inhaled particles that passes the larynx). The convention for thoracic fraction sets that 50% of the particles in air with an aerodynamic diameter of 10 μm belong to the thoracic fraction;

• Respirable fraction (the mass fraction of the inhaled particles that reaches the alveoli) The convention for respirable fraction sets that 50% of particles with an aerodynamic diameter of 4 μm belong to the respirable fraction.

The substance to be registered presented a granulometry (D50 after 2 minutes of ultrasonication) that can be considered as an inhalable fractions.