Reaction products of disodium 3,5-diamino-2-[(2-sulfonatophenyl)diazenyl]benzoate and  diazotised sodium 2-[(4-aminophenyl)sulfonyl]ethyl sulfate

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:

Experiment start date - 11 March 2003; Experiment completion date - 12 March 2003; Study completion date - 04 June 2003.

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Qualifier:

according to guideline

Guideline:

other: ECB/TM/February 1996 (Laser diffraction)

Deviations:

no

Principles of method if other than guideline:

The above mentioned guideline contains several different methods for the determination of the particle size distribution. These methods include sieving, microscopic examination, sedimentation, gravitational settling examination, cascade impaction and laser scattering /diffraction method. in the present study the laser scattering / diffraction method was applied.
The dispersing apparatus was rinsed and filled with pre-saturated 2-propanol solution of the test substance. A few ml of the stock dispersion were added slowly until the absorption of the laser was reduced by about 10 %. The particle size distribution in the suspension was quantified by laser diffraction. The test was performed with two samples of the stock dispersion and each measured in duplicate.

GLP compliance:

yes (incl. QA statement)

Type of method:

Laser scattering/diffraction

Specific details on test material used for the study:

Identity: FAT 40810/A
Batch: WP 6/02
Purity: approx. 75 %
Appearance: Solid, dark brownish powder
Expiration date: 12 December 2010
Storage: At room temperature at about 20 °C

Percentile:

D10

Mean:

< 1.6 µm

St. dev.:

0.017

Percentile:

D50

Mean:

< 5.7 µm

St. dev.:

0.085

Percentile:

D90

Mean:

< 14.3 µm

St. dev.:

0.574

Particle Size Distribution:
<0.9  µm: 5 %
<1.6  µm: 10 %
<5.7  µm: 50 %
<14.3 µm: 90 %

Mass Median Diameter:
MMD = 5.7 µm

Conclusions:

In conclusion, using a laser diffraction apparatus to study the particle size of FAT 40810/A in the range between 0.3 µm and 300 µm, the mass median diameter (MMD) was determined to be 5.7 µm. The particle size distribution was found to range from approximately 0.3 µm to 30 µm.

Executive summary:

The determination of the particle size distribution of FAT 40810/A was performed according to the European Commission, Document ECB/TM/February 1996: "Particle Size Distribution, Fibre Length and Diameter Distribution" Guidance Document using the laser diffraction method. FAT 40810/A is a dark-red agglutinated powder. Under the microscope (with a magnification of 400) ruby, spheroidal and partially plane, crystalline structures were observed. A solubility test showed that the test item is both: sparingly soluble and well dispersible in 2-propanol. The particle size distribution of FAT 40’810/A was performed with two samples of the stock dispersion each measured in duplicate. The individual measurements and the results obtained using the laser diffraction of FAT 40810/A were recorded and presented as rounded results obtained by using the exact measurement data. The results obtained during the measurements showed no relevant difference. The MMD mean value of 5.7µm with a standard deviation of ±0.085 µm resulted. The standard deviation is smaller than 5 % therefore, the study is considered to be valid and no further testing was necessary. In conclusion, using a laser diffraction apparatus to study the particle size of FAT 40810/A in the range between 0.3 µm and 300 µm, the mass median diameter (MMD) was determined to be 5.7 µm.

Description of key information

The determination of the particle size distribution of FAT 40’810/A was performed according to the European Commission, Document ECB/TM/February 1996: "Particle Size Distribution, Fibre Length and Diameter Distribution" Guidance Document using the laser diffraction method. FAT 40810/A is a dark-red agglutinated powder. Under the microscope (with a magnification of 400) ruby, spheroidal and partially plane, crystalline structures were observed. A solubility test showed that the test item is both: sparingly soluble and well dispersible in 2-propanol. The particle size distribution of FAT 40810/A was performed with two samples of the stock dispersion each measured in duplicate. The individual measurements and the results obtained using the laser diffraction of FAT 40810/A were recorded and presented as rounded results obtained by using the exact measurement data. The results obtained during the measurements showed no relevant difference. The MMD mean value of 5.7 µm with a standard deviation of ±0.085 µm resulted. The standard deviation is smaller than 5 % therefore, the study is considered to be valid and no further testing was necessary. In conclusion, using a laser diffraction apparatus to study the particle size of FAT 40810/A in the range between 0.3 µm and 300µm, the mass median diameter (MMD) was determined to be 5.7µm. This value is also taken forward as the maa median aerodynamic diameter (MMAD).