Pregna-1,4-diene-3,20-dione, 9-bromo-6-fluoro-11-hydroxy-16-methyl-21-[(1-oxopentyl)oxy]-, (6.alpha.,11.beta.,16.alpha.)-

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:

13 Jan - 13 Oct 2016

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study without detailed documentation

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions) - Method B: Fibre Length and Diameter Distributions

Deviations:

no

Principles of method if other than guideline:

In considersation of the relevance of granulometry on toxicological assessment, only the size distribution of the sieved fraction <100 µm were studied in detail.

GLP compliance:

no

Other quality assurance:

ISO/IEC 17025 (General requirements for the competence of testing and calibration laboratories)

Type of method:

sieving

Type of particle tested:

primary particle

Type of distribution:

mass based distribution

Mass median aerodynamic diameter:

34.27 µm

Key result

Percentile:

D50

Mean:

34.27 µm

Remarks on result:

other: spherical volume

No.:

#1

Size:

>= 10 - <= 100 µm

Distribution:

97.97 %

Remarks on result:

other: of the sieve fraction < 100 µm

No.:

#2

Size:

>= 4 - <= 10 µm

Distribution:

2.03 %

Remarks on result:

other: of the sieve fraction < 100µm

Result: Sieve Fraction (<100µm):

- weighted sample: 0.4704 g

- weight fraction <100 µm: 0.0672 g

- mass fraction <100 µm: 14.29 %

 

The mass fraction <100 µm was 14.29 %, and was investigated by scanning electron microscopy. The mean diameter (median) was 12.23 µm with 9.23 µm standard deviation. The median aspect ratio (median) was 1.77 with 0.60 as standard deviation.

The median diameter (mass fraction) of the particle size is given for the fraction <100 µm. The value 34.27 µm was calculated for spherical and the value 33.61 µm was calculated for cubical particles.

 

Particle Size  Spherical Volume [%]  Cubical Volume [%]  <4 µm (respirable)  0.00 0.00  4-10 µm (thoracic)  2.03 2.63  10-100 µm (inhalable)  97.97  97.37  >100 µm 0.00 0.00  Median (diameter µm) 34.27 33.61

 

Validity criteria for the measurement of the granulometry:

Target condition according to guideline:	Actual condition according to the study:	Validity criteria met:
Method B: The length and diameter distributions of fibres, if required, should be measured at least twice - using separate samplings and preparations - with at least 70 fibres per histogram. No two values in a given histogram interval should differ by more than 50 % or 3 fibres, whichever is larger.	The sample was measured more than twice.	Yes
Method B: Full length (1) and diameter (d) data are needed on fibres of dimensions d ≥ 0.1 µm and 1 ≥ 5 µm. Two histogram distributions, based on examination of at least 50 fibres each, should be prepared. For diameters, the ranges should be 0.1 - 0.5, 0.5 - 1.0, 1 - 2, 2 - 3, 3 – 5 µm and over 5 µm. For lengths they should be 0 - 5, 5 - 10, 10 - 15, 15 - 20, (etc.) µm.	Ranges given.	Yes
Method B: Number of particles per field and total number of fibres measured should be stated.	Count of particles is given.	Yes.

Conclusions:

The MMAD (Mass Median Aerodynamic Diameter < 100 µm) has a value of 34.27 µm as spherical particles.

Executive summary:

According to OECD guideline 110 the particle size distribution of bromhydrin-valerat was determined by scanning electron microscopy method for the sieved fraction (<100 µm was 14.29 % of the total sample) and presented on the basis of calculated mass fractions.

The mean diameter (median) was 12.23 µm with 9.23 µm standard deviation. The median aspect ratio (median) was 1.77 with 0.60 as standard deviation. The median diameter (mass fraction) of the particle size is given for the fraction <100 µm. The value 34.27 µm was calculated for spherical particles and hence the tested particles with sieved size smaller than 100 µm are mainly dominated by inhalable fraction as defined in EN 481.

Description of key information

The MMAD (Mass Median Aerodynamic Diameter < 100 µm) has a value of 34.27 µm as spherical particles.

Additional information

According to OECD guideline 110 the particle size distribution was determined by scanning electron microscopy method for the sieved fraction (< 100 µm, 14.29 % of total sample) and presented on the basis of calculated mass fractions. The median diameter was 34.27 µm with the main fraction of 97.97 % spherical volume distributing in the range of 10 -100 µm and hence the tested particles with sieved size smaller than 100 µm are mainly dominated by inhalable fraction as defined in EU 481. Accounting based on the total sample weight the spherical volume was 14 %.