Pregn-4-ene-3,20-dione, 21-(acetyloxy)-6-fluoro-11-hydroxy-16-methyl-, (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:

19 Jul - 19 Sep 2017

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)

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 distribution:

mass based distribution

Mass median aerodynamic diameter:

46.48 µm

Key result

Percentile:

D50

Mean:

46.48 µm

Remarks on result:

other: spherical volume

No.:

#1

Size:

>= 5 - <= 100 µm

Distribution:

100 %

Remarks on result:

other: spherical volume

Result: Sieve Fraction (<100 µm):

- weighted sample: 0.7871 g

- weight fraction <100 µm: 0.0829 g

- mass fraction <100 µm: 10.53 %

 

The mass fraction <100 µm was 10.53 %, and was investigated by scanning electron microscopy. The mean diameter (median) was 22.21 µm with 12.64 µm standard deviation. The median aspect ratio (median) was 1.57 with 0.49 as standard deviation.

 

The median diameter (mass fraction) of the particle size is given for the fraction <100 µm. The value 46.48 µm was calculated for spherical particles as MMAD (Mass Median Aerodynamic Diameter).

 

Particle Size  Spherical Volume [%] Cubical Volume [%]   <4 µm (respirable)  0.00 0.00  4-10 µm (thoracic)  0.03 0.04  10-100 µm (inhalable)  99.97  99.96  Total (>100 µm) 0.00 0.00  Median (diameter µm) 46.48 40.69

 

Validity criteria for the measurement of the particle size:

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.	For the determination of the particle size and the aspect ratio, 6 pictures have been taken by SEM at a magnification of 390 times.	Yes
Method B: Number of particles per field and total number of fibres measured should be stated.	The total number (1085) is stated.	Yes

 

Conclusions:

The MMAD (Mass Median Aerodynamic Diameter < 100 µm) of Fluocortolon-A-Acetat has a value of 46.48 µm as spherical particles.

Executive summary:

According to OECD guideline 110 the particle size distribution of Fluocortolon-A-Acetat was determined by scanning electron microscopy method for the sieved fraction (<100 µm, 10.53 % of total sample) and presented on the basis of calculated mass fractions.

The MMAD (Mass Median Aerodynamic Diameter <100 µm) was 46.48 µm with the main fraction of 10.53 % 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.

Description of key information

According to OECD guideline 110 the particle size distribution of Fluocortolon-A-Acetat was determined by scanning electron microscopy method for the sieved fraction (<100 µm, 10.53 % of total sample) and presented on the basis of calculated mass fractions.

The MMAD (Mass Median Aerodynamic Diameter <100 µm) was 46.48 µm with the main fraction of 10.53 % 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.