Norethisterone

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:

2015

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

guideline study with acceptable restrictions

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / 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

Type of method:

determination of fibre length and diameter distributions

Type of distribution:

counted distribution

Mass median aerodynamic diameter:

50.82 µm

Key result

Percentile:

D50

Mean:

50.82 µm

Remarks on result:

other: spherical volume(migrated from fields under 'Mass median diameter' as D50 percentile. No source field for Standard deviation.)

No.:

#1

Size:

3 - 5 µm

Distribution:

0 %

Remarks on result:

other: of the sieve fraction < 100 µm

No.:

#2

Size:

5 - 100 µm

Distribution:

99.81 %

Remarks on result:

other: of the sieve fraction < 100 µm

Result: Sieve Fraction (<100µm):

- weighted sample: 1.7585 g

- weight fraction <100µm: 0.5502 g

- mass fraction <100µm: 31.29 %

The mass fraction <100µm was 31.29 %, and was investigated by scanning electron microscopy. The mean diameter (median) was 11.99µm with 14.73µm standard deviation. The median aspect ratio (median) was 1.67 with 0.93 as standard deviation.

The median diameter (mass fraction) of the particle size is given for the fraction <100µm. The value 50.82µm was calculated for spherical and the value 51.11µm was calculated for cubical particles.

Particle Size  Spherical Volume [%]  Cubical Volume [%]  <4 µm (respirable)  0.00  0.00  4-10 µm (thoracic)  1.04  1.09  10-100 µm (inhalable)  98.96  98.91  >100 µm  0.00 0.00   Median (diameter µm)  50.82  51.11

Conclusions:

The MMAD (Mass Median Aerodynamic Diameter < 100 µm) of the substance has a value of 50.82 µm as spherical particles.

Executive summary:

According to OECD guideline 110 the particle size distribution was determined by scanning electron microscopy method for the sieved fraction (< 100 µm, 31.29 % of total sample) and presented on the basis of calculated mass fractions. The median diameter was 50.82 µm with the main fraction of 30.96 % 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

The MMAD (Mass Median Aerodynamic Diameter < 100 µm) of the substance has a value of 50.82 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, 31.29 % of total sample) and presented on the basis of calculated mass fractions. The median diameter was 50.82 µm with the main fraction of 30.96 % distributing in the range of 10 -100 µm.