Ethyl L-threoninate

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:

2007.08.31 to 2007.11.29

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

other: GLP study performed in accordance with recognised test guidance - European Commision Guidance Document on the Determination of Particle Size Distribution, Fibre Length and Diameter Distribution of Chemical Substances. EUR 20268 EN [draft].

Reason / purpose for cross-reference:

reference to same study

Qualifier:

according to guideline

Guideline:

other:

Deviations:

not applicable

Principles of method if other than guideline:

The particle size is measured by laser diffraction in combination with Mie theory as described in European Commision Guidance Document on the Determination of Particle Size Distribution, Fibre Lenght and Diameter Distribution of Chemical Substances. EUR 20268 EN [draft].

GLP compliance:

yes

Type of method:

Laser scattering/diffraction

Type of distribution:

volumetric distribution

Mass median aerodynamic diameter:

> 562 - < 810 µm

Geometric standard deviation:

> 46.4 - < 102.9

Percentile:

D10

Mean:

>= 81.178 - <= 97.926 µm

St. dev.:

0

Percentile:

D50

Mean:

>= 507.8 - <= 731.2 µm

St. dev.:

0

Percentile:

D90

Mean:

>= 1 292 - <= 1 444 µm

St. dev.:

0

NA

Conclusions:

A bimodal distribution of size was observed, which was considered to be broadly representative of the “short” and “long” cross-sections of a distinctly cylindrical (“fibrous”) particulate or crystalline nature, and which corresponded to the visual observations. Three data sets were evaluated, and these showed some variability in the findings, therefore overall mean values were not generated. The d(0.5) values (the particle size representing the mid-point in each averaged distribution set) were between 507.8 and 731.2 μm. The d(0.1) and d(0.9) values (the particle sizes representing the 10% and 90% points in the distributions) were respectively between 81.2 and 97.9 μm and 1292 and 1444 μm.

Because of the asymmetric nature of the test substance particles, and the inherent variability of the measurements, overall mean values for the mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) values were not able to be calculated. Values for the three data sets were respectively between 562 and 810 μm (MMAD), and 46.4 and 102.9 μm (GSD). The data distribution tables (considering all data sets) indicate that the mean proportion of test substance found below 10 μm (actual value 10.00 μm) was nil, that below nominally 50 μm (actual value 52.5 μm) was less than 1%, and that below nominally 100 μm (actual value 104.7 μm) was between 11 and 19%.

Executive summary:

The particle size of L-TEE was determined by laser diffraction in combination with Mie theory1. A bimodal distribution of size was observed, which was considered to be broadly representative of the “short” and “long” cross-sections of a distinctly cylindrical (“fibrous”) particulate or crystalline nature, and which corresponded to the visual observations.

Three data sets were evaluated, and these showed some variability in the findings, therefore overall mean values were not generated. The d(0.5) values (the particle size representing the mid-point in each averaged distribution set) were between 507.8 and 731.2 μm. The d(0.1) and d(0.9) values (the particle sizes representing the 10% and 90% points in the distributions) were respectively between 81.2 and 97.9 μm and 1292 and 1444 μm.

It was not possible to calculate overall mean values for the mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) values, the three data sets were respectively between 562-810 μm (MMAD), and 46.4-102.9 μm (GSD).

The data distribution tables (considering all data sets) indicate that the mean proportion of test substance found below 10 μm (actual value 10.00 μm) was nil, that below nominally 50 μm (actual value 52.5 μm) was less than 1%, and that below nominally 100 μm (actual value 104.7 μm) was between 11 and 19%.

Description of key information

The particle size of L-TEE was determined to be:d(0.1):81.2 – 97.9 μm, d(0.5): 507.8 and 731.2 μm and d(0.9) 1292 and 1444 μm.

Due to the asymmetric nature of the substance an overall mass median aerodynamic diameter and a geometric standard deviation could not be determined.

The data distribution tables (considering all data sets) indicated that the mean proportion of test substance found below 10 μm (actual value 10.00 μm) was nil, that below nominally 50 μm (actual value 52.5 μm) was less than 1%, and that below nominally 100 μm (actual value 104.7 μm) was between 11 and 19%.

Additional information

The particle size of L-TEE was determined by laser diffraction in combination with Mie theory1. A bimodal distribution of size was observed, which was considered to be broadly representative of the “short” and “long” cross-sections of a distinctly cylindrical (“fibrous”) particulate or crystalline nature, and which corresponded to the visual observations. Three data sets were evaluated, and these showed some variability in the findings, therefore overall mean values were not generated.

The d(0.5) values (the particle size representing the mid-point in each averaged distribution set) were between 507.8 and 731.2 μm. The d(0.1) and d(0.9) values (the particle sizes representing the 10% and 90% points in the distributions) were respectively between 81.2 and 97.9 μm and 1292 and 1444 μm.

Because of the asymmetric nature of the test substance particles, and the inherent variability of the measurements, overall mean values for the mass median aerodynamic diameter (MMAD) and geometric standard deviation (GSD) values could not be calculated. Values for the three data sets were respectively between 562 and 810 μm (MMAD), and 46.4 and 102.9 μm (GSD).

The data distribution tables (considering all data sets) indicate that the mean proportion of test substance found below 10 μm (actual value 10.00 μm) was nil, that below nominally 50 μm (actual value 52.5 μm) was less than 1%, and that below nominally 100 μm (actual value 104.7 μm) was between 11 and 19%.