Extract of Boswellia serrata (Burseraceae) obtained from exudate by solvent extraction

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:

20 July 2017

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Justification for type of information:

The study was conducted according to a EU guideline study. No deviation affected the quality of the study. The substance is considered to be adequately characterised. Therefore full validation applies.

Qualifier:

according to guideline

Guideline:

OECD Guideline 110 (Particle Size Distribution / Fibre Length and Diameter Distributions - Method A: Particle Size Distribution (effective hydrodynamic radius)

Version / remarks:

1981

Deviations:

no

Qualifier:

according to guideline

Guideline:

ISO 13320 (Particle size analysis - Laser diffraction methods)

Version / remarks:

2009

Deviations:

no

Qualifier:

according to guideline

Guideline:

EPA OPPTS 830.7520 (Particle Size, Fiber Length, and Diameter Distribution)

Version / remarks:

1996

Deviations:

no

Principles of method if other than guideline:

The particle size distribution was determined using laser diffraction. As measuring device, a Malvern Mastersizer 2000 was used. The powder was brought via a powder dispersing cell Scirocco 2000 into the laser light beam and the diffraction pattern was determined. From the diffraction pattern the particle size distribution was calculated.

GLP compliance:

yes (incl. QA statement)

Remarks:

GLP compliance programme (inspected on 11-12 October 2016 / signed on 28 February 2017)

Type of method:

Laser scattering/diffraction

Type of particle tested:

other: powder

Type of distribution:

volumetric distribution

Key result

Percentile:

D10

Mean:

1 µm

St. dev.:

0.006

Key result

Percentile:

D50

Mean:

9.4 µm

St. dev.:

0.1

Key result

Percentile:

D90

Mean:

82.8 µm

St. dev.:

3.3

No.:

#1

Size:

> 0 - < 4 µm

Distribution:

30.7 %

No.:

#2

Size:

> 0 - < 10 µm

Distribution:

51.5 %

No.:

#3

Size:

> 0 - < 100 µm

Distribution:

92.5 %

No.:

#4

Size:

> 0 - < 500 µm

Distribution:

100 %

Particle size distribution:

Two test series of 3 measurements each were performed with the test item.From each 3-fold measurement an average value was calculated.

The final result was calculated as mean value from the average values of the two samples. The test item showed a heterogeneous shape of the particles.

 

Test series 1	D10 (µm)	D50 (Median diameter, µm)	D90 (µm)
Test 1	1.000	9.351	79.110
Test 2	0.991	9.545	83.864
Test 3	0.989	9.512	85.335
Averaged	0.99	9.47	82.78

 

Test series 2	D10 (µm)	D50 (Median diameter, µm)	D90 (µm)
Test 1	0.970	9.317	78.731
Test 2	0.971	9.447	85.157
Test 3	0.969	9.390	84.749
Averaged	0.97	9.38	82.88

Average of both test series:

D₁₀:         1.0 µm

D₅₀:         9.4 µm (Median diameter)

D₉₀:         82.8 µm

Test item was visually assessed via microscope (fivefold magnification) with correlative microscopy coverslip 10x10 grids of 0.1 mm squares.

In addition, the averaged results, the fraction distribution and the cumulative distribution of both test series are shown in the report.

The results in Volume % passing at 4, 10, 100 and 500 µm are reported as follows:

Particle size /µm	Volume under / % Average 1	Volume under / % Average 2	Volume under / % Mean
4	30.57	30.89	30.7
10	51.39	51.59	51.5
100	92.46	92.52	92.5
500	100.00	100.00	100.0

 

Conclusions:

The test substance has a median particle size of D50 = 9.4 µm.
It contains 30.7%vol of particles < 4 µm (respirable fraction), 51.5%vol of particles < 10 µm (thoracic fraction) and 92.5%vol of particles < 100 µm (inhalable fraction).

Executive summary:

Particle size distribution of a sample of the substance was determined under GLP by laser diffraction measurement according to OECD/ISO/OCSPP standard methods.

Two independant determinations were conducted and the mean value was used to determine the particle size distribution of the substance.

Description of key information

The test substance has a median particle size of D50 = 9.4 µm.

It contains 30.7% vol of particles < 4 µm (respirable fraction), 51.5% vol of particles < 10 µm (thoracic fraction) and 92.5% vol of particles < 100 µm (inhalable fraction).

Additional information

A fully reliable GLP experimental study conducted according to recognized OECD/ISO/OCSPP guidelines using laser diffraction method, is available. It is considered as a key study, and the result is retained as key data.