Disodium L-cystinate

Particle size distribution (Granulometry)

Administrative data

Endpoint:

particle size distribution (granulometry)

Type of information:

experimental study

Adequacy of study:

key study

Study period:

04 Jan 2018 - 29 March 2018

Reliability:

1 (reliable without restriction)

Rationale for reliability incl. deficiencies:

guideline study

Data source

Reference

Reference Type:

study report

Title:

Unnamed

Year:

2018

Report date:

2018

Materials and methods

Test guideline

Qualifier:

according to guideline

Guideline:

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

GLP compliance:

yes

Type of method:

Laser scattering/diffraction

Type of particle tested:

agglomerate

Type of distribution:

volumetric distribution

Test material

Test material information

Constituent 1

Reference substance name:

Disodium L-cystinate

EC Number:

265-025-3

EC Name:

Disodium L-cystinate

Cas Number:

64704-23-0

Molecular formula:

C6H10N2Na2O4S2.H2O

IUPAC Name:

disodium (2R)-2-amino-3-{[(2R)-2-amino-2-carboxyethyl]disulfanyl}propanoate

Test material form:

solid: particulate/powder

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Purity test date: 98.9%

STABILITY AND STORAGE CONDITIONS OF TEST MATERIAL
- Storage condition of test material: In refrigerator (2 - 8 deg C)

Results and discussion

Mass median aerodynamic diameter:

ca. 71.597 µm

Geometric standard deviation:

> 2.046 - < 2.064

Particle size

Particle size 1

Key result

Percentile:

D10

Mean:

ca. 20.895 µm

St. dev.:

0.118

Particle size 2

Key result

Percentile:

D50

Mean:

ca. 56.079 µm

St. dev.:

0.324

Particle size 3

Key result

Percentile:

D90

Mean:

ca. 127.901 µm

St. dev.:

4.609

Any other information on results incl. tables

Using the identified parameters, the particle size was analysed over the range 0.02 μm to

2000 μm. The results of the formal analysis are presented in Table 9:1. In addition, a graph

of volume (%) versus Particle Diameter (μm), and full particle size distribution, is provided in

Graph 9.A (Average of 5 runs).

Table 9:1 : Full Test Results

	RUN 1	RUN 2	RUN 3	RUN 4	RUN 5	Average**
Volume weighted mean	65.985	68.957	72.918	73.581	70.968	70.482
Median	56.133	55.894	56.591	56.179	55.616	56.079
Mode	59.513	60.034	58.699	58.675	58.25	59.025
MMAD *	71.665	71.361	72.25	71.724	71.005	71.597
d10 (10 % of material is <)	20.94	20.757	21.101	20.842	20.84	20.895
d50 (50 % of material is <)	56.133	55.894	56.591	56.179	55.616	56.079
d90 (90 % of material is <)	124.371	122.175	134.628	131.937	128.397	127.901

All results are in µm

* Mass median aerodynamic diameter

** Average result is calculated from the entirety of data captured in each run and is not a simple arithmetic mean.

1.26 % by volume of sample was seen to be < 10.00 µm.

Table 9:2 : Standard Deviation results

	RUN 1	RUN 2	RUN 3	RUN 4	RUN 5	STDVP	% STDVP
d10	20.94	20.757	21.101	20.842	20.84	0.118	0.6
d50	56.133	55.894	56.591	56.179	55.616	0.324	0.6
d90	124.371	122.175	134.628	131.937	128.397	4.609	3.6
d15.78	27.34	27.192	27.503	27.215	27.185	0.122	0.4
GSD	2.053	2.056	2.058	2.064	2.046	0.006	0.3
MMAD	71.665	71.361	72.25	71.724	71.005	0.413	0.6

GSD = Geometric standard deviation of the lognormal particle size distribution (calculated from d50/d15.78) STDVP = standard deviation of the population

% STDVP = percentage standard deviation of the population

Coefficient of variation for d50 is less than 3%; d10 and d90 are less than 5%. Thus repeatability of the characteristic particles in the size distribution are within the acceptable limits as per the ISO 13320-1 test standard.

Applicant's summary and conclusion

Conclusions:

The particle size was analysed over the range 0.02 µm to 2000 µm using a DPM Module. The average result is calculated from the entirety of data captured in each of the five runs. The averages are: d10 - 10 % of material is <20.895, d50 - 50 % of material is <56.079, and d90 - 90 % of material is <127.901.

Executive summary:

The particle size was analysed over the range 0.02 µm to 2000 µm using a DPM Module. The average result is calculated from the entirety of data captured in each of the five runs. The averages are: d10 - 10 % of material is <20.895, d50 - 50 % of material is <56.079, and d90 - 90 % of material is <127.901.