Iron digluconate

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:

11 February 2014

Reliability:

2 (reliable with restrictions)

Rationale for reliability incl. deficiencies:

comparable to guideline study with acceptable restrictions

Qualifier:

no guideline followed

Principles of method if other than guideline:

- Principle of test: To obtain the particle size distribution of the ferrous gluconate sample by sieving and laser diffraction.

- Short description of test conditions: The sieves were assembled into two separate size ranges to allow for adequate agitation. For the size range 841 to 180 um, approximately 8.234 grams of sample was weighed and sieved. For the size range 150 to 29 um, approximately 8.867 grams of sample was weighted and sieved. The sample was taken from the top of the sample bottle. The sieves were agitated manually for approximately 1 minute. The contents of each sieve was removed and weighed. For the laser diffraction method, approximately 0.35g of the sample was transferred to the sampling chamber of the Horiba LA910 instrument until a transmittance of 75-90% was achieved. 300ml of Isopropyl Alcohol was used as dispersant fluid. The sample was constantly stirred during the particle size analysis in order to keep the heavier particles suspended. Also, the sample was sonicated for 60 seconds prior to the measurement interval. The Horiba LA910 Laser Diffraction Instrument operation conditions are listed below. Three replicate measurements were performed.

- Parameters analysed / observed:
Agitation Speed: 2
Circulation Speed: 2
Relative Refractive Index: 1.40-0.00i
Sonics Before Measurement: 60sec.
Sonics During Measurement: Off
Sampling Times: 40

GLP compliance:

no

Type of method:

Laser scattering/diffraction

Type of distribution:

volumetric distribution

Specific details on test material used for the study:

SOURCE OF TEST MATERIAL
- Source and lot/batch No.of test material:
Manufacturer Polytec International Ltd.
Batch # / Lot # 20131012

Mass median aerodynamic diameter:

ca. 370.1 µm

Key result

Percentile:

D50

Mean:

ca. 370.1 µm

St. dev.:

215.181

Percentile:

D50

Mean:

>= 342.8 - <= 407.7 µm

St. dev.:

215.181

Percentile:

D90

Mean:

>= 596.6 - <= 664.9 µm

St. dev.:

215.181

Percentile:

D10

Mean:

> 46.3 - <= 57.2 µm

St. dev.:

215.181

The particle size distribution from 841 – 28 microns obtained by a sieve method, of ferrous gluconate, is summarized in the following table.                                                       

Particle Size Distribution by the sieve method for ferrous gluconate.

Sieve designation*	Sieve Size (microns)	Weight % of sample (Wt. %)
ASTM 20	=841	43.1
	833	2.1
ASTM 30	595	25.3
ASTM 40	420	14.1
ASTM 45	354	2.6
	240	0.0
ASTM 80	180	8.8
	125	0.9
ASTM 140	105	0.1
ASTM 200	74	0.8
	58-62	0.2
ASTM 325	45	0.1
	28-32	0.0
	<28	0.0
	% Recovery	98.1%

* Sieves traceable to ASTM are listed as corresponding sieve number

A separate sample was analyzed by laser diffraction using Horiba LA-910 laser diffraction instrument. The average mean diameter was in the 358 µm size range and the average median diameter was 370 µm. The data clearly exhibits a bi-modal distribution with peaks at approximately 4 µm and ~400 µm. The largest population of particles is in the 400 µm size range. The complete laser diffraction volume-based results are shown in the following table. Comparison to the sieve method would indicate the sieve method is less effective in sieving particles >595 um which would appear to collagulate in the first sieve which is >841 um. 

Volume Based Particle Size Distribution Summary

Sample ID	Run	Mean (µm)	Mode (µm)	Median (µm)	D10	D50	D90
Sourscav 20131012	1	355.0	485.7	359.8	53.0	359.8	640.8
Sourscav 20131012	2	384.9	551.4	407.7	57.2	407.7	664.9
Sourscav 20131012	3	335.6	424.9	342.8	46.3	342.8	596.6
Average PSD	AVE.	358.5	487.3	370.1	52.2	370.1	634.1

Conclusions:

The average median diameter was reported to be 370 µm. The data clearly exhibits a bi-modal distribution with peaks at approximately 4 µm and ~400 µm. The largest population of particles is in the 400 µm size range. The result is considered to be reliable.

Description of key information

A study was conducted using sieving and laser diffraction.
The average median diameter was 370 µm.

Additional information

The particle size distribution of ferrous gluconate was measured via sieving and via laser diffraction (Baldwin 2014, Particle Size Analysis of Iron Gluconate by sieving and laser diffraction).

The average median diameter was 370 µm.

The data clearly exhibits a bi-modal distribution with peaks at approximately 4 µm and ~400 µm. The largest population of particles is in the 400 µm size range.