Search tips
Search criteria 


Logo of aapspharmspringer.comThis journalToc AlertsSubmit OnlineOpen Choice
AAPS PharmSciTech. 2006 June; 7(2): E126–E137.
Published online 2006 May 26. doi:  10.1208/pt070249
PMCID: PMC2750276

Commerical reference shape standards use in the study of particle shape effect on laser diffraction particle size analysis


The purpose of this paper is to describe the use of LGC Promochem AEA 1001 to AEA 1003 monosized fiberanalog shape standards in the study of the effect of particle shape on laser diffraction (LD) particle size analysis (psa). The psa of the AEA standards was conducted using LD psa systems from Beckman Coulter, Horiba, and Malvern Instruments. Flow speed settings, sample refractive index values, and sample cell types were varied to examine the extent to which the shape effect on LD psa results is modified by these variables. The volume and number probability plots resulting from these measurements were each characterized by a spread in the particle size distribution that roughly extended from the breadth to the longest dimension of the particles. For most of the selected sample refractive index values, the volume probability plots were characterized by apparent bimodal distributions. The results, therefore, provide experimental verification of the conclusions from theoretical studies of LD psa system response to monosized elliptical particles in which this apparent bimodality was the predicted result in the case of flow-oriented particles. The data support the findings from previous studies conducted over the past 10 years that have called into question the verity of the tenets of, and therefore the value of the application of, the equivalent spherical volume diameter theory and the random particle orientation model to the interpretation of LD psa results from measurements made on nonspherical particles.

Keywords: commercial reference shape standards, nonspherical particles, laser diffraction, equivalent spherical volume diameter, flow orientation, random orientation, mass equivalency

Full Text

The Full Text of this article is available as a PDF (619K).

Selected References

These references are in PubMed. This may not be the complete list of references from this article.
1. Jillavenkatesa A, Dapkunas SJ, Lum L-SH. NIST Recommended Practice Guide. Special publication 960-1. Particle Size Characterization. Washington, DC: National Institute of Standards and Technology, Department of Commerce, US Government Printing Office; 2001.
2. How to choose a particle size analysis method. Metropolitan Computing Corporation Web site. Available at: http://www.particlesize. com/howto.htm. Accessed: June 27, 2005.
3. Etzler FM, Sanderson MS. Particle size analysis: a comparative study of various methods. Part Part Syst Charact. 1995;12:217–224. doi: 10.1002/ppsc.19950120503. [Cross Ref]
4. Etzler FM, Deanne R. Particle-size analysis: a comparison of various methods II. Part Part Syst Charact. 1997;14:278–282. doi: 10.1002/ppsc.19970140604. [Cross Ref]
5. Etzler FM. Particle-size analysis: a comparison of methods. Am Pharm Rev. 2006;7:104–108.
6. Driscoll DF, Etzler F, Barber TA, Nehne J, Niemann W, Bistrian BR. Physicochemical assessments of parenteral lipid emulsions: light obscuration versus laser diffraction. Int J Pharm. 2001;21:21–37. doi: 10.1016/S0378-5173(01)00626-3. [PubMed] [Cross Ref]
7. Gabas N, Hiquily N, Laguuerie C. Response of laser diffraction particle sizer to anisometric particles. Part Part Syst Charact. 1994;11:121–126. doi: 10.1002/ppsc.19940110203. [Cross Ref]
8. Brewer E, Ramsland A. Particle size determination by automated microscopical imaging analysis with comparison to laser diffraction. J Pharm Sci. 1994;84:499–501. doi: 10.1002/jps.2600840421. [PubMed] [Cross Ref]
9. Heffels C, Heitzmann D, Hirleman ED, Scarlett B. Forward light scattering from sharp-edged crystals in Fraunhofer and anomalous diffraction approximations. Appl Opt. 1995;34:102–108. doi: 10.1364/AO.34.006552. [PubMed] [Cross Ref]
10. Heffels CMG, Verheijen PJT, Heitzmann D, Scarlett B. Correlation of the effect of particle shape on the size distribution measured with a laser diffraction instrument. Part Part Syst Charact. 1996;13:271–279. doi: 10.1002/ppsc.19960130504. [Cross Ref]
11. Kaye BH, Alliet D, Switzer L, Turbitt-Daoust C. The effect of shape on intermethod correlation of techniques for characterizing the size distribution of a powder, I: correlating the size distribution measured by sieving, image analysis, and diffractometer methods. Part Part Syst Charact. 1997;14:219–255.
12. Kaye BH, Alliet D, Switzer L, Turbitt-Daoust C. The effect of shape on intermethod correlation of techniques for characterizing the size distribution of a powder, II: correlating the size distribution as measured by diffractometer methods, TSI-Amherst aerosol spectrometer, and Coulter counter. Part Part Syst Charact. 1999;16:266–273. doi: 10.1002/(SICI)1521-4117(199912)16:6<266::AID-PPSC266>3.0.CO;2-3. [Cross Ref]
13. Muhlenweg H, Hirleman ED. Laser diffraction spectroscopy: influence of particle shape and a shape adaptation technique. Part Part Syst Charact. 1998;15:163–169. doi: 10.1002/(SICI)1521-4117(199808)15:4<163::AID-PPSC163>3.0.CO;2-8. [Cross Ref]
14. Naito M, Hayawaka O, Nakahira K, Mori H, Tsubaki J. Effect of particle shape on the particle size distribution measured with commercial equipment. Powder Technol. 1998;100:52–60. doi: 10.1016/S0032-5910(98)00052-7. [Cross Ref]
15. Bowen P, Humphry-Baker R, Herard C. Particle size distribution measurement of regular anisotropic particles—cylinders and platelets. Proceedings of World Congress on Particle Technology 3. World Congress on Particle Technology: July 6–9, 1998; Brighton, UK.
16. Bowen P, Sheng J, Jongen N. Particle size distribution measurement of anisotropic particles—cylinders and platelets—practical examples. Recent Progres en Genie des Procedes. 2001:251–256.
17. Bowen P. Particle size distribution measurement from millimeters to nanometers and from rods to platelets. J Dispersion Sci Technol. 2002;23:631–662. doi: 10.1081/DIS-120015368. [Cross Ref]
18. Mang JT, Skidmore CB, Kramer JF, Phillips DS, Quantitative morphological characterization of high explosive crystal grains by light diffraction and microscopy. Fraunhofer-Institut fur Chemische Technologie 31st International Conference; June 27–30, 2000; Karlsruhe, Germany, Munich, Germany: Fraun-hofer Gesellschaft; 2000:20-1—20-14.
19. Matsuyama T, Yamamoto H, Scarlett B. Transformation of diffraction pattern due to ellipsoids into equivalent diameter distribution for spheres. Part Part Syst Charact. 2000;17:41–46. doi: 10.1002/1521-4117(200006)17:2<41::AID-PPSC41>3.0.CO;2-W. [Cross Ref]
20. Pabst W, Kunes K, Gregorva E, Havrda J. Extraction of shape information from particle size measurements. Brit Ceram Trans. 2001;100:106–109. doi: 10.1179/096797801681297. [Cross Ref]
21. Xu R, Di Guida A. Size and shape characterization of small particles. Powder Technol. 2003;132:145–153. doi: 10.1016/S0032-5910(03)00048-2. [Cross Ref]
22. Berthold C, Klein R, Luhmann J, Nickel K. Characterization of fibres and fibre collectives with common laser diffractometers. Part Part Syst Charact. 2000;17:113–116. doi: 10.1002/1521-4117(200010)17:3<113::AID-PPSC113>3.0.CO;2-Z. [Cross Ref]
23. Prasanna HR, Jefferson EH, Taylor JS, Hussain AS, Karuhn RF, Lyon RC. Comparative analysis of common particle sizing techniques for pharmaceutical powders. FDA Science Poster (2001). Available at: /Bibliography/PS%20FDA%20SF01%20Poster.pdf. Accessed: June 27, 2005.
24. Mitchell JP. Aerosol generation and instrument calibration. In: Colbeck I, editor. Physical and Chemical Properties of Aerosols. London, UK: Blackie Academic and Professional; 1998. pp. 31–79.
25. Burgess DJ, Duffy E, Etzler F, Hickey AJ. Particle size analysis: AAPS Workshop Report, cosponsored by the Food and Drug Administration and the United States Pharmacopeia. AAPS J. 2006;6:E20–E20. [PMC free article] [PubMed]
26. Schellhamer M, Bowen P, Vaussourd C, Hofmann H. Accuracy of particle size distribution measurement of spherical glass beads (70–400μm) using laser diffraction. Recent Progres en Genie des Procedes. 2001;15:129–134.
27. Allen T. Powder Sampling and Particle Size Determination. Amsterdam, The Netherlands: Elsevier BV; 2003. pp. 167–167.
28. Zitoun KB, Sastry SK. Orientation distribution of solids in continuous solid-liquid flow in a vertical tube. Chem Eng Sci. 2006;59:2767–2775. doi: 10.1016/j.ces.2004.04.004. [Cross Ref]
29. Jianzhong L, Weifeng Z, Zhaosheng Y. Numerical research on the orientation distribution of fibers immersed in laminar and turbulent pipe flows. J Aerosol Sci. 2006;35:63–82. doi: 10.1016/S0021-8502(03)00388-4. [Cross Ref]
30. Bumiller M, Carson J, Prescott J. A preliminary investigation concerning the effect of particle shape on a powder’s flow properties. Paper presented at: World Congress on Particle Technology 4; July 21–25, 2002; Sydney, Australia. Available at:
31. Rawle A. The importance of particle sizing to the coating industry, Part 1: particle size measurement. Adv Colour Sci Technol. 2002;5:1–12.
32. Kippax P. Issues in the appraisal of laser diffraction particle sizing techniques. Pharm Tech Eur. 2005; 32–39.
33. International Organization for Standardization (ISO) 13320-1. Particle size analysis—laser diffraction methods, Part 1: general principles. ISO Standards Authority. 1999. Available at: Accessed: May 23, 2006.
34. United States Pharmacopoeia (USP-NF) USP General Chapter <429>. Light diffraction measurement of particle size. Pharmacopoeial Forum. 2002;29(4):1293–1298.

Articles from AAPS PharmSciTech are provided here courtesy of American Association of Pharmaceutical Scientists