Particle size analysis: A comparison of various methods ii

Etzler, Frank M.; Deanne, Richard

doi:10.1002/ppsc.19970140604

Cited by 65 publications

(43 citation statements)

References 3 publications

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“…In the above investigation, deviations from sphericity were estimated to overpredict size distribution breadth (determined by comparing the ratio: ([d 90 −d 10 ]/VMD)) by as much as 50% with the nonspherical particles having two-dimensional aspect ratios (A r ) slightly greater than 2.0 (A r =1.0 for a perfect sphere). A similar bias was also observed in another similar study by Etzler and Deanne (55). The underlying Lorenz-Mie-or Fraunhoferbased models associated with commercially available LD both assume that the particles are spherical (41).…”

Section: Laser Diffractometrysupporting

confidence: 59%

Non-impactor-Based Methods for Sizing of Aerosols Emitted from Orally Inhaled and Nasal Drug Products (OINDPs)

Mitchell

Bauer²,

Lyapustina³

et al. 2011

AAPS PharmSciTech

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Abstract. The purpose of this article is to review non-impactor-based methods for measuring particle size distributions of orally inhaled and nasal pharmaceutical aerosols. The assessment of the size distributions of sprays and aerosols from orally inhaled and nasal drug products by methods not involving multi-stage cascade impaction may offer significant potential advantages in terms of labor savings and reducing the risk for operator-related errors associated with complex-to-undertake impactor-based methods. Indeed, in the case of nasal spray products, cascade impaction is inappropriate and alternative, and preferably non-invasive methods must be sought that minimize size-related bias associated with the measurement process for these relatively large droplets. This review highlights the options that are available to those involved with product quality assessments, providing guidance on relative strengths and weaknesses, as well as highlighting precautions that should be observed to minimize bias. The advent of Raman chemical imaging, which enables an estimate to be made of the proportion of each particle comprising active pharmaceutical ingredient(s) (APIs), necessitates a re-think about the value of classical microscopy image analysis as now being capable of providing API-relevant information from collected aerosols and sprays.

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Section: Laser Diffractometrysupporting

confidence: 59%

Non-impactor-Based Methods for Sizing of Aerosols Emitted from Orally Inhaled and Nasal Drug Products (OINDPs)

Mitchell

Bauer²,

Lyapustina³

et al. 2011

AAPS PharmSciTech

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“…Though LD has shown to be an extremely powerful PSD technique in terms of its universal applicability, broad dynamic size range, (relatively) low required sample amount, user friendliness, and (high) robustness and precision, for years a serious discussion is going on regarding the suggested limited accuracy of this technology [15,16,17]. Indeed, from a measurement point of view, (a) the limited angular resolution of the detectors, (b) the limited angular scattering information and scatter intensity at a smaller particle size, and (c) the orientation of (non-spherical) particles should be mentioned.…”

Section: Introductionmentioning

confidence: 99%

Particle shape and orientation in laser diffraction and static image analysis size distribution analysis of micrometer sized rectangular particles

Tinke¹,

Carnicer

Govoreanu³

et al. 2008

Powder Technology

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A systematic study has been described on the laser diffraction (LD) and static image analysis (SIA) of rectangular particles [1]. To rule out powder sampling, sample dispersion and particle orientation as a possible root cause for differences in size distribution profile, powder samples were initially immobilized by means of a dry disperser onto a glass plate. For a defined region of the glass plate the diffraction pattern as induced by the dispersed particles, and the 2D dimensions of the individual particles were measured by LD and optical microscopy, respectively. Correlation between LD and SIA could be demonstrated considering the scattering intensity of the individual particles as the most dominating factor. For both spherical and rectangular particles, theory explains the latter to relate to the square of their projected area. In traditional LD, the size distribution profile is dominated by the maximum projected area of the particles (A), and the diffraction diameters of a rectangular particle with length L and breadth B are perceived by the LD instrument to correspond by approximation with spheres having a diameter of ∅ L and ∅ B , respectively. Weighting for differences in scattering intensity between spherical and Page 3 of 56 rectangular particles exlains each rectangular particle to contribute to the overall LD volume probability distribution proportional to A 2 /L and A 2 /B. Accordingly, for rectangular particles this scattering intensity weighted diffraction diameter (SIWDD) concept explains an overestimation of their shortest dimension and an underestimation of their longest dimension. For this study various samples have been analysed with the longest dimension of the particles ranging from ca. 10 to 1000 µm. For a variety of pharmaceutical powders all with a different rectangular particle size and shape, the demonstrated correlation between LD and SIA aims to facilitate the user in a better validation of LD methods based on SIA data.

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“…Grain size mean, mode, sorting, skewness, and kurtosis were calculated using the Fraunhofer optical model (Etzler and Deanne, 1997).…”

Section: Methodsmentioning

confidence: 99%

Stratigraphic and Paleoenvironmental Reconstruction of a Mid-Pliocene Fossil Site in the High Arctic (Ellesmere Island, Nunavut): Evidence of an Ancient Peatland with Beaver Activity + Online Appendix Figures S1 and S2 (See Article Tools)

Mitchell¹,

Rybczynski²,

Schröder-Adams³

et al. 2016

ARCTIC

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ABSTRACT. Neogene terrestrial deposits of sand and gravel with preserved wood and peat accumulations occur in many areas of the High Arctic. The Pliocene-aged Beaver Pond fossil site (Ellesmere Island, NU) is one such site that differs from other sites in the great thickness of its peat layer and the presence of a rich vertebrate faunal assemblage, along with numerous beaver-cut sticks. Although the site has been the subject of intense paleontological investigations for over two decades, there has not been a reconstruction of its depositional history. In this study, measured sections within and surrounding the site established the stratigraphy and lateral continuity of the stratigraphic units. Grain size analysis, loss on ignition, and fossil diatom assemblages were examined to reconstruct paleoenvironmental changes in the sequence. The base of the section was interpreted as a floodplain system. Using modern peat accumulation rates, the maximum thickness (240 cm) of the overlying peat layer is estimated to represent 49 000 ± 12 000 years. From this evidence, we suggest that during the peat formation interval, beaver activity may have played a role in creating an open water environment. The peat unit was overlain by sand, rich in organic matter and charcoal, suggesting environmental change and fire occurrence.

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Particle size analysis: A comparison of various methods ii

Cited by 65 publications

References 3 publications

Non-impactor-Based Methods for Sizing of Aerosols Emitted from Orally Inhaled and Nasal Drug Products (OINDPs)

Non-impactor-Based Methods for Sizing of Aerosols Emitted from Orally Inhaled and Nasal Drug Products (OINDPs)

Particle shape and orientation in laser diffraction and static image analysis size distribution analysis of micrometer sized rectangular particles

Stratigraphic and Paleoenvironmental Reconstruction of a Mid-Pliocene Fossil Site in the High Arctic (Ellesmere Island, Nunavut): Evidence of an Ancient Peatland with Beaver Activity + Online Appendix Figures S1 and S2 (See Article Tools)

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