![]() ![]() LD estimates volume-based PSD by measuring the forward light-scattering (diffraction) of light from the laser. Furthermore, the sieving time for SA is one of several factors which can significantly affect the final results of measurement (Chapeau et al., 2008). However, sieving is very labour-intensive and involves long measurement times. The significant advantage of SA is that the sieves can test large amounts of particles without being very expensive. The sieve defines a particle diameter as whether the particle can pass through the particular mesh size or not (Konert and Vandenberghe, 1997). Samples are sieved through several square meshes. Sieving is the most common method for measuring size distributions of many types of materials because of its simplicity of use and preparation. LD, FBRM and IA are among the most widely used in-process or off-line techniques (Li et al., 2005).Įach technique defines a size of particle in a different way. A variety of characteri- zation techniques are used for the determination of PSD in current chemical process industry such as Sieve Analysis (SA), Laser Diffraction (LD), Ultrasonic Attenu ation Spectroscopy (UAS), Image analysis (IA) and focused beam reflectance measurement (FBRM). Within the pharmaceutical industry, the PSD characterization of particles is generally of great concern for evaluating the quality of pharmaceutical products (Tinke et al., 2008). Particle size distribution (PSD) is an important parameter of many particulate products and it is critical for controlling process efficiency such as filtration rates, flow properties or dissolution rates (Kempkes et al., 2008 Hareland, 1994). The results obtained from FBRM were complex as its measurements depend on many factors such as its PSDs, particle optical properties and shape. It was confirmed that the square weighted Chord Distribution gives most similar results to those obtained by other techniques. The use of different statistics was evaluated to find the most suitable statistics which resemble the PSD results obtained from other techniques. It is very complicated to convert the CLDs obtained from FBRM to their corresponding PSDs as it requires complex calculations. The number based PSDs obtained by IA were converted to equivalent spherical volume based PSDs. For spherical particles, the PSDs obtained by SA, IA and LD agreed well but there was a less consistent result among different particle measurement techniques for non-spherical particles. It was observed that the results obtained by different techniques were affected by the particle shape and the type of particle. ![]() The two compounds selected for the study were spherical glass beads and non-spherical Sodium Chloride. Particle size distributions (PSDs) measured by different techniques, including Sieve Analysis (SA), Image Analysis (IA), Laser Diffraction (LD) and Focused-Beam Reflectance Measurement (FBRM), were investigated. ![]()
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