title: Image analysis of the shape of granulated powder grains.
abstract: This study presents and evaluates two new form factors for the characterization of pharmaceutical microparticles using image analysis techniques. The first factor, denoted Vr, is mean percentage variation in radial chord length (for a large number of radial chords drawn at small angular intervals) with respect to mean radial chord length. The second factor, denoted Vp, is percentage deviation of measured perimeter from the perimeter of a circle with radius equal to the mean radial chord length of the particle. Considering both ideal shapes and real pharmaceutical particle populations, these factors are compared with other form factors widely used in pharmaceutical technology. Our results indicate that Vr and Vp allow effective assessment of whether the particles of a given population show pharmaceutically significant deviations from sphericity. The two factors additionally facilitate identification of the basic shapes of particle outlines (notably ellipsoid, rectangular, and irregular). These factors may thus be of value for the characterization and monitoring of pharmaceutical pelleting processes.
authors.affiliation: Departamento de Farmacia y Tecnología Farmacéutica, Facultade de Farmacia, Universidade de Santiago de Compostela, Campus Universitario sur s/n. 15076 Santiago de Compostela, A Coruña, Spain.
authors.forename: Sergio
authors.initials: S
authors.lastname: Almeida-Prieto
authors.forename: José
authors.initials: J
authors.lastname: Blanco-Méndez
authors.forename: Francisco J
authors.initials: FJ
authors.lastname: Otero-Espinar
mesh_terms: D007089:Image Enhancement / Q000379:methods*; D010316:Particle Size; D011208:Powders / Q000032:analysis / Q000737:chemistry*; D012984:Software
chemical_list: D011208:Powders