title: Coning phenomena under laminar flow.
abstract: The purpose of the present study was to investigate coning phenomena in the paddle dissolution test under laminar flow (Reynolds number <500). The minimum rotation speed at which the coning phenomena disappear (no coning rpm, NCrpm) was measured in viscous media (23 to 147mPa∙s) using various particles. The exponent values of particle size, density, and viscosity parameters in the Zwietering equation were found to be 0.066, 0.38, and 0.22, respectively. NCrpm was appropriately predicted by the Zwietering equation (average error: 8rpm). These values are very different from those for turbulent flow, suggesting that the main physical forces governing the motion of particles can be different between turbulent flow and laminar flow. This point should be taken into account when understanding the dissolution of drug products in viscous fluids representing the fed state.
authors: Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan.
authors: Mizuki
authors: M
authors: Higuchi
authors: Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan.
authors: Katsuhide
authors: K
authors: Terada
authors: Department of Pharmaceutics, Faculty of Pharmaceutical Sciences, Toho University, 2-2-1, Miyama, Funabashi, Chiba 274-8510, Japan. Electronic address: kiyohiko.sugano@phar.toho-u.ac.jp.
authors: Kiyohiko
authors: K
authors: Sugano
mesh_terms: D009687:Nuclear Proteins; D010599:Pharmacokinetics; D016601:RNA-Binding Proteins; D012212:Rheology; D012399:Rotation; D013678:Technology, Pharmaceutical / Q000379:methods*
chemical_list: C113292:MCRS1 protein, human; D009687:Nuclear Proteins; D016601:RNA-Binding Proteins
keywords: Coning; Laminar flow; Paddle; Particle shape; Zwietering equation