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. Copyright © 2015 Elsevier B.V. All rights reserved.
Mizuki Higuchi, Katsuhide Terada, Kiyohiko Sugano. Coning phenomena under laminar flow. European journal of pharmaceutical sciences : official journal of the European Federation for Pharmaceutical Sciences. 2015 Dec 1;80:53-5
PMID: 26296866
View Full Text