Prediction of coning phenomena for irregular particles in paddle dissolution test.

The purpose of the present study was to investigate the applicability of the Zwietering equation to predict the occurrence of coning phenomena for non-spherical, porous, and swell-able particles in the paddle dissolution test. For non-spherical particles, the minimum rotation speed at which the coning phenomena disappear (no coning rpm, NCrpm) was appropriately predicted by using the Stokes diameter or the short side length of the particles. For porous and swell-able particles, NCrpm was appropriately predicted by using the Stokes density of the particles. The accuracy of the Zwietering equation was sufficient to be used for development of a dissolution test method.