Modeling of inter-tablet coating uniformity of electrostatic dry powder coating by discrete element method

The current study aims to apply an innovative mathematical model based on the discrete element method to numerically simulate the electrostatic dry powder coating process and to predict the inter-tablet coating uniformity. The newly developed mathematical model could efficiently handle millions of coating particles and precisely obtain the coating weight gain of individual tablet core online, which was highly consistent with the experimental results. And the newly developed model was applied to fully investigate the influence factors of the inter-tablet coating uniformity of electrostatic powder coating, including coating particle radius, charge intensity of the coating par-ticles, the rotating speed of the pan coater and the feeding time of the coating powders, all of which could be optimized to largely improve the coating uniformity. The study demonstrates that this newly developed model is promising in precisely simulating the electrostatic dry powder coating process for sufficient coating uniformity.