Optimization of Wurster fluid bed coating: Mathematical model validated against pharmaceutical production data

Wurster fluid bed coating is an effective way of manufacturing pharmaceutical pellets requiring specific characteristics such as high drug loading or enteric protection. The optimization of the coating process can be demanding because it necessitates many time-consuming experiments. To reduce the need for experiments and prevent undesired agglomeration, a multi-scale model has been developed. On the device scale, the model predicts the temperature, moisture content, and average coating thickness. On the micro-scale, the model estimates the evaporation time of a single sessile droplet.

Highlights

Model for a fast and accurate temperature prediction in Wurster fluid bed coating.

Micro-scale model describing evaporation kinetics of sprayed liquid.

Evaporation time of droplets can be used as a descriptor for comparison and scale up.

Parametric diagrams for faster and more reliable estimation of process conditions.

By coupling models at both length-scale, it is possible to evaluate droplet evaporation time as a function of process parameters and use it as a tool for process transfer between different production sites and equipment. The model was validated against existing production data. The predicted outlet air temperature was in good agreement, and most importantly, the predicted values of the evaporation time separated undesired agglomeration and successful coating regime. Continue on optimization of Wurster fluid bed coating

Jiří Kolář, Pavel Kovačík, Tereza Choděrová, Zdeněk Grof, František Štěpánek, Optimization of Wurster fluid bed coating: Mathematical model validated against pharmaceutical production data, Powder Technology, 2021, ISSN 0032-5910, https://doi.org/10.1016/j.powtec.2021.03.059