Upscaling of fluidized bed Wurster processes

Save the date: March 5, 2024  –  9:45 am – Speakers are Dr. Sören E. Lehmann and Dr. Norbert Pöllinger, Glatt Pharmaceutical Services

Fluidized bed coating and agglomeration are very common processes in pharmaceutical as well as in food and chemical industries. Specifically, in the manufacture of pharmaceutical products, batch processes are widely applied from small lab-scale (i.e., batch sizes of a few grams) to large commercial scale of several hundred kilograms per batch.

During the development of a new pharmaceutical product, commonly three to five upscaling steps are conducted between feasibility studies and commercial manufacture. It is crucial to maintain the intended product quality throughout every step. A reliable upscaling concept is therefore essential for smooth and efficient process development and commercial manufacture. Glatt has developed and established such an upscaling concept for fluidized bed processes with Wurster configuration. It is suitable for coating and agglomeration processes alike. The concept is based on basic thermodynamical and fluid mechanical principles, resulting in reliable scaleup factors. Thus, extensive calculations or simulations are avoided. Furthermore, it allows a good estimation of the resulting process time. The concept is of course applicable for downscaling as well.

The batch size is scaled while it is key to maintain the same product humidity and temperature to maintain product quality. Fluidization behavior, droplet size and drying capacity in the system must therefore be considered. Underlying assumptions are the availability of fluidized bed equipment that suits the upscaling concept e.g., highly similar geometric shape of the process chambers and that required process parameters such as inlet air volume flow can be realized.

The details of the scaleup concept will be introduced and discussed in this contribution. Prove of the concept will be given by examples.