Nadine Kubina

Contents

Abstract

Continuous melt granulation presents a sustainable alternative to conventional wet granulation by eliminating the need for a granulation liquid and subsequent drying step. This project therefore investigates the application of a planetary roller granulator for continuous melt granulation, with a focus on developing a comprehensive model that enables process optimization through a mechanistic understanding of transport, mixing and energy input.

Description

Granulation is a key unit operation in pharmaceutical manufacturing. Among the available techniques, melt granulation is particularly suited for moisture-sensitive active pharmaceutical ingredients, as it requires no granulation liquid and therefore no drying step. These characteristics in addition to a continuous operation contribute to a more sustainable and energy-efficient manufacturing approach. While twin-screw extruders are currently the standard equipment for continuous melt granulation, the planetary roller granulator offers a promising alternative due to its unique heating concept, which encompasses both the inner and outer boundaries of the process volume. This results in a higher ratio of free process volume to heated surface area, enhancing the potential for precise temperature control.

A key limitation of conventional melt granulation setups is that binder melting and granule formation occur simultaneously within the same processing zone. As a result, these two rate-determining processes are linked inherently. To overcome this constraint, a two-stage process configuration is proposed, in which binder melting and granule formation are separated in time and space within a single processing unit.

The central objective of this project is to develop a comprehensive model enabling optimization of the granulation process. The model addresses material transformation along the granulation stage (global scale), as a sequence of segments (local scale), thereby allowing both process and product quality to be predicted and controlled with greater precision.

Acknowledgements

This project is funded by the German research foundation (BA 7743/1-1).