The effect of screw configuration and formulation variables on liquid requirements and granule quality in a continuous twin screw wet granulation process
The effect of two screw configurations with varying stagger angle was evaluated on the liquid amount required to produce good quality granules for a highly (mannitol-based) and a poorly (DCP-based) soluble formulation containing different binders. It is generally known that the use of a higher liquid amount improves the granule quality in twin screw granulation. However, from an industrial point of view, lower liquid amounts for effective granulation are preferred, as this speeds up the production time as less time is required for drying. A screw configuration containing mixing elements with a higher stagger angle (90°) produced granules with a lower friability and a larger size at lower liquid-to-solid ratios compared to a screw configuration with all the mixing elements staggered at 60°. For each binder, incorporating a highly soluble filler into the formulation allowed granulation at lower liquid-to-solid ratios compared to a filler having a poorer aqueous solubility. The different binder types affected the granule quality and liquid requirements for granulation differently. Furthermore, similar granule quality between (partially) pregelatinized starches and in situ gelatinized starches was achieved.
L. Vandevivere, E. Van Wijmeersch, O. Häusler, T. De Beer, C. Vervaet, V. Vanhoorne,
The effect of screw configuration and formulation variables on liquid requirements and granule quality in a continuous twin screw wet granulation process,
Journal of Drug Delivery Science and Technology, Volume 68, 2022, 103042, ISSN 1773-2247,
https://doi.org/10.1016/j.jddst.2021.103042.
See also the talk of Lise Vandevivere at the ExciPerience 2021