Twin-screw melt granulation is an emerging continuous manufacturing technology. Since formulation is exposed to elevated temperature and pressure during twin-screw melt granulation, undesired physicochemical changes to drug is the primary concern.
Various approaches to maintain the stability of drug during twin-screw melt granulation will be discussed. Granules based on hydropropyl cellulose (HPC) demonstrated superior tabletability. However, higher level of chemical degradation was observed with HPC-based formulation, compared to formulations based on low melting point binders such as PEG 8000. Approaches to improve drug stability for HPC-based formulations are illustrated from processing (screw design, processing parameters, and split feeding) and formulation (plasticization) perspectives.