Study of radial die-wall pressure during high speed tableting: effect of formulation variables

With high-speed compaction cycles as applied in pharmaceutical industrial presses, robust tools like radial die-wall pressure (RDWP) are required to monitor the deformation behavior of formulations under pressure and to avoid common problems such as capping. In this study, the effects of common formulation factors such as lubricant, binder, and drug loading on RDW were investigated. Compaction simulation using Presster™ was applied for five pharmaceutical fillers with different compaction behaviors. Two lubricants, two binders and paracetamol as a model drug were used. Residual die-wall (RDP) and other compaction parameters were measured. Lubricant reduced RDP for fillers with plastic/brittle behavior(s), (p < 0.05), while increased RDP for fillers with plastic/elastic behavior, (p < 0.05), leading to higher tendency for capping in the later fillers. Binder reduced RDP for the fillers, (p < 0.05), hence, decreased capping probability. By increasing drug loading for fillers with plastic/elastic behavior(s), RDP was increased, (p = 0.00001), leading to capping, especially at high compaction pressure and speed. Die-wall instrumentation was useful in investigating formulation variables and detecting capping during high speed tableting.