Micro-feeding and mixing of pharmaceutical solid dosage forms under external vibration

This study addresses the challenges of micro-dosing and mixing in the continuous manufacturing of solid pharmaceutical formulations by developing a novel continuous feeding-mixing system based on external vibration excitation. The innovative design of a hopper structure with adjustable outlet area distribution demonstrated the potential for achieving precise mixing control of an active pharmaceutical ingredient (API) and an excipient across varying ratios. Experiments first validated the promotion of viscous particle flow by vertical vibration, achieving stable feeding within the range of 0.6–15 mg/s. Building on this, precise control of mixing ratios was enabled by designing different outlet area ratios. In mixing performance evaluation, online X-ray fluorescence spectroscopy confirmed the system achieves high-uniformity mixing with a coefficient of variation below 10 %. The study further revealed that optimal mixing stability occurs when Γ < 5, whereas excessive vibration degrades mixing quality.