Abstract: This paper reported a study on the numerical simulation for the mixing process of acetaminophen as an active pharmaceutical ingredient and poly(ethylene oxide) as a carrier during hot-melt extrusion by a Polyflow software using particle size, mixing index, separation scale and time-average mixing efficiency as characterization parameters. The influences of rotation speed and the gap between discs on the mixing process were investigated. The results indicated that the dispersion mixing and distribution mixing during hot-melt extrusion were enhanced by increasing the rotating speed and decreasing the gap between discs. Meanwhile, the particle sizes of the active pharmaceutical ingredient were obtained as preliminary data for the analysis of its dissolution mechanism.

Key words: hot-melt extrusion, active pharmaceutical ingredient, mixing process, rotary disc mixer