Study On Mixing And Dissolution Process Of Acetaminophen (APAP) During Hot Melt Extrusion

Focused on the solid dispersions of acetaminophen-polyethylene oxide(APAP-PEO),the new process of dry particle heating coating preparation applied to hot melt extrusion was proposed in this paper.Meanwhile,mixing process of APAP-PEO,mechanism of APAP melting in PEO and the experimental research on hot melt extrusion of APAP-PEO were studied in this paper.Based on the mechanism of hot melt extrusion for drug,the working principle,structure,process design and design principle of dry particle heating coating preparation device were analyzed and investigated comprehensively.Numerical simulation of the mixing process of APAP in the disc mixer was carried by means of applying the fluid dynamics software POLYFLOW.Moreover,the effects of rotating speed and gap between discs on mixing process for APAP were analyzed quantitatively.Based on data derived from numerical simulation of the mixing process,the two-dimension numerical model of APAP melting in PEO was built up.The FLUENT software was used to analyze the rule of phase transition of APAP melting in PEO according to volume change of APAP and liquid fraction change in APAP-PEO.The solid dispersions of APAP-PEO were prepared in the disc mixer and twin-rotor mixer which were self-developed.Additionally,effects of preparation methods and main process parameters on mixing,dissolution,crystallization and in vitro dissolution processes of APAP were studied.