The preparation of a solid dispersion powder of indomethacin with crospovidone using a twin-screw extruder or kneader

A solid dispersion (SD) powder of indomethacin (IM) with CrosPVP was prepared continuously using a twin-screw extruder (extruder) or twin-screw kneader (kneader), which made it possible to simultaneously control kneading, mixing, and heating. For the extruder or kneader, IM existed in an amorphous state while it was treated with a screw rotation speed of 15 min−1 or 50 min−1, respectively, while being heated to 140 °C. IM and CrosPVP interacted to maintain IM in an amorphous state. The solubility of SD powders of IM was improved about four-fold compared to crystalline IM. The retention time of the samples in the machine, screw rotation speed, and heating temperature play important roles in the preparation of SD. Although SD was prepared using a theta composer followed by heating at 125 °C for 30 min, it is more useful to be able to continuously prepare powdered SD by heating below the melting point (140 °C) in a short time (4 min) using an extruder or a kneader from the viewpoint of manufacturing.