2000 年 60 巻 1 号 p. 35-42
Organic pharmaceutical powders are highly adhesive and cause particle cohesion during the manufacturing process, preventing smooth automation. Furthermore, fine powders on the capsule cause contamination problems. Thus the removal of excess microparticles from the surface of the capsule is desirable in an automatic system. In this study, the adhesive force of fine particles on the surface of capsules was measured by the centrifugal force method. We used two types of capusules to measure the adhesive force of fine particles (HPMC capsule and gelatin capsule). Finededuster (FDD-104, Matsui MFG Co., Tokyo) was employed to remove fine particles from the capsule surface. A critical particle size of about 10 μm was found to exist, and larger particles were removed more efficiently. This situation is quite similar to that observed in other mechanical properties of powders such as angle of repose and flowability. We consider that the electical charge influenced the adhesive force of fine particles to the capsule surfaces.