1998 年 58 巻 3 号 p. 147-154
To evaluate the effects of amorphous alloy system (Ta-Fe-Ni-Cr: composition, 36:44:4:12 (%)) coating on tableting, we have investigated tablet compression by using a single-punch tableting machine whose upper and lower punch surfaces are coated with amorphous alloys (amorphous alloy-coated punch). The effects of amorphous alloy coating on the compression characteristics of pharmaceutical excipients (mixtures of lactose and crystalline cellulose with various amounts of magnesium stearate) in the presence or absence of drugs were compared with the effects observed when conventional hard chromium (Cr) plating (Cr-plated punch) was used. With the Cr-plated punch, the effect of magnesium stearate on the prevention of powder adhesion to the punch tip surface was minimal. On the other hand, powder adhesion did not occur even after 3,000 tablets were produced (running time of machine approximately 3.3 h) by using the amorphous alloy-coated punch. A marked improvement in the prevention of sticking was achieved even with the addition of only 0.1% magnesium stearate when the amorphous alloy-coated punch was used. A similar advantage in the prevention of powder adhesion was obtained by using an amorphous alloy-coated punch in a lactose and crystalline cellulose mixture containing a drug such as aspirin. The low values of surface roughness parameters and the scraper pressure, which is the shear stress between the tablet and the lower punch surface, were observed in the use of the amorphous alloy-coated punch. It seems that a high value of the contact angle of water to the amorphous alloy surface leads to high repellent characteristics and to an easy detachment of tablets from the punch tip surface.
