Development of Agglomerated Talc. III. Comparisons of the Physical Properties of the Agglomerated Talc Prepared by Three Different Processing Methods

Agglomerated talc was prepared by the wet granulation method using a fluidized-bed granulator, a planetary mixer, and a high-speed, high-shear mixer. It was found that agglomerated talc produced by a fluidized-bed granulator is more porous, has a more irregular shape, has a lower bulk density, and has more binder-talc contacts. This higher surface area of binder-talc interface and the highly porous and irregular shape of the agglomerated talc produced by the fluidized- bed granulator result in stronger intergranular bonding. The resultant compact was harder. The compression force-time curve also showed that the time required to increase the upper punch force from 10% to 90% was greater for the compaction of the fluidized-bed granulated talc. The longer exposure to shear forces would enhance plastic flow and facilitate the formation of stronger bonds. Phenylpropanolamine HCl tablets containing 77.5 % agglomerated talc as the diluent were prepared. The properties of the tablet were found to be satisfactory. The agglomerated talc developed may be a promising direct compression diluent.