Chem. Pharm. Bull. 53(5) 487—491 (2005)

lution property of poorly water soluble drugs. In general, solid dispersion is prepared with water soluble polymer, such as polyethylene glycol (PEG) or polyvinylpyrrolidone (PVP) as carrier, to disperse the drug molecules in the polymer matrix. Recently, the porous materials were also used as a carrier to disperse the drug molecules in the pores. We have already reported that the solid dispersion particles prepared with fine porous silica (Sylysia350) as carrier by spraydrying method can improve the dissolution property of indomethacin and tolbutamide. Considering the final dosage form of the solid dispersion particles, it is desirable to select the tablet among the various types of dosage form, because of its convenience in production and usage. Tablet has various advantages, such as portability, patient compliance and lower cost in production compared with other solid dosage forms. For the rapid drug dissolution from the tablet, its disintegrating property is important to ensure it. As the solid dispersion particle itself has a very rapid dissolution property, the tablet of solid dispersion has to be easily disintegrated. Based on this concept, easily dissolving sugar and sugar alcohol might be a candidate for their diluents of tablet. In the formulation of rapidly disintegrating tablets, which have recently been developed for elderly people and children who have swallowing or chewing difficulties, sugar or sugar alcohol are used as diluent. However, the sugar or sugar alcohol often has a tabletting troubles, such as capping and sticking. We have already evaluated the compaction property of sugars including mannitol by measuring the die wall pressure during tabletting process such as residual die wall pressure (RDP) and maximum die wall pressure (MDP). These powders showed the high RDP/MDP and capping tendency. Adding a little amount of magnesium stearate in the powders decreased RDP/MDP and improved capping tendency. It has been also demonstrated that a good compaction property of some disintegrants such as low substituted hydroxypropylcellulose (L-HPC) and pre-gelatinized starch (PCS) has lower RDP/MDP in the same evaluation method. In the present study, we attempted to prepare the rapidly dissolving tablet having the same dissolution rate as that of solid dispersion particles and a high tensile strength of tablet (more than 1.0 MPa). We also evaluated the compaction properties of the tablet formulations to optimize the formulation.