Chem. Pharm. Bull. 54(2) 175—180 (2006)

rapidly disintegrating oral tablets that contain disintegrants, such as microcrystalline cellulose or low substituted hydroxypropylcellulose. However, the main disadvantage of these tablets is a rough feeling in the mouth, because they are water-insoluble. To solve this problem, we used water-soluble sugars as ingredients of rapidly disintegrating oral tablets and developed a preparation method, the Crystalline Transition Method (CT method), as a promising protocol to improve medication compliance. The CT method is a method utilizing the crystalline transition of amorphous sugars. The choice of amorphous sugar is therefore a critical factor for the CT method, because each amorphous sugar has a different glass transition temperature (Tg), with a distinct amount of water absorbed under any given humidity and temperature. In addition, the formulated diluents and active drug substances, which are main components of these tablets, were anticipated to greatly influence the characteristics, i.e. tensile strength, porosity and oral disintegration time. In this study, the effects of formulated ingredients (diluent, active drug substance and amorphous sugar) on the characteristics of rapidly disintegrating oral tablets were investigated in detail. The aim of this study was to determine the optimal ingredients for rapidly disintegrating oral tablets prepared by the CT method.