20 巻 (1994) 6 号 p. 509-514
Oxaprozin (OXP) suppositories were prepared and their characteristics were investigated. In vivo rectal absorption studies were carried out in rats by measuring the plasma concentrations of OXP. The amorphous state of OXP with polyvinylpyrrolidone (PVP) was obtained using the dissolving method, and the effect of this solid dispersion on the dissolution of OXP was determined. Enhanced rectal absorption of OXP in the amorphous state was not observed in the OXP-PVP solid dispersion system. By using the pH controlled method, a 6-fold effective increase in Cmax was obtained. The increased bioavailability of OXP resulted in a modification of the dissolution characteristics of OXP by an internal buffer system with Na2HPO4.