摘要:The extent and rate of absorption of phenytoin (PHT) from tablet and powder were studied in four healthy adult volunteers. It was demonstrated by urinary fecal excretion that the almost all quantity of PHT in tablet was absorbed through the gastrointestinal tract, and the observed values of the estimated free concentration (Cest.f) estimated from mixed saliva concentration of PHT in the multiple does were in fair agreement with the calculated values of that by using computer simulation in case of tablet. On the contary, the variations were observed in Cest.f using therapeutic does of PHT powder. The values of Cest.f at steady-state in tablet administration were higher than those in powder administration. The absorption ratio of PHT powder was low and variable, and decreased upon increase of does. The ratio calculated from the Cest.f values of both dosage form at steady-state were in good correspondence to the observed values of PHT excreted in feces.