Abstract: Deflazacort (DFZ, a prodrug) is well absorbed and rapidly metabolized into the active metabolite 21-hydroxydeflazacort (21-OH DFZ) after oral administration.The aim of this study is to evaluate thepharmacokinetic properties of 21-OH DFZ in healthy Chinese volunteers after a single and multiple oraladministration of DFZ tablets under fed condition.Twelve volunteers (six males and six females) were administered a single dose of 6 mg or 12 mg or 24 mg of DFZ in three different periods separately, accordingto the 3 × 3 Latin square design.Between each administration period there was a washout period of one week.The multiple-dose study of 12 mg dose DFZ per day for 7 consecutive days was started after a 1 w washoutperiod when the single-dose study completed.The pharmacokinetic parameters of 21-OH DFZ after the single oral administration of 6 mg, 12 mg and 24 mg DFZ tablets were as follows: (37.7 ± 11.6), (61.5 ± 17.7) and(123 ± 23) ng·mL^-1 for C_max; (1.90 ± 0.32), (1.96 ± 0.27) and (2.13 ± 0.34) h for t_1/2; (96.6 ± 25.9), (190 ± 44) and (422 ± 107) ng·h·mL^-1 for AUC_{0-14 h}, respectively.After the multiple dose administration, the mean plasmaconcentration at steady-state C_av was (7.00 ± 1.66) ng · mL^-1 and the degree of plasma concentration fluctuation DF was 7.7 ± 1.2.The results showed that the pharmacokinetic characteristics of 21-OH DFZ in healthy Chinese volunteers were linear over the dose range of 6 to 24 mg.No significant gender differences were found in the pharmacokinetics of 21-OH DFZ in healthy Chinese volunteers.After the multiple dose administration of 12 mg DFZ for 7 d, no accumulation of 21-OH DFZ in healthy Chinese volunteers was observed.