Reddy’s Laboratories Ltd., Hyderabad, India) cRisperdal® tablet (Xian-Janssen Pharmaceutical Ltd., Xi-an, China) On ANOVA, using logarithmic-transformed data, no significant sequence effects, treatment effects, or period effects were observed for any pharmacokinetic property

of risperidone or its active metabolite, 9-hydroxy-risperidone. The 90% CIs of the relative values (test vs. reference) of the ln-transformed Cmax, AUCt, and AUC∞ values are shown in Table 3. For the parent drug, risperidone, these values were 97.0–124.0%, 92.7–115.1%, and 92.8–114.2%, respectively. For the active metabolite, 9-hydroxy-risperidone, these values were 104.4–117.7%, 101.0–113.7%, and 100.4–113.4%, respectively. The two formulations met the predetermined criteria for bioequivalence. In the nonparametric analysis, selleck chemical differences between the formulations did not reach the level of statistical significance in the Wilcoxon signed-rank test with regard to the tmax values for

the two compounds. Table 3 Comparison of the 90% confidence intervals of natural log-transformed pharmacokinetic parameters of the parent drug, risperidone, and its active metabolite, 9-hydroxy-risperidone, following administration of two formulations (testa/referenceb) of risperidone tablets in healthy male Chinese volunteers (n = 24) Compound and parameter Relative value [testa vs. referenceb] (%) 90% CI (%) p values <80% >125% Risperidone  ln Selleck 5-Fluoracil Cmax 111.0 97.0–124.0 0.00001 0.00001  ln AUCt 103.3 92.7–115.1

0.00002 0.003  ln AUC∞ 102.9 92.8–114.2 0.00002 0.002 9-hydroxy-risperidone  ln Cmax 109.8 104.4–117.7 0.00001 0.00002  ln AUCt 107.1 101.0–113.7 0.00001 0.00003  ln AUC∞ 106.7 100.4–113.4 0.00002 0.00001 AUC area under the plasma concentration–time curve, AUC t AUC from time zero to time t, AUC ∞ AUC from time zero to infinity, Thiamet G CI confidence interval, C max maximum plasma drug concentration, ln natural log-transformed aRisperidone tablet (Dr. Reddy’s Laboratories Ltd., Hyderabad, India) bRisperdal® tablet (Xian-Janssen Pharmaceutical Ltd., Xi-an, China) 4 Discussion This study examined the pharmacokinetic properties and bioequivalence of two formulations of risperidone tablets in healthy adult male Chinese subjects. As shown in Fig. 1, we found nearly overlapping concentration–time curves for the two risperidone formulations. Moreover, the mean AUC∞ and Cmax values were not significantly different, and the 90% CIs of both the parent drug, risperidone, and the active metabolite, 9-hydroxy-risperidone, were completely contained within the predefined bioequivalence criteria of 80–125% for the primary endpoints of the AUC and Cmax [20]. There are few reports in the literature regarding the pharmacokinetics of risperidone, and the existing reports appear to differ [10, 11].