As Study of the Pharmacokinetics of Paliperidone Extended-release and Risperidone Immediate-release Formulations

The purpose of this study is to compare the steady-state pharmacokinetics of paliperidone after oral administration of 15 mg extended-release (ER) OROS paliperidone once daily with the steady-state pharmacokinetics of paliperidone after oral administration of 8 mg immediate-release (IR) risperidone twice daily; and to explore the dose-proportionality of 9 mg and 15 mg ER OROS paliperidone. Other objectives are to 1) document the disposition of the enantiomers of paliperidone; 2) explore the relationship between genotype (CYP2D6, CYP3A4, CYP3A5, UGT1A1, and UGT1A6) and pharmacokinetic parameters; and 3) assess safety and tolerability.