The effect of the co-administration of verapamil on the steady state PK of solifenacin succinate and tamsulosin HCl OCAS (Oral Controlled Absorption System) is evaluated in this study.~Verapamil has been chosen to represent the effect of moderate CYP3A4 inhibitors on the combined administration of solifenacin and tamsulosin given as combination tablet EC905.~Subjects are admitted to the clinic on Day -1. From Days 1-10, they receive one daily dose of EC905 to obtain steady state, followed by 20 days (Days 11-30) combined dosing of EC905 and verapamil.~On Day 10 a 24-hour PK profile is obtained for solifenacin/tamsulosin. After the last dosing on Day 30, a post-dose 24-hour PK profile for solifenacin/tamsulosin and verapamil is obtained.~Additionally, vital signs, safety ECG (Electrocardiogram) measurements, safety laboratory assessments, adverse events and concomitant medications are monitored throughout the investigational period.~Subjects return for an ESV (End of Study Visit) 10 days after the last dosing.
This study investigates the effect of the co-administration of verapamil on the steady-state pharmacokinetics (PK) of solifenacin succinate and tamsulosin given as a combination tablet, EC905.