This was an open-label, 1-sequence study in patients who are were stable oral risperidone treatment. The study consisted of a screening visit, 1 treatment period with inpatient and outpatient visits, and a Follow-up visit.~Patients who were receiving existing oral risperidone treatment (4 mg) continued the oral regimen for 1 week to achieve steady-state concentrations of risperidone (Treatment A). Following the oral risperidone treatment, a single IM dose of 100 mg Risperidone ISM® was administered deeply into the gluteal muscle. A total of 4 IM doses were given, each dose separated by 4 weeks (Treatment B).~Safety assessments and PK sampling were performed once each dosing day and each outpatient visit. A final Follow-up visit was conducted to assess each patient for safety and to obtain PK samples.~Approximately 80 (with no screening failure) patients were planned for enrolment, with the intent to complete 48 patients with the assumption of an approximate drop-out/not valuable PK rate of 40%.~The primary objective of this study was to evaluate the steady-state comparative bioavailability of 100 mg Risperidone ISM® injectable every 4 weeks compared to once-daily 4 mg oral risperidone in patients with schizophrenia stabilized on oral risperidone treatment.~The secondary objective of this study was to evaluate the safety and tolerability of 100 mg Risperidone ISM® injectable every 4 weeks compared to once-daily 4 mg oral risperidone in patients with schizophrenia stabilized on oral risperidone treatment.
This is an Open-Label, One-Sequence Study to Evaluate the Steady- State Comparative Bioavailability of Intramuscular Risperidone ISM® and EU Risperdal® (Sourced From Germany).