Pharmacokinetic, Safety, and Tolerability Study of Risperidone ISM® at Different Dose Strengths

Inclusion Criteria: * Capable of providing informed consent. * Male or female aged ≥ 18 years to \< 65 years * Current diagnosis of schizophrenia or schizoaffective disorder, according to the Structured Clinical Interview for Diagnostic and Statistical Manual of Mental Disorders Clinical Trials (SCID-CT) or the DSM-IV-TR * Medically stable over the last month, and psychiatrically stable without significant symptom exacerbation over the last three months based on the investigator's judgment * Score of ≤ 4 (moderately ill) on the Clinical Global Impression - Severity of Illness (CGI-S) * If a sexually active female of childbearing potential, using a medically accepted contraceptive method. Exclusion Criteria: * Presence of an uncontrolled, unstable, clinically significant medical condition that in the opinion of the investigator may interfere with the interpretation of safety and PK evaluations * If female, a positive serum pregnancy test, or planning to become pregnant between now and one month after the last dose of trial medication, or currently breastfeeding a child * History of neuroleptic malignant syndrome and current or past history of tardive dyskinesia * Positive urine drug/alcohol screen finding, unless the positive finding can be accounted for by documented prescription use. * In the investigator's opinion, at imminent risk of committing self-harm * Use of depot antipsychotics within the last three months * Receipt of any investigational drugs within the last three months * Current participation in any other clinical trial