The bioavailability of once-daily trazodone extended-release 300 mg caplets (test product) and trazodone immediate-release 100 mg tablets administered q8h (reference product) will be compared in healthy adult volunteers in a randomized, crossover fashion. Morning doses will be administered after an overnight fast. Blood samples will be collected predose and at pre-defined times over 72 hours following the morning dose. Pharmacokinetic parameters will be analyzed using ANOVA. Comparative bioavailability will be assessed on the basis of the ratio of least-squares means and/or 90% confidence interval criteria.