Development, Physicochemical Characteristics and Pharmacokinetics of a New Sustained-Release Bilayer Tablet Formulation of Tramadol with an Immediate-Release Component for Twice-Daily Administration.

Background And Objective: There are some potential concerns about the currently marketed solid oral dosage forms of tramadol, including decreased adherence to immediate-release (IR) formulations due to the high number of doses taken each day and the slow rise in the blood tramadol concentration after administration of sustained-release (SR) formulations, which may not achieve a rapid analgesic effect. To overcome these potential concerns, a twice-daily double-layered tablet formulation of tramadol comprising IR and SR layers was developed. This article reports studies that assessed its physicochemical and pharmacokinetic properties.