The purpose of this study is to evaluate the bioequivalence of a newly developed ULTRACET extended-release (ER) tablet of tramadol hydrochloride and acetaminophen, to the current marketed ULTRACET ER tablet, in healthy participants under fasted condition.

Inclusion Criteria:

• Signed an informed consent document indicating they understand the purpose of and procedures required for the study and are willing to participate
• Must agree to use an adequate contraception method as deemed appropriate by the investigator (e.g., vasectomy, double-barrier, partner using effective contraception) and to not donate sperm during the study and for 3 months after receiving the last dose of study drug
• Body mass index (weight [kg]/height2 [m]2) between 18.5 and 30 kg/m2 (inclusive), and body weight not less than 50 kg
• Blood pressure (after the participant is sitting for 5 minutes) between 90 and 140 mm Hg systolic, inclusive, and no higher than 90 mm Hg diastolic
• A 12-lead electrocardiogram (ECG) consistent with normal cardiac function, including sinus rhythm, pulse rate between 45 and 90 bpm, QTc interval <= 450 ms, QRS interval of <110 ms, PR interval <200 ms, and morphology consistent with healthy cardiac function

Exclusion Criteria:

• History of or current clinically significant medical illness including (but not limited to) cardiac arrhythmias or other cardiac disease, hematologic (blood) disease, coagulation disorders (including any abnormal bleeding), lipid abnormalities, significant lung disease (including bronchospastic respiratory disease), diabetes mellitus, kidney or liver insufficiency, thyroid disease, neurologic or psychiatric disease, infection, or any other illness that the investigator considers should exclude the participant or that could interfere with the interpretation of the study results
• Clinically significant abnormal values for hematology, clinical chemistry or urinalysis at screening or at admission to the study center as deemed appropriate by the investigator
• Clinically significant abnormal physical examination, vital signs or 12-lead ECG at screening (or at admission to the study center) as deemed appropriate by the investigator
• Use of any prescription or nonprescription medication (including vitamins and herbal supplements), except for oral contraceptives and hormonal replacement therapy within 14 days before the first dose of the study drug is scheduled
• History of, or reason to believe a participant has a history of, drug or alcohol abuse within the past 5 years