Bioequivalence trial in healthy adult subjects to determine the bioavailability of 3 different sustained release formulations of naproxen 660 mg relative to the established commercial Aleve 220 mg tablet.

Inclusion Criteria:

• Healthy ambulatory male and female subjects 18 to 55 years of age, inclusive
• Body Mass Index (BMI) of approximately 18.0 to 30.0 kg/m2, and a total body weight >50 kg (110 lbs)
• Results of screening and clinical laboratory tests are within normal limits or considered not clinically significant by the Principal Investigator or Sponsor
• Female subjects of childbearing potential must be using a medically acceptable form of birth control for at least 1 month prior to screening (3 months on oral contraceptives), e.g., oral or patch contraceptives, intrauterine device, intramuscular injection or double-barrier and have a negative pregnancy test at Screening and on Day 0 of each treatment period. Female subjects of nonchildbearing potential must be amenorrheic for at least 2 years or had a hysterectomy and/or bilateral oophorectomy.
• Provide a personally signed and dated informed consent prior to inclusion in the trial indicating that the subject has been informed of all pertinent aspects of the trial.

Exclusion Criteria:

• History of hypersensitivity to aspirin (ASA), naproxen sodium, or acetaminophen, and similar pharmacological agents or components of the products
• History of gastrointestinal bleeding or perforation, including bleeding related to previous NSAID therapy. Active, or history of recurrent peptic ulcer/hemorrhage (two or more distinct episodes of proven ulceration or bleeding).
• Have taken ASA, ASA-containing products, acetaminophen (acetyl-para-amino-phenol or APAP) or any other NSAID (OTC or prescription) 7 days prior to dosing or during the treatment period, other than study treatment
• Loss of blood in excess of 500 mL within 56 days of the first dose of trial treatment (e.g., donation, plasmapheresis, or injury)
• Evidence or history of clinically significant hematological, renal, endocrine, pulmonary, gastrointestinal, cardiovascular, hepatic, psychiatric, neurologic, or allergic disease (including drug allergies, but excluding untreated, asymptomatic, seasonal allergies at time of dosing)
• Positive alcohol or drug screen at Screening or on Day 0 of Treatment Periods 1 or 2
• Females who are pregnant or lactating
• Smokers or currently consuming any type of tobacco product(s) including any smoking cessation nicotine-containing product (eg, nicotine patch, nicotine gum).