Phase I Study to Evaluate Bioavailability of Naproxen as PN400 Compared to Naproxen as Proxen S and Naprosyn E

Inclusion Criteria: * Body Mass Index (BMI) of greater than or equal to 19 to less than or equal to 30 kg/m2 and weight of greater than or equal to 50 to less than or equal to 100 kg * Clinically normal physical exams and laboratory measurements Exclusion Criteria: * Subject has received another investigational drug within 4 weeks preceding this study or planning to participate in another study at any time during the period of this study * Any significant medical or psychiatric condition that could affect the interpretation of the PK data, or which otherwise would contraindicate participation in a clinical trial * Any GI disease, abnormality or gastric surgery that may interfere with gastric emptying, motility and drug absorption * Subject who has donated a unit of blood or plasma within 3 months prior to the Screening Visit