A Phase I, Open-label, Randomised, 3-way Crossover Study to demonstrate Bioequivalence of a Single Oral Dose of Naproxen administered as VIMOVO manufactured at AstraZeneca AB compared to that of VIMOVO manufactured by Patheon Pharmaceuticals and a marketed enteric-coated Naproxen Formulation (Manufactured by Roche) in Healthy Volunteers.