2 different formulations and doses of tafamidis will be compared. All subjects will receive both doses/formulations. Subjects will take tafamidis for 7 days, on the first 2 days they will take tafamidis twice, 12 hours apart and then once a day for the next 5 days. Subjects will be fasted before taking the drug. Blood samples will be taken to measure the amount of tafamidis starting on day 7 and ending on day 8. At least 16 days after the first formulation/dose is given, all subjects will repeat the procedure with the other formulation/dose.