This study is designed to assess prototype formulations compared to the aqueous dispersion of Active Pharmaceutical Ingredient used in Phase I and Phase IIa studies to date. It is hoped that the bioavailability of OZ439 can be enhanced in the fasted state to be close to that observed when given after food. This will improve the utility of OZ439 in the field as well as decreasing the cost of treatment (by decreasing the dose of OZ439 required) which is very important for an antimalarial drug product destined for use in developing counties.