To evaluate the pharmacokinetics of AZD3241 following multiple administration of 2 new, different extended release formulations of tablets of AZD3241 (300 mg), in relation to the 100 mg extended release tablet used in a previous study and potential food interaction. The safety and tolerability of AZD 3241 will also be investigated as a secondary objective. In addition to these a number of exploratory objectives will be investigated with blood sampling.