A 5-Period, Single Dose, Phase 1 Study in Healthy Elderly Subjects to Assess Relative Bioavailability and Food Effect of Two Oral Formulations of GSK1325756 (Free Base vs HBr Salt) and Food Effect on the HBr Formulation When Given With Omeprazole

Inclusion Criteria: * Between 65 and 80 years of age at screening (inclusive) * Healthy, as determined by a responsible and experienced physician, based on a medical evaluation including medical history, physical examination, laboratory tests and cardiac monitoring or a subject with a clinical abnormality or laboratory parameters outside the reference range for the population being studied may be included if the investigator and the GlaxoSmithKline (GSK) Medical Monitor agree that the finding is unlikely to introduce risk factors and will not interfere with the study procedures and objectives. * Body Mass Index between 19 and 34 (inclusive) * Male or Female Males: Male subjects with female partners of child bearing potential must comply with the following contraception requirements from the time of first dose of study medication until a cycle of spermatogenesis following five terminal half- lives after the last dose of study medication. a. Vasectomy with documentation of azoospermia. b. Male condom plus partner use of one of the contraceptive options: Contraceptive subdermal implant, Intrauterine device or intrauterine system, Oral Contraceptive, either combined or progestogen alone Injectable progestogen, Contraceptive vaginal ring, Percutaneous contraceptive patches. This is an all-inclusive list of those methods that meet the following GSK definition of highly effective: having a failure rate of less than 1% per year when used consistently and correctly and, when applica…