The purpose of this research study is to look at concentrations of GSK189075 in blood when different long and short acting forms of the drug are taken by mouth. The results will help to decide whether a long-acting form of GSK189075 can be made. The effects of the drug on the body and safety will also be studied.

Inclusion Criteria:

• Are a healthy, non-smoking adult, 18 to 55 years old.
• Are not overly thin or overly heavy for your height.
• Are a female who is unable to have children, or is willing to use birth control throughout the study.
• Are willing and able to follow all study-related instructions provided by the site staff. - Are willing to provide signed consent.

Exclusion Criteria:

• Are a pregnant or a nursing female.
• Have a past or current disease such as heart, liver, kidney, blood, brain, or other disease.
• Have had certain infections within 4 weeks before the expected the first dose of study drug.
• Have HIV or hepatitis, or have alcohol in your system at the screening visit.
• Have a history of alcohol abuse.
• Have been in another research study in the last month or have taken certain medications in the 2 weeks before study drug would be taken.
• Have laboratory tests that are outside the normal range.