This is a research study for an investigational drug being developed for the treatment of HIV-1 infection (Human Immunodeficiency Virus-1). The purpose of this study is to evaluate the safety and tolerability (side effects) of the study drug at gradually increasing dose levels. The study will also measure how much of the study drug and its breakdown products gets into the bloodstream (and certain kinds of blood cells), and how long it takes the body to get rid of it. In addition, this study will compare how much of the study drug gets into the bloodstream between 2 different forms of the study drug (tablet and a liquid solution drink).