Pre-exposure prophylaxis (PrEP) is an experimental HIV-prevention strategy using antiretroviral (ARV) agents to protect HIV negative individuals from HIV infection.TMC278 is a new drug being developed for this type of HIV treatment. It is hoped that this drug may be used to help prevent HIV transmission in future. A 'long acting' formulation of TMC278 has been developed. Long acting means that the drug will be present in the blood for longer. It is this formulation of the drug that will be investigated in this study. Subjects will receive the drug by injection.