A Pilot Study for Toxicity Evaluation of HIV Rectal Microbicides

Inclusion Criteria: * Greater than or equal to 21 years of age * Prior history of receptive anal intercourse (RAI) * Subjects must have a history of using commercially-available personal lubricants for RAI. * Ability to provide signed informed consent. * Willingness to abstain from lubricant use and anal receptive intercourse for 48 hours prior to and 48 hours after Phases A and B. * Willingness to use a single dose of rectally-applied N-9. Exclusion Criteria: * Mental handicap or impaired cognitive performance status as judged by the investigator. * Coagulation abnormality which would put the subject at risk for bleeding as judged by the Principal Investigator. * History of anorectal surgery within the last month or the presence of any anorectal disease or condition that in the judgment of the investigator could affect permeability of the rectal mucosa. * Presence of any painful anorectal conditions or anorectal lesions that would be tender to manipulation. * History of occupational radiation exposure. * History of acute or chronic diarrhea defined as three or more loose stools per day. * History of any allergic response to rectal lubricants. * History of sleep apnea, or airway problems with previous sedation procedures. * History of significant adverse reaction to sedation medications.