Each participant will undergo screening to evaluate eligibility. Baseline visit will assess safety, PD, and behavioral readout baselines. Three products described below (Product A, B, and C) are dosed sequentially as a dose-escalation within each subject. Safety, PK, PD, and behavioral readouts are assessed at specified times for one week after each dose, followed by a variable washout period before the next escalation dose. Johns Hopkins University (JHU) participants only will have SPECT/CT imaging to assess distribution and permeability of radiolabeled product. After two of the study product doses (Product A and Product C) and their respective sampling periods, a normal saline (NS) solution and ½ normal saline (½ NS) solution will be taken at home in the context of receptive anal intercourse.