Ex vivo vaginal tissue studies are performed with human or rabbit vaginal tissue. The test device is a Franz cell. Test formulations (typically creams) are applied to the upper (mucosal) surface, and samples are removed at predetermined time points from the reservoir containing buffer that is in contact with the lower (serosal) surface. Reference compounds are either co-dosed (if the test compound is in solution) or run in parallel if the test compound is in some other type of formulation for quality control.
The tissue is often extracted at the end of the study to quantify accumulation of the test compound. We can also incubate test formulations with tissue homogenates to assess the metabolic stability of the test compound. Vaginal tissue studies are used to assess the feasibility of vaginal administration, to rank-order compounds in terms of permeability or accumulation, and to optimize formulations.