Vaginal permeation

Table 3 Vaginal permeation parameters of representative steroids...

Recently, several in vitro experiments substantiated the potential of the human vaginal mucosa as a good administration route relating to the degree of permeation when compared with other mucosal surfaces. In fact, the vagina can be more permeable to some commonly used model substances, such as water, 17[3-cstradiol (Figure 3), arecoline, arecaidine, and vasopressin, than colonic or small intestinal mucosa, or at least as permeable as when compared to human buccal mucosa [46,47],... 

It is also noteworthy that many of the in vitro results of vaginal permeability studies cited in the literature have limitations related to the experimental conditions that were used, particularly pH values at which they have been performed. Differences in permeability values are particularly expected when ionization characteristics change between experimental pH and vaginal pH [183], However, in vitro results should only be considered as evidence that the vaginal mucosa is able to be permeated. 

The apparent permeability coefficient Papp for vaginal membrane permeation is defined by... 

Various studies found that the absorption of non-oxynol-9 through the vaginal membrane was very slow and suggested a dependence of molecular weight of the oligomeric components that make up the spermicide. Permeation studies have found the hydro-... 

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