Persistence of amphotericin B in the bagina. Estimation by a novel sampling method.

This report describes a method of estimating the duration of fungicidal activity of amphotericin B in the vagina after its insertion in a cream base. Various localized vaginal infections are treated by the insertion of a pessary or cream into the vagina. This method of treatment is not entirely satisfactory since failure to respond may be due to the method of application rather than to the limitations of the preparation or the resistance of the infection to the active principle. The effectiveness of this procedure depends on the distribution of the active principle over the whole surface of the vaginal mucosa. A variety of factors may combine to prevent or delay this dispersal. When inserting a pessary the patient may fail to introduce it high enough into the vagina to ensure uniform spread throughout its surface. The composition of a pessary together with local anatomical, physiological, or pathological conditions may prevent its rapid and complete disintegration, thereby delaying the liberation of the active principle. Although much work has been done on the composition of pessaries to ensure their rapid disintegration in the vagina, the practical difficulties of application remain and make the efficacy of this particular form of treatment extremely difficult to assess in any individual patient. In some respects the use of a cream inserted with an applicator is preferable to a pessary. The cream spreads more uniformly over the vaginal mucosa but the amount of leakage varies considerably between patients. A pregnant ambulant multiparous woman near term may lose a very substantial proportion of the total dose in this way. Whichever vehicle is used, the convenience of the patient demands that the active principle should be present in effective concentrations at all vaginal sites for at least 24 hours, or a multiple thereof, so