CERVICAL-MUCUS - PROBLEMS AND OPPORTUNITIES FOR DRUG-DELIVERY VIA THEVAGINA AND CERVIX

The vagina has been targeted as the site for delivery of a variety of drugs, and several different delivery systems have been utilized for t his purpose. The compounds have almost exclusively been delivered to t he vaginal epithelium. The presence of a mucus-laden cervix in women p rovides an opportunity as an alternative, or conjoint site for such dr ug delivery. An obvious application is the delivery of drugs that dest roy, or render dysfunctional, spermatozoa and pathogens such as viruse s and bacteria. In principle, a reservoir of a compound in the cervica l mucus could achieve other physiological goals, as well. This article reviews the biology of human cervical mucus and its interaction with spermatozoa. It then focuses upon the critical problem of understandin g the mechanisms of drug entry and permeation through the cervical muc us. This problem is only partially understood at present, and salient biophysical concepts are presented which will aid in its further study . It is concluded that there are good prospects for improved utilizati on of the cervical mucus for drug delivery, but that their realization will require improved understanding of the mechanisms of drug transpo rt and bioactivity within the mucus.