Vaginal Mucosa and Drug Delivery

Polymer-based nanocarriers for vaginal drug delivery

“…ACCEPTED MANUSCRIPT 5 With the advent of pharmaceutical nanotechnology and nanomedicine, new windows of opportunity have opened up for innovative pharmacotherapeutic approaches [12], namely when considering vaginal drug delivery. Different nanotechnology-based systems, either possessing intrinsic activity or used for drug delivery, have been extensively investigated for vaginal use, in particular for developing microbicides with the purpose of preventing sexual HIV transmission [13][14][15][16].…”

“…Moreover, avoidance of the hepatic first-pass effect of active molecules absorbed at the vaginal level constitutes another valuable attribute, as similar blood concentrations can often be obtained with only a fraction of otherwise required oral doses [4]. Semi-solid dosage forms, namely gels, have been traditionally regarded as preferable for vaginal drug administration but others such as tablets, vaginal suppositories (ovules), foams, solutions and inserts have also been commonly used [5]. Currently, vaginal formulations based on films and rings are attracting a great deal of attention namely in the field of vaginal microbicides.…”

New strategies for local treatment of vaginal infections

“…The normal vagina flora, in reproductive aged women, is characterized by the dominance of lactic acid producing bacteria (LAB), mainly Lactobacillus spp. which, consequently, maintain the acidic pH of vaginal fluids (3.5-4.5) that is currently accepted as a biomarker of an healthy status [7].…”

“…Additionally, other fluids, originated in the uterine cavity, or at higher structures (from and through the tubes), or lower ones (vestibular glands), as well as transudation through the vaginal walls, and immune and epithelial cells can be found in the vaginal content. In normal conditions, it will be expected to find 0.5-0.75 g of vaginal fluid in the vagina, representing a total daily production of 6 g [7,8]. Variations in vaginal fluid amount and composition occur not only as a consequence of physiological changes related to age (from puberty to menopause) and to menstrual cycle ("dry and wet" days), but is also driven by vaginal practices (such as douching), by sexual stimulation and intercourse [7] and by pathological conditions such as A C C E P T E D M A N U S C R I P T ACCEPTED MANUSCRIPT 7 vaginal infections.…”

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“…In addition, a prolonged contact of a delivery system with the vaginal mucosa may be achieved more easily than at other absorption sites like the rectum or intestinal mucosa. However, despite all the advantages of a vaginal application, changes in the membrane during the menstrual cycle and postmenopausal period are major challenges [25][26][27] . Quite often, the delivery systems suffer from migration within the vaginal/rectal lumen, which might affect the delivery of the active agent to the specific location (target site) 28 .…”