Lecture 14 Vaginal Drug Delivery Flashcards
Describe the vaginal mucosal epithelium.
The vaginal mucosal epithelium is stratified, squamous, and non-keratinised.
What is the histology of the cervix?
The cervix consists of columnar and stratified squamous epithelial tissue, with the endocervix being columnar and the ectocervix being squamous.
How is the vaginal blood supply connected to the common iliac artery?
The common iliac artery branches into the internal iliac artery, which further branches into vaginal arteries supplying blood to the vagina.
Define the first pass effect in vaginal drug delivery.
The first pass effect refers to the direct transportation of vaginally administered drugs to the uterus, with the extent of effect depending on the exact location of administration within the vagina.
What are some advantages of vaginal drug delivery?
Advantages include accessibility, non-invasiveness, avoidance of first-pass metabolism, high tissue perfusion, and the potential for local or systemic drug effects.
Describe some disadvantages of vaginal drug delivery.
Disadvantages include cultural and hygiene issues, poor retention of drug delivery devices, mucosal irritation, low user compliance, and the strong influence of estrogen concentration on tissue permeability.
How do vaginal enzymes impact drug delivery?
Enzymes in the lumenal and basal cell layers of the vagina can affect drug metabolism and activity, influencing the pharmacokinetics of drugs designed for systemic action.
What is the significance of the squamocolumnar junction in the cervix?
The squamocolumnar junction marks the meeting point of the columnar and squamous epithelia in the cervix, with the ectocervix being less sensitive to hormonal influences compared to the endocervix.
Describe the clinical indications for vaginal delivery.
Vaginal delivery is recommended for various women’s health and reproductive issues, including cervical ripening, estrogen replacement therapy, treatment of vaginal infections, mucosal vaccination, cervicovaginal cancers, and HIV microbicides.
What are the different types of vaginal rings and how are they manufactured?
Vaginal rings can be matrix type (drug dispersed throughout the entire ring volume, manufactured via one-step injection molding) or reservoir type (drug dispersed throughout the central core only, more complex manufacturing process involving multi-step injection molding or co-extrusion).
How do vaginal gels typically differ from thin polymer films in terms of composition and application?
Vaginal gels are water-based semi-solid gels containing water, gelling agents, preservatives, and active ingredients, applied using a plastic applicator. In contrast, thin polymer films dissolve rapidly in the target cavity with minimal fluid present, allowing for rapid drug release.
Define spermicidal contraception and its mechanism of action.
Spermicidal contraception involves the use of spermicides to immobilize or kill sperm, typically through the disruption of their cell membranes, preventing fertilization.
How are vaginal pessaries designed to work in the body?
Vaginal pessaries are solid, dissolvable inserts that melt at body temperature in the vaginal cavity, releasing medication or active ingredients for local or systemic effects.
