Vaginal drug delivery

Question 1

What do we currently treat using vaginal drug delivery?

Answer 1

1. Local vaginal issues→ Antifungals, Antibiotics, Steroids, Spermicides, Lubrication, Hygiene & Microbicides
2. Systemic treatments→ Oestrogen, progestogens & Prostaglandins analogues

Question 2

What are the advantages of vaginal drug delivery?

Answer 2

• Smaller doses are required than the oral route
  
  • The patient may have GI tract issues
  • The drug may be prone to degradation at a particular PH
  • Enzymatic degradation
  • Taste of the medication can not be masked & may not be favorable
  • Therefore, the vaginal route is favored!
• Reduced absorption and systemic distribution/toxicity for locally acting drugs
• Some systemically delivered drugs have a higher vaginal bioavailability → Oestrogens and Progesterone’s (they reach the systemic circulation without passing through the liver- the extent of metabolism is reduced so higher bioavailability)
• Good where oral route is restricted
• Avoids GI interactions and first pass metabolism
• Potential for preferential delivery to the uterus

Question 3

What are the disadvantages of vaginal drug delivery?

Answer 3

• Gender specific
• Hormonal Variations affecting drug absorption
• Varying volume of cervico-vaginal fluids can affect drug release
• Leakage likely (limited by volume of fluid and surface area)
• Physiological acidic PH may enhance drug degradation
• Systemic absorption of locally acting drugs
• Stigma of administration

Question 4

Outline the anatomy of the vagina?

Answer 4

• A fibromuscular tube connecting to the uterus to the external environment. It is coated with mucus/cervicovaginal fluid
• Mucin (glycoprotein) secretes mucus. The mucus lines the epithelial membrane
• It has an acidic PH 3.5-4.5 & is because of the Microflora (lactobacullius)

Question 5

What is the function of Microflora?

Answer 5

Transforms glycogen to lactic acid