Nasal Drug Delivery Flashcards Preview

Pharmacy Stage 2 > Nasal Drug Delivery > Flashcards

Flashcards in Nasal Drug Delivery Deck (15)
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1
Q

what are the advantages of the nasal route of administration?

A
  1. large SA
  2. low enzyme activity
  3. thin epithelium (short diffusion pathway)
  4. non-invasive
  5. direct route to brain possible
  6. easy to administer
  7. patient acceptability
  8. Nasal-Associated Lymphoid Tissue (NALT)-good target for vaccines
2
Q

where does absorption occur in the nose?

A

across turbunates and the septum

3
Q

how are lipophilic drugs transported in the nose?

A

they are transported transcellularly either by:

a) passive diffusion
b) receptor/carrier mediated transport mechanisms
c) vesicular transport mechanism

4
Q

how are polar drugs transported in the nose?

A

they pass through the epithelium via gaps and pores between cells (paracellular)

5
Q

what is the size of the gaps between cells and what sized particles can pass through them?

A

size between cells: 10 Angstroms

size of particles that can pass through: 1000 daltons

6
Q

what is the bioavailability of polar drugs with a low molecular weight?

A

~10%

7
Q

which has a higher bioavailability, polar drugs with higher molecular weight or lower molecular weight?

A

lower molecular weight

8
Q

why are polar molecules poorly transported?

A
  1. have low permeability
  2. are rapidly cleared
  3. degraded by enzymes
9
Q

what can be used to increase the bioavailability of a drug?

A

absorption enhancers and bioadhesives

10
Q

how does chitosan work?

A
  • it is a positively charged bioadhesive that is non-toxic and non-irritant.
  • it works by disrupting the tight junctions hence increasing the paracelluar transport of molecules
11
Q

why does sniffing cocaine cause euphoria rapidly?

A
  • because of the direct pathway from the nasal cavity to the CNS and
  • because the drug could concentrate selectively in specific regions of the brain.
12
Q

how does the nose deliver chemicals to the brain?

A
  • by direct transport of chemicals across the olfactory region transcellularly or paracellularly.
  • can also be transported intracellularly through axons to the olfactory bulb
13
Q

what is the target site of nasal vaccines?

A

the NALT (nasal-associated lymphoid tissue) which is in the pharynx as a ring of lymphoid tissue.

14
Q

what are the two major types of nasal vaccines?

A
  1. particulate antigen delivery systems (antigen is entrapped or presented on particle surface)
  2. Solution systems (antigen dissolved or suspended within a solution vehicle)
15
Q

what drains the NALT?

A

the posterior cervical lymph nodes

Decks in Pharmacy Stage 2 Class (85):