nasal delivery

Question 1

What are the primary therapeutic uses of nasal drug delivery?

Answer 1

Localized effect, systemic effect, vaccine delivery, and direct nose-to-brain delivery.

Question 2

Why is nasal drug delivery advantageous?

Answer 2

It provides rapid onset of action, avoids hepatic/GI metabolism, is accessible and convenient, and is cost-effective.

Question 3

What are common drug formulations for nasal delivery?

Answer 3

Solutions, emulsions, suspensions, gels, ointments, creams, and powders.

Question 4

Name some conditions treated by nasal drug delivery for local effects.

Answer 4

Allergic rhinitis, nasal congestion, and nasal infections.

Question 5

List some drugs used for systemic effects via nasal delivery.

Answer 5

Hormones (e.g., Desmopressin), opioids (e.g., Fentanyl), and nicotine.

Question 6

What is the role of the turbinates in nasal drug delivery?

Answer 6

They increase surface area, facilitate drug deposition, and have a rich blood supply for absorption.

Question 7

What are the two main pathways for nasal drug absorption?

Answer 7

1. Transcellular diffusion (lipophilic drugs, mainly passive diffusion)
2. paracellular diffusion (small hydrophilic drugs, rate proportional to molecular size).

Question 8

What factors affect drug absorption in nasal delivery?

Answer 8

1. Mucociliary clearance
2. mucus layer
3. enzymatic activity
4. epithelial barrier.

Question 9

Name strategies to improve nasal drug absorption.

Answer 9

1. Mucoadhesive polymers
2. enzyme inhibitors
3. permeation enhancers
4. solubility enhancers.

Question 10

What is mucoadhesion in nasal drug delivery?

Answer 10

The attachment of a drug carrier to the mucus layer to extend contact time.

Question 11

explain how bioadhesion works

Answer 11

two biological materials are held together by interfacial forces (nasal epithial surface)

Question 12

Describe the two stages of mucoadhesion.

Answer 12

1. Contact stage (initial attachment)
2. consolidation stage (bond formation between mucus and polymer). + (formation of chemical bonds like VDW, H bonding etc.)

Question 13

list some factors affecting absorption

Answer 13

1. physiochemical factors ie solubility, conc, pH, Log P
2. patient factcors (compliance, disease, environmental)
3. delivery device (volume, spray, site)

Question 14

What are some formulation considerations for nasal drug products?

Answer 14

Solubility, pH, molecular size, stability, and minimising excipients.

Question 15

List types of nasal delivery devices.

Answer 15

Nasal sprays, droppers, breath-actuated devices, and electronic atomizers.

Question 16

What are the advantages of nasal drug delivery?

Answer 16

1. Non-invasive
2. rapid effect
3. avoids first-pass metabolism
4. lower doses are required.

Question 17

What are some limitations of nasal drug delivery?

Answer 17

1. Limited volume capacity
2. mucociliary clearance
3. enzymatic activity
4. low permeability for hydrophilic drugs
5. potential drug instability.