Aural And Nadal

Question 1

Advantages of the nasal route

Answer 1

• Easy to administer.
• Non-invasive, painless.
• Avoids first-pass effect
• Low enzymatic activity
• Direct route to brain is possible
• Potential to elicit a rapid onset of action.
• Newer formulations potentially allow for peptide delivery.
• Could achieve better systemic bioavailability than the oral
route:

Question 2

Describe the nasal anatomy

Answer 2

• Split in to 2 halves by nasal septum
• Covered with mucous membrane containing
  goblet cells secreting mucus.
  • Absorption occurs across turbinates and septum

Question 3

How are lipophilic and polar drugs transported across the nasal epithelium?

Answer 3

1. Lipophilic Drugs: Transported transcellularly via:
   • Passive diffusion (concentration-dependent)
   • Receptor/carrier-mediated transport
   • Vesicular transport mechanisms
2. Polar Drugs: Pass through epithelial tight junctions (paracellular pathway)
   • Limited by molecular size (<1000 Da for effective transport)

Question 4

What are the key functions of the nose in air filtration and drug delivery ?

Answer 4

• Functions of the Nose = passageway for air to the respiratory tract , Humidifies and warms incoming air
• Large particles trapped in nasal filter undergo rapid clearance
• Particles deposited on mucus are moved by ciliated epithelial cells toward the pharynx
• Site of particle deposition and clearance rate are crucial for local and systemic drug delivery

Question 5

What is the function of the clearance system ?

Answer 5

• The function of this clearance system is to remove foreign substances from the nasal cavity, and this includes drugs.

Question 6

What is local drug delivery ?

Answer 6

• Deliver directly at site of action
• rapid relief at lower dose compared to oral
• reduce systemic side effects
• eg. Nasal corticosteroids (reduces nasal mucosa
  inflammation)

Question 7

Why is intranasal delivery useful for systemic drug delivery, and what are some examples?

Answer 7

• Provides rapid onset of action, useful in emergencies.
• Bypasses first-pass metabolism, leading to faster drug absorption.

• eg. Fentanyl: Provides quick pain relief.

• Nasal delivery is effective but has low bioavailability.

Question 8

How does solubility affect systemic absorption ?

Answer 8

• drug must be in solution to be absorbed