Nasal Delivery

Question 1

What are the functions of the nose?

Answer 1

-heating and humidification (withstand all air types)
-olfaction (smell)
-Tone of voice
-Defence- particle filtration, Mucociliary clearance, and microbial/viral immune clearance

Question 2

Which part of the nasal cavity is the area for optimal drug delivery and why?

Answer 2

-superior turbinate (nasal conchae)
-thin epithelium, maximised surface area, heavily vascularised, bony elements

Question 3

What is the vestibule?

Answer 3

Entrance to nasal cavity- tough to withstand the environmental conditions

Question 4

What is the nasopharynx?

Answer 4

Area between nasal cavity and throat

Question 5

What is the olfactory epithelium?

Answer 5

Cluster of nerve endings which allows nose to brain drug delivery
Helps with sense of smell
No blood brain barrier

Question 6

What is the superior turbinate also known as?

Answer 6

Nasal conchae

Question 7

Where is mucus secreted from and what is its function?

Answer 7

-Submucosal glands-goblet cells
-Covers mucosa, protects physically and enzymatically
-Permits heat transfer and has water capacity for ion transport
-Exhibits electrical activity regulates cilia beat

Question 8

How much mucus is secreted daily?

Answer 8

1.5 to 2 L daily

Question 9

What is the mucus blanket made up of?

Answer 9

-A lower gel layer with low viscosity
-An upper gel layer with high viscosity
-Micro thick

Question 10

What is mucociliary clearance?

Answer 10

Particles adhere to mucus lining and passed down the nasopharynx
Immune defence system

Question 11

Why use nasal drug delivery route?

Answer 11

-IV alternative
-Epithelium is thin porous and highly permeable
-Large surface area
-Highly vascularised
-Direct to systemic circulation
-Nose to brain delivery
-Overdose has a risk

Question 12

What are limitations of nasal drug delivery?

Answer 12

• The nasal cavity volume
  -Large hydrophilic molecules are not absorbed
  -mucocilary clearance- half life 21mins
  -Enzymatic barrier

Question 13

What makes an optimal nasal delivery system?

Answer 13

-Good aqueous solubility and absorption (0.2ml per nostril)
-low-dose less than 25 mg
-Non-irritating to nose
-Rapid onset
-Suitable stability

Question 14

What nasal delivery system was designed for influenza?

Answer 14

-Fluenz (Astrazeneca)
-Contains live attenuated influenza a and B strains

Question 15

What ingredients of influenz can be an allergy concern?

Answer 15

-Egg protein and gentamycin

Question 16

What are other examples of nasal drug delivery?

Answer 16

-hormones- desmopressin- diabetes
-Migraine- sumatriptan (imigran)

Question 17

What is a barrier of the nasal cavity?

Answer 17

-mucus layer

Question 18

What characteristics of particles favour nasal drug delivery?

Answer 18

-low MW (<300Da)
-Nonpolar
-PH 4.5 to 6.5 to avoid irritation (unionised)

Question 19

What effects nasal drug absorption?

Answer 19

-Mucocilary clearance
-infection
-Blood flow
-Stability of drug

Question 20

How can nasal drug absorption be enhanced?

Answer 20

-use a surfactant- solubiliser and stabiliser
-Use a penetration enhancer- increases membrane fluidity, increases nasal blood flow, decreases mucus viscosity, inhibits enzymes
-Decreasing mucociliary clearance increases drug residence

Question 21

What is a nasal device used for nose to brain delivery?

Answer 21

-Optinose- exhale into the device soft pallet closes the nasal cavity breath enters one nostril particles are released into airflow and deposited in olfactory region airflow traffics around cavity and exits the other nostril