Pharm Tech I (intranasal)

Question 1

True or false?

Paracellular transport is a passive process, while transcellular intraneuronal transport is an active one

Answer 1

True

Question 2

True or false?

Paracellular transport is slower than transcellular transport

Answer 2

False
Paracellular transport is faster (rapid uptake), high turnover of olfactory sensory neurons can leave more gaps.
Transcellular transport is a slow process (upwards of 13 hours)

Question 3

True or false?

Intraneuronal transport is passive and slow

Answer 3

False, is active and triggered by transporter molecules. It is a slow process

Question 4

What is the volume of the nasal cavity?

Answer 4

~15cm2 (10% of nasal surface area)

Question 5

List some of the barriers of CNS drug delivery by intranasal means.
(hint: there are 7 in total :))

Answer 5

• Nasal epithelial layer (must bypass this first to be absorbed into bloodstream and get to target site)
• Nasal mucus (~5um) (slow down and traps foreign materials)
• Metabolic enzymes (remove foreign materials)
• Efflux pumps (remove foreign materials)
• Hair (filter)
• Mucociliary clearance
• Volume (larger V, lower concentration of particles and thus lower delivery)

Question 6

Choose the correct word

Lipophilic/hydrophilic drugs are absorbed well in the nasal cavity, while lipophilic/hydrophilic drugs are poorly absorbed

Answer 6

Lipophilic drugs are absorbed well in the nasal cavity, while hydrophilic drugs are poorly absorbed

Question 7

True or false?

Non-ionized drug molecules are well absorbed

Answer 7

True

Question 8

Excipients in formulations must be __________

Answer 8

pharmacologically inert

Question 9

What is the target pH of nasal spray formulations?

Answer 9

4-7.4

Question 10

What is the target tonicity of nasal spray formulations?

Answer 10

300 - 700 mOsm

Question 11

What is the target volume of nasal spray formulations?

Answer 11

max 200uL

If volume is too much -> draining to the back of the throat, drug is not delivery to CNS/ target site and is wasted

Question 12

What are the advantages of intranasal delivery? (4)

Answer 12

• Non-invasive
• Can be self-administered
• Bypass hepatic 1st pass effect
• Short onset of effect

Question 13

Intranasal delivery systems can:
* Make the drug physically ____________
* Improve drug ________
* Improve drug ________
* Improve drug ________
* Protect drug candidate from ________ and ________
* Reduce ________
* Increase ________
* Reduce ________ of administration

Answer 13

• Make the drug physically manageable
• Improve drug solubility
• Improve drug absorption
• Improve drug retention
• Protect drug candidate from degradation and excretion
• Reduce SEs (through targeting)
• Increase dosing (load more drug in)
• Reduce frequency of administration (improve pateint compliance)

Question 14

What are the benefits of intranasal delivery as compared to oral and parenteral deliveries?

Answer 14

• Avoids gastrointestinal absorption and hepatic 1st pass effect, enhancing drug bioavailability
• Circumvent the obstacles for blood-brain barrier (BBB) allowing the direct drug delivery to CNS

Question 15

True or false?

Buffering and pH adjusting agents are needed in non-ionisable formulations

Answer 15

False! Don’t need

Question 16

In situ gels are ________ viscosity solutions initially, but viscosity ________ once administered. This is because they are activated by stimulus such as ____________, which helps to ________ retention time

Answer 16

In situ gels are low viscosity solutions initially, but viscosity increases once administered. This is because they are activated by stimulus such as changes in salt concentrations, pH, temperature, etc., which helps to enhance retention time

Delayed mucociliary clearnace, reduced immobility

Question 17

What is the function of a buffer?

Answer 17

A buffer is a solution that can resist pH change upon the addition of an acidic or basic components

Question 18

What is the function of diluents and solvents?

Answer 18

They are used to dissolve or dilute other substances or materials