Pulmonary Drug Delivery

Question 1

Pulmonary drug delivery is for (local/systemic) therapy

Answer 1

local

Question 2

Why is pulmonary drug delivery accomplished via airways?

Answer 2

1. Big surface area

2. Ease of accessibility

Question 3

Does the pulmonary drug delivery avoid first pass effect?

Answer 3

It does (renal), but the lung itself has some metabolic capability so the benefit is neglibigle

Question 4

What is found within the upper respiratory tract?

Answer 4

1. Nose
2. Throat
3. Pharynx
4. Larynx

Question 5

What is found within the lower respiratory tract?

Answer 5

1. Trachea
2. Bronchi
3. Bronchioles
4. Alveoli

Question 6

What are the two regions of the lower respiratory tract?

Answer 6

1. Conducting

2. Respiratory

Question 7

What is found within the conducting region?

Answer 7

Trachea to terminal bronchioles

Question 8

What is found within the respiratory region?

Answer 8

Respiratory bronchioles + alveolar region

Question 9

What are the conducting airways lined with?

Answer 9

Ciliated epithelial cells

Question 10

If an insoluble particle is deposited on these airways, what happens?

Answer 10

Trapped by mucus
Swept upwards
Either expelled via exhalation or swallowed

Question 11

How are most drugs absorbed?

Answer 11

Passive diffusion

Question 12

What is the rate limiting barrier of drugs into the blood?

Answer 12

Epithelium

Question 13

Is there systemic absorption?

Answer 13

There is, but very small. Goal = local effect

Question 14

(Ionized/unionized) form is the preferred way to pulmonary absorption

Answer 14

Unionized

Question 15

How could you slow the absorption rate?

Answer 15

Use suspension formulation, powders of less water soluble salts, or novel drug delivery systems (liposomes)

Question 16

Can drugs accumulate in the lungs?

Answer 16

Yes

Question 17

(Acidic/Basic) drugs usually accumulate in the lung

Answer 17

Basic

Question 18

What size of aerosols typically deposit in the upper respiratory tract? How is it removed?

Answer 18

> 5micrometers

Muco-ciliary clearance

Question 19

Where is cilia found?

Answer 19

Trachea to terminal bronchioles

Question 20

Do alveoli have cilia?

Answer 20

Nope

Question 21

How does the alveoli remove foreign particles?

Answer 21

They have phagocytic cells; uses lymphatic + circulatory systems

Question 22

What are the three main mechanisms for particle deposition in the lung?

Answer 22

1. Inertial impaction
2. Gravitational sedimentation
3. Diffusion

Question 23

Describe Inertial Impaction

Answer 23

High momentum particles will impact on airway walls

Question 24

Describe Gravitational Sedimentation

Answer 24

Particles move due to gravity

Dependent on size and density

Uses Stokes’ Law

Question 25

Describe Diffusion

Answer 25

Brownian Motion

Main mechanism for small particles

Diffusion is inversely proportional to particle size

Question 26

For MDIs, does the pressure inside container always stay consistent?

Answer 26

Yes

Question 27

What are some disadvantages of pMDIs?

Answer 27

Inefficient at drug delivery

Droplets exit at high velocity and drug is lost thru impaction

Question 28

What is the most common problem w/ pulmonary deliveries?

Answer 28

Incorrect use by pts

Question 29

What is the advantage of Dry Powder Inhalers (DPIs)?

Answer 29

1. Propellant free

2. Can deliver more drug than pMDIs

Question 30

What are some disadvantages of DPIs?

Answer 30

1. Aggregated materials wont reach lower regions of lung

2. Drug delivery is less efficient than pMDIs

Question 31

What are some advantages of Nebulizers?

Answer 31

1. Useful for pt who have difficulty w/ pMDIs + DPIs

2. You can just breath normally

Question 32

What are some disadvantages of Nebulizers?

Answer 32

1. Poorly efficient; material released into environment

Question 33

What kind of Nebulizer CANT deliver suspensions, liposomes, etc?

Answer 33

Ultrasonic