Respiratory System

Question 1

Routes of delivery for inhaled drugs

Answer 1

Nasal or pulmonary

Question 2

Advantages of RDD

Answer 2

BOTH SYSTEMIC AND LOCAL EFFECTS
Rapid onset
Needle free
Reduced total amount of drug
Reduce side effects
Avoids first-pass

Question 3

Disadvantages of RDD

Answer 3

Not suitable for long term
Dose inaccuracy
Do not absorb
Local side effects
Mucociliary clearance
Not for prolong release effects

Question 4

Formulations of PDD

Answer 4

Particle deposition
Paricle size
Aerosols
Dry powder based

Question 5

Devices of PDD

Answer 5

Nebulizers
Metered dose inhalers
Dry powder inhalers

Question 6

Factors concerning PDD

Answer 6

Physiological and pathological condition of the lungs

Drug absorption and kinetics

Question 7

A&P of PDD

Answer 7

Starts at the nose and ends at the alveolar sac in the lung

• Nasopharyngeal region
• Tracheo-bronchial region
• Alveolar region

Question 8

Nasopharyngeal region

Answer 8

Includes airways from the nose to larynx

Question 9

Tracheo-bronchial region

Answer 9

Central or conducting airway

Larynx to the terminal bronchioles (includes tranchea, and bronchi)

Question 10

Alveolar region

Answer 10

Respiratory/peripheral/pulmonary airway

Comprised of respiratory, bronchioles, alveolar ducts, and alveoli

Question 11

Branching of the airways

Answer 11

Single daughter branch is smaller than its mother
Sum of two daughter branches is larger than their mother
Increases with each order, further from the mouth –> larger the area

Question 12

Surface areas of airways

Answer 12

Increase with increase in the generation

Increase with increasing distance of the airway from the glottis

Question 13

Diameter of airways

Answer 13

Decrease with the increasing generation of airways

Question 14

Inhaled drugs are delivered as

Answer 14

Droplets or particles

- Must be deposited in an appropriate lung region in sufficient quantity to be effective

Question 15

Deposition by inertial impaction

Answer 15

Greater than 5 micrometers
Large or fast particles cannot travel in the same direction as the air stream
Increased with particle velocity, diameter, and density
- Based on SPEED/INERTIA

Question 16

Deposition by sedimentation

Answer 16

Depends on GRAVITY
Varies with time and density
Low velocity
- Max residence time, small airways and lung periphery

Question 17

Deposition by diffusion

Answer 17

Increased with TIME
Decreases with particle diameter
Independent of density
- Small airways and lung periphery

Question 18

Physiological factors that affect particle deposition?

Answer 18

Lung anatomy
Oral vs nasal inhalation
Inspiratory flow rate
Coordination of generation and inspiration
Tidal volume
Diseases

Question 19

Routes of inhalation

Answer 19

Oral: lungs
Nasal: not oral

Question 20

Inspiratory flow

Answer 20

Deposition in the first few generation of the respiratory tract increase with the increase inspiratory flow rate

Question 21

Increasing IFR

Answer 21

Increased particle momentum and turbulence –> increase impaction in the proximal tracheobronchial region
- Decrease particle size

Question 22

Slow IFR

Answer 22

advantageous for penetration of drug to the target receptor site in the small peripheral airways

Question 23

Breath holding

Answer 23

• Deposition drugs
  Hold breath for period of 5-10 seconds post inspiration
• Particles will settle during this time

Question 24

Pressurized meter dosing requires

Answer 24

hand-mouth coordinaiotn

Question 25

Aerosol velocity

Answer 25

Droplet velocity is greater than IFR, droplet deposit in the oropharyngel region - No hand eye coordination

Question 26

Particle density

Answer 26

Micronized particles for inhalation have particles densities around 1 g Large pourous particles physical diameters of 20 um and 0.4 densities = deposited

Question 27

Aerodynamic diameter

Answer 27

Diameter of a sphere of unit density that has the same settling velocity in air as the aerosol particles in question

Question 28

MMAD

Answer 28

Mass median aerodynamic diameter - Attach inhaler with the throat, align plates, apply vacuum, collect powder and weigh, plot and determine the size from 50% at weight scale

Question 29

Physical diameter increased with an what in particle density?

Answer 29

Decrease

Question 30

Aerodynamic diameter decreases with an what in density?

Answer 30

Decrease

Question 31

Size of droplets from MDIs

Answer 31

may decrease due to solvent evaporation

Question 32

Broad respirable particle size range?

Answer 32

10-1 uM

Question 33

Respirable fraction

Answer 33

Less than 5 um

Question 34

Fine particle fraction

Answer 34

1-5 um

Question 35

Particles 5-10 um

Answer 35

Impact in the upper airways but removed by coughing, swallowing and mucociliary processes

Question 36

Particles between 0.5 - 5 um

Answer 36

Deposit in the alveolar levels by impaction and sedimentation

Question 37

> 0.5 um particles

Answer 37

50% deposit in the alveoli by diffusion | Rest are exhaled

Question 38

Effective penetration into the lungs?

Answer 38

1-5 um

Question 39

Mucus barrier

Answer 39

Dry drugs dissolve in the mucus containing 90-95% water Poorly soluble drugs, dissolution is the rate limiting step for absorption - Highly soluble drugs dissolve in highly humid airways

Question 40

Rate of diffusion depends on?

Answer 40

Mucus thickness Drug weight Drug mucus interaction

Question 41

Mucociliary clearance

Answer 41

Respiratory system eliminates fluid, bacteria, and particulates Accomplished by the close coordination of ciliary function, airway surface fluid secretion and mucin secretion

Question 42

Alverolar clearance

Answer 42

Engulfed by macrophages | Eliminated via lumphatic system or into the pulmonary circulation

Question 43

Hugh surface area?

Answer 43

Slightly larger than the small intestine | - Rapidly delivered to this area

Question 44

Thin absorption barrier

Answer 44

Thickness is less

Question 45

Rich vasculature

Answer 45

Receive 100% of cardiac output | Directly to the heart bypassing first pass

Question 46

Nominal dose

Answer 46

Written on the package label

Question 47

Metered dose

Answer 47

Amount contained in the metering unit

Question 48

Delivered dose

Answer 48

Amount leaving the device

Question 49

Fine particle dose

Answer 49

Amount contained in particles

Question 50

Recovered amount

Answer 50

Amount recovered from wiping the face and hands with a tissue

Question 51

Dose to subject

Answer 51

Inhaled dose minues the amount of drug leaving the subject through exhalation and mouth rinsing