pMDIs and DPIs

Question 1

Pressurized metered dose inhaler

Answer 1

Delivers drugs for multiple dosing using metering valves with the help of PROPELLANTS

Question 2

Major components of pMDI

Answer 2

Container
Metering valve (25-100 microL)
Spray actuator

Question 3

Formulation for pMDI

Answer 3

Drug
Propellants
Surfactants and lubes

Question 4

Surfactants are used for?

Answer 4

To disperse drug particles in suspension or lube the valve

Question 5

What does the acutator do?

Answer 5

Provides an orifice for discharge of spray to patient’s mouth

Question 6

How doe pMDIs work?

Answer 6

Aersolization begins with propellants leave the actuator as a plume due to vaporization
Particle size decreases rapidly due to evaporation as the cloud moves away from the nozzel

Question 7

Breath actuated MDIs?

Answer 7

Reduce or eliminate the hand-breath coordination
Senses the patient inhalation through the actuator and fire the inhaler automatically
- Autohaler

Question 8

Autohaler

Answer 8

Patient life to prime the device before inhalation

Patients press and breathe at the same time

Question 9

Propellant free MDIs

Answer 9

Produce aerosols without propellants

- Respimat

Question 10

Respimat?

Answer 10

Transform aqueous solution to liquid aerosol droplets

Propellant free multi-dose hand held inhaler

Question 11

Correct use of pMDIs?

Answer 11

Shake before inhalation

Prime several times to make sure there aren’t erratic first sprays

Question 12

Spacer devices?

Answer 12

Reduce oropharyngela deposition and increase lung deposition
Increase distance between point of spray and mouth
Faster particles will strike the container
Reduce or eliminate the coordination between actuation and inhalation

Question 13

Medical benefit of spacer devices?

Answer 13

Reduces the risk of oral candiasis and dysphonia with inhaled corticosteroids
Reduce potential systemic absorption from GIT

Question 14

Disadvantages of spacer devices?

Answer 14

Cumbersome
Reduce dose bc of electrostatic charge
- Charge removed by priming chamber or washing with ionic detergent

Question 15

Types of spacers?

Answer 15

Simple tube extension
Valved holding chamber
Reverse flow device

Question 16

Valved holding chamber

Answer 16

One way valve for the aerosol to remain within the device until patients inhales
- Helps prevent blowing away the dose

Question 17

Reverse flow devices

Answer 17

Use a bag which collapses upon inhalation

Use a chamber with air vent that opens during inhalation

Question 18

Dry powder inhalers

Answer 18

Contain solid drug suspended in a dry powder mix that can be fluidized when patients inhales

• Micronized drug particles with larger carrier particles
• Powders are solid when static, liquid when they flow

Question 19

Carriers?

Answer 19

Prevent aggregation and improve flow

Question 20

Dry powder inhaler particle movement?

Answer 20

Passive or active

Question 21

Passive

Answer 21

Patients activate and inhale
- Breath actuated
Inhalation: airflow creates shear and turbulence and air is introduced in the powder bed -> fluid and enters patient
- Deep in the lungs but deposition depends on patient’s inspiratory airflow

Question 22

Active

Answer 22

Power assisted

• Pneumatic, impact force and vibratory
• Drugs with narrow therapeutic windows
• Spiros and Microdose

Question 23

Excipients in DPIs?

Answer 23

Lactose
Mannitol and Glucose
OR none (plumicort and turbuhaler)

Question 24

Lactose

Answer 24

improves handling, dispensing and metering of the drug by reducing cohesive forces between drug particles

Question 25

Large porous particles for DPIs

Answer 25

Aerodynamic diameter is smaller than their volume diameter

Made in the respiratory aerdynamic diameter range (even if they are 20 micrometers)

Question 26

PulmoSpheres (Large porous particles)

Answer 26

Low density particles
Lesser susceptibility to phagocytosis
Lesser aggregation
- Tobi-Podhaler

Question 27

Unit dose with drug in hard gelatin capsules

Answer 27

Placed individually in device

- Handihaler

Question 28

Multidose with drug in foil blister

Answer 28

Loaded by patient

- Diskhaler

Question 29

Multi-dose with drug preloaded in the devide

Answer 29

Preloaded and sealed

- Diskus

Question 30

Reservoir type of device

Answer 30

A dose is measured and delivered from a drug reservoir

• Metering cups are filled by gravity from reservoir and delivered to an inhalation passage
• Clickhaler

Question 31

Diskhaler

Answer 31

Multidose
Reloadable
- Pierce the foil to release the dose

Question 32

Diskus

Answer 32

Dosage pack sealed during manufacturing

Wheels guide the foil strips and aligns each newly opened blister with air passageways

Question 33

Nebulizers Advantages

Answer 33

No specific inhalation technique or coordination required
Aerozolizes most drug solutions
Deliver large doses
Good for infants or sick patients

Question 34

Nebulizers Disadvantages

Answer 34

Time consuming
Bulky
Non-portable
Easy contaminated
Poor delivery efficiency
Drug wastage
Huge variation

Question 35

pMDIs Advantages

Answer 35

Compact 
Portable
Multi-dose
Inexpensive
Sealed environment
Reproducible dosing

Question 36

pMDIs Disadvantages

Answer 36

Partient coordination
High oral deposition
5 mg max dose
Limited range of drug available

Question 37

DPIs Advantages

Answer 37

Compact
Portable
Breath actuated
Easy to use
No coordination

Question 38

DPIs Disadvantages

Answer 38

Respirable dose dependent on inspiration
Humidity: aggregation
Lose the dose if exhale into the device
Contains lactose

Question 39

Inhaled Insulin Exubera

Answer 39

Rapid acting insulin
Blister packages
No longer used