pMDIs

Question 1

What is a pMDI?

Answer 1

Compact, pressurised aerosol dispenser designed for oral inhalation delivery of multiple doses of finely dispersed drug to the lung, valve volume 25-100 microliters

Question 2

What are the 2 types of pMDIs?

Answer 2

• Suspension formulation
• Solution formulation

Question 3

What does a surfactant do?

Answer 3

Maintain uniform suspension and lubricate valve

Question 4

What does a co-solvent do?

Answer 4

improve solubility of surfactant - ethanol up to 10% w/v

Question 5

What is a propellant?

Answer 5

Liquified gas

Question 6

What does no co-solvent mean?

Answer 6

better solubility

Question 7

What happens when viscosity increases?

Answer 7

droplet size increases and may give stream

Question 8

What is a valve?

Answer 8

A device used to seal aerosol container and permit a controlled discharge of the contents.

Question 9

What is cold filling?

Answer 9

Contents and propellant are cooled sufficiently so volatilisation is minimised.

Question 10

What is pressure filling?

Answer 10

Contents/propellant kept under pressure, no refrigeration needed

Question 11

What is stokes’ diameter diameter?

Answer 11

Diameter of a sphere that has the same density and settling velocity as the particle

Question 12

What is a cascade impactor?

Answer 12

used to characterise aerodynamic particle size