Therapeutic Aerosols

Question 1

What is an aerosol?

Answer 1

Fine suspension of liquid/ solid particles in a gas

Question 2

What is an aerosol in pharmacy?

Answer 2

sprayable product under pressure of liquedied/compressed gas propellant.

Question 3

List the 4 topical uses of aerosols

Answer 3

local analgesics
antiseptics
local anaesthetics
skin dressing

Question 4

List the 4 areas of administration to body cavities by aerosols

Answer 4

Ear, nose, throat and mouth

Question 5

What are the advantages of aerosols?

Answer 5

• Efficient drug dispersion
• Uniform dose
• Rapid response
• Immediate application
• Drug delivered in high conc to limited areas

Question 6

What are the disadvantages of aerosols?

Answer 6

• Expensive
• Difficulty disposing
• Must be kept cool
• Formulation issues if drugs are insoluble

Question 7

What are the two types of aerosols?

Answer 7

liquefied compressed gases and compressed gases

Question 8

Describe the 2 phases of liquefied compressed gases and give an example of a highly volatile gas used.

Answer 8

1. Liquid - propellant with soluble drug
2. Vapour - vapour from propellant
   example - LPG

Question 9

How is equilibrium re-established in liquefied compressed gas aerosol?

Answer 9

Through propellant converting to vapour

Question 10

Give an example of a soluble and insoluble gas used in compressed gas aerosols.

Answer 10

CO2 - water soluble
Air - insoluble

Question 11

Give a reason why compressed gas aerosols fail to deliver all contents

Answer 11

Due to a decrease in pressure during use

Question 12

Describe how compressed gases work?

Answer 12

• Depress actuator button so pressure forces propellant up and out of dip tube.
• Close actuator and volume vapour increases giving vapour drop.