Particle size formulation

Question 1

what are some pharmaceutical aerosol products?

Answer 1

• nebuliser, air jet and ultrasonic
• metered dose inhaler
• dry powder inhaler

Question 2

why is size important for inhaled drug delivery

Answer 2

• aerodynamic in the airways and lungs, breathing during the inhalation of the medication
• particles travel through the airway, aerosol deposition site is dictated by particle size

Question 3

what are the 4 main processes that influence particle deposition in the lungs?

Answer 3

• impaction
• gravitational settling
• electrostatic interactions
• Brownian diffusion

Question 4

what size should particles be to deposit in the nose mouth and upper through?

Answer 4

larger than 10 micrometers

Question 5

what size should particles be to deposit in the upper airway?

Answer 5

larger than 5 micrometers

Question 6

whys it important that particles are less than 0.5 micrometers?

Answer 6

because they collide with other molecules in the lungs and may impact the lung wall.

Question 7

what is asbestosis?

Answer 7

it is a chronic inflammatory kung disease, caused by breathing in asbestos fibres that penetrate deep into the lung including into the alveoli. the fibrous tissue grows around the asbesto particles and causes shortness of breath and respiratory failure

Question 8

what are the effects of particle density on lung deposition?

Answer 8

-denser particles behave as if they were larger

Question 9

what particle size gives desired particle deposition?

Answer 9

MMAD between 1-5 micrometers gives a good lower airway and alveolar deposition

Question 10

what size deposit too high and what other size has minimum deposition?

Answer 10

particles more than 5 micrometers deposit too high up to be real use and approx 0.5 micrometers have minimum deposition