Aerosols

Dr. Aws Alshamsan

Department of Pharmaceutics

Office: AA87

Tel: 4677363

aalshamsan@ksu.edu.sa

Respiratory tract characteristics

Large surface area, good vascularization, immense capacity for solute exchange, ultra-thinness of the pulmonary epithelium

Conducting region :

Nasal cavity, nasopharynx, bronchi, bronchioles

Respiratory region :

respiratory bronchioles, alveolar ducts and sacs

Why and why not?

• Advantages:

- Less systemic toxicity

- Rapid onset of medication

- Delivery to target of action

- Higher concentrations available in the lung• Disadvantages:

- Time and effort consuming

- Limitation of delivery device

Methods Of Delivery

• Medications may be given by: Metered Dose Inhaler (MDI) Dry Powdered Inhaler (DPI)

Respiratory Aerosols

Particle Size

• MMAD: mass median aerodynamic diameter

MMAD <1μm: exhaledMMAD 1~5μm: targetMMAD >5μm: oropharynx

• Strict control of MMAD of the particles ensures the reproducibility of aerosol deposition and retention.

How MDI Technology Works

Inhaler• Hold upright, remove the

dustcap.• Shake well.• Breathe out fully and tip chin

up.• Place puffer in mouth or three

fingers distance from mouth.• Start to breathe in and press the

canister.• Continue to breathe in for 5

seconds.• Hold breath for 10 seconds (or

as long as comfortably possible).

• Breathe out gently. For additional doses repeat steps 1 – 8.

Addition of Spacers

Aerosol Metered Dose Inhalers and Chambers / Spacers

• Use a spacer with an aerosol inhalerGets more medication into the lungs (~5 x more than

MDI alone)Fewer side effects such as smaller amount of absorbed

medication systemically, less oral thrush and dyphonia

F27

Turbuhaler

Need deep, forceful inhalationMay use Turbutester to help determine if

an individual is able to useCounter (dots in window) turns red when

doses running out

Turbuhaler

Turbuhaler• Remove cap.• Hold upright (coloured base

at the bottom) and twist the coloured base as far as possible to the right (anti-clockwise) and then left (clockwise) until it clicks.

• Place mouthpiece in mouth.• Suck in deeply and

forcefully.• Breathe out gently.• For next dose repeat steps 2

– 5.

Diskus