Delivery Devices Flashcards
Describe the advantage of the inhaled route
- Direct target to lungs compared to oral or IV routes
- Smaller dose can be used
- Rapid onset of action
- Less side effects
Name some inhaler devices
- pMDI
- Spacers
- DPI
- Nebulisers
- Soft-mist inhalers
What are some advantages of using a pMDI
- Compact and portable
- Rapid onset
- Multi-dose
- Inexpesnive
Slow and deep inhalation is better
Describe some disadvantages for pMDI
- Difficult co-ordination
- Poor comliance/technique
- High oral deposition
- Difficult to assess empty canister
- Propellants can affect climate change (CFC-free, HFA)
- Cold Freon effect
- Cold impact on patients oropharynx, they abort inhalation and get a different dose
- Cold Freon effect
What are the benefits of using a spacer with an inhaler
- Removes the need for co-ordination
- Standing cloud in spacer
- ↓Aerosol Velocity at mouth and therefore impaction at oropharynx
- Allows propellant evaporation -> smaller particles -> greater lung deposition
Describe some advantages for using DPI
- Compact and portable
- Rapid Onset
- Breath actuated
- Removes need for hand-mouth co-ordination
- No propellants
- ‘Cold Freon’ effect
Describe some disadvantages of DPI
- Reliant on sufficient inspiratory flow to disperse drug
- High oral deposition
- Older devices not mluti-dose
- Contains additives
- Lactose to disperse particles
- Lactose intolerants
- Lactose to disperse particles
- Humidity leads to drug degradation
Describe advantages of nebulisers
- Relaxed tidal breathing technique
- Large drug dose can be given
- Aerosolise many drugs
- No propellants
- Suitable for young, old and acutely ill
Describe disadvantages of nebulisers
- Bulky
- Long treatement time
- Expensive
- Wasted drug in nebuliser
- Need power source
- Variation in aerosol output performance between models
Describe advantages of soft-mist inhalers
- Compact and portable
- Multi-dose
- Low oral depostition
- Slow mist
- Small droplet
- No power source required
Describe disadvantages of soft-mist inhalers
- Only one device available
- Some co-ordination necessary
- Contain som additives
What factors affect lung deposition of medical aerosols?
- Particle Characteristics
- Size (1.5um)
- Density
- Charge
- Lipophilicty
- Patient factors
- Inhalation quality (volume, flow)
- Compliance
- Airway disease severity
Why are small particles preferred in inhaled therapy
- Higher total lung deposition
- Good Peripheral Deposition
- Less oropharyngeal deposition
- Less affected by inhalation flow
In conjunction with slow inhalation, there is better deposition deeper in the lungs
Describe some differences in CFC and HFA inhalers
CFC much faster and bigger particles
HFA slower and smaller particles
Future of inhaler technology: What are some potential novel inhaler devices
Smart nebulisers
Digital logging systems (dose time frequency)
?Aerosolised vaccines
