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| Inhaler | Formulation | Metering system | Advantages | Disadvantages |
|
| pMDI | Drug suspended or dissolved in propellant (with surfactant and cosolvent) | Metering valve and reservoir | Portable and compact
Multidose device
Relatively cheap
Cannot contaminate contents
Available for most inhaled medications | Contains propellants
Not breath-actuated
Many patients cannot use it correctly
High oropharyngeal deposition |
| pMDI + spacer | Easier to coordinate
Large drug doses delivered more conveniently
Less oropharyngeal deposition
Higher lung deposition than a pMDI | Less portable than pMDI
Plastic spacers may acquire static charge
Additional cost to pMDI |
|
| BA-MDI | Drug suspended in propellant | Metering valve and reservoir | Portable and compact
Multidose device
Breath-actuated (no coordination needed)
Cannot contaminate contents | Contains propellants
“Cold Freon’’ effect
Requires moderate inspiratory flow to be triggered |
|
| DPI | Drug blend in lactose, drug alone, drug/excipient particles | Capsules, blisters, multidose
blister packs reservoirs | Portable and compact
Breath-actuated (no coordination needed)
Does not contain propellants | Requires a minimum inspiratory flow
May not appropriate for emergency situations
Many patients cannot use it correctly
Most types are moisture sensitive |
|
| SMI (Respimat) | Aqueous solution or suspension | Unit dose blisters or
reservoirs | Portable and compact
Multidose device
High lung deposition
Does not contain propellants | Not breath-actuated
Not currently available in most countries
Relatively expensive |
|
| Nebulisers | Aqueous solution or suspension | Nebule dispensed into reservoir chamber of nebulizer | May be used at any age
No specific inhalation technique required
Vibrating mesh is portable and does not require an outside energy source
May dispense drugs not available with pMDIs or DPIs | Jet and ultrasonic nebulisers require an outside energy source
Treatment times can be long
Performance varies between nebulisers
Jet nebulisers cannot aerosolise a certain volume of solution
Risk of bacterial contamination
Newer nebulisers are expensive |
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