pMDIs and special patient groups Flashcards
1
Q
pMDIs and special patient groups
A
- Ability of a patient to use a pulmonary drug delivery device needs to be considered
- A valved holding chamber and spacer used with young children
2
Q
Why are spacers benificial
A
- Do not require the patient to coordinate their breathing
with the actuation of the pMDI - Reduce intial droplet velocity allows time for propellant to evaporate
3
Q
Structure of spacer
A
- One way valve
- Cap removed and patient inhales through
- pMDI mouthpiece
4
Q
Patients that would use a spacer
A
- Patients with limited dexterity, e.g. arthritis
– Partially-sighted patients or with reduced vision
– Patients with cognitive impairment
– Elderly – lung function reduces over time
5
Q
Alternative therapy that can be used for specific patient groups
A
Breath-actuated pMDIs or nebulizer therapy
6
Q
Young infant using inhaler
A
- Nebulizer + mask may be used
7
Q
Breath-actuated pMDIs
A
- Easyhaler, Autohaler, Easi-
Breathe - Inspiration by the patient triggers the release of drug
8
Q
Dry powder inhalers
A
- DPIs use no propellant and rely on the force of the patient’s
inspiration to carry the drug
9
Q
Two types of DPIs
A
- Drug in hard capsule DPIs
- Multidose DPIs
10
Q
Advantages of DPI
A
- Propellent free better for environment
- Being breath-actuated avoid inspiration and actuation coodination issues
- Can deliver larger doses of drug that pMDI
11
Q
Disadvantage of DPI
A
- DPI requires insiratory flow rate of 30-90 l/mim
- Higher upfront cost
- DPI more exposed to ambient air which may cause stability issues
12
Q
Formulation of DPIs
A
- Drug should be <5 mcg for biopharmaceutical reasons need to be micronised
13
Q
Micronisation process
A
- Milling/ Grinding
- Spray drying
- Spray freeze drying
- Supercritical fluid processes
14
Q
Properties of Micronized particles
A
- Poor flow properties due to static / cohesive / adhesive nature
- Drug mixed with carrier to improve flow
- Lactose typically used for carrier particles
15
Q
Lactose and micronised particles adherance
A
- Formulated so that micronized drug particles adhere to the larger lactose particles
- Leads to more uniform device filling and improved liberation of drug from the DPI
- Turbulent airflow causes the drug particles and carrier particles to disaggregate
16
Q
Drug in hard capsule DPIs
A
- Drug in hard capsule DPIs
- Capsule is loaded into the device by the patient
- Punctured by two metal needles inside the device
- Inspiration by the patient causes a rotor to rotate and this causes a turbovibratory air pattern to disrupt the powder in the capsule
17
Q
Multidose DPIs
A
- Diskhaler or Accuhaler
18
Q
Reservoir based inhaler
A
- Requires initial click
- Only one reservoir may have stability issues
- Clickhaler and Turbohaler
19
Q
Smart inhaler
A
- Sensor device. Detect and record on the use of inhaler
- Connects via Bluetooth to a smartphone and device
- GoResp Digihaler DPI contain Budesonide
-Records data how often used and inspiration flow
20
Q
Nebuliser
A
- larger pulmonary delivery devices generate aerosol from the contents of unit dose of nebules
- Large vol of drug solution
-Drug inhaled during normal breathing - Used in hospital not portable due to size
21
Q
Formulation of nebules
A
- Dissolved in normal saline (0.9% w/v NaCl aqueous solution)
- purified water
-Sulphuric acid
22
Q
Steroid nebules suspension formulation
A
- Has polysorbate surfactant
- Sorbitan laureate
- Water for injection
- NaCl
23
Q
Jet nebuliser
A
- Require compressed air from cylinder or electrical compressor
- Aerosol droplet size determined by compressed gas flow rate
- Baffle ensure that large non respirable particles are not inhaled
- Compressed air passed through the venturi nozzle - low pressure cause draws up liquid from reservoir
24
Q
Ultrasonic Nebuliser
A
- Large aerosol droplets are emitted from the apex and smaller droplets from the
lower areas - Energy to generate aerosol comes from a vibrating piezoelectric crystal
