1
Q
- it exhibits a large amount of drug wastage, especially within the device itself.
A
Traditional jet nebulizer or SVN
2
Q
Traditional SVN, the typical emitted dose and loss pattern is as follows:
- Lung deposition: __________
- Oropharynx: _________
- Device Loss: ________
- Exhaled: ________
A
- 12.4 (4.5)
- 1.5 ( 0.9)
- 66.3 (8.6)
19.7 (3.9)
3
Q
- this is the traditional nebulizer, in which aerosol is produced constantly during inspiration and expiration.
Emitted aerosol is lost to the environment during exhalation or breath hold because of using 6 inches of expiratory reservoir tubing, which reduces but does not eliminate ambient contamination.
A
Constant Output
4
Q
- Nebulizer operation allows more aerosol release during inspiration with decreased output during exhalation or breath hold.
Ex: PARI LC Nebulizer
A
Breath enhanced
5
Q
- Aerosol is released only during inspiration and all released aerosol is available for patient inhalation.
Ex: AeroEclipse/Circulaire
A
Dosimetric
6
Q
- this device use a vibrating plate or mesh with multiple apertures (small holes).
newest technology, this devices are battery powered and do not require gas source making them portable.
A
Vibrating plate technology
7
Q
- it is gas powered, breath actuated, aerosol generated only during inspiratory effort.
Ex: B agonists
: Lung deposition of 39%
A
AeroEclipse
8
Q
- battery powered, unit-dose drug blister packs; microprocessor- controlled delivery based on inspiratory flow volumes
Ex: Insulin, Morphine
: Lung deposition of Up to 75-80%
A
AERx
9
Q
Spring-powered, button actuated multidose device, with single breath unit drug dose delivery and soft mist plume.
Ex: Fenoterol, Flunisolide
:Lung deposition of 30 to 40%
A
Respimat Soft Mist
10
Q
- battery powered, breath-actuated adaptive aerosol delivery, specific metering chambers for unit dose delivery.
Ex: Iloprost
:Lung deposition of 82 to 100%
A
iNeb
11
Q
- theses devices are small pressurized canister for oral or nasal inhalation of aerosol drugs and contain multiple doses of accurately metered drug.
A
Metered Dose Inhaler
12
Q
5 MAJOR COMPONENTS FOUND IN MDI
A
- drug
- propellant/excipient mixture
- canister
- metering valve
- mouthpiece/actuator
13
Q
The drug in MDI is either suspension of ________ ______ in a liquified propellant or a solution of the active ingredient in a ______ (usually ethanol) mixed with the propellant.
A
- micronized powder
- cosolvent
14
Q
CORRECT USE OF A METERED DOSE INHALER
- What is the major problem with MDI?
- The most common error?
A
- the difficulty of patient use
- the failure to coordinate inhalation and actuation of inhaler.
15
Q
FACTORS AFFECTING MEYERED DOSE INHALER PERFORMANCE
A
- Loss of Dose
- Shaking the cannister
- Timing of Actuation Intervals
- Open-mouth Vs. Closed-mouth Use of a MDI
- Loss of Prime
- Storage temperature
16
Q
- refers to the loss of dose refers to the loss of drug content in the valve even though propellant may seem to discharge a normal dose.
- A dose wit less than the nominal amount of drug noted on first actuating a MDI when the canister is stored in the valve-down position, even after only a few hours and with shaking before discharge
- 25->50%
- Not observed in the valve-up position
A
Loss of dose
17
Q
- Many drugs in MDI formulation are suspensions that can separate fom the propellants on standing (creaming)
- If the suspended drug is either lighter or heavier than the propellant and separation occurs, a second actuation could deliver more or less concentrated drug if the canister is not shaken to mix thoroughly.
- The MDI shld be shaken before the first actuation after standing, so that the metering valve refills with adequately mixed suspension from the canister.
A
Shaking the cannister
18
Q
- A pause of 1 to 5 mins has been advocated between each puff in an attempt to improve distribution of the inhaled drug in the lung.
- 2 actuations 1 seconds apart caused no change in total drug output, although there was a 15.8% decrease in the amount of particles below 6.8um.
- 4 actuations 1 sec apart led to significant reductions in dose output
- Loss of dose probably occurs as a result of turbulence and coalescence of particles with more than 2 rapid actuations
A
Timing of Actuation Intervals
19
Q
- Actuating the MDI several cms in front of the open mouth theoretically allows for slowing of the particle velocity and evaporation of aerosol droplets, resulting in less oropharyngeal impaction and loss
- Studies with both adult and children have shown no difference.
A
Open-Mouth VS Closed-Mouth Use of a MDI
20
Q
- Refers to the loss of propellant from the metering valve of the MDI so little or no drug will be discharged on actuation
- Takes days to week to occur so regular use prevents this
- Shaking of the canister and discharge of a waste dose are suggested after long periods of no use, to prime the valve with propellant and drug.
A
Loss of prime
21
Q
- Data indicate that dose delivery from CFC-propelled MDIs of albuterol decrease at lower temp.
- Decrease of 65-70% of the usual dose has been observed at 10°C
- HFA-propelled remained constant in total dose over the range of -20 to 20°C
A
Storage temperature
22
Q
- it offers an alternative for individuals who find it difficult to coordinate MDI actuation with inhalation.
Ex: Adrenergic bronchodilator pirbuterol (Maxair)
A
Breath Actuated Inhalers
23
Q
- a conventional pressurized MDI canister is fitted within the autohaler actuator.
A
Autohaler
24
Q
Devices that are similar to autohaler
A
- Easi-breathe
- K-haler
- MD turbo
- Xcelovent
- SmartMist
25
1 CFC molecule can destroy _________ molecules of stratospheric ozone.
- 100,000
26
- have been identified as propellants that are non toxic to the atmosphere and to the patient, and that have properties suitable for MDI aerosol generation.
Hydrofluorocarbons or hydrofluoroalkanes
27
- the CFC propellant that is most commonly used
- it has a vapor pressure similar to that CFC 12
- CFC 12
- HFA134a
28
29
PHARMACOLOGY MIDTERM
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