Nebulizers delivery efficiency

The delivery efficiency, or the nebulizer output, can be expressed in many different ways, as widely documented in the literature. Sometimes it is represented as the volume output, or solution mass output. However, it is more practical to use the drug mass emitted from the nebulizer at or near the mouthpiece to estimate the nebulizer output, because the amount of aerosolized drug mass at this point in the system is the best measure of how much drug the patient has available to inhale. 

Nebulizers fitted with a T-mouthpiece have an unrestricted flow of ambient air passing through the nebulizer output, supplying inhaled air flow, which effectively increases drug output. In vented nebulizers, the inhaled air must flow through the droplet production region. Therefore, the breathing pattern of the patient has an effect on the aerosol characteristics produced by such devices. The delivery efficiency of... 

At the start of the 1990s the only available aqueous solution-based pulmonary delivery systems were the nebulizers that had their routes in technology developed at the turn of the nineteenth century. From a patient perspective, nebulizer therapy is time consuming, equipment costs are high, and cleaning and maintenance can be problematic from a pharmaceutical perspective, nebulizers exhibit poor delivery efficiency and high variability [22], However, nebulizers... 

Rudolph C, Muller RH, Rosenecker J. Jet nebulization of PEI/DNA polyplexes physical stability and in vitro gene delivery efficiency. J Gene Med, 2002,4(1), 66-74. 

Newman, S.P., Steed, K., Reader, S., Flooper, G., and Zierenberg. B., Efficient delivery to the lungs of flunisolide aerosol from a new portable hand-held multidose nebulizer, J. Pharm. Sci., 85 960-964 (1996). 

Many reviews on the relevant technical aspects for drug nebulization are available (e.g. [43 5]. The greatest disadvantages of nebulizers are their poor deposition efficiency (see Section 3.11) and low output rate (e.g. [46]). Several developments have been reported to improve their efficacy, like the use of open vents or breath-assisted open vents [47] and adapted aerosol delivery [48]. A renewed interest in nebulizer therapy may also come from the generation of special aerosols, such as hposomes [49]. 

Delivery devices play a major role in the efficiency of pulmonary delivery, and major advances have been made in the development of new devices in recent years. The most commonly used devices for pulmonary drug delivery include nebulizers, metered-dose inhalers (MDIs) and dry-powder inhalers (DPIs). These de-... 

Some companies are focusing on the development of a new generation of liquid systems that are portable, more efficient, more gentle on the macromolecule and that can deliver the medicine in far fewer puffs than the old fashioned nebulizer. Two companies who are developing advanced pulmonary delivery liquid systems are Aradigm Corporation, Hayward, CA, and AeroGen, Inc., Sunnyvale, CA. 

P3). The average mass median aerodynamic diameter was 3.55 0.07 pm with the geometric standard deviation of 2.55. The test was also conducted to compare the device performance with other small-volume nebulizers,and found to be more efficient in the delivery rate (mass out per minute) than that of other SVNs. 

Fok TF, Monkman S, Dolovich M, Gray S, Coates G, Paes B, et al. Efficiency of aerosol medication delivery from a metered-dose inhaler versus jet nebulizer in infants with bronchopulmonary dysplasia. Pediatr Pulmonol 1996 21(5) 301 -309. 

The performance of pMDIs and DPIs is scrutinized in terms of efficiency and reproducibility of dose delivery, particle size, and distribution under a range of storage conditions, with respect to temperature and humidity, for extended periods of time (up to 2 years).50 Since nebulizer products do not bring the device in contact with the drug until the point of use, a slightly different approach is taken to their approval. Recommended devices and conditions of operation for the delivery of a particular drug must now be stated. The solution formulation is then viewed as a sterile parenteral product and requires concomitant testing. 

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