Jet nebulization

FIG. 1. Fast 1 -min SPECT coronal-section lung images of a healthy subject after inhalation of normal saline aerosols containing TC-DTPA in large and small droplet sizes (7 im, top panel 3 pm, bottom panel) generated by air jet nebulizers. The difference in deposition between the two aerosols is clearly shown in these images. 

Budesonide respules - Administer by the inhaled route via jet nebulizer connected to an air compressor in asthmatic patients 12 months to 8 years of age. Improvement in asthma control following inhaled administration of budesonide can occur within 2 to 8 days of initiation of treatment, although maximum benefit may not be achieved for 4 to 6 weeks. It is desirable to downward-titrate to the lowest effective dose once asthma stability is achieved. In symptomatic children not responding to nonsteroidal therapy and in patients who require maintenance therapy of their asthma, a starting dose of 0.25 mg once daily may also be considered. 

DuoNeb The recommended dose is one 3 mL vial administered 4 times/day via nebulization with up to 2 additional 3 mL doses allowed per day, if needed. Administer via jet nebulizer connected to an air compressor with an adequate air flow, equipped with mouthpiece or suitable face mask. 

Nebulizers are designed primarily for the atomization of aqueous formulations either as solutions or suspensions, and typically contain additional excipients. These systems are nonpressurized formulations and do not contain propellants. Traditionally, nebulizers operated using one of two basic mechanisms jet nebulization or ultrasonic nebulization. Jet nebulizers (Fig. 3) function using the Venturi effect to... 

Wu-Pong and Byron [15] have contributed a review of the issues associated with pulmonary delivery of ASOs. Since ASOs are freely soluble and highly hygroscopic, it would be reasonable to assume that initial dosage forms will rely upon the aerosolization of simple aqueous solutions. Our data indicate that commercially available nebulization devices will generate suitable aerosolizations of ASO solutions at concentrations up to 180 mg/mL [3]. Ultrasonic and jet nebulizations were found to have essentially no effect on the phosphorothioate stability of the ASO over 40 min, which is longer than typical treatment times. 

Nebulizer jet nebulization ultrasonic nebulization. Generates small particles with higher delivery capacities than pMDIs and DPIs no coordination required. Inconvenient long inhalation times poor dose control lack of portability expensive. More compact and portable devices breath enhanced nebulizers dosimetric nebulizers. 

The compressed gas source is from either cylinders or air compressors and hence air-jet nebulizers tend to be more frequently encountered in hospitals than in the domiciliary environment. 

Although they are compact units and hence easily portable, the dense aerosol plume produced often has a population of drops with a higher MMAD and GSD in comparison to air-jet nebulizers and hence ultrasonic nebulizers tend to be less widely used. 

Waldrep, J. C., Gilbert, B. E., Black, M., and Knight, V. (1997), Operating characteristics of 18 different continuous-flow jet nebulizers with beclomethasone dipropionate liposome aerosol, Chest, 111, 316-323. 

One of the oldest medical aerosol delivery systems is the air jet nebulizer, which forms a fine mist of liquid droplets from a drug solution that a patient breathes over a period of 10-30 min/dose. The cumbersome... 

Spontaneously charged liquid droplets may be generated by spraying, as discussed above. Droplets of deionized water produced from a jet nebulizer were found to carry a positive charge. The net charge of the aerosol also varied with different starting volumes of water in the nebulizer. 

The jet nebulizer is driven by air pressurized typically at 20-40 psi. The compressed air accelerates through an arrow orifice to break the bulk liquid into sheets, jets, films, or streams. Those ligaments are accelerated to a velocity sufficient to impact on baffles or on the nebulizer wall. The outgoing air becomes saturated with water vapors derived from the liquid retained in the nebulizer, and this has two important consequences ... 

An extensive study was conducted by McCallion et al. investigating the effects of different physicochemical properties on the performance of the jet nebulizer. Materials with different viscosity and... 

Newman et al. evaluated the concentration change using four different jet nebulizers, with a gentamicin solution, which is used to treat patients for cystic fibrosis. The types of nebulizers used were the Bird micronebulizer, DeVilbiss 646, Bard Inspiron mini-neb, and Medic-Aid Upmist. All were operated... 

Finlay, Stapleton, and Zuberbuhler recently tested 15 different jet nebulizers available commercially to investigate the performance of nebulizers. The drug compound used in the study was a 2.5 ml unit dose of Ventolin (containing 1 mg/ml of salbutamol sulfate), which corresponds to a 2.5 mg in nominal dose per drug container. Table 3 shows the experimental results for the different nebulizers. 

Fig. 6 The diagram of the Pari LC Plus jet nebulizer. (Courtesy of Pari GmbH.)...

Advantages and disadvantages of the ultrasonic nebulizer for the delivery of pharmaceutical compounds to the human respiratory airways are listed in Table 8. The output of drug compound leaving the ultrasonic nebulizer is at a relatively slow velocity compared with the jet nebulizer. Therefore, less patient coordination is required during treatment. 

As with jet nebulizers and pMDIs, the formulation characteristics include liquid density, surface tension, viscosity, and vapor pressure. Many of these that effect nebulizer performance of formulation properties are described in the above equation. The configuration... 

Niven, R.W. Ip, A.Y. Mittelman, S.D. Farrar, C. Arakawa, T. Prestrelski, S.J. Protein nebulization I. Stability of lactate dehydrogenase and recombinant granulo- 56. cyte-colony stimulating factor to air-jet nebulization. Int. 

Whereas air-jet nebulizers are usually disposable or sterilizable, ultrasonic nebulizers are too expensive to be produced as disposable units and are thus used repeatedly/ running the risk of bacterial contami-nationJ Cleaning nebulizers and connecting tubing is difficult, and the transfer of Gram-negative bacteria between nebulization equipment and patients has been reported ... 

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