Nebulizer dosimetric

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. 

In critical evaluation of the effect of a gas, vapor, or aerosol inhaled in to the respiratory tract of an animal, the dosimetric method has been recommended (Oberst, 1961). However, due to the complexity of measuring the various parameters simultaneously, only a few studies on gaseous drugs or chemicals have employed the dosimetric method (Weston and Karel, 1946 Adams et al., 1952 Leong and MacFarland, 1965 Landy et al., 1983 Stott and McKenna, 1984 Dallas et al., 1986, 1989). For studies on liquid or powdery aerosols, modified techniques such as intratracheal instillation (Brain et al., 1976) or endotracheal nebulization (Leong et al., 1988) were used to deliver an exact dose of the test material into the lower respiratory tract (LRT) while bypassing the URT and ignoring the ventilatory parameters. 

Leong, B.K.J., Coombs, J.K., Petzold, E.N. and Hanchar, A.J. (1988). A dosimetric endotracheal nebulization technique for pulmonary metabolic disposition studies in laboratory animals. Inhal. Toxicol, (premier issue) 37-51. 

Rau, J. L., Ari, A., and Restrepo, R. D. (2004), Performance comparison of nebulizer designs Constant-output, breath-enhanced, and dosimetric, Respir. Care, 49, 174-179. 

New adaptations of existing jet nebulizer technology to produce dosimetric systems for conventional generic nebulized drug delivery— e.g., Halolite and Circulaire... 

The characteristics of both Respimat and AERx clearly differentiate them from traditional nebulizers and those traditional nebulizer systems that have been modified to increase output (Circulaire) or deliver discrete doses (Halolite). Both are being developed and marketed in conjunction with specific drugs that subsequently undergo clinical trials. Both are dosimetric in operation, are reported to have very low residual volumes, have low or no electrical power requirements, and both Respimat and AERx are thought to have good dose reproducibility. 

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