Le Brun P P, de Boer A H, Heijerman H G, Frijlink H W
Central Hospital Pharmacy, The Hague, Den Haag, The Netherlands.
Pharm World Sci. 2000 Jun;22(3):75-81. doi: 10.1023/a:1008786600530.
Nebulizers are widely used for the inhalation of drug solutions in a variety of respiratory diseases. The efficacy of nebulizer therapy is influenced by a great number of factors, including the design of the device and the characteristics of the drug solution. Incorrect cleaning, maintenance and disinfection procedures may change the nebulizer performance in time, whereas patient factors can influence the lung deposition of the generated aerosol. In this review the technical aspects of nebulization of drug solutions will be discussed. Two main parameters are generally used to evaluate the performance of nebulizers: the droplet size distribution of the aerosol and the drug output rate. The droplet size distribution and the drug output rate are basically determined by the design and user conditions of the nebulizer. A higher gas flow of the compressor in a jet nebulizer or a higher vibration frequency of the piezo electric crystal in an ultrasonic nebulizer, decreases the droplet size. The choice of the type of nebulizer for nebulization of a certain drug solution may initially be based on laboratory evaluation. The major part of the mass or volume distribution should preferably correspond with aerodynamic particle diameters in the range of 1 to 5 micrometer. The intended drug output must be realized within a reasonable nebulization time (less than 30 min). From the drug output only a minor fraction will be deposited in the lung. The relation between in vitro and in vivo deposition is only partly understood and to date it has not been possible to predict drug delivery only from in vitro studies on nebulizers. Therefore, studies in patients should be performed before a drug solution for nebulization can be recommended for clinical practice. The mechanical properties of nebulizers are likely to change during use. An average utilization time of nebulizers is not available. Therefore, the performance of nebulizers should be checked periodically. Patient compliance in nebulizer therapy is relatively low. This is partly due to the fact that, at present, drug solutions for nebulizers cannot be administered efficiently within a short period of time. More efficient systems should be developed. If possible, nebulizers should be substituted to more efficient systems, e.g. dry powder inhalers or metered dose inhalers.
雾化器广泛用于多种呼吸道疾病的药物溶液吸入治疗。雾化器疗法的疗效受多种因素影响，包括设备设计和药物溶液特性。不正确的清洁、维护和消毒程序可能会随时间改变雾化器性能，而患者因素会影响所产生气溶胶在肺部的沉积。在本综述中，将讨论药物溶液雾化的技术方面。通常使用两个主要参数来评估雾化器的性能：气溶胶的液滴大小分布和药物输出率。液滴大小分布和药物输出率基本上由雾化器的设计和使用条件决定。喷射雾化器中压缩机的气流较高或超声雾化器中压电晶体的振动频率较高，会减小液滴大小。对于特定药物溶液雾化所选用的雾化器类型，最初可基于实验室评估。质量或体积分布的主要部分最好与空气动力学粒径在1至5微米范围内相对应。预期的药物输出必须在合理的雾化时间（少于30分钟）内实现。从药物输出量来看，只有一小部分会沉积在肺部。体外和体内沉积之间的关系仅部分为人所知，迄今为止，仅通过雾化器的体外研究还无法预测药物递送情况。因此，在一种雾化用药物溶液被推荐用于临床实践之前，应开展患者研究。雾化器的机械性能在使用过程中可能会发生变化。雾化器的平均使用时间尚无定论。因此，应定期检查雾化器的性能。患者对雾化器疗法的依从性相对较低。部分原因在于，目前雾化用药物溶液无法在短时间内高效给药。应开发更高效的系统。如有可能，应将雾化器替换为更高效的系统，例如干粉吸入器或定量吸入器。
