International journal of pharmaceutics
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Comparative Study
Effects of flow pattern, device and formulation on particle size distribution of nebulized aerosol.
The evaluation of particle size recommended in the pharmacopeias requires a constant flow rate, and the method for pediatric inhaled drugs is the same as for adult drugs. In this study, the aerosol concentration and particle size distribution (PSD) were measured under a realistic breathing pattern and constant flow. Two types of nebulizer (i.e., breath-enhanced nebulizer and vibrating-mesh nebulizer) and two formulations (i.e., budesonide suspension and albuterol solution) were chosen for comparison. ⋯ Furthermore, all vibrating-mesh nebulizers produced aerosol droplets having larger mean diameter and narrower size distribution than those of the air-jet nebulizers. We conclude that it will be more conducive to the evaluation of particle size to use a laser diffractometer under a realistic pattern and make up for the shortcomings of cascade impactors. The effects of flow pattern, nebulizer and formulation should be taken into account in the evaluation of the qualities of nebulizer products in pharmaceutical practice.