Effects on aerosol performance of mixing of either budesonide or beclomethasone dipropionate with albuterol and ipratropium bromide.

BACKGROUND Mixing of nebulized drugs is common in real life, but its consequences on aerosol output and granulometry are poorly known. METHODS In an in vitro study I evaluated the effects on aerosol output, drug output, and aerosol particle size characteristics of mixing either beclomethasone dipropionate or budesonide with albuterol and ipratropium bromide. I tested the SideStream and VentStream-Pro nebulizers, run with the AirClinic compressor. Using the same fill volume in all experiments, I nebulized and evaluated each studied drug alone, and 2 drug mixtures: beclomethasone plus albuterol plus ipratropium; and budesonide plus albuterol plus ipratropium. I measured aerosol output via gravimetrics. I measured drug delivery by collecting the aerosol on a filter in the inspiratory limb, and the residual solution in the reservoir and the circuit after nebulization, and assayed those liquids with chromatography. I measured particle size distribution via cascade impaction. RESULTS Mixing tended to reduce drug output and to increase mass median aerodynamic diameter with the SideStream, but not always with the VentStream-Pro. However, the drug output always remained satisfactory and the mass median aerodynamic diameters were within the respirable range. When nebulized alone, the respirable mass of bronchodilators ranged from 18% to 40% of the nominal dose; when mixed, it ranged from 13% to 37%. When nebulized alone, the respirable mass of corticosteroids ranged from 10% to 24% of the nominal dose; when mixed, it ranged from 10% to 17%. CONCLUSIONS Both the SideStream and VentStream-Pro have good aerosol performance in nebulizing budesonide or beclomethasone dipropionate alone, and when mixed with albuterol and ipratropium bromide.