Background: The use of valved holding chambers (VHCs) with pressurized metered dose inhalers (pMDIs) is reported to reduce the oral deposition of inhaled drugs and to facilitate the handling of these devices by patients, especially children. Although the number of commercially available VHCs is increasing, the correct choice of VHC in clinical practice is important, because VHCs are not equally effective regarding medication delivery. Hence, we aimed to evaluate the use of three small-volume VHCs-Vortex(®), AeroChamber(®) Plus (ACP), and Able Spacer™ (AS)-along with a commercial pMDI containing a combination of beclomethasone and formoterol (Innovair(®)) frequently used by asthma patients.
Methods: Evaluation of the delivered dose of both drugs and analysis of particle size distribution of aerosols emitted for the inhaler were performed using the Next Generation Impactor with and without the tested VHCs.
Results: The VHCs retained significant quantities of both drugs and dramatically reduced the quantity of drugs deposited in the throat of the impactor, indicating that particles with large size were preferably retained in the VHCs. Interestingly, although the delivered dose of both drugs was reduced by the use of VHCs, the use of the Vortex and the ACP resulted in comparable fine particle doses (FPDs) to that obtained when the pMDI was used alone, whereas the AS VHC significantly reduced the FPDs of both drugs. This may be due to the fact that, unlike the AS VHC, the Vortex and the ACP VHCs are made of antistatic materials that minimize the electrostatic interaction with emitted aerosols, enhancing medication delivery.
Conclusion: The Vortex and the ACP VHCs present interesting advantages over the AS VHC to be used with Innovair pMDI. However, these results are based on an in vitro evaluation and need to be validated in an in vivo study in order to clinically assess the performance of these VHCs.