In vitro and clinical characterization of the valved holding chamber AeroChamber Plus ® Flow-Vu ® for administrating tiotropium Respimat ® in 1–5-year-old children with persistent asthmatic symptoms

Abstract

The trial was registered under NCT01634113 at http://www.clinicaltrials.gov.

In Vitro Evaluation of Aerosol Performance and Delivery Efficiency During Mechanical Ventilation Between Soft Mist Inhaler and Pressurized Metered-Dose Inhaler

“…31 Furthermore, previous research reported larger MMADs than those measured in our study. [16][17][18] It is inferred that impactors used in previous research were not able to measure the range of PSD in SMI aerosols; Wachtel et al 17 also noted that approximately one quarter of the SMI label dose was collected at the microorifice collector (cut-off diameter: 0.54 mm) of the next-generation impactor at a flow of 30 L/min. In contrast, the MOUDI impactor utilized in our study can measure the particle size down to 0.056 mm and revealed the PSD of SMI aerosols < 0.54 mm.…”

“…Previous research has noted that SMIs can generate drug aerosols with a mass median aerodynamic diameter (MMAD) < 5 mm and an FPF > 60%. 2,[16][17][18] Moreover, because inhalation aids such as a spacer or a valved holding chamber (VHC) can improve the PSD and hand-breath coordination, pMDIs are recommended to be used along with an inhalation aid. 19,20 As for SMIs, studies have reported that drug delivery from an SMI with a VHC reduces fine particle masses, and the literature advises against the use of inhalation aids with an SMI for adults and older children.…”

“…19,20 As for SMIs, studies have reported that drug delivery from an SMI with a VHC reduces fine particle masses, and the literature advises against the use of inhalation aids with an SMI for adults and older children. 17,[21][22][23] However, other studies suggest that an inhalation aid is needed for children # 5 y old and patients who are unable to coordinate. 24,25 Wachtel and colleagues 17 used the next-generation impactor at flow of 30 L/min to measure the PSD of SMIs alone or coupled to a VHC under pediatric and adult flows.…”

“…17,[21][22][23] However, other studies suggest that an inhalation aid is needed for children # 5 y old and patients who are unable to coordinate. 24,25 Wachtel and colleagues 17 used the next-generation impactor at flow of 30 L/min to measure the PSD of SMIs alone or coupled to a VHC under pediatric and adult flows. They reported that the FPFs of the SMI alone and the SMI with a VHC were 63% and 51%, respectively, and there were approximately 25% and 20% of label dose, respectively, deposited at the microorifice collector, which captures particles with < 0.54 mm in size.…”

“…They reported that the FPFs of the SMI alone and the SMI with a VHC were 63% and 51%, respectively, and there were approximately 25% and 20% of label dose, respectively, deposited at the microorifice collector, which captures particles with < 0.54 mm in size. 17 The aerosols captured at the microorifice collector belong to the size range of particles that tend to be exhaled; therefore, the high proportion of this particle fraction generated with an SMI suggests that the normal breathing pattern may not be suitable for receiving SMI aerosols. Thus, measuring the whole span of PSD generated from an SMI alone and from an SMI with an inhalation aid is important to understand the particle deposition tendency in the human lung.…”