Comparison of tiotropium delivery with the ODAPT adapter and a valved holding chamber

Abstract

RATIONALE: Facemasks are commonly used by certain patients requiring assistance for aerosol medication delivery. Adapters are used as connectors between facemasks and inhalers. The valved holding chamber (VHC) is commonly prescribed with pressurized metered dose inhalers (pMDIs) to improve medication delivery. Recently, the VHC has been used with the Respimat Soft Mist Inhaler (SMI), which is a propellant-free inhaler. The ODAPT soft mist adapter was previously designed to serve as a connector for facemasks used with the Respimat SMI. OBJECTIVE The purpose of this in vitro study is to compare the Respimat medication delivery and losses using facemasks when connected separately to 1) the VHC and 2) the ODAPT adapter. METHODS Tiotropium was delivered via the Spiriva Respimat SMI with add-ons (either ODAPT adapter or VHC) and without add-ons under different humidity levels (40–50% and >90%) at 28.3 L/min using an 8-stage Andersen cascade impactor. The particle deposition was assessed via UV-visible spectrophotometry. MEASUREMENTS AND MAIN RESULTS: Under ambient humidity conditions, 7.39% and 19.10% loss of fine particle fraction (FPF) were found using the ODAPT adapter and VHC, respectively. However, for higher humidity, mimicking humidity levels in the lungs, a loss of medication of 16.74% and 30.20% was found using the ODAPT adapter and VHC, respectively. Significant differences were found in medication delivery using the two different connectors, where higher medication losses were found using the VHC. CONCLUSION The ODAPT adapter connected to the Respimat SMI was shown to provide higher medication deposition and to minimize drug losses.