Inspiratory Profiles from Volunteer Adults who Have Read the Patient Instructions for Use for Two Passive Dry Powder Inhalers (DPIs) Compared with Those from a Pressurized Metered Dose Inhaler with Valved Holding Chamber (pMDI+VHC)
Mark W Nagel1, Cathy Doyle1, Rubina Ali1, Jason A Suggett! & Jolyon P Mitchell2
1Trudell Medical International, 725 Baransway Drive, London, Ontario, N65 5G4, Canada
2 Jolyon Mitchell Inhaler Consulting Services Inc., 1154 St. Anthony Rd., London, Ontario, N6H 2R1, Canada
We recorded inhalation waveforms by pneumotachometer (SpiroQuant-H flow sensor, connected to a data recorder) from adult healthy volunteers with basic training in placebo inhaler use. We measured inhaled volume per inspiration (Vi) and peak inspiratory flow rate (PIFR) to explore natural variability within male (M) and female (F) volunteers. Before using each inhaler, the volunteers were asked to read the instructions-for-use. For the pMDI/AeroChamber* Plus VHC-breath-hold option, the volunteer exhaled then pressed the inhaler once at the beginning of a slow inhalation, then inhaled slowly and deeply through the chamber until a full breath had been taken followed by a breath-hold lasting 5 to 10 seconds. For the Turbuhaler* and Ellipta* DPIs, each volunteer inhaled strongly and deeply. Values of both parameters (mean ± SD) varied widely between both sexes for all inhaler types (Vi: pMDI/VHC M=2334 ± 1465 mL; F=1425 ± 803 mL: Turbuhaler* DPI M=2879 ± 948 mL; F=1870 ± 881 mL: Ellipta* DPI M=2796 ± 859 mL; F=1873 ± 669mL); (PIFR: pMDI/VHC M=47 ± 27 L/min; F=34 ± 18 L/min: Turbuhaler* DPI M=86 ± 24 L/min; F=85 ± 17 L/min: Ellipta* DPI M=90 ± 2 9 L/min; F=85 ± 26 L/min). This variability masked sex-based differences. Vi for the males using the Turbuhaler* DPIs were comparable to the females (2-way t-test, p=0.13, but corresponding values for the males using the Ellipta* DPI were significantly larger (p=0.008). PIFR for the same comparison were similar (p⋟0.66). Sex-based differences in either parameter for the VHC configuration were insignificant (p=0.083).
Inhalation waveforms have been recorded from 24 adult healthy volunteers (12 male, 12 female) each with basic training in inhaler use measuring inhaled volume per inspiration (Vi) and peak inspiratory flow rate (PIFR) to explore the natural variability within male and female members of the cohort.