Comparative evaluation of a novel card-based spacer (MDI PLUS®) versus traditional aerochamber plus®: In-vivo and ex-vivo bioavailability study

Abstract

Background: Effective aerosol delivery via pressurized metered dose inhalers (pMDIs) is often compromised by poor actuation-inhalation coordination. Spacer devices are commonly used to improve lung deposition. This study aimed to compare the lung and systemic bioavailability of salbutamol delivered via pMDI alone, with a traditional AeroChamber Plus® spacer, and with a novel disposable MDI Plus® carton spacer.

Methods: In a randomized, three-period crossover study, 20 healthy adults received 5 puffs (100 µg/puff) of salbutamol via each inhalation setup. Urine samples were collected 30 min post-inhalation (for lung bioavailability) and over 24 h (for systemic absorption). An ex-vivo setup using inhalation filters was also employed to quantify total delivered dose.

Results: The ex-vivo mean ± SD total collected dose of salbutamol was significantly higher with pMDI alone (352.35±23.41 µg) than AeroChamber Plus (196.57±13.32 µg, p < 0.001) and MDI Plus (182.86±11.34 µg, p < 0.001). Urinary salbutamol values at 30 min were significantly greater with AeroChamber Plus (14.61±4.36 µg, p < 0.001) and MDI Plus (10.97±3.83 µg, p < 0.01) compared to pMDI alone (5.92±1.07 µg). Urinary salbutamol at 24 h showed higher systemic bioavailability with pMDI alone (139.09±15.68 µg) versus when connected with both AeroChamber Plus and MDI Plus, 79.57±19.48, and 59.26±18.12 µg, p < 0.001, respectively.

Conclusion: Compared to the pMDI alone, both spacers significantly enhanced lung delivery and reduced systemic absorption. Whilst the AeroChamber Plus® delivered slightly more medication to the lung, the MDI Plus® spacer offers a cost-effective alternative that is suitable for emergencies and outdoor use.

Keywords: AeroChamber Plus spacer; MDI Plus; Metered dose inhaler; aerosolized therapy; inhaler; salbutamol, pMDI, Spacer, Aerosol delivery, Lung deposition, Respiratory diseases, Asthma care.