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.