Respirable dose delivery of fluticasone propionate from a small valved holding chamber, a compact breath actuated integrated vortex device and a metered dose inhaler

AIMS

To compare the respirable dose delivery of the hydrofluroalkane fluticasone propionate (HFA-FP) via an optimally prepared Aerochamber Plus spacer (AP), via a Synchro-Breathe (SB) device, and pMDI Evohaler (EH).

METHODS

Seventeen mild to moderate asthmatics completed the study using a randomized, double-blind, double-dummy, three way crossover design. Single doses of placebo or HFA-FP 2.0 mg were administered via the EH, AP, and SB devices. The overnight urinary cortisol : creatinine ratio (OUCC) was measured at baseline and after each dose.

RESULTS

Significant suppression of OUCC occurred from baseline with AP and SB but not EH devices (geometric mean fold suppression, 95% CI): AP: 3.18 (2.29, 4.36), P < 0.001; SB: 1.79 (1.31, 2.40), P = 0.001; EH: 1.12 (0.69, 1.44), p = 0.37 (equating to 68%, 45% and 9% falls, respectively). Significant differences in OUCC between devices were as follows: (geometric mean fold difference, 95% CI): AP vs. EH. 2.83 (2.09, 3.82), P < 0.001; AP vs. SB: 1.78 fold (1.21, 2.60), P = 0.003; SB vs. EH: 1.59 (1.09, 2.31), P = 0.013 (equating to 65%, 44% and 37% differences, respectively).

CONCLUSIONS

The use of an optimally prepared AP spacer and breath actuated SB device, when compared with pMDI, significantly increased the respirable dose of HFA-FP.

WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT

• Respirable dose delivery of inhaled steroids may be improved by the use of conventional valved holding chambers (such as the Aerochamber Plus spacer), but these are bulky and cumbersome to use.
• A novel compact breath actuated device with integrated vortex chamber (Synchro-Breathe) has been developed to overcome these problems,
• The lung bioavailability of inhaled fluticasone propionate is dependant on respirable dose delivery, and hence the performance of inhaler devices can be quantified by measuring the degree of adrenal suppression as a surrogate for relative lung dose.

WHAT THIS STUDY ADDS

• This study compares the respirable dose delivery (as relative adrenal suppression) of inhaled fluticasone delivered via Synchro-Breathe, conventional pMDI (Evohaler), and an optimally prepared Aerochamber Plus spacer in patients with asthma.
• The Aerochamber Plus and the Synchro-Breathe devices produced significantly higher respirable dose delivery of inhaled fluticasone than the pMDI, in terms of the relative degree of adrenal suppression.