Comparative Study of Lung Bioavailability of HFA-Seretide Via Current Spacer Devices in Healthy Volunteers

Conventional plastic spacers are bulky and can be influenced by electrostatic charge, which can reduce respirable dose delivery especially when used brand new "out of the box". Breath actuated integrated vortex spacer (Synchro-Breathe) is a compact palm sized antistatic device with a vortex chamber which is designed to be more patient friendly and free from the effects of electrostatic charge. The systemic bioavailability from the lung of inhaled fluticasone and salmeterol is dependent on respirable dose delivery, and hence the performance of inhaler devices can be quantified by measuring the degree of adrenal suppression and fall in serum potassium(K) as surrogates for delivered lung dose. This study attempts to compares the systemic bioavailability from the lung in real life conditions for Fluticasone/Salmeterol combination (measured in terms of relative adrenal suppression and fall in serum K) via the breath actuated Synchro-Breathe device, pMDI( Seretide Evohaler), and Aerochamber Plus & Volumatic spacer used brand new "out of the box" in healthy volunteers.