Detection and assessment of co-association in inhalable drug particles using aerosol time-of-flight mass spectrometry.

Aerosol Time-of-Flight Mass Spectrometry (AToFMS) was used to examine co-association between two inhaled drugs, fluticasone propionate (FP) and salmeterol xinofoate (SX), in fine aerosolised particles emitted from Seretide (R)/Advair (R) inhaled combination products. Principal Component. I y. fragmentation patterns indicative of either pure or co Analysis (PCA) was used to identify-associated particles (particles containing both drugs). A third component of the particles emitted from dry powder inhalers (DPIs), lactose, gave only a very weak mass spectral signal and no interpretable data was acquired for this compound; however, it was not found to interfere with the detection of the two drug substances. High levels of co-association were found in the emitted doses from both pressurised metered dose inhaler (pMDI) and dry powder inhaler (DPI) products. Copyright (C) 2008 John Wiley & Sons, Ltd.