Delivery of formoterol from a novel multi-dose inhaler Airmax™

Using a proprietary technology known as the X-ACT(TM) system-Active-metering, Cyclone-separator Technology, a novel multi-dose inhaler (Airmax(TM)) was developed to provide accurate and consistent dosing and a high-fine particle fraction of the drug. Formoterol, present as a blend with lactose monohydrate was delivered from Airmax(TM) to obtain a nominal formoterol dose of 6 or 12 mug. The devices were tested using a five-stage liquid impinger and a unit dose sampling apparatus, operated under conditions specified in European Pharmacopoeia (2000). Fine-particle dose (FPD) was defined as the dose of the aerosolized drug particles with an aerodynamic diameter <5 mum and fine particle fraction (FPF) was the ratio of FPD to the total recovered dose. Dose per actuation was found to be 97.0+/-11.5% label claim (LC)or 5.8+/-0.7 mug (n=140), and 100+/-9.4% LC or 12+/-1.1 mug (n=440), for the 6 and 12 mug strengths, respectively. The mass median aerodynamic diameter was 2.4+/-0.1 mum (n=14), the geometric standard deviation 2.1+/-0.1 (n=14), and FPF 44.4+/-2.4% (n=14) for both strengths. Thus, the combination of active metering and cyclone separator produces highly consistent doses of formoterol that have a large respirable fraction. (C) 2002 Elsevier Science Ltd.