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

Abstract

Using a proprietary technology known as the X-ACT™ system-Active-metering, Cyclone-separator Technology a novel multi-dose inhaler (Airmax™) 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™ to obtain a nominal formoterol dose of 6 or 12 μg. 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 μm 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 μg (n=140), and 100 ± 9.4% LC or 12 ± 1.1 μg (n=440), for the 6 and 12 μg strengths, respectively. The mass median aerodynamic diameter was 2.4 ± 0.1 μm (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. © 2002 Elsevier Science Ltd.