Comparison of the Aerosol Velocity and Spray Duration of Respimat® Soft Mist™ Inhaler and Pressurized Metered Dose Inhalers

Abstract

Apart from particle size distribution, spray velocity is one of the most important aerosol characteristics that influence lung deposition of inhaled drugs. The time period over which the aerosol is released (spray duration) is also important for coordination of inhalation. Respimat Soft Mist Inhaler (SMI) is a new generation, propellant-free inhaler that delivers drug to the lung much more efficiently than pressurised metered dose inhalers (pMDIs). The objective of this study was to compare the velocity and spray duration of aerosol clouds produced by Respimat SMI with those from a variety of chlorofluorocarbon (CFC) and hydrofluoroalkane (HFA) pMDIs. All inhalers contained solutions or suspensions of bronchodilators. A videorecording method was used to determine the aerosol velocity. For spray duration, the time for generation of the Soft Mist by Respimat SMI was initially determined using three different methods (videorecording [techniques A and B], laser light diffraction and rotating disc). Videorecording was then used to compare the spray duration of Respimat SMI with those from the other inhalers. The Soft Mist produced by Respimat SMI moved much more slowly and had a more prolonged duration than aerosol clouds from pMDIs (mean velocity at a 10-cm distance from the nozzle: Respimat SMI, 0.8 m/sec; pMDIs, 2.0-8.4 m/sec; mean duration: Respimat SMI, 1.5 sec; pMDIs, 0.15-0.36 sec). These characteristics should result in improved lung and reduced oropharyngeal deposition, and are likely to simplify coordination of inhaler actuation and inhalation compared with pMDIs.

In vivo animal models for drug delivery across the lung mucosal barrier☆

“…These include a new generation of liquid-spray devices [34,35] that generate an aerosol mechanically, vibrating mesh technologies [17] and dry powder inhalers that produce inhalable aerosols independent of the patients' inspiratory flow rate and volume [36,18].…”

A Handling Study to Assess the Use of the Respimat® Soft Mist™ Inhaler in Children Aged 4–12 Years

“…The Respimat SMI generates a slow-moving aerosol cloud that is independent of inspiratory flow rate [7,13,14].…”

“…The Respimat Ò Soft Mist TM inhaler (SMI) is a novel, hand-held, propellant-free, multidose inhalation device that generates a slow-moving, long-lasting aerosol cloud containing a high fine-particle fraction that enables efficient drug delivery to the lungs [5][6][7][8][9][10]. For optimal use of the Respimat SMI, the patient is directed to breathe out slowly and deeply.…”

“…A number of studies have shown that patients may find it easier to inhale with the Respimat because of the slow release of the aerosol-approximately 1.5 s, compared with approximately 0.2 s for a chlorofluorocarbon MDI, and 0.3 s for a hydrofluoroalkane MDIand low cloud velocity (\0.8 m/s) with the Respimat [7,11,12]. However, it is possible that longer spray duration could also lead to a certain ''loss'' of aerosol, if inspiration stops before the end of the aerosol release.…”

Development of Nicotine Loaded Chitosan Nanoparticles for Lung Delivery

“…Respimat is a nebulization device, which makes it easy for patients who have difficulties to coordinate the inhalation and pMDI actuation. It produces the slow-moving cloud of aerosol , reducing deposition rate in the mouth-throat and increasing deposition in the lung compared with pMDIs (Hochrainer et al, 2005). However, in many cases, nebulizers are quite bulky.…”