Currently, most drugs used in the treatment of asthma and airflow obstruction are given by the inhaled route. This includes bronchodilators such as β2-agonists and anti-cholinergics, and anti-inflammatory medications such as corticosteroids, cromolyn sodium, and nedocromil sodium. Inhaled medication is preferable to oral medication because the drug is delivered directly to the airways, allowing lower doses to be used, usually a more rapid onset of action, and a reduced incidence of side effects. The pressurized metered-dose inhaler (MDI) is the most widely used inhaler device. It has the advantages of being compact, portable, relatively cheap, and easy to use. However, many patients, especially children and the elderly, do not obtain optimal benefit because they fail to use their MDIs effectively. cialis professional online
Most conventional MDIs contain chlorofluorocarbon (CFC) propellants. However, CFCs are thought to contribute to ozone depletion in the atmosphere and from January 1996, the production of CFCs has become severely restricted in line with the Montreal Protocol. Therefore, alternative drug delivery systems for inhalation therapy are needed. MDIs with alternative propellants that do not affect atmospheric ozone are being developed, and considerable attention has been focused on the development of dry powder inhalers.
All currently available inhaler devices have advantages and disadvantages, and there is still a clear need for alternative inhaler devices in order to maximize therapeutic benefits and minimize systemic adverse effects of inhaled medication. The RESPIMAT device (Boehringer Ingelheim) (Fig 1) is a novel, hand-held, multidose device that uses mechanical power from a spring rather than volatile gas propellants to release metered doses (15 μL volume) of solutions for inhalation through a sophisticated system of nozzles. This generates a slow, gentle release of active substance over >1 s with a high proportion of respirable particles. Because of the novel mechanism of aerosol generation and the qualities of the spray generated by RESPIMAT, the term “soft mist inhaler” has been coined as a generic term to describe the device.
Figure 1. RESPIMAT inhaler, from Zierenberg et al. From Figure 4, “Setup of the BINEB®” from Zierenberg, Eicher, Dunne, and Freund. Boehringer Ingelheim Nebulizer BINEB: A New Approach to Inhalation Delivery. In: Dalby, Byron, and Farr, eds. Respiratory Drug Delivery. Copyright © 1996 by Interpharm Press, Inc. All rights reserved. Reprinted by permission.