ABSTRACT
Dry powder inhalers have been through a number of periods of development over the last half century. The first period of the 1960s and 1970s saw early passive inhalation devices, which lacked sophistication and performed poorly, using the patients’ inspiratory flow to disperse the drug, as alternatives to the then dominant propellant-driven metered dose inhaler (MDI) products. In the 1980s and 1990s, sophisticated passive inhalers and active systems, the latter using applied energy for dispersion of drug, were developed. These products were unique in that they were, in some cases, first market entry products for asthma compounds or were developed for the new market for systemic delivery of drugs. Early indications, from the recent introduction of combination products, are that dry powder inhalers may supersede MDIs and potentially dominate the inhaled drug market. Since the beginning of the millennium, new strategies have emerged to improve dry powder inhaler performance and it is anticipated that the next generation of devices will be suitable for the treatment of a variety of diseases in a technologically efficient and clinically effective manner.
