A new millenium for inhaler technology
In recent years dramatic developments have occurred in the technology associated with aerosol delivery of drugs to the lungs. Propellant-based metered-dose inhalers have entered a new phase in which chlorofluorocarbons have been joined by so-called environmentally friendly propellants as a means of aerosol propulsion. Active emission dry powder inhalers have been manufactured, and may supersede those based on the passive inspiratory flow of the patient. Self-contained, hand-held, aqueous spray systems are being introduced and are capable of competing with metered-dose inhalers and dry powder inhalers. The current status of pharmaceutical inhalation aerosol technology indicates of bright future for drug delivery to the lungs, not only as the site of action but also as a route of administration.