Inhalation therapy: an historical review.

Inhalation has been employed as a method for delivering medications for more than two thousand years, and the benefits of delivering medication directly to the affected site - the lungs - have been understood for more than two hundred years. At the beginning of the Industrial Revolution, physicians were inventing therapies and experimenting with ideas for devices: it was a time of great creativity. However, by the end of the period the scientist and the regulated pharmaceutical industry had emerged and the role of the physician had been constrained. Few of the devices invented then remain in use today, but many of the principles used are still embodied in modern devices. This review traces the developments produced by the early pioneers who applied their creative thoughts to inhalation therapy, and examines how inhaled drug delivery has progressed. The devices pictured are from www.inhalatorium.com, an online museum of inhalation technologies.