Inhalation therapy: an historical review

Abstract

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.

Dry powder inhalation: past, present and future

“…These inhalers contained a lactosebased drug formulation in small capsules or 'sifters'. For the development of the first device marketed in this period, the Fisons Spinhaler ® (1967), the high dose (20 mg of cromoglycate sodium, which is too high for MDIs) was the main driver [4,10]. Bell et al tested a lactose-based formulation (1:1 with the drug by weight) for this drug too and concluded that the emptying efficiency of the capsule depends very much on the size fraction of the lactose used [11].…”

“…The history of inhalation therapy has been described before [1][2][3][4]. It dates back to more than 4000 years ago when in India powdered Durata stramonium and Durata ferox, containing potent alkaloids with anticholinergic bronchodilating properties, were smoked after mixing with other compounds such as ginger and pepper [1].…”

“…It dates back to more than 4000 years ago when in India powdered Durata stramonium and Durata ferox, containing potent alkaloids with anticholinergic bronchodilating properties, were smoked after mixing with other compounds such as ginger and pepper [1]. Drug inhalation gained interest for the treatment of respiratory diseases particularly after Philip Stern acknowledged in 1764, 'the only possible way of applying medicines directly to the lung is through the windpipe' [4]. This resulted in the development of a variety of ceramic inhalers in the eighteenth century for drawing the inhaled air through infusions of plants and other ingredients [1].…”

Devices for Dry Powder Drug Delivery to the Lung

“…As requested by the Montreal Protocol in 1987, CFCs eventually were substituted in 1995 by more Benvironmental friendly^hydrofluoroalkane (HFA) gases, which were shown not to disturb the oxygen/ ozone equilibrium in the upper stratosphere (3)(4)(5)(6). It has since been realized that HFA gases are up to 2000-fold more potent than carbon dioxide as greenhouse gases, even so they are estimated to contribute less than 0.1% to global greenhouse gas emission (7,8). pMDIs also suffer from potential difficulties caused by the propellant used (9,10).…”

Dispersing the Mists: An Experimental History of Medicine Study into the Quality of Volatile Inhalations

“…Inhalation became increasingly noted as a therapeutic form in the late-18 th century, first with Philip Stern advocating his own recipe of balsamic vapours in 1764, 3 then John Mudge's invention of a simple pewter inhaler in 1778 (seemingly the first use of the word 'inhaler' by a physician), 4 and finally Thomas Beddoes and Humphry Davy's experiments at the Pneumatic Institute in Bristol in the 1780s and 1790s. 2,5 British (Victorian) physicianinventors were introduced to inhalation anaesthesia from Boston (US America) in 1846-47, which served likewise to normalize perceptions of inhaled medicines and accelerate the exploitation of new materials (e.g. rubber and basic plastics) from the empires.…”