Inhaling has been used as a way of delivering smoke, vapour or powdered substances to the body since ancient times. The first inhaling devices in Europe were developed in the 18th Century to treat lung complaints. English doctor John Mudge invented an inhaler in 1778 based on a pewter tankard and recommended its use to treat coughs by the inhalation of opium vapour. Atomisers and nebulisers were invented in France in the mid-1800s. These devices were based on perfume sprays, and delivered drugs in the form of a liquid spray.
But we can thank the thirteen-year-old daughter of George Maison, president of Riker Laboratories in the United States for the modern-day asthma inhaler – a now ubiquitous device based on a pressurised canister that can expel measured doses of a drug directly into the lungs with a single push of a button.
It was the early 1950s and Maison’s daughter suffered from severe asthma. Like other asthma sufferers at the time, she used the standard apparatus of the day, a squeeze-bulb glass nebuliser, to deliver freshly-loaded doses of medicine. It was cumbersome, difficult to use and although it successfully got the drug into the lungs, the nebuliser was not always able to deliver a uniform dose.
“Why can’t they put my asthma medicine in a spray can like they do for perfume?” the teenager asked her father. Maison thought why not indeed, so he asked his pharmaceutical development team to come up with a way of putting his daughter’s request into action.
Using a gas propellant, alcohol to dissolve the drug, an old ice-cream freezer, empty soda bottles as pressure containers and a bottle capper, the team soon devised a working prototype. By 1956, a new drug application was approved for a PTC bronchodilator Medihaler-Epi (epinephrine) and the prescription only version of Medihaler-Iso (isoproterenol) for the treatment of asthma.
Today, the metered dose inhaler (MDI) is the standard method of delivering specific amounts of medication to the lungs as a short burst of an aerosolised medicine, such as salbutamol. It is the most commonly used device used in the treatment of asthma – an inflammatory disease of the airways affecting about 250 million people worldwide.