Improving inhalers

SEEDA has awarded aerodynamics research engineers S&C Thermofluids a grant towards a £70k research project to improve asthma inhalers.

The South-East England Development Agency (SEEDA) has awarded aerodynamics research engineer S&C Thermofluids a grant towards a £70,000 research project to improve the mixing and efficacy of drug delivery for pressurised metered dose inhalers (pMDIs) – a common type of asthma inhaler.

Although widely used, relatively cheap and easily portable, pMDIs are not a particularly efficient way of delivering drugs to the lungs, with a high proportion of the dose being deposited on the inhaler or in the mouth and throat of the user.


Research suggests as little as 10 to 15 per cent of the dose from a standard pMDI may reach the lungs.

S&C are applying their expertise in what is known as the Coanda effect, used in the design of rapid mixing devices, to investigate and develop a novel nozzle design for pMDIs.


By mixing the spray from the pMDI more rapidly with the inhaled air stream, it is expected that a finer, gentler spray will be produced, which will follow the respiratory tract more readily.

A test version of the new nozzle concept is currently being evaluated and it is expected that a working prototype will be available in 2009.

If successful, the new design should provide a cost effective improvement to a commonly used medical device, allowing lower drug doses to be used for the same clinical benefit and potentially reducing side-effects experienced by asthma sufferers.