The importance of usability for inhalation devices

Published: December 2022

Caroline Mackie, Design Consultant

The majority of inhalers deposit less than 20% of the dose into the lungs, most of the dose ends up in the mouth or stomach. With inhalation being the most common drug delivery system, mainly for asthma and COPD (Chronic Obstructive Pulmonary Disease), the challenges of administration need to be explored; it was concluded that the ability of asthma patients to use the correct inhaler technique has not improved over the last 40 years.

Delivering drugs to the lungs is a critical process that is extremely complex. This is because the lungs consist of a branch of airways, often described as the ‘bronchial tree’. For a particle to be deposited into the lungs it must first pass through multiple airway divisions, adding to this the lungs work to keep inhaled particles out thus making it even more difficult to ensure that medications reach the correct site.

The pharmacokinetics of inhaled drug delivery is dependent on drug formulation, ease of use of device and patient ability to inhale the required amount. So, what can be done to improve usability and adherence for inhalation devices?

Drug delivery to the lungs poses many challenges

The importance of technique

80% of the 5.4 million people living with asthma in the UK are using their inhalers incorrectly. More worryingly, less than 10% of HCPs (healthcare professionals) are competent at advising patients on best use practices for metered dose inhalers. Despite advancements in asthma formulations the effectiveness of drug delivery relies on the patient’s technique and compliance. In 2019 Asthma Lung UK reported that ‘more than a million people with asthma in the UK could be at risk of a potentially life-threatening asthma attack because they did not get their inhaler technique checked.

It was quoted that ‘successful asthma management is 10% medication and 90% education’.

Graphical representation of the percentage of participants performing inhaler technique errors according to age. Source: https://err.ersjournals.com/content/26/146/170055

Opportunities

With multiple steps and timing requirements that may be difficult for some users, it is no surprise that feedback would be hugely beneficial not only alerting the user when they are doing something incorrectly but also positively acknowledging when they are doing something well. It is essential that user needs and requirements are at the forefront of the development process. The biggest question is what opportunities exist to improve usability and thus reduce the number of errors when using an inhalation device.

Smart Inhalers

With the acceleration of digital technologies, there are opportunities to integrate smart sensors into the inhaler to give real time feedback on the inhalation technique or an add on device which would work with existing inhalers. Having a smart inhaler with an easy to use, engaging app that could give real-time feedback on how the user is using the device will make HCPs aware of which patients require further training and support to improve adherence.

When developing smart devices, we have found that including techniques to motivate users, such as rewarding interactions to provoke moments of reflection and encouragement, subsequently improves the self-administration of drugs.

Although there are limited smart inhalers on the market currently, it is anticipated that this area will grow by 21.26% by 2026.

Training Devices

Another mindset is that users should have a better way of understanding whether they are using their existing inhaler correctly and are confident in doing so.

Users can ask their healthcare professional to check their technique during an annual review however nearly 1 in 5 (19%) of people aren’t getting this checked. With so many steps some users may find that even after a demonstration they could forget about key small steps.

A complete training solution can be delivered through training products that mimic a parent device in feel, form, and function.

These products can play an important role in improving patient confidence, as well as maintaining drug regimen and efficacy. They can also foster a better understanding of the treatment and minimising potential user errors.

Training products improve user confidence

In the same way as a smart inhaler, a training device which can give feedback on the patient’s performance could be a huge benefit. We believe the key to producing the perfect training solution is to work closely with pharma customers and device manufacturers to qualify the functional and performance needs of the product.

There has been an increase in the number of deaths from asthma attacks of more than 33% in the UK with Asthma UK saying a lack of basic asthma care may have contributed to the rise. With more and more individuals living with asthma, it’s clear that there is a need for further education and training in the use of inhalers and vital that devices are being used correctly to prevent long term issues.

At Shore, we have a wide range of expertise and experience in training devices and put focus into understanding user and behaviour, drug delivery requirements, and connected device development to create standalone or connected devices that deliver which are truly effective training for patients.

If you’re developing or looking to improve the usability of an inhalation device, then contact us to discuss these opportunities further.

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