Inhalation Products: Addressing Unmet Needs
This month’s discussion group bought together experts on inhaled product development and focused on two main areas. First, the session started with an outline of the history of inhalation products and continued with an overview of the advantages and disadvantages of different types of inhalers. One key area of interest was current-day challenges with aerosol delivery, which could be addressed through smart inhalers and other innovative new devices.
The group was led by Pavan Muttil, Associate Professor at New Mexico University. Pavan has over 15 years of research experience in aerosol formulation, characterisation, and pulmonary delivery of drugs and vaccines in preclinical models. Towards his research endeavours, Dr. Muttil has received funding from various grant agencies, including Bill and Melinda Gates Foundation Grand Challenges Exploration, National Institute of Health (USA), and the Defense Threat Reduction Agency (DTRA-USA).
Inhalation Products: Innovation Through Unmet Needs
Pavan began the session with a short presentation on the history of inhalation, focusing on how deficiencies of existing inhalers led to innovation and the creation of new devices.
MDI
Metered-dose inhalers (MDI) are small, easy to use, and relatively inexpensive. MDIs’ advantages are that they protect the medication from exposure to light, oxygen, and water. Additionally, patients cannot overdose as the delivery is controlled through metered valves.
While they are often considered easy to use, Pavan points out that “more often than not, patients forget how to use the various steps to take the dose correctly, which results in poor medication delivery to the lung. One of the big issues I have seen is hand-eye coordination. You have to actuate the inhaler and, at the same time, inhale. We have seen patients struggle to do this, and the additions (spacers or valved holding chamber) meant to overcome this make the device bulky. This further reduces the patient adherence to their inhaled medication which needs to be taken regularly for chronic diseases such as asthma and COPD.” Actuating MDIs can also be challenging for patients with conditions such as arthritis or muscular diseases
One of the big issues I have seen is hand-eye coordination.
DPI
The very first dry powder inhaler (DPI) was made all the way back in the 1850s in Boston, USA. However, there was a significant gap between creation and commercial production; the first devices from pharmaceutical companies were marketed in the 1940s. The big push for dry powder inhalers came towards the end of the previous century when regulatory agencies began phasing out CFC due to environmental concerns.
DPI differs from MDIs because they are breath-actuated and easier to use. With that said, patients need sufficient respiratory force to inhale the powder, which can be a barrier for some. Before inhalation, a preparation step may be required; patients with low dexterity or cognitive impairment may find this problematic. Some DPIs need patients to insert a capsule before each use, and all require users to push a button or pull back on a lever to start the powder exposure process. All these steps can lead to poor medication adherence if the inhaler needs to be used regularly.
Nebulisers
Nebulisers use liquid drugs which are cost-effective in the long run but have a high initial price. Pavan explains that “the big disadvantage here is that it's bulky, it’s noisy, and one of the things I didn’t mention in the dry powder inhalers was the fate of Exubera, the inhaled insulin device that Pfizer had developed in the 2000s. One of the drawbacks of Exubera was its huge size. Patients don’t want to carry a large device, and the inconvenience decreases patient compliance; this is a disadvantage of most of the nebulisers currently on the market. The pharma industry is trying to create much smaller nebulisers and decrease treatment times. With ultrasonic nebulisers, we have decreased the time to a few minutes. Still, many inhalers require 15 or 20 minutes each time a patient has to take a dose, and that, again, decreases the compliance of the patient.”
Smart Inhalers: Addressing Unmet Needs?
Smart inhalers, like previous devices, were created to try and overcome some of the challenges of existing products. Currently, they are not widely used, and while the evidence of their benefits is increasing, concerns remain, particularly on product costs.
Patient Compliance
patients suffering from chronic diseases, like asthma or COPD, are more likely to miss doses, particularly from maintenance inhalers.
The most common cause of patient noncompliance is the incorrect use of the inhaler. Using inhalers, particularly long-term, is still somewhat arduous for patients, leading to missed doses and incorrect use of devices. Pavan explains that smart inhalers can help address this, saying, “one of the things smart inhalers can do is send reminders; this is helpful as patients suffering from chronic diseases, like asthma or COPD, are more likely to miss doses, particularly from maintenance inhalers. Maintenance inhalers are supposed to be taken at regular times. If the patient is not having any problems or asthma attacks, they are more likely not to take the maintenance inhaler. If the patient skips their daily dose, research has shown they are more likely to have complications and increased chances of future hospitalisation. That’s why many of the smart inhalers are sending reminders to patients. Unfortunately, while this does help in the short-term, just like smartphone notifications, people can become desensitised and are likely to ignore these notifications in the long term. Therefore, patient compliance remains a key issue that needs to be addressed with chronic diseases such as asthma and COPD.”
Guidance & Feedback
Educating patients on the correct methods to use a device can be difficult, particularly for more complex inhalers. Pavan explains that smart inhalers can guide patients through the “different steps that you need to take when taking a dose, for example, shaking the inhaler or holding your breath for 10 seconds. Every time a patient activates an inhaler, the smart inhaler tells the patient the correct methods”. Smart inhalers can also provide feedback to users. In a study by Sulaiman (2018), smart inhaler feedback resulted in around 10% higher patient compliance and correct dosage intake than traditional patient education methods, resulting in fewer missed and additional doses.
Final Thoughts & Conclusion
For more information about the latest news and developments in inhalation devices and formulations, you can sign up to Oxford Global’s formulation & delivery newsletter to receive new content every month. Why not also consider seeing the experts in the field speak in person at our Formulation & Delivery: US event, taking place 11-12th October in San Diego.
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