Q: Have you seen differences in the treatment of asthma around the world affecting demand for MDIs?
A: Treatment of this disease in the developing world varies according to a complex pattern, some of which is in response to unique local conditions.
A variety of dosage forms are used, starting with traditional treatment which used to – and in some instances still do – consist of advice to stay away from sources of antigens, through menthol inhalation, to syrups and tablets that typically have only a marginal benefit.
The leading dosage form, of course, is the MDI, which has the advantages of intuitive ease of use, physical and environmental robustness and is a near universal delivery platform for a wide range of medications; however, the fact that a multi-dose MDI cannot be subdivided can be a problem in many situations.
A single MDI may cost much less in the developing world than in the US –typically $2 for a patient in India vs. $30-50 for a US patient – but $2 can still represent a major purchase for a patient living in poverty. Patients like this struggle to “bulk-buy” their medication, such as a 200-dose MDI, and would prefer to buy a few doses only.
I’ve heard of some pretty alarming practices in certain parts of the world that come about as a result, such as patients paying a few cents for a puff on a salbutamol sulfate relief medication MDI chained to a pharmacy counter.
Another issue with MDIs in Islamic countries is the alcohol content of certain formulations, which can be as high as 15% for drugs like beclamethasone diproprionate . Although religious authorities in these countries have reviewed the situation and issued fatwas permitting the devout to use such aerosols despite the prohibition on drinking alcohol, many Muslims still avoid them.
Q: What about competition from dry powder inhalers (DPIs)?
A: At present, I see only limited appetite for multidose DPIs in the developing world as they represent the most upfront costly way of providing medication and can be more prone to humidity issues, a problem in many of the tropical countries. However, the older, single dose capsule technology, declining in the developed world, does possibly have an interesting future.
Not only are single dose capsule systems more resistant to humidity, but also the doses can be purchased in small numbers. The per dose cost is much higher than that of an MDI, but the ability to just buy a few, for just a few cents, is an attractive, useful feature.
Patients also want to be as discreet as possible due to the stigma associated with asthma; small MDIs or single dose DPIs both score well on discretion, whereas MDIs with spacers or large elaborate multidose DPIs are difficult to conceal.
