The research update was presented by Robert Sievers, who led the research team, at the national meeting of the American Chemical Society.
Sievers’ team are attempting to create an inhaled formulation that can match the price of needle delivery, which is currently 27 US cents (19 Euro cents).
This effort has brought together 25 people from nine organisations, including the Serum Institute of India that has taken responsibility for some manufacturing operations.
At the institute myo-inositol was substituted for sorbitol, which is currently used in one of the institute’s commercial products, to create a new formulation.
Myo-inositol is an excipient created by the University of Colorado to act as a stabiliser and Sievers believes that it could have applications in other vaccines and pharmaceuticals.
When substituted for sorbitol the excipient improves dispersion and reduces stickiness. These characteristics were sought by the researchers and consequently this formulation was selected from over 100 candidates.
In addition the formulation has been shipped to India and back without aggregation occurring.
Dry powder delivery
The stability conferred by myo-inositol is also helped by the choice of dry powder, which Sievers believes could allow the researchers to achieve a two year shelf life for the product.
This shelf life assumes the vaccine is stored at two to six degrees Celsius but it will remain effective if stored at 37ºC for a week. Sievers envisages the vaccine being kept in the cold chain until needed and then transferred to the site of use before the heat limits its efficacy.
The dry powder will be delivered by either of the two affordable inhalers the team had developed.
Sievers referred to Pfizer’s Exubera inhaler as a “technological tour de force” but noted that the complexity was unsuitable for the measles vaccine. In addition Sievers believes that simpler drug delivery devices will gain prominence even in established markets in coming years.
The formulation has been tested in four animal models and further toxicity studies are planned for the coming months. Sievers anticipates starting Phase I trials in India in 2010.