The match between adhesive mixture formulation and device.  

Kyrre Thalberg1,2, Rasia Ahmadi1, Peter Elfman2 & Mårten Svensson2

1Department of Food Technology, Engineering and Nutrition, Lund University, Sweden.
2Emmace Consulting AB, 223 63 Lund, Sweden.


This work deals with the basic question of dry powder inhaler technology: is it the device or the formulation that determines the performance? To address the question, three reservoir type DPI products: Novopulmon Novolizer®, Giona Easyhaler® and DuoResp Spiromax®, were analyzed using the Next Generation Impactor, NGI. Thereafter, the devices were carefully opened and emptied, and formulations were switched between devices and analyzed. Finally, ‘prototype’ formulations containing 2.0% budesonide and carriers of different size were tested in the Novolizer and Easyhaler devices.

The inhalers equipped with a cyclone (Novolizer and Spiromax) provided markedly higher fine particle fractions, FPFs, than the one without (Easyhaler). The switch study showed that Novolizer gave a high FPF also for the Easyhaler formulation, while the Novolizer formulation yielded a very low FPF in the Easyhaler device. When filled into Easyhaler, all prototype formulations dispersed poorly, with significantly lower FPF values than the Easyhaler product. When applied in Novolizer, the FPF level was higher, although lower than for the original Novolizer. It can be concluded that devices with a cyclone give considerably higher FPF’s than devices without, regardless of the formulation. Additionally, a trend of increasing FPF for smaller carrier particle size could be observed in the Easyhaler device.

Key Message

Reservoir devices equipped with an active dispersion principle such as a cyclone provide a considerably higher fine particle fraction, FPF, than those without, regardless of the formulation.