The effect of mixing on the dispersibility of adhesive mixtures for inhalation. Comparison of high shear and Turbula mixers.

This study investigates the effect of different mixers and the applicability of the mixing energy (ME) concept to dry powder formulations for inhalation. With the aim to step-wise build and expand this concept, adhesive mixtures of 2 % budesonide and lactose carrier were investigated, both with 1 % magnesium stearate (MgSt) added in a 'coating' step, and without, the latter referred to as 'naked' formulations. For high shear mixed formulations, the fine particle fraction (FPF) was found to increase with increasing ME up to 60 % and thereafter decreased, using the Novolizer device.

The match between adhesive mixture powder formulations for inhalation and the inhaler device.

The device or the formulation? Which one governs drug dispersibility from the inhaler? To address this question, three budesonide-containing reservoir DPIs: Novopulmon Novolizer®, Giona Easyhaler® and DuoResp Spiromax®, were analyzed using the Next Generation Impactor, NGI. Thereafter, the devices were carefully opened, emptied, and formulations were switched between devices. Finally, three 'prototype' formulations with carriers of different particle size were produced and tested in the Novolizer and Easyhaler devices.