For active pharmaceutical ingredients (API) delivered to the lung it is of main importance that they reach the deeper lung, in order to cause the intended therapeutic effect. To ensure lung deposition and uniform dosage, adhesive mixtures of API particles in the size range of 05 mu m-5 mu m and inert carrier particles in the size range of 50 mu m-200 mu m are used in dry powder inhalers (DPI). The performance of DPIs and adhesive mixtures are mainly governed by interparticle forces like Van der Weals and tribo-electric forces between the active and the carrier as well as between the particles of the adhesive mixture and between adhesive mixture particles and inhaler wall. The arising tribo-charge on the mixtures during handling is influenced by various particle and material characteristics. For adequate inhaler performance especially the charge arising on the powder during the release from the inhaler is of interest Therefore the aim of this work is to investigate how tribo-charging during aerosolization and release of the powder from a common DPI (Novolizer) is affected by the carrier particle characteristics of surface roughness and shape and how the accumulated charge further influences the inhaler performance. Tribo-charge measurement of the pure carriers and the adhesive mixtures was performed using an open-end faraday cup. As model API and carrier salbutamol sulphate and spray dried mannitol were used. It was possible to show that tribo-charging during aerosolization is significantly influenced by the above mentioned particle characteristics. Further it was shown that this charge has also significant effects on the important performance properties of the DPI like fine particle dose and fine particle fraction. (C) 2014 Elsevier B.V. All rights reserved.