In this paper, the author's aim was to develop a dry powder formulation of mucolytic N-acetylcysteine (NAC) intended for inhalation. As a method of preparation, spray drying was chosen. It was confirmed that spray drying of NAC is problematic due to its high hygroscopicity and low glass transition temperature (Tg). Different excipients were applied in order to enhance the powder performance - sodium hydroxide (salt formation and reduction of hygroscopicity), dextran or maltodextrin (reduction of Tg), chitosan (encapsulation), and leucine (reduction of hygroscopicity, anti-adherent). Every approach led to spherical particles, but only increasing the content of leucine generated separated particles showing the best results in 20-25 % of solid content. However, further research is needed to decrease particle size.