An inhaler for producing an inhalable aerosol of powdered medicament is disclosed. The inhaler includes an aerosolizing device having a chamber of substantially circular cross-section, inlet and outlet ports as opposite ends of the chamber for the flow of drug laden air through the chamber between said ports and, a bypass air inlet for the flow of clean air into the chamber. The bypass air inlet is configured so that air entering the chamber through said inlet forms a cyclone in the chamber that interacts with the drug laden air flowing between the inlet and outlet ports.本發明揭露一種用以產生可吸入之氣霧狀藥粉的吸入器。該吸入器包括一氣霧化裝置以及一空氣分流道入口，其中之氣霧化裝置具有圓形橫截面之一容室及位於容室兩端的多個入口與出口，其用以令攜帶藥劑之空氣在該等孔洞間之容室流動，而其中之空氣分流道入口用以令乾淨空氣流入容室。空氣分流道入口配置成使經由該入口進入容室的空氣在容室內形成一氣旋，其與攜帶藥粉的空氣在入口與出口之間流動而產生互動。
