Recombinant human interferon alpha-2b (IFNα-2b), an endogenous cytokine, possesses antivirus, antiproliferation and immunomodulation properties. In this article, aerosol dry powder form of the protein was investigated as an alternate administration route to traditional injections. The comprehensive studies on IFNα-2b dry powder for inhalation was performed based on the protein stability, dispersibility of the dry powder and the pharmacokinetic and pharmacodynamic behavior. Five main sections were included i...