Using ovalbumin as a model antigen, the aim of this project was to develop a dry powder vaccine containing antigen-loaded nanoparticles which is stable at room temperature and suitable for delivery to the lungs. Chitosan nanoparticles were produced via ionic gelation whereby ovalbumin was encapsulated. Subsequently, the resulting nanosuspension was spray dried with the addition of mannitol as an immediately soluble matrix to transfer the nanosuspension into a dry respirable powder. Directly after manufacturing the powder was characterised with respect to redispersion behaviour and resulting particle size of the nanosuspension. Antigen loading and integrity was determined to confirm that the protein was successfully incorporated. Particle size distribution of the dry powder was characterised by laser diffraction to be 2.5 µm (x50). The powder could be dispersed efficiently using the Cyclohaler as a model device. To determine long term stability the samples were stored at different conditions (refrigerated and at 25°C/60%rH) for up to 6 months. At predefined time points, samples were taken and analysed. It was shown that after storage time there were no major changes detectable in formulation, independent from storage conditions.