The purpose of this research work was to prepare nanosized formulation of alpha ketoglutarate as dry powder inhaler for cyanide poisoning. Nanosizing can be approached by solid phase and liquid phase method. The different conditions encountered in both these approaches can greatly affect the particle characteristics. In this study milling and precipitation technique were compared to study their effect on α-KG particles characteristics. Differences in choice of stabilizers were observed between the two processing techniques. Sonication processes followed by HPH produced small sized particles in which Pluronic F68 was employed as stabilizing agent. Precipitation approach produced ultrafine drug particles by utilizing combination of stabilizers (PVA + PEG 400). Amongst the two sonication processes, probe sonication process produced well stabilized small sized particles. The designed particles showed 43.13 ± 2.36% lung deposition when compared with ultrasonication and precipitation technique that showed 31.69% and 21.67% respirable fraction. The MMAD of the designed particles was found suitable for deep alveolar deposition. Clinical studies (Phase-I trial) showed whole lung deposition of 52.51% for DPI. The P/C ratio was found to be 1.02 suggesting uniform distribution of particles in different lung compartments.