Dry powder inhalation of Celecoxib nanoparticles: formulation and in vitro characterization

Abstract

Background: In order to treat lung cancer, Celecoxib is more efficient in the form of inhalable nanoparticles, but any DPI formulation of Celecoxib nanocrystals is not still developed. Aim: The present study was designed to develop and optimize Celecoxib nanocrystals for pulmonary delivery of Celecoxib in the treatment of lung cancer and estimated the lung deposition of nanocrystals following the NGI tests of co-spray dried drug nanocrystals with various amounts of mannitol. Methods: Celecoxib nanocrystals were prepared by the liquid non solvent method via homogenization technique using lecithin as stabilizer. Size and size distribution of nanocrystals were evaluated by laser light scattering method. The optimized nanocrystals were turned into dry powder form by co-spray drying with varying amounts of mannitol. The aerosolization efficiency and aerodynamic properties of dry powders were determined by next generation impactor (NGI). The amount of Celecoxib in the stages of NGI was measured by our developed HPLC technique. Results: The optimized Nanocrystal composed of Celecoxib and Lecithin was prepared in the size of 110 nm (volume mean diameter) with narrow size distribution pattern. Optimized formulation with an optimized ratio of drug: carrier showed Fine Particle Fraction (FPF) of 3.45, Mass Median Aerodynamic Diameter (MMAD) of 6.71 and Geometric Standard Deviation (GSD) of 2.08. Conclusion: The law melting point and hygroscopic characteristic of lecithin might be responsible for observed not ideal aerosolization performance of formulations. Our obligation in application of just few excipients in the formulation of dry powders for pulmonary administration makes the discussion to be open yet to obtain efficient formulations for pulmonary drug delivery.