Fabrication of inhalable spore like pharmaceutical particles for deep lung deposition.

An innovative strategy of fabricating uniform spore like drug particles to improve pulmonary drug delivery efficiency was disclosed in the present study. Spore like particles were prepared through combination of high gravity controlled precipitation and spray drying process with insulin as model drug first, showing rough surface and hollow core. The shell of such spore-like particle was composed of nanoparticles in loose agglomerate and could form nanosuspension upon contacting antisolvent. Further characterization confirmed secondary structure and bio-activity was well preserved in spore like particles of insulin. Stable aerosol performance at different dosages with fine powder fraction (FPF) of 80% and comparable FPF (69-76%) for formulated powder were achieved, significantly higher than marketed product Exubera. On the other hand spore like particles of bovine serum albumin, lysozyme and salbutamol sulfate showed similar high FPF of 80%, regardless of different shape of primary nanoparticles, indicating various application of this new process in significant improvement of pulmonary drug delivery.