Highly loaded nanoparticulate formulation of progesterone for emergency traumatic brain injury treatment.

BACKGROUND Progesterone (PG), a promising therapeutic for treating traumatic brain injury, has been difficult to formulate into a high-dose/low-volume form for emergency intravenous administration due to its hydrophobicity and crystallinity. RESULTS This work demonstrates the use of Flash NanoPrecipitation to produce 300-nm PG-loaded polymeric nanoparticles with approximately 24 wt% drug loading using only components that are classified by the US FDA as generally recognized as safe. Approximately 80% of the encapsulated PG is in dissolved, rather than crystalline form. For prolonged stability, the nanoparticles are freeze-dried with Pluronic F68 and can be reproducibly reconstituted by hand agitation for 1 min without particle aggregation to produce injectable formulations with approximately 30-mg/ml PG, which is more than ten-times higher than has been previously reported. CONCLUSION This formulation can allow for administration of therapeutically viable concentrations of PG, which has been impossible with all previously reported nanoparticulate formulations because of low drug loadings and concentrations.