Polycaprolactone nanoparticles containing encapsulated progesterone prepared using a scCO_2 emulsion drying technique

摘要

Well-defined polycaprolactone (PCL) nanoparticles loaded with progesterone (P4) were obtained by scCO_2 antisolvent expansion of emulsions as a drying strategy. PCL nanoparticles with an average diameter of 82 nm were formed by the emulsification of an ethyl acetate-water mixture containing P4 and poly(vinyl alcohol) (PVA) as the stabilizing agent under ultrasonic irradiation. Emulsion particles were dried in scCO_2 and the results were compared with drying at ambient conditions. The scCO_2 expansion-dried PCL nanoparticles showed a smaller average diameter and the dynamic light scattering (DLS) analysis revealed a narrower particle size distribution when compared to the diameter of nanoparticles formed with the conventional process (174 nm). The use of scCO_2 expansion technology as a drying strategy for the production of PCL nanoparticles with a narrow size distribution for P4 delivery represents an improvement over the conventional drying processes.