Characterization of progesterone loaded biodegradable blend polymeric nanoparticles

The encapsulation of progesterone in poly (hydroxybutirate-co-hydroxyvalerate) (PHBV), poly (epsilon-caprolactone) (PCL), poly (L-lactic acid) (PLLA) nanoparticles and PHBV/PCL and PHBV/PLLA blend nanoparticles was investigated in this research. Nanoparticles were produced by miniemulsion/solvent evaporation technique with lecithin as surfactant and were characterized regarding to z-average diameter (Dz) and polydispersity (PDI), progesterone recovery yield and encapsulation efficiency. Possible interactions between progesterone and the polymer matrices were investigated by Fourier Transform Infrared Spectroscopy (FTIR). High recoveries (up to 102.43 +/- 1.80% for the PHBV/PLLA blend) and encapsulation efficiencies (up to 99.53 +/- 0.04% for PCL) were achieved and the nanoparticles presented narrow size distribution (0.12 +/- 0.03 for PLLA). PCL nanoparticles (217.5 +/- 2.12nm) presented significant difference with the Dz from all the other formulations (P<0.05). The most evident interaction between progesterone and the nanoparticles polymeric matrix was found to PHBV/PCL due to the increase in the intensity of the band located in 1631 cm(-1).