PLGA particles in the 200-400 nm size range were formulated through the nanoprecipitation and solvent evaporation methods. Different concentrations were tested for polymer and stabilizer (Pluronic® F68) in order to identify the best conditions for making PLGA particles of suitable size, stable in time, to be used as carriers for brain targeting drugs. The particles with the best characteristics for delivery system design were those formulated by nanoprecipitation with an organic/water phase ratio of 2/30, a polymer concentration of 25 mg/mL and a surfactant concentration of 0.83 mg/mL; their surface charge was reasonably negative (~ -27 mV) and the average size of the almost monodisperse population was roughly 250 nm. Particle characterization was obtained through ζ-potential measurements, SEM observations and particle size distribution (PSD) determinations, the latter achieved by both PCS (photon correlation spectroscopy) and SdFFF (sedimentation field flow fractionation). SdFFF, the technique considered more reliable than PCS in describing the possible PSD modifications was used to investigate the effects three months of storage at 4 °C had on the lyophilized particles.
Influence of secondary preparative parameters and aging effects on PLGA particle size distribution: a sedimentation field flow fractionation investigation.
CONTADO, Catia;DALPIAZ, Alessandro;
2013
Abstract
PLGA particles in the 200-400 nm size range were formulated through the nanoprecipitation and solvent evaporation methods. Different concentrations were tested for polymer and stabilizer (Pluronic® F68) in order to identify the best conditions for making PLGA particles of suitable size, stable in time, to be used as carriers for brain targeting drugs. The particles with the best characteristics for delivery system design were those formulated by nanoprecipitation with an organic/water phase ratio of 2/30, a polymer concentration of 25 mg/mL and a surfactant concentration of 0.83 mg/mL; their surface charge was reasonably negative (~ -27 mV) and the average size of the almost monodisperse population was roughly 250 nm. Particle characterization was obtained through ζ-potential measurements, SEM observations and particle size distribution (PSD) determinations, the latter achieved by both PCS (photon correlation spectroscopy) and SdFFF (sedimentation field flow fractionation). SdFFF, the technique considered more reliable than PCS in describing the possible PSD modifications was used to investigate the effects three months of storage at 4 °C had on the lyophilized particles.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
