Poly(lactic-co-glycolic acid) (PLGA) is a well-characterized polymer from the ester family, widely used in the biomedical industry since its degradation byproducts are non toxic. As biodegradable colloidal particle, PLGA is an excellent delivery carrier for drugs, genes, proteins and various other macromolecules because it shows high stability, has high carrier capacity, can feasibly incorporate both hydrophilic and hydrophobic substances, and offers various feasibly routes of administration. Several methods are currently employed to formulate PLGA particles with the smallest possible sizes and maximum stability for pharmaceutical applications In this project PLGA particles, in the 200-400 nm size range, were prepared by nanoprecipitation and single emulsion (or solvent evaporation) methods in order to achieve particles which can be stable in the long run, that have appropriate dimensions for injectable uses and that disperse themselves well in aqueous media, a key requirement for uses as vehicles to induce in vivo drug targeting. Different concentrations of polymer and stabilizing (Pluronic® F68) were tested 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 accomplished by using SEM to check the morphology, calculating the surface charge through -potential measurements and determining the average sizes and particle size distributions (PSDs), 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 and aging effects on PLGA particle size distribution: a sedimentation field-flow fractionation investigation
CONTADO, Catia;
2012
Abstract
Poly(lactic-co-glycolic acid) (PLGA) is a well-characterized polymer from the ester family, widely used in the biomedical industry since its degradation byproducts are non toxic. As biodegradable colloidal particle, PLGA is an excellent delivery carrier for drugs, genes, proteins and various other macromolecules because it shows high stability, has high carrier capacity, can feasibly incorporate both hydrophilic and hydrophobic substances, and offers various feasibly routes of administration. Several methods are currently employed to formulate PLGA particles with the smallest possible sizes and maximum stability for pharmaceutical applications In this project PLGA particles, in the 200-400 nm size range, were prepared by nanoprecipitation and single emulsion (or solvent evaporation) methods in order to achieve particles which can be stable in the long run, that have appropriate dimensions for injectable uses and that disperse themselves well in aqueous media, a key requirement for uses as vehicles to induce in vivo drug targeting. Different concentrations of polymer and stabilizing (Pluronic® F68) were tested 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 accomplished by using SEM to check the morphology, calculating the surface charge through -potential measurements and determining the average sizes and particle size distributions (PSDs), 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.
