Biodegradable colloidal particles of PLGA (Poly(lactic-co-glycolic acid)) are excellent delivery carriers for drugs because they show high stability and high carrier capacity; they 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 work PLGA particles were prepared by nanoprecipitation and single emulsion (or solvent evaporation) methods in order to achieve particles stable in the long run, with appropriate dimensions for injectable uses (200-400 nm size range). 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, that disperse themselves well in aqueous media, a key requirement for uses as vehicles to induce in vivo drug targeting, 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.

The sedimentation field flow fractionation technique to study the effects on PLGA particles of secondary preparative parameters and aging

CONTADO, Catia
2013

Abstract

Biodegradable colloidal particles of PLGA (Poly(lactic-co-glycolic acid)) are excellent delivery carriers for drugs because they show high stability and high carrier capacity; they 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 work PLGA particles were prepared by nanoprecipitation and single emulsion (or solvent evaporation) methods in order to achieve particles stable in the long run, with appropriate dimensions for injectable uses (200-400 nm size range). 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, that disperse themselves well in aqueous media, a key requirement for uses as vehicles to induce in vivo drug targeting, 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.
2013
PLGA nanoparticles; SdFFF; aging
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Utilizza questo identificativo per citare o creare un link a questo documento: https://hdl.handle.net/11392/1826705
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