Facile technique for the preparation of monodispersed biodegradable polymer nanospheres using a solvent evaporation method

• Size of prepared emulsion droplets in PVA/ethanol water phase was smaller ones.
• PLGA nanospheres by solvent evaporated the smaller droplets were prepared.
• Monodispersed 170-nm PLGA nanospheres were prepared using a simple method.

A facile technique was developed for the preparation of monodispersed nanospheres composed of poly(lactide-co-glycolide) (PLGA) for use as a biodegradable polymer in a liquid–liquid system. The preparation of PLGA particles by solvent evaporation from an emulsion prepared by adding a nonionic or reactive surfactant to the water phase was examined. The size of the PLGA particles gradually decreased as the surfactant concentration in the water phase increased. However, nanosized PLGA particles were difficult to prepare using this procedure. Preparation of nanosized particles of PLGA by solvent evaporation from a mixture of an aqueous solution of polyvinylalcohol (PVA) and ethanol was also examined. As the amount of ethanol was increased relative to the amount of PVA solution, the size of the PLGA particles decreased. At a ratio of 50:40 v/v% PVA(aq):ethanol, monodispersed spherical PLGA particles, 170 nm in diameter, were generated. Nanosized PLGA particles in liquid–liquid systems are generally prepared using solvent evaporation methods after emulsion droplets are first prepared using a particulate disperser apparatus (e.g., an ultrasonic homogenizer), although the resulting particles are polydispersed. In this study, monodispersed nanosized PLGA particles were generated even though we used a simple high-speed rotary homogenizer, which is usually not capable of preparing nanosized particles, without the use of a particulate mechanical disperser or a combination of particulate emulsion techniques. The technique used in this study may also be applicable to the preparation of other types of polymers and emulsion particles.

Figure optionsDownload as PowerPoint slide