Size control of drug nanoparticles stabilized by mPEG-b-PCL during flash nanoprecipitation

Flash nanoprecipitation (FNP) is an ideal method to rapidly prepare nanosized drug particles with high drug-loading efficiency, where amphiphilic block copolymers are used as stabilizer to protect the nanoparticles from aggregation. In this paper, stable β-carotene-loaded nanoparticles with tunable size, narrow size distribution, and high drug-loading efficiency (> 86%) were prepared by carefully controlling the input drug concentration. The size and size distribution of the prepared nanoparticles kept almost unchanged for more than half a month. It is found that the input drug concentration during FNP showed significant impact on the stability of nanoparticles. By increasing the stream velocity, Reynolds number or the molecular weight of amphiphilic block copolymer, the size of nanoparticle can be reduced, while the nanoparticle size increased upon reducing the hydrophilic block proportion of amphiphilic block copolymer. This work should be very helpful to control the preparation of stable nanoparticles by FNP.