Production of Bioabsorbible Nanoparticles of Polycaprolactone by Using a Recirculating System

G. Colmenares, L. Agudelo, R. Pinal, L. Hoyos
Universidad Pontificia Bolivariana,

Keywords: nanoparticles, polycaprolactone, nanoprecipitation, encapsulation, delivery


Encapsulation and controlled release of substances using polymeric nanoparticles require that these have a high reproducibility, homogeneity, and control over their properties, especially when they are to be used in medical, pharmaceutical or food applications among others. By conventional production systems, it is difficult to ensure these features and the cost increases when trying to promote these. This work shows a system for synthesizing polymeric nanoparticles that can easily control the characteristics of nanoparticles and does not require specialized equipment. Additionally, the system is quite flexible and can obtain small amounts of nanoparticles or can be adjusted to obtain large volumes quickly. The system is based on a continuous tubular reactor that initially recirculates the aqueous phase (which may be composed of water, surfactants and other additives). To this stream, the organic phase is injected (which may be composed of organic solvents, polymers, the active substance and other additives) and then the mixture of the streams is recirculated with the continuous addition of the organic phase to complete 100% of this. Flows of both streams can be controlled to modify the characteristics of nanoparticles, and the composition of the organic phase and the aqueous phase. The formation of nanoparticles occurs instantaneously in turbulent regimes giving the phenomenon of nanoprecipitation. This study evaluated the effect of molecular weight of the polymer (Polycaprolactone (PCL) Mw=14.000, 45.000 and 80.000 g-mol-1), the type of surfactant (Poloxamer 188, Pluronic F-127 and Tween 80) and the relationship between the volume of the aqueous phase and the organic phase (2:1, 5:1 and 10:1). It was found that the first two variables have a statistically significant effect on the diameter of the nanoparticles while the relationship between the volume of the aqueous phase and the organic phase does not significantly affect the diameter of the nanoparticles. Additionally, it was found that none of the three variables significantly affects the polydispersity index (PI) of nanoparticles in this system.