Study of sonication parameters on PLA nanoparticles preparation by simple emulsion-evaporation solvent technique

The design of polymeric nanoparticles (PNPs) for delivery and controlled release of drugs has been increasing in the last decades, where polymeric materials such as biocompatible and degradable polyesters have advantages. However, it is necessary to control and modulate the size of the nanoparticles (NPs) to prevent uptake and clearance by the reticuloendothelial system and achieve selective delivery on a pharmaceutical target. In this mediation, the modulation of the particle size (PS) and polydispersity index (PDI) is one of the most sought parameters. In this work, a study of external parameters such as power, time, and cycles in sonication for the preparation of polymeric nanoparticles (PNPs) with polylactic acid (PLA) by the simple emulsion-solvent evaporation (SE-SE) technique using ultrasound was carried out. A Box-Behnken method was used to improve and optimize the conditions for obtaining the nanoformulation, which allowed obtaining response surfaces to figure out the effect of the parameters on PS, PDI, and ζ-Potential. This study showed that the main influential parameter on particle size and PDI is power, followed by the time of sonication, and finally, the number of sonication cycles. The statistical model allowed the prediction and modulation of the variables to obtain particle diameters between 110 and 240 nm, PDI 0.09–0.32, and ζ-Potential remained relatively constant in each experiment with an average value of −21.0 mV. The adequate conditions for preparing PNPs are using 20% of the power of ultrasound employed, 20 s of sonication, and two cycles with a pause of 10 s between each pulse when a PLA of 136 kDa is used. The particle size and PDI of the optimized PLA NPs were 144.5 ± 0.5 nm and 0.1347 ± 0.0064, respectively. Additionally, this model can develop desired PS nanoformulations with excellent size homogeneity.