Microencapsulated silymarin nanoparticles prepared by atomized instantaneous solidification: Structural characterization, molecular interactions, improved solubility and bioavailability

To enhance the solubility and bioavailability of silymarin (SLM), SLM nanoparticles (SLM-NP) were prepared using sunflower phospholipid (SPL), Tween 80, and sodium alginate (SA); subsequently, redispersible microencapsulated silymarin nanoparticles (SLM-NMP) were obtained via atomized instantaneous solidification. SLM-NMP retained 97.86 ± 0.33% and 99.15 ± 0.27% of SLM after storage at 60 °C for 24 h followed by storage at room temperature for 28 days, with no significant changes in particle size and PDI during the 28-day period. Characterizations confirmed amorphous SLM encapsulation and rounded shape of SLM-NMP. Molecular dynamics simulations aligned with experimental results. In vitro, SLM-NMP achieved >80% cumulative release rate within 0.5 h in pH 1.2, 4.0 and 6.8, significantly outperforming SLM and silymarin liposome (SLM-LIP). In vivo studies confirmed enhanced bioavailability and safety of SLM-NMP. This approach combined solubilizers and electrolytes in NP offering a promising strategy for hydrophobic bioactives delivery, with microencapsulation further improving stability.