Co-encapsulation of milk thistle and barberry extracts in beta-sitosterol-modified phytosomes: Formulation and characterization

This study introduces a novel approach for co-encapsulating milk thistle and barberry extracts within a beta-sitosterol-modified phytosomal system. Beta-sitosterol was incorporated into the phospholipid bilayer to enhance structural integrity. Phytosomes were prepared using the thin-layer hydration method with varying beta-sitosterol ratios. The optimal formulation (active component:Soy phosphatidylcholine: beta-sitosterol = 1:0.8:0.2) had a particle size of 240 nm and showed improved characteristics: reduced polydispersity index (0.18), high zeta potential (-47 mV), and enhanced encapsulation. Encapsulation efficiency reached 77% for silymarin and 81% for anthocyanins, indicating potential for dual delivery of lipophilic and hydrophilic compounds. In vitro gastrointestinal release studies showed a condition-dependent pattern. Anthocyanins exhibited higher gastric release (≈25.7% at 120 min) due to their hydrophilic nature, while silymarin showed limited gastric release (