Optimization and Characterization of Cuscuta reflexa Extract Loaded Phytosomes by the Box-Behnken Design to Improve...

The purpose of this study is to determine whether the complexing hydroalcoholic extract of Cuscuta reflexa (HECR) with phosphatidyl choline increases its bioavailability. As a result, a novel phytosomal delivery system for the HECR-soya lecithin complex was developed (HECR-phytosome). The HECR-phytosome complex was synthesized and characterized as phytovesicles. The formulation was prepared using a variable concentration of soya lecithin (1:1-1:3 percent w/v), a temperature range of (45-65°C), and sonication time (4-8 min). Optimization of HECR-loaded phytosomal formulations was performed using Design Expert software. A three-factor, three-level Box-Behnken design was used to optimize this HECR delivery system, as dependent variables, vesicular size and entrapment efficiency were evaluated using a Box Behnken factorial design. Further characterization of the optimized formulation included vesicle size, PDI, zeta potential, entrapment efficiency, FTIR, DSC, TEM, and in vitro release. Vesicle sizes ranged from 173.5±6.17 nm to 215.9±6.53 nm, and response rates for entrapment efficiency ranged from 52.9±1.65 to 77.2±1.1%. The uniform structure and spherical shape were demonstrated by transmission electron microscopy. Among the drug release kinetic models, the formulation followed the Higuchi model (R² = 0.9978), releasing 96.3±3.7% of the polyphenol and flavonoids phytoconstituents from HECR-loaded phytosomes in 12 hours, compared to 49.3±2.5% in the plain extract. In addition, the optimized formulation passes the stability test. Therefore, the results demonstrated that phytosomal nanocarriers have the potential to increase the bioavailability of Cuscuta reflexa extract.