Development and characterization of a natural amphiphilic complex from soy lecithin and fenugreek extract for improved drug solubility and delivery

The low water solubility of hydrophobic drugs continues to be a critical challenge in drug formulations due to its impact on bioavailability and efficacy. While synthetic amphiphilic polymers are commonly applied to increase solubility, their toxicity, immunogenicity or environmental impact restricts their use. Here, a new natural amphiphilic complex was prepared from soy lecithin and fenugreek extract as biodegradable and biocompatible materials. The amphiphilic complex was prepared using a solvent-assisted self-assembly method, in which the fenugreek extract (prepared by Soxhlet extraction) was mixed with soy lecithin and then probe sonicated, precipitated and dried. The delivery system was evaluated using dynamic light scattering (DLS), zeta potential, FTIR, transmission electron microscopy (TEM), UV-vis and differential scanning calorimetry (DSC). The amphiphilic complex had an average particle diameter of 201 nm, polydispersity index (PDI) of 0.43, and a zeta potential of -44.51 mV, suggesting stability. FTIR spectroscopy demonstrated the presence of interactions between the molecules, and TEM showed spherical nanostructures (55-160 nm). The CMC was approximately determined at 2.5-3.0 mL of the sample volume in the dilution series (mean value 2.75 mL), (roughly 0.025-0.030 mg/mL), indicating favourable self-assembly. The system was soluble and had a near-neutral pH (6.5 ± 0.2). The material is a self-assembled amphiphilic complex (rather than a copolymer) formed through non-covalent bonding. In conclusion, the complex has good promising physicochemical properties and the future potential of being developed as a nanocarrier; drug loading, release and biological testing should be studied to establish its efficacy as a drug delivery system.