Surface Functionalization of Piperine-Loaded Liposomes with Sophorolipids Improves Drug Loading and Stability

Purpose The application of amphiphilic biosurfactants in drug delivery systems has sparked interest in recent years. In this study, piperine-loaded liposomes were modified with the biosurfactant sophorolipids to better stabilize and disperse the liposomal formulation and the properties of the liposomes were evaluated. Methods Sophorolipid-modified liposomes were prepared and the particle sizes and entrapment efficiencies (EEs) of piperine were measured. The stability of liposomes was also evaluated in serum, under 4 °C storage and under various NaCl concentrations and pH conditions respectively. The in vitro release profile of piperine was also investigated. Results Sophorolipids helped stabilize and disperse liposomes as evidenced by the decreased particle sizes, lowered PDIs, and increased serum stability after the addition. They also elevated the EEs of piperine into liposomes and stabilized piperine-loaded liposomes during 4 °C storage. Under high NaCl concentrations as well as various pH conditions, sophorolipid-modified liposomes showed favorable in vitro stability in terms of particle sizes and EEs. Sophorolipid-functionalized piperine-loaded liposomes also exhibited sustained in vitro drug release profiles. Conclusion This preliminary study validated the feasibility of grafting liposomes with amphiphile biosurfactant sophorolipids for formulation stabilization, demonstrating their applicability in improving the liposomal loading of hydrophobic nutraceuticals such as piperine.