Improved ability of liposomes to encapsulate ascorbic acid via coating with xanthan gum

Abstract The ability of liposomes (LP) to entrap ascorbic acid (AA) was improved via coating with xanthan gum (XG). The encapsulation efficiency of AA liposomes (AA-LP) increased from 29.7% to 76.2%, and their retention ratio in simulated gastric and intestinal fluids reduced from 43.0% to 29.4% and 78.56% to 49.2%, respectively, after coating with XG, indicating that AA-LP stability was effectively increased. XG-AA-LP zeta potential and particle size increased from −29.4 to −51.6 mV and 240.9 to 291.4 nm, respectively. The increase in XG-AA-LP p values indicated that XG inhibited the movement of phospholipids, leading to a decrease in phospholipid bilayer mobility. Furthermore, Fourier transform infrared (FTIR) results implied that noncovalent bonding forces such as hydrogen bonding, electrostatic forces, etc. played crucial roles in the binding of XG to AA-Lip, and differential scanning calorimetry results indicated that the thermal stability of LP increased after coating with XG. Transmission electron microscopy results signified that some irregular substances bound to the surface of AA-LP and the liposome particles became larger compared to those of AA-LP, and the surface of AA-LP was coated with XG. These findings suggest that XG coating can be an effective strategy to develop LP ability to deliver AA and to increase AA-LP stability.