Tailored saturated phosphatidylcholine liposomes enhance the physicochemical stability and intestinal bioavailability of ascorbic acid and calcium ascorbate.

This study evaluated tailored saturated phosphatidylcholine (PC) liposomes for improving the physicochemical stability and intestinal bioavailability of ascorbic acid (AA) and calcium ascorbate (CA). High-purity 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC), 1,2-distearoyl-sn-glycero-3-phosphocholine (DSPC), and 1-palmitoyl-2-stearoyl-sn-glycero-3-phosphocholine (PSPC)/1-stearoyl-2-palmitoyl-sn-glycero-3-phosphocholine (SPPC)-rich mixture were synthesized. Liposomes encapsulating AA and CA were prepared using synthesized PCs and their mixtures (PCMs). The liposomes showed nanoparticle sizes (100-125 nm) and low polydispersity (0.10-0.18). Encapsulation efficiency depended on PC composition, with PCM achieving the highest efficiencies for AA (∼50%) and CA (∼93%). Compared with soy PC liposomes, saturated PC-based liposomes showed significantly improved physicochemical and storage stability. In vitro gastrointestinal digestion demonstrated that PCM-I liposomes (DMPC:DSPC = 70:30, wt/wt) effectively protected encapsulated AA and CA than their free forms. Caco-2 cell assays confirmed enhanced intracellular uptake and transepithelial transport, particularly for Liposomal-CA. These results demonstrate that tailored saturated PC liposomes are effective nano-delivery systems for improving the stability and intestinal absorption of AA derivatives.