Liposomes mimic natural cell membranes and have long been investigated as drug carriers due to excellent entrapment capacity, biocompatibility and safety. Despite the success of parenteral liposomes, oral delivery of liposomes is impeded by various barriers such as instability in the gastrointestinal tract, difficulties in crossing biomembranes, and mass production problems. By modulating the compositions of the lipid bilayers and adding polymers or ligands, both the stability and permeability of liposomes can be greatly improved for oral drug delivery. This review provides an overview of the challenges and current approaches toward the oral delivery of liposomes.
Keywords: APC, antigen-presenting cell; AUC, area under curve; Absorption; BSA, bovine serum albumin; Bioavailability; DC, dendritic cells; DMPC, dimyristoyl phosphatidyl choline; DPPC, dipalmitoyl phosphotidylcholine; Drug delivery; FAE, follicle-associated epithelia; FITC, fluorescein isothiocyannate; GIT, gastrointestinal tract; LUV, large unilamellar vesicles; Liposomes; MLV, multilamellar vesicles; MRT, mean residence time; MVL, multivesicular liposomes; Oral; PC, phosphatidylcholine; PEG, polyethylene glycol; RES, reticulo-endothelial; SC, sodium cholate; SDC, sodium deoxycholate; SGC, sodium glycocholate; SPC, soy phosphatidylcholine; STC, sodium taurocholate; SUV, small unilamellar vesicles; Stability; TPGS, tocopherol polyethylene glycol succinate; Tgel, gelling temperature; Tp, phase transition temperature; UEA 1, ulex europaeus agglutinin 1; WGA, wheat germ agglutinin; rhEGF, recombinant human epithelial growth factor.