Elastic liposomes as novel carriers: recent advances in drug delivery

Abstract

Elastic liposomes (EL) are some of the most versatile deformable vesicular carriers that comprise physiologically biocompatible lipids and surfactants for the delivery of numerous challenging molecules and have marked advantages over other colloidal systems. They have been investigated for a wide range of applications in pharmaceutical technology through topical, transdermal, nasal, and oral routes for efficient and effective drug delivery. Increased drug encapsulation efficiency, enhanced drug permeation and penetration into or across the skin, and ultradeformability have led to widespread interest in ELs to modulate drug release, permeation, and drug action more efficiently than conventional drug-release vehicles. This review provides insights into the versatile role that ELs play in the delivery of numerous drugs and biomolecules by improving drug release, permeation, and penetration across the skin as well as stability. Furthermore, it provides future directions that should ensure the widespread use of ELs across all medical fields.

Keywords: drug delivery; elastic liposomes; enhanced delivery; topical; transdermal.

Figure 1

Schematic illustration of bilayer elastic liposomes displaying various components and structural morphology.

Figure 2

Schematic presentation of sequentially involved steps in the elastic liposome preparation of 5-fluorouracil. Abbreviations: EL, elastic liposome; S-EL, solidified elastic liposome.

Figure 3

(A) Scanning electron microscopy and (B) transmission electron microscopy of elastic liposomes.

Figure 4

Schematic illustration of permeation mechanisms across the skin. Squeezing and deformability of vesicles through microscopic spaces results in their permeation and penetration.

Figure 5

Permeation flux rate of 5-fluorouracil-loaded elastic liposomes prepared from different edge activators as compared to conventional liposomes, marketed flonida, and drug solution across the skin in rats.

Figure 6

Effect of variable factors (PC and Span 80 [S80]) on permeation flux rate (µg/cm²/h) and % EE responses of 5-fluorouracil-loaded elastic liposomes assessed by the experimental technique (Design Expert software). Notes: (A–C) Permeation flux increases with an increase in PC and S80 content, as shown in 3D and contour plots along with actual and predicted graphs; (D–F) % EE increases linearly with increases in concentrations of PC and S80, as elucidated in the 3D and contour plots. A and B indicate the first independent variable for PC and second independent variable for S80, respectively. Abbreviations: PC, phosphatidylcholine; EE, entrapment efficiency.