A comprehensive review on: liposomes as drug delivery system

Liposomes are round, bubble-like structures used to deliver drugs. They are made from one or more layers of phospholipids that form a barrier around a water-filled centre. These structures are popular in the pharmaceutical world because they are safe for the body, break down naturally, and can hold both water-soluble and fat-soluble drugs. Cholesterol is often added to make the structure more stable and prevent the drug from leaking out. Liposomes come in different forms depending on their structure and what they're made of, such as small single-layer vesicles, large single-layer vesicles, multi-layer vesicles, regular liposomes, PEG-coated liposomes, and targeted liposomes. To make them, scientists use methods like making a thin film and then adding water, using sound waves, pushing through tiny holes, adding alcohol, or evaporating a solvent in the reverse way. When they test these liposomes, they check for size, how uniform the size is, electrical charge, shape, how well the drug is trapped, how much drug is inside, how it releases in a lab setting, and how stable it is over time. Using liposomes helps drugs dissolve better, reach the body more effectively, release slowly, stay in the bloodstream longer, target specific areas, and be less harmful. PEG-coated liposomes can stay in the body longer, and liposomes with special molecules can help drugs gather at certain parts of the body. These systems are used for treating cancer, fungal infections, bacteria, vaccines, delivering genes, and giving proteins and peptides. However, there are some issues, like drugs leaking out, lipids breaking down, physical changes, high costs to make them, and problems scaling up production. Scientists are working on new types of liposomes that respond to certain signals and can actively target specific areas to overcome these problems. Overall, liposomes are a promising way to make medicines work better, be safer, and deliver drugs more effectively.