Liposomes are miniature vesicles with a bilayer structure made from lecithin, ceramides, etc. ‌. Its structure is similar to the cell membrane of the skin, and it has good biocompatibility and moisturizing effects. It is often used in cosmetics and personal care products. ‌

The definition and basic concepts of liposomes

Liposomes are closed small vesicles with a bilayer structure formed by the dispersion of lipids such as phospholipids in water. Because their structure is similar to that of biological membranes, they can also be called artificial biological membranes. Phospholipids, the main raw material for the preparation of liposomes, are an inherent component of human cells, with good biocompatibility and no immunogenicity. Liposomes can be prepared into nanoscale particles, making it easier for them to pass through biological barriers such as blood vessel walls and cell membranes.

The application fields of liposomes

Youdaoplaceholder0 Drug carriers ‌ : Liposomes have great potential as drug carriers in targeted drug delivery therapy for malignant tumors. It has targeting and lymphatic directionality and can be used as a passive targeted drug for the reticular system of the liver and spleen. Liposomes can also reduce the toxicity of drugs. For example, amphotericin B liposomes can effectively reduce the toxicity to the heart.

Youdaoplaceholder0 Cosmetics ‌ : Liposome technology has a wide range of applications in cosmetics. It can encapsulate the active ingredients within the lipid bilayer, promote the penetration of the active ingredients into the skin, enhance the accumulation of the active ingredients in the local skin area, improve bioavailability and have moisturizing and skin care effects. For instance, in 1986, the Dior brand released a liposome cosmetic product named "capture", pioneering the liposome cosmetic industry.

The preparation methods and quality control of liposomes

The preparation methods of liposomes mainly include dispersing lipids such as phospholipids and cholesterol in water to form microvesicles with a bilayer. In terms of quality control, the morphology, particle size and its distribution, encapsulation efficiency, drug loading capacity and stability of liposomes are all important considerations. For instance, the particle size of liposomes for injection should be less than 200nm, and they should be evenly distributed. The encapsulation rate is usually required to reach over 80%.