Also called lipid vesicles or vesicle. Aqueous (i.e., watery) compartments enclosed by a lipid bilayer. They can be formed by suspending a suitable lipid, such as phosphatidyl choline, in an aqueous medium. This mixture is then sonicated (i.e., agitated by high-frequency sound waves) to give a dispersion of closed vesicles (i.e., compartments) that are quite uniform in size. Ahematively, liposomes can be prepared by rapidly mixing a solution of lipid in ethanol with water, which yields vesicles that are nearly spherical in shape and have a diameter of 500 A (Angstroms). Larger vesicles (10,000 A or 1 μm, or 0.00003937 inch in diameter) can be prepared by slowly evaporating the organic solvent from a suspension of phospholipid in mixed solvent system. Liposomes can be made to contain certain drugs for protective, controlled release delivery to targeted tissues. For example, pharmaceuticals which tend to be rapidly degraded in the bloodstream could be enclosed within liposomes so that more of the nondegraded pharmaceutical would remain by the time it reached the targeted tissue. The controlled release property enables larger doses (of drugs possessing toxic side effects) to be prescribed, knowing that the drug will be released in the body over an extended period of time.
A small spherical particle in an aqueous solution, formed by a bi-layer of phospholipid molecules.
Sealed shell formed when certain fatty substances are in a water-based solution. As it forms, the liposome traps part of the solution in the shell. Liposomes may be filled with a number of different substances and used to transport medications to specific organs.
Tiny oil droplets consisting of layers of fatty material, known as phospholipid, separated by water. Drugs can be incorporated into the liposomes, which are then injected into the bloodstream or muscles, or given by mouth. Using this method of administration, it is possible to protect drugs from being broken down in the body before they reach the part of the body where their curative effect is required: for example, in the liver or in a tumour.
The sealed concentric shells formed when certain lipid substances are in an aqueous solution. As it forms, the liposome entraps a portion of the solution in the shell. Liposomes may be manufactured and filled with a variety of medications. These have been used to deliver substances to particular organs. These drug forms may be more effective and less toxic than drugs given by other means.