ABSTRACT
Skin is the largest human organ, and although topical administration is a promising route, it acts as an extraordinary main barrier for drug delivery, diffusion, and bioavailability. Lipid molecules such as phospholipids and cholesterol are the major components of the vesicular carriers. Liposomes can be classified according to the preparation method, lamellarity and size: unilamellar vesicles, multilamellar vesicles, oligolamellar vesicles, multi-vesicular vesicles large unilamellar vesicles and small unilamellar vesicles. Different mechanical procedures may be performed in order to obtain homogenous mean size lipid vesicles. Some methods of lipid vesicles production have in common the removal of organic solvents. The characterization of lipid vesicles often involves the use of several methodologies, including physical, chemical, and biological techniques. The release kinetic is dependent on the entrapped active molecule, lipid composition, vesicles preparation method and administration route. Ligand target liposomes are capable of recognizing and binding to receptors at the cells of interest with increased drug accumulation.
