Formulation, Development and Evaluation of Nano Ethosomal Gel of Tramadol Hydrochloride

Ethosomes are innovative nanovesicles containing the drug in a matrix of lipids, ethanol and water. The ethosomes are soft and a highly flexible vesicle efficiently penetrates through the skin and increases the drug delivery of drug molecules. Ethosomes are elastic vesicles made up of Phospholipids containing 20-45% ethanol. Ethanol also acts as a penetration enhancer by dissolving the skin lipids. The ethosomes overcomes the disadvantages of Liposomes and proliposomes such as less stability, scalability issues, leakage of drugs, fusion of vesicles and breaking of vesicles. Ethanol is a well-known permeation enhancer. Ethosomes are highly flexible which permits the elastic vesicles to squeeze themselves among the skin pores. Ethanol gives the net negative charge on the surface of ethosome vesicles due to which aggregation is avoided because of electrostatic repulsion. Ethosomes are much more stable than the Liposomes and proliposomes. Topically administered ethosomes increases the residence time of the drug molecule in the different layers of skin such as stratum corneum, epidermis and reduces the systemic absorption. Because of all these properties, ethosomes get easily permeated in the deeper layer of skin and circulation. Ethanol in deeper layers of skin leads to disruption of the skin which increases the lipid fluidity that allows enhanced permeation of drug molecule through the skin. Ethosomes fuses with the skin lipids to release the drug into the deeper layers of skin [1-4].