Ethosomes for Dermal and Transdermal Drug Delivery Systems

The process by which a therapeutic agent or drug is administered to the body for achieving desired effects is known as drug delivery. In the transdermal route, the drug is delivered topically through the skin. It is one of the most patient-friendly drug delivery routes favoring instant local effect. The intended drug is released at regular intervals and gradually reaches the systemic circulation. The stratum corneum of the epidermis becomes the main hindrance to effective delivery of the drug which becomes one of the drawbacks of this drug delivery route. The ethosomes were therefore conceptualized for providing an appropriate mechanism for the delivery of intended drugs directly to the targeted area through the transdermal route. Ethosomes are soft, malleable vesicles which are primarily composed of phospholipids (phosphatidylcholine/phosphatidylserine/phosphatidic acid), ethanol, and water. The barrier function of the stratum corneum is disrupted by the collective action of ethanol and phospholipid. Being a penetration enhancer, ethanol disturbs the arrangement of the lipid bilayer in the stratum corneum, thereby facilitating the soft and malleable ethosomal vesicles to squeeze and fuse with the inner lipid bilayer. Hence, the drug is subsequently released to the deeper layer of the skin for intended therapeutic application.