Ethosomes: Carrier for Enhanced Transdermal Drug Delivery System

INTRODUCTION Skin is the largest human organ and consists of three functional layers: epidermis, dermis, and sub cutis. It has a wide variety of functions. One major task of the skin is to protect the organism from water loss and mechanical, chemical, microbial and physical influences. The protective properties are provided by the outermost layer (epidermis) of the skin. Dermal drug delivery is used for the treatment of various skin diseases. This has the advantage that high concentrations of drugs can be localized at the site of action, reducing the systemic side effects. Transdermal drug delivery system can be used as an alternative delivery of drug into the systemic circulation.1-2, Transdermal drug delivery offers many advantages as compared to traditional drug delivery systems, including oral and parenteral drug delivery system. Transdermal route is a better alternative to achieve constant plasma levels for prolonged periods of time, which additionally could be advantageous because of less frequent dosing regimens (Cal et al 2008). Advantages claimed are increased patient acceptability, avoidance of first pass metabolism, predictable and extended duration of activity, minimizing side effects and utility of short half life drugs, improving physiological and pharmacological response, avoiding the fluctuation in drug levels. The barrier function govern by stratum coneum is main problem for delivery of drugs across the skin.5-12 The stratum corneum consists of corneocytes surrounded by lipid layers, which play an essential role in the barrier properties of the stratum corneum. In order to increase the number of drugs administered via transdermal route, novel drug delivery systems have to be designed. These systems include use of physical means, such as iontophoresis, sonophoresis, micro needles, etc. and chemical means like penetration enhancers (surfactants and organic solvents) and biochemical means using liposome, noisome, transferosomes and Ethosomes also have been reported to enhance permeability of drug through the stratum corneum .The vesicles have been well known for their importance in cellular communication and particle transportation for many years. Researchers have understood the properties of vesicles structure for use in better drug delivery within their cavities, Review Article