Transdermal drug delivery

Ethosomes are advanced and modified form of liposomes, which are applied as carriers for transdermal drug delivery. These are developed by Professor Elka Touitou from the Hebrew University of Jerusalem, to enhance the drug administration of amphiphilic drugs. These are soft and flexible lipid vesicles having phospholipids, water, and alcohol in high concentrations about to 20-45% approximately. Ethosomes are easy to prepare through different common methods named as thin film hydration method, cold method, hot method and injection method. These provide enhanced permeation of drugs, highly drug loading capacity, better control over drug release, non-parenteral drug delivery having ability to encapsulate diverse molecular spectrum range. Another key advantage of ethosomes is that they provide excellent patient compliance since these are able to apply as semi-solid formulations, such as gel or cream. The evaluation criteria, such as vesicle size, zeta potential, entrapment efficiency, In-vitro permeation studies and In-vivo permeation studies, support their effectiveness in targeted drug delivery. Ethosomes demonstrated positive results and the capability to enhance the distribution of amphiphilic drug molecules. This article provides a comprehensive review of ethosomes including their distinctive properties, composition, methods of preparation, physicochemical properties, methods of penetration and the areas of their application in pharmaceutical and cosmeceutical industries. The article examines objectives of ethosomal research as one way of achieving the goal of developing non-invasive drug delivery systems and reports on recent advancements, issues and future prospects. They also put sufficient evidence of the effectiveness of ethosomal therapy in being viable nanocarriers for drug delivery. 

Transdermal delivery holds a promising carrier in the transport of drugs to get direct access across the skin deep into the systemic circulation. It has attracted many researchers due to various biomedical advantages. The barrier nature of stratum corneum poses a threat to the drug delivery. Recently, the use of microneedles in increasing skin permeability has been proposed and shown to dramatically increase transdermal delivery, especially for macromolecules. In the microelectronics industry, microneedles have been fabricated with a range of sizes, shapes and materials. Most drug delivery studies have emphasized solid microneedles, which have been shown to increase skin permeability to a broad range of molecules and nanoparticles in vitro Microneedles can be used to enhance transdermal drug delivery. In this review different types of microneedles are described and their methods of fabrication highlighted. There are also hydrogel-forming microneedles. These are innovative microneedles which do not contain drugs but imbibe interstitial fluid to form continuous conduits between dermal microcirculation and an attached patch-type reservoir. Several microneedles approved by regulatory authorities for clinical use are also examined. It also focuses on the delivery of various therapeutic agents effectively different carriers emphasizing mainly on the potential role of microneedles as transdermal system.