Liposomal systems, transdermal drug delivery

Pierre MBR, Costa IdSM. Liposomal systems as drug delivery vehicles for dermal and transdermal applications. Archives of Dermatological Research. 2011 303(9) 607-621. 

G. Cevc, Transfersomes, liposomes and other lipid suspensions on the skin permeation enhancement, vesicle penetration, and transdermal drug delivery, Crit. Rev. Therap. Drug Carrier Systems, 73 257-388 (1996). 

Liposomes have been used for years as components of drug delivery systems, and as transdermal carriers of active ingredients in the cosmetic industry (307, 308). More recently, liposomes have found use in the food and nutritional supplement industries. Keller (308) lists more than a dozen nutritional products on the market that have been formulated with novel liposome-based delivery systems. In the food area, hposomes have been studied for their ability to encapsulate and provide controlled release of enzymes (309, 310), and liposome-encapsulated enzymes have been used to accelerate the ripening of cheese (311). 

In addition to traditional dermal and transdermal delivery formulations, such as creams, ointments, gels, and patches, several other systems have been evaluated. In the pharmaceutical semisolid and liquid formulation area,these include sprays, foams, multiple emulsions, microemulsions, liposomal formulations, transfersomes, niosomes, ethosomes, cyclodextrins, glycospheres, dermal membrane structures, and microsponges. Many of these novel systems use vesicles to modulate drug delivery. Novel transdermal... 

Formulation and/or development of advanced drug-delivery systems such as microencapsulated molecules, transdermal patches, or liposomes are frequently accomplished in the laboratory. However, large-scale production of these dosage forms may be problematic because the same conditions of manufacture may not be attainable or desirable in the plant setting. Consultation with process development personnel during the finalization of the prototype development phase is one way of minimizing scale-up difficulties. 

Dermal and transdermal delivery requires efficient penetration of compounds through the skin barrier, the bilayer domains of intercellular lipid matrices, and keratin bundles in the stratum corneum (SC). Lipid vesicular systems are a recognized mode of enhanced delivery of drugs into and through the skin. However, it is noteworthy that not every lipid vesicular system has the adequate characteristics to enhance skin membrane permeation. Specially designed lipid vesicles in contrast to classic liposomal compositions could achieve this goal. This chapter describes the structure, main physicochemical characteristics, and mechanism of action of prominent vesicular carriers in this field and reviews reported data on their enhanced delivery performance. 

Knepp, V.M., F.C. Szoka, and R.H. Guy. 1990. Controlled drug release from a novel liposome delivery system. II. Transdermal delivery characteristics. J Control Release 12 25. 

Recently, for the transdermal delivery of drugs using carrier systems, attention has been focused on the development of transformable [284,285] or elastic vesicles [12], These vesicles are liposomes that contain surfactants or in general edge activators in addition to phospholipids in their lipid membranes (Figure 10), a fact that... 

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