Transdermal drug delivery enhancer systems

A new generation of transdermal drug delivery (TDD) system was developed to contain one or more skin permeation enhancers in the surface adhesive coating layers. This TDD system has been found, experimentally, to release the enhancers to the surface of stratum corneum to modify the skin s barrier properties, prior to the controlled delivery of the active drug. The extent of enhancement in skin permeability appears to be dependent upon the chemical structure of drug to be delivered transdermally as well as the type and the concentration of enhancer used. The mechanism of skin permeation enhancement have been explored and are analyzed in this report. 

Walters, K.A. (1989). Penetration enhancers and their use in transdermal therapeutic systems. In Transdermal Drug Delivery — Development Issues and Research Initiatives, J. Hadgraft and R.H. Guy, eds. Marcel Dekker, New York, 197-246. 

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). 

Transdermal Drug Delivery System with Enhanced Skin Permeability... 

This new type of transdermal drug delivery system is capable of releasing one or a combination of two or more skin permeation enhancers to the stratum corneum surface in order to modify the skin s barrier properties (10), prior to the controlled delivery... 

Transdermal drug delivery (TDD) is known to offer many advantages over the oral and injectable routes for systemic drug delivery. However, the skin is a complex and dynamic organ with marked barrier function, which results in limitations and variations in the amount and nature of drugs that can be delivered across the skin and into the bloodstream. Thus a continual search for ways to optimize the permeation of drugs across the skin exists, in an attempt to enhance delivery and improve patient compliance. 

Over the last 20 years, transdermal route of delivery has been considered as a means for systemic drug administration. Over this period, sonophoresis has been attempted to enhance systemic transdermal delivery. Levy et al. ° showed that 3-5 min of ultrasound exposure (IMHz, 1.5W/cm ) increased transdermal permeation of mannitol and physostigmine across hairless rat skin in vivo by up to 15-fold. They also reported that the lag time typically associated with transdermal drug delivery was nearly-completely eliminated after exposure to ultrasound. ° ... 

Pfister WR, Hsieh DST. Permeation enhancers compatible with transdermal drug delivery systems. Part I Selection and formulation considerations. Pharm Technol 1990 14(9) 132—140. 

Bhattachrya A, Ghosal SK. Effect of hydrophobic permeation enhancers on the release and skin permeation kinetics from matrix type transdermal drug delivery system of ketotifen fumarate. Acta Pol Pharm 2001 58(2) 101-105. 

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