Iontophoresis, transdermal drug delivery

Helmstadter, A. (2001) The history of electrically assisted transdermal drug delivery (iontophoresis) , Pharmazie. 56, 583-587. 

The development of the first transdermal patches in the 1980s generated considerable interest in this route of drug administration. Soon afterwards, iontophoresis was rediscovered and its potential to contribute to the new field of transdermal drug delivery was examined. This work provided the basic principles for modern iontophoretic devices [13,18-21]. Furthermore, and importantly, they demonstrated the existence of a (primarily) electroosmotic, convective solvent flux during transdermal iontophoresis [10,11,22-24], and it was shown that the permselective properties of the skin (a) could be exploited to enhance the transport of neutral, polar species and (b) have a clear impact on ionic transport. Subsequent research has better characterized skin permselectivity and the factors which determine the magnitude of electroosmosis [25-27],... 

Burnette, R.R. 1989. Iontophoresis. In Transdermal drug delivery, eds. J. Hadrgraft and R.H. Guy. New York and Basel Marcel Dekker, chap. 11. 

Ointments, creams, and plasters are used for transdermal drug delivery. In the latter case, sustained release is accomplished by diffusion from a reservoir through a microporous membrane and into the skin [26,48,49]. Iontophoresis and electroporation has been reported to successfully promote transdermal delivery rates [50-52]. 

Burnette, R. R. Iontophoresis. In Transdermal Drug Delivery Developmental Issues and Research Initiatives. J. Hadgraft and R. H. Guy, eds. Dekker New Yoric, 1989, pp. 247-291. 

The present summary will cover only those technologies where the drug formulation itself is used to penetrate the skin via its mechanical energy. It will not describe any technology where a needle is used to puncture the skin, even if the needle is not visible to the patient or only the epidermis is punctured, such as mini-needles, microneedles, pen injectors, or autoinjectors. Also excluded are systems that ablate the skin mechanically or otherwise disrupt its chemical or mechanical structure to increase its permeability, such as laser ablation, microdermal ablation, electroporation, or iontophoresis. These are usually referred to as transdermal drug delivery, but can also be described as needle free. 

Burnette, R.R. Iontophoresis. In Transdermal Drug Delivery Development Issues and Research Initatives Hadgraft, L, Guy, R.H., Eds. Marcel Dekker, Inc. New York, 1989 247-291. 

The transport of charged substances through the skin iontophoresis and transdermal drug delivery) was shown early by the famous experiment by Munk (1873). He applied an... 

Transdermal drug delivery through iontophoresis has received widespread attention. A long-term delivery with transdermal DC voltage of <5 V was used (Phquett and Weaver, 1996). High-voltage pulses up to 200 V decaying in about 1 ms have also been used on human skin for enhancement of transport by electroporation (Phquett and Weaver, 1996). The effect was found to be due to the creation of aqueous pathways in the stratum corneum. 

Singh J, Roberts M. Transdermal delivery of drugs by iontophoresis a review. Drug Delivery 1989 4 1-12. 

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