ABSTRACT

The most common applications of iontophoresis involve the delivery of therapeutic substances across the skin, though there are numerous examples of the use of iontophoresis to treat conditions of the eye, ear, nose, and mouth. Iontophoresis can also be used to remove substances from the body. The most common therapeutic applications of iontophoresis are topical administration of lidocaine as a local anesthetic and dexamethasone for treatment of local inflammation. The competitive effect of buffer anions on transport of anionic drugs has also been reported. Standard phosphate and citrate buffers have been successfully used in formulations for transdermal iontophoresis of drug ions. Many drugs have a broad pH range in which drug solubility and stability are adequate for transdermal delivery by iontophoresis. However, optimal drug delivery and biocompatibility are usually restricted to amore narrow range of formulation pH.