Polymeric gels have emerged as promising vehicles for drug delivery across the skin. Stratum corneum, the topmost layer of the skin, does not allow hydrophilic and high molecular weight drugs to
permeate without enhancing techniques. A number of enhancement techniques are being developed to increase the transdermal drug permeation. The transdermal route has many advantages and has therefore
evolved as an attractive and convenient alternative to the existing routes of drug delivery that causes many side effects. In the present chapter, we shall be focusing on the physical enhancement
techniques of iontophoresis, electroporation and sonophoresis for transport of drug molecules across skin using polymeric gels.
