Transdermal drug delivery (TDD) is an alternative method of drug administration for drugs whose delivery by conventional oral, topical, intravenous and intramuscular methods is of limited efficacy. Recent advances in TDD involve the use of nanoparticles (NPs), which exhibit a great potential to enhance drug permeation across the skin. NPs can also provide controlled release, the ability to deliver both hydrophilic and hydrophobic drugs and reduce side effects, and when used in a TDD method they are also non-invasive. Another developing technology for TDD employs skin patches containing microneedles. Microneedles represent a painless and minimally invasive method of TDD in which micron-sized pores are created in the epidermis to allow delivery of drugs to the blood vessels present in the dermal layer of the skin. New researches have focussed on combining different TDD approaches to overcome previous constraints of drug delivery via conventional methods.
Keywords: Transdermal drug delivery; microneedle; nanoparticle; skin patch; stratum corneum.