Nanoparticles and Their Combination with Physical Methods for Dermal and Transdermal Drug Delivery

Abstract

Nanocarriers have been recently intensively studied due to their penetration enhancement ability regarding dermal and transdermal drug delivery, as well as due to their ability to encapsulate hydrophilic and lipophilic drugs, thereby preserving their stability. Among different nanocarriers, lipid-based and polymer-based nanoparticles have gained a lot of interest. However, nanoparticles, when applied alone, mostly deliver drugs to the skin, as they accumulate at the skin surface and do not penetrate the intact skin. Therefore, they are mostly used to treat skin diseases. In order to achieve effective systemic drug absorption, nanocarriers are used together with physical enhancement methods. These are able to bypass or disrupt the stratum corneum (SC) barrier by different mechanisms. In this chapter, we describe the use of nanoparticles combined with different physical enhancement methods, such as the use of microneedles (MNs), iontophoresis and electroporation. The described studies revealed that physical methods mostly enhanced the efficiency of nanoparticles and that this combination of different methods was promising, as nanoparticles and physical methods act synergistically in enhancing percutaneous drug penetration, but via different mechanisms of action. Most promising application of this approach is its use for achieving transcutaneous immunization, and various studies confirmed that the combined use of nanoparticles and physical methods may be an alternative method for transcutaneous immunization. In this way with the use of needle-free vaccination, numerous drawbacks of the conventional vaccination (with syringes and needles), such as pain, fear, spread of diseases, would be circumvented. In addition, this approach can be used for percutaneous penetration enhancement not only of low-molecular-weight drugs, but also of high-molecular-weight drugs that usually are not able to penetrate the SC, such as peptide/protein drugs, like antibodies, insulin, genes, etc.