Recent Advancement of Medical Patch for Transdermal Drug Delivery

Abstract

Transdermal patches are a non-invasive method of drug administration. It is an adhesive patch designed to deliver a specific dose of medication through the skin and into the bloodstream throughout the body. Transdermal drug delivery has several advantages over other routes of administration, for instance, it is less invasive, patient-friendly, and has the ability to bypass first-pass metabolism and the destructive acidic environment of the stomach that occurs upon the oral ingestion of drugs. For decades, transdermal patches have attracted attention and were used to deliver drugs such as nicotine, fentanyl, nitroglycerin, and clonidine to treat various diseases or conditions. Recently, this method is also being explored as a means of delivering biologics in various applications. Here, we review the existing literatures on the design and usage of medical patches in transdermal drug delivery, with a focus on the recent advances in innovation and technology that led to the emergence of smart, dissolvable/biodegradable, and high-loading/release, as well as 3D-printed patches.

Keywords: development and technology; drug delivery; medical patch; transdermal.

Figure 1

Basic component of a transdermal medical patch.

Figure 2

Types of transdermal patches: (A) drug-in adhesive system; (B) Reservoir system; (C) matrix system; (D) Micro-reservoir system.

Figure 3

The microneedle-based patch: (A) solid; (B) hollow; (C) coated; (D) dissolving.

Figure 4

The microneedle-based patch painlessly penetrates into the skin layer. The smart patch contains insulin and the glucose-sensing enzyme glucose oxidase, which converts glucose into gluconate. Higher glucose oxidase activity in response to increased glucose triggers nanoparticle degradation and insulin release.

Figure 5

The microneedles in these patches are made out of biodegradable materials. After gentamicin has been released from the patch, the microneedle dissolve on the skin.