Challenges in the implementation of transdermal skin patches.
The available transdermal delivery patches in the market can only deliver a limited number of drug molecules (Paudel et al., 2010). That means transdermal patches can only treat a narrow number of conditions while leaving other disease-stricken individuals to endure the problems presented by traditional drug delivery methods. Transdermal patch developers have also not managed to overcome the permeability issues presented by the tough barrier of the stratum corneum. Furthermore, transdermal patch users still experience skin irritation. The repeated disturbance of the stratum and changes in the skin’s pH during drug delivery are some of the factors that cause skin irritation. Nevertheless, the emergence of advanced skin permeability technology promises lower irritation and increases permeability via the stratum corneum.
Iontophoresis patches employ an electric current to drive drug molecules into the skin. However, the technique does not increase skin permeability but helps provide the force required to transport drug molecules into the skin. Moreover, the presence of enzymes in the skin, such as peptides during drug delivery, can metabolize drug molecules, thereby lowering the efficacy of the drug (Chaudhari et al., 2012). Another crucial problem that affects drug delivery is the molecular weight of the drug. For a successful delivery, the drug molecule must weigh less than 500 daltons. The efficient diffusion of drug particles through the skin has inversely related to the size of their size. Transdermal patches are also unable to deliver high doses of potent drugs. The patches can only provide a maximum daily payload of 20mg, thus posing a significant challenge in delivering strong medication that requires a higher dosage.