Transdermal

Definition

Transdermal refers to the administration of medication through the skin, allowing the active ingredients to be absorbed into the bloodstream. This method of drug delivery bypasses the gastrointestinal tract and liver, providing a direct route for the drug to reach the systemic circulation.

5 Must Know Facts For Your Next Test

1. Transdermal drug delivery is advantageous for medications that have poor oral bioavailability or require sustained, controlled release.
2. The skin's barrier function, known as the stratum corneum, must be overcome for effective transdermal absorption, which can be achieved through various formulation strategies.
3. Transdermal patches are a common example of a transdermal drug delivery system, allowing for continuous, controlled release of the medication over an extended period.
4. Transdermal administration is used for a variety of drugs, including nicotine replacement therapy, hormonal therapy, and certain pain medications.
5. The rate and extent of transdermal drug absorption can be influenced by factors such as skin permeability, drug physicochemical properties, and the design of the transdermal system.

Review Questions

• Explain how transdermal drug delivery differs from other administration routes and the advantages it offers.
  • Transdermal drug delivery differs from other routes, such as oral or parenteral, in that the medication is administered through the skin, bypassing the gastrointestinal tract and first-pass metabolism in the liver. This can be advantageous for drugs with poor oral bioavailability or those that require sustained, controlled release. Transdermal administration can provide more consistent drug levels, improved patient compliance, and reduced side effects compared to other routes.
• Describe the role of the skin's barrier function in transdermal drug absorption and the strategies used to overcome it.
  • The skin's barrier function, primarily provided by the stratum corneum, must be overcome for effective transdermal drug absorption. Various formulation strategies can be employed to enhance skin permeability, such as the use of penetration enhancers, prodrugs, or specialized drug delivery systems like transdermal patches. These approaches aim to increase the solubility, partition, and diffusion of the drug through the skin layers, facilitating its entry into the systemic circulation.
• Analyze the potential applications of transdermal drug delivery in the context of specific therapeutic areas, such as nicotine use disorder, masculinizing hormonal therapy, and dermatologic conditions.
  • Transdermal drug delivery has found applications in various therapeutic areas. For nicotine use disorder, transdermal nicotine patches provide a convenient and effective means of delivering nicotine replacement therapy, allowing for controlled release and improved patient compliance compared to other routes. In masculinizing hormonal therapy, transdermal administration of testosterone can offer a non-invasive alternative to intramuscular injections. Furthermore, transdermal drug delivery is utilized for the management of certain dermatologic conditions, where topical application of medications can directly target the affected skin area. The advantages of transdermal administration, such as improved bioavailability, sustained drug release, and reduced systemic side effects, make it a valuable approach in these diverse therapeutic contexts.

Related terms

Percutaneous: Relating to or denoting the administration of a drug or other substance through the skin, especially for systemic effect.

Topical: Relating to or applied to a particular area of the body or skin.

Dermal: Relating to or affecting the skin.