Transdermal Drug Delivery Systems (TDDDs) Overview

A drug delivery method that uses the skin's intact surface to deliver medicine directly into the bloodstream.

Medicines delivered through the skin bypass the digestive system, reducing breakdown and improving absorption.

The skin's outermost layer, the stratum corneum, acts as a barrier against external substances.

Transdermal drug delivery systems (TDDDs) are particularly well-suited for chronic conditions requiring ongoing medication.

The skin's multi-layered structure, including both the epidermis and the dermis, presents challenges for delivering medicines through the skin.

TDDDs offer a convenient and relatively painless alternative to injections or oral medications, especially for children and elderly patients.

TDDDs can be designed to release medicine according to specific needs, ensuring consistent therapeutic effects.

TDDDs have the potential to revolutionize medicine delivery but face challenges in overcoming the skin's natural barrier.

A method of enhancing drug delivery through the skin by using substances that increase drug penetration or solubility.

A key requirement for drugs to effectively penetrate the skin barrier.

A type of drug delivery system that uses microscopic vesicles to carry drugs through the skin.

A type of vesicle composed of phospholipids, which naturally form spherical structures.

A process of applying heat to tissues, often achieved by lasers or radiofrequency energy.

Using lasers to create tiny holes in the skin to increase the absorption of medications.

An important characteristic for drugs used in TDDDs, as it influences their absorption and effectiveness.

A key factor in ensuring adequate penetration of drugs through the skin.

A critical factor for drugs delivered through the skin, affecting their absorption and distribution within the body.

The skin's outermost layer, the stratum corneum, acts as a barrier that prevents substances from easily entering the body. This poses a challenge for drugs trying to be delivered through the skin.

Transdermal Drug Delivery Systems, or TDDDs, utilize the skin's surface to deliver medications directly into the bloodstream, bypassing the digestive system. This reduces the amount of drug breakdown and improves absorption.

For substances with small molecular weights, the delivery process typically uses the spaces between skin cells, known as the intracellular pathway. These molecules navigate through the gaps between the skin cells to reach the bloodstream.

Larger molecules, those with greater molecular weights, face greater challenges getting through the skin. They often require specialized methods and use a combination of intracellular and intercellular pathways to penetrate the skin.

Iontophoresis is a technique that uses a low voltage electric current to enhance the delivery of charged medications through the skin. It helps to propel these medications across the skin barrier.

By applying a small externally applied potential difference, iontophoresis allows charged molecules to move through the membrane of the skin. This enhances skin penetration and increases the rate at which medications are released.

Iontophoresis can be used to deliver both positively charged (cations) and negatively charged (anions) medications by placing the electrode of the opposite charge on the skin.

The skin is composed of multiple layers, each with its own unique properties. The epidermis, which contains the stratum corneum, acts as a barrier, while the dermis contains vessels and nerves.

TDDDs, in addition to overcoming the barrier of the stratum corneum, must also navigate through the cellular and vascular tissue to reach the target tissue and deliver the medication effectively.

Active drug delivery systems use external stimuli, like electrical, mechanical, or physical forces, to improve the penetration of drugs into the skin. They are considered a more effective method than simple topical application.

A method of drug delivery that uses tiny needles to penetrate the skin, allowing drugs to reach the bloodstream.

A type of microneedle that is coated with drugs and dissolves in the body, releasing the drugs over time.

A process that uses electrical pulses to temporarily create pores in the skin, allowing drugs to pass through.

The outermost layer of the skin, which acts as a barrier against external substances.

Molecules that have both water-loving (hydrophilic) and oil-loving (hydrophobic) properties, allowing them to encapsulate both water-soluble and fat-soluble substances.

Liposomes can only stay on the skin's surface and cannot penetrate deep into the skin layers.

A type of liposome that is highly deformable, allowing it to penetrate skin pores much smaller than its own size.

Transfersomes are designed with single-chain surfactants that make the phospholipid bilayer fluid and flexible.

Ethosomes are composed of phospholipids, alcohols, and water, with a higher concentration of alcohol compared to liposomes.

Ethosomes are known for their ability to promote drug penetration through the skin.

Nanoparticles (NPs) are tiny carriers with sizes ranging from 1 to 1000 nanometers.

Nanoparticles can be classified based on their composition into different types.

NPs are designed for targeted drug delivery and controlled release, which helps extend the drug's presence in the body and reduce side effects.

Drug administration in the form of NPs can improve drug bioavailability, reduce toxicity, and improve the drug's effectiveness.