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The success of a transdermal drug delivery system depends to a large extent on the selection of the appropriate excipient. Ethylene-vinyl acetate copolymers, polypropylene, PVA, polysiloxane, PVC, dimethyl sulfoxide, oleic acid and lauric acid are key excipients that contribute to drug absorption, stability and patient compliance.

Eight Excipients Commonly Used In Transdermal Drug Delivery Systems

Transdermal drug delivery systems have gained considerable importance in the pharmaceutical industry due to their convenience, effectiveness, and ease of use. These systems rely on various excipients, which are inactive substances that help deliver and absorb active drug compounds through the skin. In this article, we will discuss eight important excipients commonly used in transdermal drug delivery systems, their properties, and their role in enhancing drug absorption.

Ethylene-vinyl acetate copolymer

Ethylene-vinyl acetate copolymer (EVA) is widely used as a substrate for transdermal drug delivery systems. With its excellent film forming and bonding properties, it helps to form a protective layer on the skin and enhances drug penetration. EVA also has good flexibility, biocompatibility, and controlled drug release, making it the first choice for transdermal patches.

Polypropylene

Polypropylene is another excipient commonly used in transdermal drug delivery systems because of its excellent barrier properties. It acts as a protective layer, preventing the loss of the drug and controlling its release. In addition, it is resistant to moisture, oxygen and other environmental factors, ensuring the stability and efficacy of the drug.

Polyvinyl alcohol (PVA)

PVA is a widely used excipient in transdermal drug delivery systems. Its film-forming ability, biocompatibility and low toxicity make it an excellent choice for drug penetration. PVA also enhances drug penetration into the skin by moisturizing the stratum corneum, thereby increasing its flexibility and improving drug diffusion.

Polysiloxane

Polysiloxane, also known as silicone, is a widely used excipient due to its unique properties, such as low surface tension and excellent spreading ability. These properties allow the drug to spread better across the skin, thus enhancing drug absorption. In addition, polysiloxanes form a protective film that minimizes skin water loss, promotes drug stability and improves patient compliance.

Polyvinyl chloride (PVC)

Due to its excellent mechanical and barrier properties, PVC is commonly used in the manufacture of transdermal drug delivery systems. It has durability, flexibility, and compatibility with multiple drugs. PVC also acts as a barrier to physical and chemical interactions, ensuring drug stability while allowing controlled release.

Dimethyl sulfoxide (DMSO)

Dimethyl sulfoxide is a common solvent used in transdermal drug delivery systems. Due to its ability to penetrate biofilms, it can carry active compounds through layers of skin to enhance drug absorption. DMSO can also act as a penetration enhancer by altering the cuticle structure, increasing drug solubility, and improving skin hydration.

Oleic acid

Oleic acid is a natural fatty acid that is commonly used as a penetration enhancer in transdermal drug delivery systems. It enhances drug penetration by disrupting skin barrier function and promoting drug dissolution. Oleic acid has a high affinity for lipids in the stratum corneum, thereby improving drug diffusion and increasing drug bioavailability.

Lauric acid

Lauric acid is another fatty acid that exhibits excellent penetration-enhancing properties in transdermal drug delivery systems. It breaks down the skin barrier, increases drug solubility, and enhances drug distribution into the stratum corneum. Lauric acid also has antibacterial and antimicrobial properties, making it suitable for topical preparations.

In summary, the success of a transdermal drug delivery system largely depends on the choice of the appropriate excipient. Ethylene-vinyl acetate copolymers, polypropylene, PVA, polysiloxane, PVC, dimethyl sulfoxide, oleic acid and lauric acid are key excipients that contribute to drug absorption, stability and patient compliance. These excipients play a vital role in enhancing the effectiveness of the transdermal drug delivery system, providing a convenient and effective route of administration.