Transdermal delivery is a method of administering medication through the skin, also known as topical administration. This approach involves applying a medication in the form of a patch or cream to the skin, where it is then absorbed into the bloodstream. Transdermal delivery is used to provide a controlled and sustained release of medication, allowing for a more consistent and longer-lasting effect compared to other methods of administration. This route of drug delivery is commonly used for hormone replacement therapy, pain management, and nicotine replacement therapy. Research in this area focuses on improving the efficiency and effectiveness of transdermal delivery systems, such as enhancing drug permeation through the skin and optimizing drug formulation for better bioavailability.