TRANSDERMAL PATCHES

<p>The skin is the most readily accessible organ of the body and acts as a barrier against the micro and macromolecules of the environment because of its low permeability to such substances. The skin of an average adult body has approximately 2&thinsp;m2 surface area and it receives about one-third of the total blood circulating throughout the body. Percutaneous absorption of drug through skin mainly occurs via stratum corneum. Stratum corneum is made up of dead keratinized epidermal cells having thickness of 10&thinsp;&micro;m and acts as a barrier for permeation of drugs. Therefore transport of drug molecules across the skin is difficult.</p><p>Transdermal therapeutics systems are defined as self contained discrete dosage formswhen applied to the intact skin deliver the drugs through the skin at controlled rate to thesystemic circulation. The advantages of delivering drugs across the skin for systemic therapy arewell documented. Some of the main advantages of a transdermal drug delivery system are:The simplified medication regimen leads to improved patient compliance and reduced inter andintra patient variability.</p>