engleză
Transdermal drug delivery systems are defined as self-contained, discrete dosage forms which, when applied to the intact skin, deliver the drug, through the skin, at a controlled rate to the systemic circulation.Transdermal drug delivery systems are adhesive, drug containing devices of defined surface area that deliver a pre-determined amount of drug to the surface of intact skin at a pre-programmed rate. These systems provide drug systemically at a predictable rate and maintain the rate for extended periods of time.Transdermal drug delivery system involves the passage of substances from the skin surface through the skin layers, into the systemic circulation. The skin has been commonly used as a site for topical administration of drugs, when the skin serves as a port for administration of systemically active drugs. The drug applied topically is distributed following absorption, first into the systemic circulation and then transported to the target tissue, which can be relatively remote from the site of drug application to achieve its therapeutic action .
