The aim of this thesis was to explore the benefits provided by transdermal administration of drugs and set aside the limitations and problems associated with this method of administration. Also, the aim of this thesis was to study drug candidates, passive delivery and new technologies, get acquainted with transdermal patches that are present on the Croatian market, to study their indications, methods of administration and side effects. Application of the drug through the skin by transdermal patch is a simple and painless method for patients, and it is easy to achieve a controlled release of the drug, it also reduces dosage frequency and bypasses the first pass through the liver and gastrointestinal inactivation. Termination of the therapy is simple, and it is achieved by simply removing the patch. Transdermal patch forming, even after fifty years, still represents a challenge for professionals who work in this area. Transdermal drug delivery is not suitable for all drugs, but by using active and minimally invasive technologies such as iontophoresis, sonophoresis, micro-needle, laser beams etc. the number of drugs that can be delivered through the skin is increasing. To achieve the active substance concentration and decrease the barrier function of the skin, scientists use chemical enhancers of transdermal absorption by influencing on the diffusion of the drug (oleic acid, Azone) and the solubility of the drug in the skin (ethanol, propylene glycol) which increases the drug permeability. Adhesion is an essential parameter of the efficiency and safety of a transdermal patch. To ensure a firm and soft contact, polymers such as polyisobutylene (PIB), silicone and acrylates are most commonly used. Transdermal delivery is a relatively new area of drug delivery which is being intensely explored and developed because of its advantages . Therefore, its prosperous future is yet to come.