RESUMO
The development of new medications increasing bio-availability and efficacy of existing pharmaceuticals is considered as an alternative to implementation of new medications that can significantly reduce time-frame and costs of bringing medication to the market, acquired in recent decades high practical and scientific importance. The new effective medications include trans-dermal therapeutic systems (TTS) that are capable of providing a controlled release of the active pharmaceutical ingredient (API) through the skin into the bloodstream at a therapeutically optimal rate for a long time. The application of TTS is painless and convenient. It eliminates losses associated with metabolism in the gastrointestinal tract and liver and allows wide variation of dosage and to discontinue treatment at any moment. The key problem of trans-dermal delivery is difficulty in penetrating API through the skin, which has complex multilayer structure. The understanding of all aspects affecting permeability of API through the skin is crucial for the development of new TTS and is a subject of special research interest in modern pharmacological science.