RESUMEN
The critical problem to be solved in the study of transdermal drug delivery system is to improve the transdermal penetration of drugs through the skin. Most essential oils from Chinese material medica, considered as a large class of penetration enhancers, possess enhanced percutaneous absorption, minor skin irritation, certain therapeutic efficacy, and a synergistic effect with transdermal drugs. However, the essential oils have poor solubility and unstable problems. Some special preparations, including patch, clathrate, gel plasters, gels, microemulsion, and so on, can increase the solubility of the essential oils, improve the effect of permeability, and can significantly boost the stability of the essential oils. In this paper, the techniques of the related preparations on essential oil from Chinese materia medica should be reviewed, and the research direction of the later stage should be discussed.