Topical administration of traditional Chinese medicine and the methods for the promotion of drug penetration

Monomer component extracted from the herb is the main effective component of traditional Chinese medicine(TCM). Topical administrations of monomer component of TCM has attracted more and more attention due to the convenience of administration and the concentration enrichment in lesion. The main task for the studies of topical drug delivery system is to design the methods which can promote the penetration of the drugs. Currently, the main methods used to improve the penetration of monomer component of TCM includes the synthesis of different dosage forms and the application of physical and chemical techniques to facilitate the penetration of the drugs. This review summarizes the progress in different indications and mechanisms of diverse monomer components of TCM, different dosage forms, and physicochemical techniques used to facilitate drug penetration.