[Transdermal permeation of effective components in Huoxue Zhitong patch]

To establish a determination method for the contents of paeonol, eugenol and piperine in receptor liquid and to research the transdermal permeability of Huoxue Zhitong patch. The contents of paeonol, eugenol and piperine in receptor liquid were determined by high pressure liquid chromatography(HPLC); and the receptor liquid was optimized by taking accumulative amount penetrated within 24 hours, percutaneous permeation rate and skin irritation as indexes. In vitro Franz diffusion experiment was applied to assess the percutaneous penetration characteristics and regularity of Huoxue Zhitong patch. The results showed that the accumulative penetration amount and penetration rate by using PEG 400-ethanol-normal saline 3∶3∶4 as receptor liquid were higher than those by using propylene glycol∶ethanol∶normal saline 3∶3∶4 and ethanol-normal saline 3∶7, the and skin irritation of PEG 400-ethanol-normal saline 3∶3∶4 was smaller than propylene glycol:ethanol: normal saline 3∶3∶4. Results of percutaneous permeability experiments displayed that the accumulative amount penetrated of paeonol, eugenol and piperine within 24 hours was 2.84, 19.9, and 0.753 μg•cm⁻² respectively in Huoxue Zhitong patch and the penetration rate was 0.18, 1.22, and 0.02 μg•cm⁻²•h⁻¹ respectively. Thus, the permeation of paeonol, eugenol and piperine through the skin was a diffusion process, which was irrelevant to their content in patch.