[Study on evaluation index of acupoint transdermal administration--drug delivery coefficient]

To investigate the correlation of skin electric resistance changes with the blood drug content in acupoint transdermal administration, and to establish an new evaluation index for drug delivery efficiency through acupoints.

Twenty-four rabbits were randomly divided into an observation group and a control group. In the observation group, aminophylline was administrated through "Feishu" (BL 13), "Geshu" (BL 17) and "Danzhong" (CV 17) which are commonly used for treatment of bronchial asthma, and the control group through sham-points on the back. The skin resistance and plasma aminophylline content were determined after application of aminophylline to the points, and their changes with time were observed. The ratio of Css/Rss at stability was defined as delivery coefficient (DC) which reflects the efficiency of delivering drug at acupoints and sham acupoints.

Both the plasma aminophylline and the skin resistance value tended to steady about 6-8 h after application of aminophyiophylline. The DC in the acupoints was higher than that in the sham-acupoints (P < 0.01). And there was significant difference as DC of the "Feishu"was significant difference (BL 13) and "Danzhongas DC of the "Feish" (BLCV 17) compared with that of "Geshu" (BL 17) (P < 0.01).

The bigger the DC is, the higher the efficiency of drug delivery is; the efficiency of drug delivery through acupoints is higher than that through sham-acupoints.